Initial revision

3 files changed, 5944 insertions, 0 deletions

diff --git a/sys/net/ppp_deflate.c b/sys/net/ppp_deflate.c
new file mode 100644
index 0000000..697cac6
--- /dev/null
+++ b/sys/net/ppp_deflate.c
@@ -0,0 +1,665 @@
+/*	$Id: ppp-deflate.c,v 1.6 1997/04/30 05:47:23 paulus Exp $	*/
+
+/*
+ * ppp_deflate.c - interface the zlib procedures for Deflate compression
+ * and decompression (as used by gzip) to the PPP code.
+ * This version is for use with mbufs on BSD-derived systems.
+ *
+ * Copyright (c) 1994 The Australian National University.
+ * All rights reserved.
+ *
+ * Permission to use, copy, modify, and distribute this software and its
+ * documentation is hereby granted, provided that the above copyright
+ * notice appears in all copies.  This software is provided without any
+ * warranty, express or implied. The Australian National University
+ * makes no representations about the suitability of this software for
+ * any purpose.
+ *
+ * IN NO EVENT SHALL THE AUSTRALIAN NATIONAL UNIVERSITY BE LIABLE TO ANY
+ * PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
+ * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
+ * THE AUSTRALIAN NATIONAL UNIVERSITY HAS BEEN ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * THE AUSTRALIAN NATIONAL UNIVERSITY SPECIFICALLY DISCLAIMS ANY WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
+ * ON AN "AS IS" BASIS, AND THE AUSTRALIAN NATIONAL UNIVERSITY HAS NO
+ * OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS,
+ * OR MODIFICATIONS.
+ */
+
+#include <sys/param.h>
+#include <sys/types.h>
+#include <sys/systm.h>
+#include <sys/mbuf.h>
+#include <net/ppp_defs.h>
+#include <net/zlib.h>
+
+#define PACKETPTR	struct mbuf *
+#include <net/ppp-comp.h>
+
+#if DO_DEFLATE
+
+#define DEFLATE_DEBUG	1
+
+/*
+ * State for a Deflate (de)compressor.
+ */
+struct deflate_state {
+    int		seqno;
+    int		w_size;
+    int		unit;
+    int		hdrlen;
+    int		mru;
+    int		debug;
+    z_stream	strm;
+    struct compstat stats;
+};
+
+#define DEFLATE_OVHD	2		/* Deflate overhead/packet */
+
+static void	*zalloc __P((void *, u_int items, u_int size));
+static void	zfree __P((void *, void *ptr, u_int nb));
+static void	*z_comp_alloc __P((u_char *options, int opt_len));
+static void	*z_decomp_alloc __P((u_char *options, int opt_len));
+static void	z_comp_free __P((void *state));
+static void	z_decomp_free __P((void *state));
+static int	z_comp_init __P((void *state, u_char *options, int opt_len,
+				 int unit, int hdrlen, int debug));
+static int	z_decomp_init __P((void *state, u_char *options, int opt_len,
+				     int unit, int hdrlen, int mru, int debug));
+static int	z_compress __P((void *state, struct mbuf **mret,
+				  struct mbuf *mp, int slen, int maxolen));
+static void	z_incomp __P((void *state, struct mbuf *dmsg));
+static int	z_decompress __P((void *state, struct mbuf *cmp,
+				    struct mbuf **dmpp));
+static void	z_comp_reset __P((void *state));
+static void	z_decomp_reset __P((void *state));
+static void	z_comp_stats __P((void *state, struct compstat *stats));
+
+/*
+ * Procedures exported to if_ppp.c.
+ */
+struct compressor ppp_deflate = {
+    CI_DEFLATE,			/* compress_proto */
+    z_comp_alloc,		/* comp_alloc */
+    z_comp_free,		/* comp_free */
+    z_comp_init,		/* comp_init */
+    z_comp_reset,		/* comp_reset */
+    z_compress,			/* compress */
+    z_comp_stats,		/* comp_stat */
+    z_decomp_alloc,		/* decomp_alloc */
+    z_decomp_free,		/* decomp_free */
+    z_decomp_init,		/* decomp_init */
+    z_decomp_reset,		/* decomp_reset */
+    z_decompress,		/* decompress */
+    z_incomp,			/* incomp */
+    z_comp_stats,		/* decomp_stat */
+};
+
+/*
+ * Space allocation and freeing routines for use by zlib routines.
+ */
+void *
+zalloc(notused, items, size)
+    void *notused;
+    u_int items, size;
+{
+    void *ptr;
+
+    MALLOC(ptr, void *, items * size, M_DEVBUF, M_NOWAIT);
+    return ptr;
+}
+
+void
+zfree(notused, ptr, nbytes)
+    void *notused;
+    void *ptr;
+    u_int nbytes;
+{
+    FREE(ptr, M_DEVBUF);
+}
+
+/*
+ * Allocate space for a compressor.
+ */
+static void *
+z_comp_alloc(options, opt_len)
+    u_char *options;
+    int opt_len;
+{
+    struct deflate_state *state;
+    int w_size;
+
+    if (opt_len != CILEN_DEFLATE || options[0] != CI_DEFLATE
+	|| options[1] != CILEN_DEFLATE
+	|| DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL
+	|| options[3] != DEFLATE_CHK_SEQUENCE)
+	return NULL;
+    w_size = DEFLATE_SIZE(options[2]);
+    if (w_size < DEFLATE_MIN_SIZE || w_size > DEFLATE_MAX_SIZE)
+	return NULL;
+
+    MALLOC(state, struct deflate_state *, sizeof(struct deflate_state),
+	   M_DEVBUF, M_NOWAIT);
+    if (state == NULL)
+	return NULL;
+
+    state->strm.next_in = NULL;
+    state->strm.zalloc = zalloc;
+    state->strm.zalloc_init = zalloc;
+    state->strm.zfree = zfree;
+    if (deflateInit2(&state->strm, Z_DEFAULT_COMPRESSION, DEFLATE_METHOD_VAL,
+		     -w_size, 8, Z_DEFAULT_STRATEGY, DEFLATE_OVHD+2) != Z_OK) {
+	FREE(state, M_DEVBUF);
+	return NULL;
+    }
+
+    state->w_size = w_size;
+    bzero(&state->stats, sizeof(state->stats));
+    return (void *) state;
+}
+
+static void
+z_comp_free(arg)
+    void *arg;
+{
+    struct deflate_state *state = (struct deflate_state *) arg;
+
+    deflateEnd(&state->strm);
+    FREE(state, M_DEVBUF);
+}
+
+static int
+z_comp_init(arg, options, opt_len, unit, hdrlen, debug)
+    void *arg;
+    u_char *options;
+    int opt_len, unit, hdrlen, debug;
+{
+    struct deflate_state *state = (struct deflate_state *) arg;
+
+    if (opt_len < CILEN_DEFLATE || options[0] != CI_DEFLATE
+	|| options[1] != CILEN_DEFLATE
+	|| DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL
+	|| DEFLATE_SIZE(options[2]) != state->w_size
+	|| options[3] != DEFLATE_CHK_SEQUENCE)
+	return 0;
+
+    state->seqno = 0;
+    state->unit = unit;
+    state->hdrlen = hdrlen;
+    state->debug = debug;
+
+    deflateReset(&state->strm);
+
+    return 1;
+}
+
+static void
+z_comp_reset(arg)
+    void *arg;
+{
+    struct deflate_state *state = (struct deflate_state *) arg;
+
+    state->seqno = 0;
+    deflateReset(&state->strm);
+}
+
+int
+z_compress(arg, mret, mp, orig_len, maxolen)
+    void *arg;
+    struct mbuf **mret;		/* compressed packet (out) */
+    struct mbuf *mp;		/* uncompressed packet (in) */
+    int orig_len, maxolen;
+{
+    struct deflate_state *state = (struct deflate_state *) arg;
+    u_char *rptr, *wptr;
+    int proto, olen, wspace, r, flush;
+    struct mbuf *m;
+
+    /*
+     * Check that the protocol is in the range we handle.
+     */
+    rptr = mtod(mp, u_char *);
+    proto = PPP_PROTOCOL(rptr);
+    if (proto > 0x3fff || proto == 0xfd || proto == 0xfb) {
+	*mret = NULL;
+	return orig_len;
+    }
+
+    /* Allocate one mbuf initially. */
+    if (maxolen > orig_len)
+	maxolen = orig_len;
+    MGET(m, M_DONTWAIT, MT_DATA);
+    *mret = m;
+    if (m != NULL) {
+	m->m_len = 0;
+	if (maxolen + state->hdrlen > MLEN)
+	    MCLGET(m, M_DONTWAIT);
+	wspace = M_TRAILINGSPACE(m);
+	if (state->hdrlen + PPP_HDRLEN + 2 < wspace) {
+	    m->m_data += state->hdrlen;
+	    wspace -= state->hdrlen;
+	}
+	wptr = mtod(m, u_char *);
+
+	/*
+	 * Copy over the PPP header and store the 2-byte sequence number.
+	 */
+	wptr[0] = PPP_ADDRESS(rptr);
+	wptr[1] = PPP_CONTROL(rptr);
+	wptr[2] = PPP_COMP >> 8;
+	wptr[3] = PPP_COMP;
+	wptr += PPP_HDRLEN;
+	wptr[0] = state->seqno >> 8;
+	wptr[1] = state->seqno;
+	wptr += 2;
+	state->strm.next_out = wptr;
+	state->strm.avail_out = wspace - (PPP_HDRLEN + 2);
+    } else {
+	state->strm.next_out = NULL;
+	state->strm.avail_out = 1000000;
+	wptr = NULL;
+	wspace = 0;
+    }
+    ++state->seqno;
+
+    rptr += (proto > 0xff)? 2: 3;	/* skip 1st proto byte if 0 */
+    state->strm.next_in = rptr;
+    state->strm.avail_in = mtod(mp, u_char *) + mp->m_len - rptr;
+    mp = mp->m_next;
+    flush = (mp == NULL)? Z_PACKET_FLUSH: Z_NO_FLUSH;
+    olen = 0;
+    for (;;) {
+	r = deflate(&state->strm, flush);
+	if (r != Z_OK) {
+	    printf("z_compress: deflate returned %d (%s)\n",
+		   r, (state->strm.msg? state->strm.msg: ""));
+	    break;
+	}
+	if (flush != Z_NO_FLUSH && state->strm.avail_out != 0)
+	    break;		/* all done */
+	if (state->strm.avail_in == 0 && mp != NULL) {
+	    state->strm.next_in = mtod(mp, u_char *);
+	    state->strm.avail_in = mp->m_len;
+	    mp = mp->m_next;
+	    if (mp == NULL)
+		flush = Z_PACKET_FLUSH;
+	}
+	if (state->strm.avail_out == 0) {
+	    if (m != NULL) {
+		m->m_len = wspace;
+		olen += wspace;
+		MGET(m->m_next, M_DONTWAIT, MT_DATA);
+		m = m->m_next;
+		if (m != NULL) {
+		    m->m_len = 0;
+		    if (maxolen - olen > MLEN)
+			MCLGET(m, M_DONTWAIT);
+		    state->strm.next_out = mtod(m, u_char *);
+		    state->strm.avail_out = wspace = M_TRAILINGSPACE(m);
+		}
+	    }
+	    if (m == NULL) {
+		state->strm.next_out = NULL;
+		state->strm.avail_out = 1000000;
+	    }
+	}
+    }
+    if (m != NULL)
+	olen += (m->m_len = wspace - state->strm.avail_out);
+
+    /*
+     * See if we managed to reduce the size of the packet.
+     * If the compressor just gave us a single zero byte, it means
+     * the packet was incompressible.
+     */
+    if (m != NULL && olen < orig_len
+	&& !(olen == PPP_HDRLEN + 3 && *wptr == 0)) {
+	state->stats.comp_bytes += olen;
+	state->stats.comp_packets++;
+    } else {
+	if (*mret != NULL) {
+	    m_freem(*mret);
+	    *mret = NULL;
+	}
+	state->stats.inc_bytes += orig_len;
+	state->stats.inc_packets++;
+	olen = orig_len;
+    }
+    state->stats.unc_bytes += orig_len;
+    state->stats.unc_packets++;
+
+    return olen;
+}
+
+static void
+z_comp_stats(arg, stats)
+    void *arg;
+    struct compstat *stats;
+{
+    struct deflate_state *state = (struct deflate_state *) arg;
+    u_int out;
+
+    *stats = state->stats;
+    stats->ratio = stats->unc_bytes;
+    out = stats->comp_bytes + stats->inc_bytes;
+    if (stats->ratio <= 0x7ffffff)
+	stats->ratio <<= 8;
+    else
+	out >>= 8;
+    if (out != 0)
+	stats->ratio /= out;
+}
+
+/*
+ * Allocate space for a decompressor.
+ */
+static void *
+z_decomp_alloc(options, opt_len)
+    u_char *options;
+    int opt_len;
+{
+    struct deflate_state *state;
+    int w_size;
+
+    if (opt_len != CILEN_DEFLATE || options[0] != CI_DEFLATE
+	|| options[1] != CILEN_DEFLATE
+	|| DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL
+	|| options[3] != DEFLATE_CHK_SEQUENCE)
+	return NULL;
+    w_size = DEFLATE_SIZE(options[2]);
+    if (w_size < DEFLATE_MIN_SIZE || w_size > DEFLATE_MAX_SIZE)
+	return NULL;
+
+    MALLOC(state, struct deflate_state *, sizeof(struct deflate_state),
+	   M_DEVBUF, M_NOWAIT);
+    if (state == NULL)
+	return NULL;
+
+    state->strm.next_out = NULL;
+    state->strm.zalloc = zalloc;
+    state->strm.zalloc_init = zalloc;
+    state->strm.zfree = zfree;
+    if (inflateInit2(&state->strm, -w_size) != Z_OK) {
+	FREE(state, M_DEVBUF);
+	return NULL;
+    }
+
+    state->w_size = w_size;
+    bzero(&state->stats, sizeof(state->stats));
+    return (void *) state;
+}
+
+static void
+z_decomp_free(arg)
+    void *arg;
+{
+    struct deflate_state *state = (struct deflate_state *) arg;
+
+    inflateEnd(&state->strm);
+    FREE(state, M_DEVBUF);
+}
+
+static int
+z_decomp_init(arg, options, opt_len, unit, hdrlen, mru, debug)
+    void *arg;
+    u_char *options;
+    int opt_len, unit, hdrlen, mru, debug;
+{
+    struct deflate_state *state = (struct deflate_state *) arg;
+
+    if (opt_len < CILEN_DEFLATE || options[0] != CI_DEFLATE
+	|| options[1] != CILEN_DEFLATE
+	|| DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL
+	|| DEFLATE_SIZE(options[2]) != state->w_size
+	|| options[3] != DEFLATE_CHK_SEQUENCE)
+	return 0;
+
+    state->seqno = 0;
+    state->unit = unit;
+    state->hdrlen = hdrlen;
+    state->debug = debug;
+    state->mru = mru;
+
+    inflateReset(&state->strm);
+
+    return 1;
+}
+
+static void
+z_decomp_reset(arg)
+    void *arg;
+{
+    struct deflate_state *state = (struct deflate_state *) arg;
+
+    state->seqno = 0;
+    inflateReset(&state->strm);
+}
+
+/*
+ * Decompress a Deflate-compressed packet.
+ *
+ * Because of patent problems, we return DECOMP_ERROR for errors
+ * found by inspecting the input data and for system problems, but
+ * DECOMP_FATALERROR for any errors which could possibly be said to
+ * be being detected "after" decompression.  For DECOMP_ERROR,
+ * we can issue a CCP reset-request; for DECOMP_FATALERROR, we may be
+ * infringing a patent of Motorola's if we do, so we take CCP down
+ * instead.
+ *
+ * Given that the frame has the correct sequence number and a good FCS,
+ * errors such as invalid codes in the input most likely indicate a
+ * bug, so we return DECOMP_FATALERROR for them in order to turn off
+ * compression, even though they are detected by inspecting the input.
+ */
+int
+z_decompress(arg, mi, mop)
+    void *arg;
+    struct mbuf *mi, **mop;
+{
+    struct deflate_state *state = (struct deflate_state *) arg;
+    struct mbuf *mo, *mo_head;
+    u_char *rptr, *wptr;
+    int rlen, olen, ospace;
+    int seq, i, flush, r, decode_proto;
+    u_char hdr[PPP_HDRLEN + DEFLATE_OVHD];
+
+    *mop = NULL;
+    rptr = mtod(mi, u_char *);
+    rlen = mi->m_len;
+    for (i = 0; i < PPP_HDRLEN + DEFLATE_OVHD; ++i) {
+	while (rlen <= 0) {
+	    mi = mi->m_next;
+	    if (mi == NULL)
+		return DECOMP_ERROR;
+	    rptr = mtod(mi, u_char *);
+	    rlen = mi->m_len;
+	}
+	hdr[i] = *rptr++;
+	--rlen;
+    }
+
+    /* Check the sequence number. */
+    seq = (hdr[PPP_HDRLEN] << 8) + hdr[PPP_HDRLEN+1];
+    if (seq != state->seqno) {
+	if (state->debug)
+	    printf("z_decompress%d: bad seq # %d, expected %d\n",
+		   state->unit, seq, state->seqno);
+	return DECOMP_ERROR;
+    }
+    ++state->seqno;
+
+    /* Allocate an output mbuf. */
+    MGETHDR(mo, M_DONTWAIT, MT_DATA);
+    if (mo == NULL)
+	return DECOMP_ERROR;
+    mo_head = mo;
+    mo->m_len = 0;
+    mo->m_next = NULL;
+    MCLGET(mo, M_DONTWAIT);
+    ospace = M_TRAILINGSPACE(mo);
+    if (state->hdrlen + PPP_HDRLEN < ospace) {
+	mo->m_data += state->hdrlen;
+	ospace -= state->hdrlen;
+    }
+
+    /*
+     * Fill in the first part of the PPP header.  The protocol field
+     * comes from the decompressed data.
+     */
+    wptr = mtod(mo, u_char *);
+    wptr[0] = PPP_ADDRESS(hdr);
+    wptr[1] = PPP_CONTROL(hdr);
+    wptr[2] = 0;
+
+    /*
+     * Set up to call inflate.  We set avail_out to 1 initially so we can
+     * look at the first byte of the output and decide whether we have
+     * a 1-byte or 2-byte protocol field.
+     */
+    state->strm.next_in = rptr;
+    state->strm.avail_in = rlen;
+    mi = mi->m_next;
+    flush = (mi == NULL)? Z_PACKET_FLUSH: Z_NO_FLUSH;
+    rlen += PPP_HDRLEN + DEFLATE_OVHD;
+    state->strm.next_out = wptr + 3;
+    state->strm.avail_out = 1;
+    decode_proto = 1;
+    olen = PPP_HDRLEN;
+
+    /*
+     * Call inflate, supplying more input or output as needed.
+     */
+    for (;;) {
+	r = inflate(&state->strm, flush);
+	if (r != Z_OK) {
+#if !DEFLATE_DEBUG
+	    if (state->debug)
+#endif
+		printf("z_decompress%d: inflate returned %d (%s)\n",
+		       state->unit, r, (state->strm.msg? state->strm.msg: ""));
+	    m_freem(mo_head);
+	    return DECOMP_FATALERROR;
+	}
+	if (flush != Z_NO_FLUSH && state->strm.avail_out != 0)
+	    break;		/* all done */
+	if (state->strm.avail_in == 0 && mi != NULL) {
+	    state->strm.next_in = mtod(mi, u_char *);
+	    state->strm.avail_in = mi->m_len;
+	    rlen += mi->m_len;
+	    mi = mi->m_next;
+	    if (mi == NULL)
+		flush = Z_PACKET_FLUSH;
+	}
+	if (state->strm.avail_out == 0) {
+	    if (decode_proto) {
+		state->strm.avail_out = ospace - PPP_HDRLEN;
+		if ((wptr[3] & 1) == 0) {
+		    /* 2-byte protocol field */
+		    wptr[2] = wptr[3];
+		    --state->strm.next_out;
+		    ++state->strm.avail_out;
+		    --olen;
+		}
+		decode_proto = 0;
+	    } else {
+		mo->m_len = ospace;
+		olen += ospace;
+		MGET(mo->m_next, M_DONTWAIT, MT_DATA);
+		mo = mo->m_next;
+		if (mo == NULL) {
+		    m_freem(mo_head);
+		    return DECOMP_ERROR;
+		}
+		MCLGET(mo, M_DONTWAIT);
+		state->strm.next_out = mtod(mo, u_char *);
+		state->strm.avail_out = ospace = M_TRAILINGSPACE(mo);
+	    }
+	}
+    }
+    if (decode_proto) {
+	m_freem(mo_head);
+	return DECOMP_ERROR;
+    }
+    olen += (mo->m_len = ospace - state->strm.avail_out);
+#if DEFLATE_DEBUG
+    if (olen > state->mru + PPP_HDRLEN)
+	printf("ppp_deflate%d: exceeded mru (%d > %d)\n",
+	       state->unit, olen, state->mru + PPP_HDRLEN);
+#endif
+
+    state->stats.unc_bytes += olen;
+    state->stats.unc_packets++;
+    state->stats.comp_bytes += rlen;
+    state->stats.comp_packets++;
+
+    *mop = mo_head;
+    return DECOMP_OK;
+}
+
+/*
+ * Incompressible data has arrived - add it to the history.
+ */
+static void
+z_incomp(arg, mi)
+    void *arg;
+    struct mbuf *mi;
+{
+    struct deflate_state *state = (struct deflate_state *) arg;
+    u_char *rptr;
+    int rlen, proto, r;
+
+    /*
+     * Check that the protocol is one we handle.
+     */
+    rptr = mtod(mi, u_char *);
+    proto = PPP_PROTOCOL(rptr);
+    if (proto > 0x3fff || proto == 0xfd || proto == 0xfb)
+	return;
+
+    ++state->seqno;
+
+    /*
+     * Iterate through the mbufs, adding the characters in them
+     * to the decompressor's history.  For the first mbuf, we start
+     * at the either the 1st or 2nd byte of the protocol field,
+     * depending on whether the protocol value is compressible.
+     */
+    rlen = mi->m_len;
+    state->strm.next_in = rptr + 3;
+    state->strm.avail_in = rlen - 3;
+    if (proto > 0xff) {
+	--state->strm.next_in;
+	++state->strm.avail_in;
+    }
+    for (;;) {
+	r = inflateIncomp(&state->strm);
+	if (r != Z_OK) {
+	    /* gak! */
+#if !DEFLATE_DEBUG
+	    if (state->debug)
+#endif
+		printf("z_incomp%d: inflateIncomp returned %d (%s)\n",
+		       state->unit, r, (state->strm.msg? state->strm.msg: ""));
+	    return;
+	}
+	mi = mi->m_next;
+	if (mi == NULL)
+	    break;
+	state->strm.next_in = mtod(mi, u_char *);
+	state->strm.avail_in = mi->m_len;
+	rlen += mi->m_len;
+    }
+
+    /*
+     * Update stats.
+     */
+    state->stats.inc_bytes += rlen;
+    state->stats.inc_packets++;
+    state->stats.unc_bytes += rlen;
+    state->stats.unc_packets++;
+}
+
+#endif /* DO_DEFLATE */
diff --git a/sys/net/zlib.c b/sys/net/zlib.c
new file mode 100644
index 0000000..b9da5f9
--- /dev/null
+++ b/sys/net/zlib.c
@@ -0,0 +1,4636 @@
+/*
+ * This file is derived from various .h and .c files from the zlib-0.95
+ * distribution by Jean-loup Gailly and Mark Adler, with some additions
+ * by Paul Mackerras to aid in implementing Deflate compression and
+ * decompression for PPP packets.  See zlib.h for conditions of
+ * distribution and use.
+ *
+ * Changes that have been made include:
+ * - changed functions not used outside this file to "local"
+ * - added minCompression parameter to deflateInit2
+ * - added Z_PACKET_FLUSH (see zlib.h for details)
+ * - added inflateIncomp
+ *
+ * $Id: zlib.c,v 1.7 1997/05/22 06:44:39 paulus Exp $
+ */
+
+/* 
+ *  ==FILEVERSION 970501==
+ *
+ * This marker is used by the Linux installation script to determine
+ * whether an up-to-date version of this file is already installed.
+ */
+
+/*+++++*/
+/* zutil.h -- internal interface and configuration of the compression library
+ * Copyright (C) 1995 Jean-loup Gailly.
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/* WARNING: this file should *not* be used by applications. It is
+   part of the implementation of the compression library and is
+   subject to change. Applications should only use zlib.h.
+ */
+
+/* From: zutil.h,v 1.9 1995/05/03 17:27:12 jloup Exp */
+
+#define _Z_UTIL_H
+
+#include "zlib.h"
+
+#ifndef local
+#  define local static
+#endif
+/* compile with -Dlocal if your debugger can't find static symbols */
+
+#define FAR
+
+typedef unsigned char  uch;
+typedef uch FAR uchf;
+typedef unsigned short ush;
+typedef ush FAR ushf;
+typedef unsigned long  ulg;
+
+extern char *z_errmsg[]; /* indexed by 1-zlib_error */
+
+#define ERR_RETURN(strm,err) return (strm->msg=z_errmsg[1-err], err)
+/* To be used only when the state is known to be valid */
+
+#ifndef NULL
+#define NULL	((void *) 0)
+#endif
+
+        /* common constants */
+
+#define DEFLATED   8
+
+#ifndef DEF_WBITS
+#  define DEF_WBITS MAX_WBITS
+#endif
+/* default windowBits for decompression. MAX_WBITS is for compression only */
+
+#if MAX_MEM_LEVEL >= 8
+#  define DEF_MEM_LEVEL 8
+#else
+#  define DEF_MEM_LEVEL  MAX_MEM_LEVEL
+#endif
+/* default memLevel */
+
+#define STORED_BLOCK 0
+#define STATIC_TREES 1
+#define DYN_TREES    2
+/* The three kinds of block type */
+
+#define MIN_MATCH  3
+#define MAX_MATCH  258
+/* The minimum and maximum match lengths */
+
+         /* functions */
+
+#if defined(KERNEL) || defined(_KERNEL)
+#include <sys/types.h>
+#include <sys/time.h>
+#include <sys/systm.h>
+#  define zmemcpy(d, s, n)	bcopy((s), (d), (n))
+#  define zmemzero		bzero
+
+#else
+#if defined(__KERNEL__)
+/* Assume this is Linux */
+#include <linux/string.h>
+#define zmemcpy memcpy
+#define zmemzero(dest, len)	memset(dest, 0, len)
+
+#else /* not kernel */
+#if defined(STDC) && !defined(HAVE_MEMCPY) && !defined(NO_MEMCPY)
+#  define HAVE_MEMCPY
+#endif
+#ifdef HAVE_MEMCPY
+#    define zmemcpy memcpy
+#    define zmemzero(dest, len) memset(dest, 0, len)
+#else
+   extern void zmemcpy  OF((Bytef* dest, Bytef* source, uInt len));
+   extern void zmemzero OF((Bytef* dest, uInt len));
+#endif
+#endif	/* __KERNEL__ */
+#endif	/* KERNEL */
+
+/* Diagnostic functions */
+#ifdef DEBUG_ZLIB
+#  include <stdio.h>
+#  ifndef verbose
+#    define verbose 0
+#  endif
+#  define Assert(cond,msg) {if(!(cond)) z_error(msg);}
+#  define Trace(x) fprintf x
+#  define Tracev(x) {if (verbose) fprintf x ;}
+#  define Tracevv(x) {if (verbose>1) fprintf x ;}
+#  define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
+#  define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
+#else
+#  define Assert(cond,msg)
+#  define Trace(x)
+#  define Tracev(x)
+#  define Tracevv(x)
+#  define Tracec(c,x)
+#  define Tracecv(c,x)
+#endif
+
+
+typedef uLong (*check_func) OF((uLong check, Bytef *buf, uInt len));
+
+/* voidpf zcalloc OF((voidpf opaque, unsigned items, unsigned size)); */
+/* void   zcfree  OF((voidpf opaque, voidpf ptr)); */
+
+#define ZALLOC(strm, items, size) \
+           (*((strm)->zalloc))((strm)->opaque, (items), (size))
+#define ZALLOC_INIT(strm, items, size) \
+           (*((strm)->zalloc_init))((strm)->opaque, (items), (size))
+#define ZFREE(strm, addr, size)	\
+	   (*((strm)->zfree))((strm)->opaque, (voidpf)(addr), (size))
+#define TRY_FREE(s, p, n) {if (p) ZFREE(s, p, n);}
+
+/* deflate.h -- internal compression state
+ * Copyright (C) 1995 Jean-loup Gailly
+ * For conditions of distribution and use, see copyright notice in zlib.h 
+ */
+
+/* WARNING: this file should *not* be used by applications. It is
+   part of the implementation of the compression library and is
+   subject to change. Applications should only use zlib.h.
+ */
+
+
+/*+++++*/
+/* From: deflate.h,v 1.5 1995/05/03 17:27:09 jloup Exp */
+
+/* ===========================================================================
+ * Internal compression state.
+ */
+
+/* Data type */
+#define Z_BINARY  0
+#define ASCII   1
+#define UNKNOWN 2
+
+#define LENGTH_CODES 29
+/* number of length codes, not counting the special END_BLOCK code */
+
+#define LITERALS  256
+/* number of literal bytes 0..255 */
+
+#define L_CODES (LITERALS+1+LENGTH_CODES)
+/* number of Literal or Length codes, including the END_BLOCK code */
+
+#define D_CODES   30
+/* number of distance codes */
+
+#define BL_CODES  19
+/* number of codes used to transfer the bit lengths */
+
+#define HEAP_SIZE (2*L_CODES+1)
+/* maximum heap size */
+
+#define MAX_BITS 15
+/* All codes must not exceed MAX_BITS bits */
+
+#define INIT_STATE    42
+#define BUSY_STATE   113
+#define FLUSH_STATE  124
+#define FINISH_STATE 666
+/* Stream status */
+
+
+/* Data structure describing a single value and its code string. */
+typedef struct ct_data_s {
+    union {
+        ush  freq;       /* frequency count */
+        ush  code;       /* bit string */
+    } fc;
+    union {
+        ush  dad;        /* father node in Huffman tree */
+        ush  len;        /* length of bit string */
+    } dl;
+} FAR ct_data;
+
+#define Freq fc.freq
+#define Code fc.code
+#define Dad  dl.dad
+#define Len  dl.len
+
+typedef struct static_tree_desc_s  static_tree_desc;
+
+typedef struct tree_desc_s {
+    ct_data *dyn_tree;           /* the dynamic tree */
+    int     max_code;            /* largest code with non zero frequency */
+    static_tree_desc *stat_desc; /* the corresponding static tree */
+} FAR tree_desc;
+
+typedef ush Pos;
+typedef Pos FAR Posf;
+typedef unsigned IPos;
+
+/* A Pos is an index in the character window. We use short instead of int to
+ * save space in the various tables. IPos is used only for parameter passing.
+ */
+
+typedef struct deflate_state {
+    z_stream *strm;      /* pointer back to this zlib stream */
+    int   status;        /* as the name implies */
+    Bytef *pending_buf;  /* output still pending */
+    Bytef *pending_out;  /* next pending byte to output to the stream */
+    int   pending;       /* nb of bytes in the pending buffer */
+    uLong adler;         /* adler32 of uncompressed data */
+    int   noheader;      /* suppress zlib header and adler32 */
+    Byte  data_type;     /* UNKNOWN, Z_BINARY or ASCII */
+    Byte  method;        /* STORED (for zip only) or DEFLATED */
+    int	  minCompr;	 /* min size decrease for Z_FLUSH_NOSTORE */
+
+                /* used by deflate.c: */
+
+    uInt  w_size;        /* LZ77 window size (32K by default) */
+    uInt  w_bits;        /* log2(w_size)  (8..16) */
+    uInt  w_mask;        /* w_size - 1 */
+
+    Bytef *window;
+    /* Sliding window. Input bytes are read into the second half of the window,
+     * and move to the first half later to keep a dictionary of at least wSize
+     * bytes. With this organization, matches are limited to a distance of
+     * wSize-MAX_MATCH bytes, but this ensures that IO is always
+     * performed with a length multiple of the block size. Also, it limits
+     * the window size to 64K, which is quite useful on MSDOS.
+     * To do: use the user input buffer as sliding window.
+     */
+
+    ulg window_size;
+    /* Actual size of window: 2*wSize, except when the user input buffer
+     * is directly used as sliding window.
+     */
+
+    Posf *prev;
+    /* Link to older string with same hash index. To limit the size of this
+     * array to 64K, this link is maintained only for the last 32K strings.
+     * An index in this array is thus a window index modulo 32K.
+     */
+
+    Posf *head; /* Heads of the hash chains or NIL. */
+
+    uInt  ins_h;          /* hash index of string to be inserted */
+    uInt  hash_size;      /* number of elements in hash table */
+    uInt  hash_bits;      /* log2(hash_size) */
+    uInt  hash_mask;      /* hash_size-1 */
+
+    uInt  hash_shift;
+    /* Number of bits by which ins_h must be shifted at each input
+     * step. It must be such that after MIN_MATCH steps, the oldest
+     * byte no longer takes part in the hash key, that is:
+     *   hash_shift * MIN_MATCH >= hash_bits
+     */
+
+    long block_start;
+    /* Window position at the beginning of the current output block. Gets
+     * negative when the window is moved backwards.
+     */
+
+    uInt match_length;           /* length of best match */
+    IPos prev_match;             /* previous match */
+    int match_available;         /* set if previous match exists */
+    uInt strstart;               /* start of string to insert */
+    uInt match_start;            /* start of matching string */
+    uInt lookahead;              /* number of valid bytes ahead in window */
+
+    uInt prev_length;
+    /* Length of the best match at previous step. Matches not greater than this
+     * are discarded. This is used in the lazy match evaluation.
+     */
+
+    uInt max_chain_length;
+    /* To speed up deflation, hash chains are never searched beyond this
+     * length.  A higher limit improves compression ratio but degrades the
+     * speed.
+     */
+
+    uInt max_lazy_match;
+    /* Attempt to find a better match only when the current match is strictly
+     * smaller than this value. This mechanism is used only for compression
+     * levels >= 4.
+     */
+#   define max_insert_length  max_lazy_match
+    /* Insert new strings in the hash table only if the match length is not
+     * greater than this length. This saves time but degrades compression.
+     * max_insert_length is used only for compression levels <= 3.
+     */
+
+    int level;    /* compression level (1..9) */
+    int strategy; /* favor or force Huffman coding*/
+
+    uInt good_match;
+    /* Use a faster search when the previous match is longer than this */
+
+     int nice_match; /* Stop searching when current match exceeds this */
+
+                /* used by trees.c: */
+    /* Didn't use ct_data typedef below to supress compiler warning */
+    struct ct_data_s dyn_ltree[HEAP_SIZE];   /* literal and length tree */
+    struct ct_data_s dyn_dtree[2*D_CODES+1]; /* distance tree */
+    struct ct_data_s bl_tree[2*BL_CODES+1];  /* Huffman tree for bit lengths */
+
+    struct tree_desc_s l_desc;               /* desc. for literal tree */
+    struct tree_desc_s d_desc;               /* desc. for distance tree */
+    struct tree_desc_s bl_desc;              /* desc. for bit length tree */
+
+    ush bl_count[MAX_BITS+1];
+    /* number of codes at each bit length for an optimal tree */
+
+    int heap[2*L_CODES+1];      /* heap used to build the Huffman trees */
+    int heap_len;               /* number of elements in the heap */
+    int heap_max;               /* element of largest frequency */
+    /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
+     * The same heap array is used to build all trees.
+     */
+
+    uch depth[2*L_CODES+1];
+    /* Depth of each subtree used as tie breaker for trees of equal frequency
+     */
+
+    uchf *l_buf;          /* buffer for literals or lengths */
+
+    uInt  lit_bufsize;
+    /* Size of match buffer for literals/lengths.  There are 4 reasons for
+     * limiting lit_bufsize to 64K:
+     *   - frequencies can be kept in 16 bit counters
+     *   - if compression is not successful for the first block, all input
+     *     data is still in the window so we can still emit a stored block even
+     *     when input comes from standard input.  (This can also be done for
+     *     all blocks if lit_bufsize is not greater than 32K.)
+     *   - if compression is not successful for a file smaller than 64K, we can
+     *     even emit a stored file instead of a stored block (saving 5 bytes).
+     *     This is applicable only for zip (not gzip or zlib).
+     *   - creating new Huffman trees less frequently may not provide fast
+     *     adaptation to changes in the input data statistics. (Take for
+     *     example a binary file with poorly compressible code followed by
+     *     a highly compressible string table.) Smaller buffer sizes give
+     *     fast adaptation but have of course the overhead of transmitting
+     *     trees more frequently.
+     *   - I can't count above 4
+     */
+
+    uInt last_lit;      /* running index in l_buf */
+
+    ushf *d_buf;
+    /* Buffer for distances. To simplify the code, d_buf and l_buf have
+     * the same number of elements. To use different lengths, an extra flag
+     * array would be necessary.
+     */
+
+    ulg opt_len;        /* bit length of current block with optimal trees */
+    ulg static_len;     /* bit length of current block with static trees */
+    ulg compressed_len; /* total bit length of compressed file */
+    uInt matches;       /* number of string matches in current block */
+    int last_eob_len;   /* bit length of EOB code for last block */
+
+#ifdef DEBUG_ZLIB
+    ulg bits_sent;      /* bit length of the compressed data */
+#endif
+
+    ush bi_buf;
+    /* Output buffer. bits are inserted starting at the bottom (least
+     * significant bits).
+     */
+    int bi_valid;
+    /* Number of valid bits in bi_buf.  All bits above the last valid bit
+     * are always zero.
+     */
+
+    uInt blocks_in_packet;
+    /* Number of blocks produced since the last time Z_PACKET_FLUSH
+     * was used.
+     */
+
+} FAR deflate_state;
+
+/* Output a byte on the stream.
+ * IN assertion: there is enough room in pending_buf.
+ */
+#define put_byte(s, c) {s->pending_buf[s->pending++] = (c);}
+
+
+#define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
+/* Minimum amount of lookahead, except at the end of the input file.
+ * See deflate.c for comments about the MIN_MATCH+1.
+ */
+
+#define MAX_DIST(s)  ((s)->w_size-MIN_LOOKAHEAD)
+/* In order to simplify the code, particularly on 16 bit machines, match
+ * distances are limited to MAX_DIST instead of WSIZE.
+ */
+
+        /* in trees.c */
+local void ct_init       OF((deflate_state *s));
+local int  ct_tally      OF((deflate_state *s, int dist, int lc));
+local ulg ct_flush_block OF((deflate_state *s, charf *buf, ulg stored_len,
+			     int flush));
+local void ct_align      OF((deflate_state *s));
+local void ct_stored_block OF((deflate_state *s, charf *buf, ulg stored_len,
+                          int eof));
+local void ct_stored_type_only OF((deflate_state *s));
+
+
+/*+++++*/
+/* deflate.c -- compress data using the deflation algorithm
+ * Copyright (C) 1995 Jean-loup Gailly.
+ * For conditions of distribution and use, see copyright notice in zlib.h 
+ */
+
+/*
+ *  ALGORITHM
+ *
+ *      The "deflation" process depends on being able to identify portions
+ *      of the input text which are identical to earlier input (within a
+ *      sliding window trailing behind the input currently being processed).
+ *
+ *      The most straightforward technique turns out to be the fastest for
+ *      most input files: try all possible matches and select the longest.
+ *      The key feature of this algorithm is that insertions into the string
+ *      dictionary are very simple and thus fast, and deletions are avoided
+ *      completely. Insertions are performed at each input character, whereas
+ *      string matches are performed only when the previous match ends. So it
+ *      is preferable to spend more time in matches to allow very fast string
+ *      insertions and avoid deletions. The matching algorithm for small
+ *      strings is inspired from that of Rabin & Karp. A brute force approach
+ *      is used to find longer strings when a small match has been found.
+ *      A similar algorithm is used in comic (by Jan-Mark Wams) and freeze
+ *      (by Leonid Broukhis).
+ *         A previous version of this file used a more sophisticated algorithm
+ *      (by Fiala and Greene) which is guaranteed to run in linear amortized
+ *      time, but has a larger average cost, uses more memory and is patented.
+ *      However the F&G algorithm may be faster for some highly redundant
+ *      files if the parameter max_chain_length (described below) is too large.
+ *
+ *  ACKNOWLEDGEMENTS
+ *
+ *      The idea of lazy evaluation of matches is due to Jan-Mark Wams, and
+ *      I found it in 'freeze' written by Leonid Broukhis.
+ *      Thanks to many people for bug reports and testing.
+ *
+ *  REFERENCES
+ *
+ *      Deutsch, L.P.,"'Deflate' Compressed Data Format Specification".
+ *      Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc
+ *
+ *      A description of the Rabin and Karp algorithm is given in the book
+ *         "Algorithms" by R. Sedgewick, Addison-Wesley, p252.
+ *
+ *      Fiala,E.R., and Greene,D.H.
+ *         Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595
+ *
+ */
+
+/* From: deflate.c,v 1.8 1995/05/03 17:27:08 jloup Exp */
+
+local char zlib_copyright[] = " deflate Copyright 1995 Jean-loup Gailly ";
+/*
+  If you use the zlib library in a product, an acknowledgment is welcome
+  in the documentation of your product. If for some reason you cannot
+  include such an acknowledgment, I would appreciate that you keep this
+  copyright string in the executable of your product.
+ */
+
+#define NIL 0
+/* Tail of hash chains */
+
+#ifndef TOO_FAR
+#  define TOO_FAR 4096
+#endif
+/* Matches of length 3 are discarded if their distance exceeds TOO_FAR */
+
+#define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
+/* Minimum amount of lookahead, except at the end of the input file.
+ * See deflate.c for comments about the MIN_MATCH+1.
+ */
+
+/* Values for max_lazy_match, good_match and max_chain_length, depending on
+ * the desired pack level (0..9). The values given below have been tuned to
+ * exclude worst case performance for pathological files. Better values may be
+ * found for specific files.
+ */
+
+typedef struct config_s {
+   ush good_length; /* reduce lazy search above this match length */
+   ush max_lazy;    /* do not perform lazy search above this match length */
+   ush nice_length; /* quit search above this match length */
+   ush max_chain;
+} config;
+
+local config configuration_table[10] = {
+/*      good lazy nice chain */
+/* 0 */ {0,    0,  0,    0},  /* store only */
+/* 1 */ {4,    4,  8,    4},  /* maximum speed, no lazy matches */
+/* 2 */ {4,    5, 16,    8},
+/* 3 */ {4,    6, 32,   32},
+
+/* 4 */ {4,    4, 16,   16},  /* lazy matches */
+/* 5 */ {8,   16, 32,   32},
+/* 6 */ {8,   16, 128, 128},
+/* 7 */ {8,   32, 128, 256},
+/* 8 */ {32, 128, 258, 1024},
+/* 9 */ {32, 258, 258, 4096}}; /* maximum compression */
+
+/* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4
+ * For deflate_fast() (levels <= 3) good is ignored and lazy has a different
+ * meaning.
+ */
+
+#define EQUAL 0
+/* result of memcmp for equal strings */
+
+/* ===========================================================================
+ *  Prototypes for local functions.
+ */
+
+local void fill_window   OF((deflate_state *s));
+local int  deflate_fast  OF((deflate_state *s, int flush));
+local int  deflate_slow  OF((deflate_state *s, int flush));
+local void lm_init       OF((deflate_state *s));
+local int longest_match  OF((deflate_state *s, IPos cur_match));
+local void putShortMSB   OF((deflate_state *s, uInt b));
+local void flush_pending OF((z_stream *strm));
+local int read_buf       OF((z_stream *strm, charf *buf, unsigned size));
+#ifdef ASMV
+      void match_init OF((void)); /* asm code initialization */
+#endif
+
+#ifdef DEBUG_ZLIB
+local  void check_match OF((deflate_state *s, IPos start, IPos match,
+                            int length));
+#endif
+
+
+/* ===========================================================================
+ * Update a hash value with the given input byte
+ * IN  assertion: all calls to to UPDATE_HASH are made with consecutive
+ *    input characters, so that a running hash key can be computed from the
+ *    previous key instead of complete recalculation each time.
+ */
+#define UPDATE_HASH(s,h,c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask)
+
+
+/* ===========================================================================
+ * Insert string str in the dictionary and set match_head to the previous head
+ * of the hash chain (the most recent string with same hash key). Return
+ * the previous length of the hash chain.
+ * IN  assertion: all calls to to INSERT_STRING are made with consecutive
+ *    input characters and the first MIN_MATCH bytes of str are valid
+ *    (except for the last MIN_MATCH-1 bytes of the input file).
+ */
+#define INSERT_STRING(s, str, match_head) \
+   (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
+    s->prev[(str) & s->w_mask] = match_head = s->head[s->ins_h], \
+    s->head[s->ins_h] = (str))
+
+/* ===========================================================================
+ * Initialize the hash table (avoiding 64K overflow for 16 bit systems).
+ * prev[] will be initialized on the fly.
+ */
+#define CLEAR_HASH(s) \
+    s->head[s->hash_size-1] = NIL; \
+    zmemzero((charf *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head));
+
+/* ========================================================================= */
+int deflateInit (strm, level)
+    z_stream *strm;
+    int level;
+{
+    return deflateInit2 (strm, level, DEFLATED, MAX_WBITS, DEF_MEM_LEVEL,
+			 0, 0);
+    /* To do: ignore strm->next_in if we use it as window */
+}
+
+/* ========================================================================= */
+int deflateInit2 (strm, level, method, windowBits, memLevel,
+		  strategy, minCompression)
+    z_stream *strm;
+    int  level;
+    int  method;
+    int  windowBits;
+    int  memLevel;
+    int  strategy;
+    int  minCompression;
+{
+    deflate_state *s;
+    int noheader = 0;
+
+    if (strm == Z_NULL) return Z_STREAM_ERROR;
+
+    strm->msg = Z_NULL;
+/*    if (strm->zalloc == Z_NULL) strm->zalloc = zcalloc; */
+/*    if (strm->zfree == Z_NULL) strm->zfree = zcfree; */
+
+    if (level == Z_DEFAULT_COMPRESSION) level = 6;
+
+    if (windowBits < 0) { /* undocumented feature: suppress zlib header */
+        noheader = 1;
+        windowBits = -windowBits;
+    }
+    if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != DEFLATED ||
+        windowBits < 8 || windowBits > 15 || level < 1 || level > 9) {
+        return Z_STREAM_ERROR;
+    }
+    s = (deflate_state *) ZALLOC_INIT(strm, 1, sizeof(deflate_state));
+    if (s == Z_NULL) return Z_MEM_ERROR;
+    strm->state = (struct internal_state FAR *)s;
+    s->strm = strm;
+
+    s->noheader = noheader;
+    s->w_bits = windowBits;
+    s->w_size = 1 << s->w_bits;
+    s->w_mask = s->w_size - 1;
+
+    s->hash_bits = memLevel + 7;
+    s->hash_size = 1 << s->hash_bits;
+    s->hash_mask = s->hash_size - 1;
+    s->hash_shift =  ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH);
+
+    s->window = (Bytef *) ZALLOC_INIT(strm, s->w_size, 2*sizeof(Byte));
+    s->prev   = (Posf *)  ZALLOC_INIT(strm, s->w_size, sizeof(Pos));
+    s->head   = (Posf *)  ZALLOC_INIT(strm, s->hash_size, sizeof(Pos));
+
+    s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */
+
+    s->pending_buf = (uchf *) ZALLOC_INIT(strm, s->lit_bufsize, 2*sizeof(ush));
+
+    if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL ||
+        s->pending_buf == Z_NULL) {
+        strm->msg = z_errmsg[1-Z_MEM_ERROR];
+        deflateEnd (strm);
+        return Z_MEM_ERROR;
+    }
+    s->d_buf = (ushf *) &(s->pending_buf[s->lit_bufsize]);
+    s->l_buf = (uchf *) &(s->pending_buf[3*s->lit_bufsize]);
+    /* We overlay pending_buf and d_buf+l_buf. This works since the average
+     * output size for (length,distance) codes is <= 32 bits (worst case
+     * is 15+15+13=33).
+     */
+
+    s->level = level;
+    s->strategy = strategy;
+    s->method = (Byte)method;
+    s->minCompr = minCompression;
+    s->blocks_in_packet = 0;
+
+    return deflateReset(strm);
+}
+
+/* ========================================================================= */
+int deflateReset (strm)
+    z_stream *strm;
+{
+    deflate_state *s;
+    
+    if (strm == Z_NULL || strm->state == Z_NULL ||
+        strm->zalloc == Z_NULL || strm->zfree == Z_NULL ||
+	strm->zalloc_init == Z_NULL) return Z_STREAM_ERROR;
+
+    strm->total_in = strm->total_out = 0;
+    strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */
+    strm->data_type = Z_UNKNOWN;
+
+    s = (deflate_state *)strm->state;
+    s->pending = 0;
+    s->pending_out = s->pending_buf;
+
+    if (s->noheader < 0) {
+        s->noheader = 0; /* was set to -1 by deflate(..., Z_FINISH); */
+    }
+    s->status = s->noheader ? BUSY_STATE : INIT_STATE;
+    s->adler = 1;
+
+    ct_init(s);
+    lm_init(s);
+
+    return Z_OK;
+}
+
+/* =========================================================================
+ * Put a short in the pending buffer. The 16-bit value is put in MSB order.
+ * IN assertion: the stream state is correct and there is enough room in
+ * pending_buf.
+ */
+local void putShortMSB (s, b)
+    deflate_state *s;
+    uInt b;
+{
+    put_byte(s, (Byte)(b >> 8));
+    put_byte(s, (Byte)(b & 0xff));
+}   
+
+/* =========================================================================
+ * Flush as much pending output as possible.
+ */
+local void flush_pending(strm)
+    z_stream *strm;
+{
+    deflate_state *state = (deflate_state *) strm->state;
+    unsigned len = state->pending;
+
+    if (len > strm->avail_out) len = strm->avail_out;
+    if (len == 0) return;
+
+    if (strm->next_out != NULL) {
+	zmemcpy(strm->next_out, state->pending_out, len);
+	strm->next_out += len;
+    }
+    state->pending_out += len;
+    strm->total_out += len;
+    strm->avail_out -= len;
+    state->pending -= len;
+    if (state->pending == 0) {
+        state->pending_out = state->pending_buf;
+    }
+}
+
+/* ========================================================================= */
+int deflate (strm, flush)
+    z_stream *strm;
+    int flush;
+{
+    deflate_state *state = (deflate_state *) strm->state;
+
+    if (strm == Z_NULL || state == Z_NULL) return Z_STREAM_ERROR;
+    
+    if (strm->next_in == Z_NULL && strm->avail_in != 0) {
+        ERR_RETURN(strm, Z_STREAM_ERROR);
+    }
+    if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR);
+
+    state->strm = strm; /* just in case */
+
+    /* Write the zlib header */
+    if (state->status == INIT_STATE) {
+
+        uInt header = (DEFLATED + ((state->w_bits-8)<<4)) << 8;
+        uInt level_flags = (state->level-1) >> 1;
+
+        if (level_flags > 3) level_flags = 3;
+        header |= (level_flags << 6);
+        header += 31 - (header % 31);
+
+        state->status = BUSY_STATE;
+        putShortMSB(state, header);
+    }
+
+    /* Flush as much pending output as possible */
+    if (state->pending != 0) {
+        flush_pending(strm);
+        if (strm->avail_out == 0) return Z_OK;
+    }
+
+    /* If we came back in here to get the last output from
+     * a previous flush, we're done for now.
+     */
+    if (state->status == FLUSH_STATE) {
+	state->status = BUSY_STATE;
+	if (flush != Z_NO_FLUSH && flush != Z_FINISH)
+	    return Z_OK;
+    }
+
+    /* User must not provide more input after the first FINISH: */
+    if (state->status == FINISH_STATE && strm->avail_in != 0) {
+        ERR_RETURN(strm, Z_BUF_ERROR);
+    }
+
+    /* Start a new block or continue the current one.
+     */
+    if (strm->avail_in != 0 || state->lookahead != 0 ||
+        (flush == Z_FINISH && state->status != FINISH_STATE)) {
+        int quit;
+
+        if (flush == Z_FINISH) {
+            state->status = FINISH_STATE;
+        }
+        if (state->level <= 3) {
+            quit = deflate_fast(state, flush);
+        } else {
+            quit = deflate_slow(state, flush);
+        }
+        if (quit || strm->avail_out == 0)
+	    return Z_OK;
+        /* If flush != Z_NO_FLUSH && avail_out == 0, the next call
+         * of deflate should use the same flush parameter to make sure
+         * that the flush is complete. So we don't have to output an
+         * empty block here, this will be done at next call. This also
+         * ensures that for a very small output buffer, we emit at most
+         * one empty block.
+         */
+    }
+
+    /* If a flush was requested, we have a little more to output now. */
+    if (flush != Z_NO_FLUSH && flush != Z_FINISH
+	&& state->status != FINISH_STATE) {
+	switch (flush) {
+	case Z_PARTIAL_FLUSH:
+	    ct_align(state);
+	    break;
+	case Z_PACKET_FLUSH:
+	    /* Output just the 3-bit `stored' block type value,
+	       but not a zero length. */
+	    ct_stored_type_only(state);
+	    break;
+	default:
+	    ct_stored_block(state, (char*)0, 0L, 0);
+	    /* For a full flush, this empty block will be recognized
+	     * as a special marker by inflate_sync().
+	     */
+	    if (flush == Z_FULL_FLUSH) {
+		CLEAR_HASH(state);             /* forget history */
+	    }
+	}
+	flush_pending(strm);
+	if (strm->avail_out == 0) {
+	    /* We'll have to come back to get the rest of the output;
+	     * this ensures we don't output a second zero-length stored
+	     * block (or whatever).
+	     */
+	    state->status = FLUSH_STATE;
+	    return Z_OK;
+	}
+    }
+
+    Assert(strm->avail_out > 0, "bug2");
+
+    if (flush != Z_FINISH) return Z_OK;
+    if (state->noheader) return Z_STREAM_END;
+
+    /* Write the zlib trailer (adler32) */
+    putShortMSB(state, (uInt)(state->adler >> 16));
+    putShortMSB(state, (uInt)(state->adler & 0xffff));
+    flush_pending(strm);
+    /* If avail_out is zero, the application will call deflate again
+     * to flush the rest.
+     */
+    state->noheader = -1; /* write the trailer only once! */
+    return state->pending != 0 ? Z_OK : Z_STREAM_END;
+}
+
+/* ========================================================================= */
+int deflateEnd (strm)
+    z_stream *strm;
+{
+    deflate_state *state = (deflate_state *) strm->state;
+
+    if (strm == Z_NULL || state == Z_NULL) return Z_STREAM_ERROR;
+
+    TRY_FREE(strm, state->window, state->w_size * 2 * sizeof(Byte));
+    TRY_FREE(strm, state->prev, state->w_size * sizeof(Pos));
+    TRY_FREE(strm, state->head, state->hash_size * sizeof(Pos));
+    TRY_FREE(strm, state->pending_buf, state->lit_bufsize * 2 * sizeof(ush));
+
+    ZFREE(strm, state, sizeof(deflate_state));
+    strm->state = Z_NULL;
+
+    return Z_OK;
+}
+
+/* ===========================================================================
+ * Read a new buffer from the current input stream, update the adler32
+ * and total number of bytes read.
+ */
+local int read_buf(strm, buf, size)
+    z_stream *strm;
+    charf *buf;
+    unsigned size;
+{
+    unsigned len = strm->avail_in;
+    deflate_state *state = (deflate_state *) strm->state;
+
+    if (len > size) len = size;
+    if (len == 0) return 0;
+
+    strm->avail_in  -= len;
+
+    if (!state->noheader) {
+        state->adler = adler32(state->adler, strm->next_in, len);
+    }
+    zmemcpy(buf, strm->next_in, len);
+    strm->next_in  += len;
+    strm->total_in += len;
+
+    return (int)len;
+}
+
+/* ===========================================================================
+ * Initialize the "longest match" routines for a new zlib stream
+ */
+local void lm_init (s)
+    deflate_state *s;
+{
+    s->window_size = (ulg)2L*s->w_size;
+
+    CLEAR_HASH(s);
+
+    /* Set the default configuration parameters:
+     */
+    s->max_lazy_match   = configuration_table[s->level].max_lazy;
+    s->good_match       = configuration_table[s->level].good_length;
+    s->nice_match       = configuration_table[s->level].nice_length;
+    s->max_chain_length = configuration_table[s->level].max_chain;
+
+    s->strstart = 0;
+    s->block_start = 0L;
+    s->lookahead = 0;
+    s->match_length = MIN_MATCH-1;
+    s->match_available = 0;
+    s->ins_h = 0;
+#ifdef ASMV
+    match_init(); /* initialize the asm code */
+#endif
+}
+
+/* ===========================================================================
+ * Set match_start to the longest match starting at the given string and
+ * return its length. Matches shorter or equal to prev_length are discarded,
+ * in which case the result is equal to prev_length and match_start is
+ * garbage.
+ * IN assertions: cur_match is the head of the hash chain for the current
+ *   string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
+ */
+#ifndef ASMV
+/* For 80x86 and 680x0, an optimized version will be provided in match.asm or
+ * match.S. The code will be functionally equivalent.
+ */
+local int longest_match(s, cur_match)
+    deflate_state *s;
+    IPos cur_match;                             /* current match */
+{
+    unsigned chain_length = s->max_chain_length;/* max hash chain length */
+    register Bytef *scan = s->window + s->strstart; /* current string */
+    register Bytef *match;                       /* matched string */
+    register int len;                           /* length of current match */
+    int best_len = s->prev_length;              /* best match length so far */
+    IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
+        s->strstart - (IPos)MAX_DIST(s) : NIL;
+    /* Stop when cur_match becomes <= limit. To simplify the code,
+     * we prevent matches with the string of window index 0.
+     */
+    Posf *prev = s->prev;
+    uInt wmask = s->w_mask;
+
+#ifdef UNALIGNED_OK
+    /* Compare two bytes at a time. Note: this is not always beneficial.
+     * Try with and without -DUNALIGNED_OK to check.
+     */
+    register Bytef *strend = s->window + s->strstart + MAX_MATCH - 1;
+    register ush scan_start = *(ushf*)scan;
+    register ush scan_end   = *(ushf*)(scan+best_len-1);
+#else
+    register Bytef *strend = s->window + s->strstart + MAX_MATCH;
+    register Byte scan_end1  = scan[best_len-1];
+    register Byte scan_end   = scan[best_len];
+#endif
+
+    /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
+     * It is easy to get rid of this optimization if necessary.
+     */
+    Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
+
+    /* Do not waste too much time if we already have a good match: */
+    if (s->prev_length >= s->good_match) {
+        chain_length >>= 2;
+    }
+    Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
+
+    do {
+        Assert(cur_match < s->strstart, "no future");
+        match = s->window + cur_match;
+
+        /* Skip to next match if the match length cannot increase
+         * or if the match length is less than 2:
+         */
+#if (defined(UNALIGNED_OK) && MAX_MATCH == 258)
+        /* This code assumes sizeof(unsigned short) == 2. Do not use
+         * UNALIGNED_OK if your compiler uses a different size.
+         */
+        if (*(ushf*)(match+best_len-1) != scan_end ||
+            *(ushf*)match != scan_start) continue;
+
+        /* It is not necessary to compare scan[2] and match[2] since they are
+         * always equal when the other bytes match, given that the hash keys
+         * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at
+         * strstart+3, +5, ... up to strstart+257. We check for insufficient
+         * lookahead only every 4th comparison; the 128th check will be made
+         * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is
+         * necessary to put more guard bytes at the end of the window, or
+         * to check more often for insufficient lookahead.
+         */
+        Assert(scan[2] == match[2], "scan[2]?");
+        scan++, match++;
+        do {
+        } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
+                 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
+                 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
+                 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
+                 scan < strend);
+        /* The funny "do {}" generates better code on most compilers */
+
+        /* Here, scan <= window+strstart+257 */
+        Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
+        if (*scan == *match) scan++;
+
+        len = (MAX_MATCH - 1) - (int)(strend-scan);
+        scan = strend - (MAX_MATCH-1);
+
+#else /* UNALIGNED_OK */
+
+        if (match[best_len]   != scan_end  ||
+            match[best_len-1] != scan_end1 ||
+            *match            != *scan     ||
+            *++match          != scan[1])      continue;
+
+        /* The check at best_len-1 can be removed because it will be made
+         * again later. (This heuristic is not always a win.)
+         * It is not necessary to compare scan[2] and match[2] since they
+         * are always equal when the other bytes match, given that
+         * the hash keys are equal and that HASH_BITS >= 8.
+         */
+        scan += 2, match++;
+        Assert(*scan == *match, "match[2]?");
+
+        /* We check for insufficient lookahead only every 8th comparison;
+         * the 256th check will be made at strstart+258.
+         */
+        do {
+        } while (*++scan == *++match && *++scan == *++match &&
+                 *++scan == *++match && *++scan == *++match &&
+                 *++scan == *++match && *++scan == *++match &&
+                 *++scan == *++match && *++scan == *++match &&
+                 scan < strend);
+
+        Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
+
+        len = MAX_MATCH - (int)(strend - scan);
+        scan = strend - MAX_MATCH;
+
+#endif /* UNALIGNED_OK */
+
+        if (len > best_len) {
+            s->match_start = cur_match;
+            best_len = len;
+            if (len >= s->nice_match) break;
+#ifdef UNALIGNED_OK
+            scan_end = *(ushf*)(scan+best_len-1);
+#else
+            scan_end1  = scan[best_len-1];
+            scan_end   = scan[best_len];
+#endif
+        }
+    } while ((cur_match = prev[cur_match & wmask]) > limit
+             && --chain_length != 0);
+
+    return best_len;
+}
+#endif /* ASMV */
+
+#ifdef DEBUG_ZLIB
+/* ===========================================================================
+ * Check that the match at match_start is indeed a match.
+ */
+local void check_match(s, start, match, length)
+    deflate_state *s;
+    IPos start, match;
+    int length;
+{
+    /* check that the match is indeed a match */
+    if (memcmp((charf *)s->window + match,
+                (charf *)s->window + start, length) != EQUAL) {
+        fprintf(stderr,
+            " start %u, match %u, length %d\n",
+            start, match, length);
+        do { fprintf(stderr, "%c%c", s->window[match++],
+                     s->window[start++]); } while (--length != 0);
+        z_error("invalid match");
+    }
+    if (verbose > 1) {
+        fprintf(stderr,"\\[%d,%d]", start-match, length);
+        do { putc(s->window[start++], stderr); } while (--length != 0);
+    }
+}
+#else
+#  define check_match(s, start, match, length)
+#endif
+
+/* ===========================================================================
+ * Fill the window when the lookahead becomes insufficient.
+ * Updates strstart and lookahead.
+ *
+ * IN assertion: lookahead < MIN_LOOKAHEAD
+ * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD
+ *    At least one byte has been read, or avail_in == 0; reads are
+ *    performed for at least two bytes (required for the zip translate_eol
+ *    option -- not supported here).
+ */
+local void fill_window(s)
+    deflate_state *s;
+{
+    register unsigned n, m;
+    register Posf *p;
+    unsigned more;    /* Amount of free space at the end of the window. */
+    uInt wsize = s->w_size;
+
+    do {
+        more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart);
+
+        /* Deal with !@#$% 64K limit: */
+        if (more == 0 && s->strstart == 0 && s->lookahead == 0) {
+            more = wsize;
+        } else if (more == (unsigned)(-1)) {
+            /* Very unlikely, but possible on 16 bit machine if strstart == 0
+             * and lookahead == 1 (input done one byte at time)
+             */
+            more--;
+
+        /* If the window is almost full and there is insufficient lookahead,
+         * move the upper half to the lower one to make room in the upper half.
+         */
+        } else if (s->strstart >= wsize+MAX_DIST(s)) {
+
+            /* By the IN assertion, the window is not empty so we can't confuse
+             * more == 0 with more == 64K on a 16 bit machine.
+             */
+            zmemcpy((charf *)s->window, (charf *)s->window+wsize,
+                   (unsigned)wsize);
+            s->match_start -= wsize;
+            s->strstart    -= wsize; /* we now have strstart >= MAX_DIST */
+
+            s->block_start -= (long) wsize;
+
+            /* Slide the hash table (could be avoided with 32 bit values
+               at the expense of memory usage):
+             */
+            n = s->hash_size;
+            p = &s->head[n];
+            do {
+                m = *--p;
+                *p = (Pos)(m >= wsize ? m-wsize : NIL);
+            } while (--n);
+
+            n = wsize;
+            p = &s->prev[n];
+            do {
+                m = *--p;
+                *p = (Pos)(m >= wsize ? m-wsize : NIL);
+                /* If n is not on any hash chain, prev[n] is garbage but
+                 * its value will never be used.
+                 */
+            } while (--n);
+
+            more += wsize;
+        }
+        if (s->strm->avail_in == 0) return;
+
+        /* If there was no sliding:
+         *    strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
+         *    more == window_size - lookahead - strstart
+         * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
+         * => more >= window_size - 2*WSIZE + 2
+         * In the BIG_MEM or MMAP case (not yet supported),
+         *   window_size == input_size + MIN_LOOKAHEAD  &&
+         *   strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD.
+         * Otherwise, window_size == 2*WSIZE so more >= 2.
+         * If there was sliding, more >= WSIZE. So in all cases, more >= 2.
+         */
+        Assert(more >= 2, "more < 2");
+
+        n = read_buf(s->strm, (charf *)s->window + s->strstart + s->lookahead,
+                     more);
+        s->lookahead += n;
+
+        /* Initialize the hash value now that we have some input: */
+        if (s->lookahead >= MIN_MATCH) {
+            s->ins_h = s->window[s->strstart];
+            UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
+#if MIN_MATCH != 3
+            Call UPDATE_HASH() MIN_MATCH-3 more times
+#endif
+        }
+        /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage,
+         * but this is not important since only literal bytes will be emitted.
+         */
+
+    } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0);
+}
+
+/* ===========================================================================
+ * Flush the current block, with given end-of-file flag.
+ * IN assertion: strstart is set to the end of the current match.
+ */
+#define FLUSH_BLOCK_ONLY(s, flush) { \
+   ct_flush_block(s, (s->block_start >= 0L ? \
+           (charf *)&s->window[(unsigned)s->block_start] : \
+           (charf *)Z_NULL), (long)s->strstart - s->block_start, (flush)); \
+   s->block_start = s->strstart; \
+   flush_pending(s->strm); \
+   Tracev((stderr,"[FLUSH]")); \
+}
+
+/* Same but force premature exit if necessary. */
+#define FLUSH_BLOCK(s, flush) { \
+   FLUSH_BLOCK_ONLY(s, flush); \
+   if (s->strm->avail_out == 0) return 1; \
+}
+
+/* ===========================================================================
+ * Compress as much as possible from the input stream, return true if
+ * processing was terminated prematurely (no more input or output space).
+ * This function does not perform lazy evaluationof matches and inserts
+ * new strings in the dictionary only for unmatched strings or for short
+ * matches. It is used only for the fast compression options.
+ */
+local int deflate_fast(s, flush)
+    deflate_state *s;
+    int flush;
+{
+    IPos hash_head = NIL; /* head of the hash chain */
+    int bflush;     /* set if current block must be flushed */
+
+    s->prev_length = MIN_MATCH-1;
+
+    for (;;) {
+        /* Make sure that we always have enough lookahead, except
+         * at the end of the input file. We need MAX_MATCH bytes
+         * for the next match, plus MIN_MATCH bytes to insert the
+         * string following the next match.
+         */
+        if (s->lookahead < MIN_LOOKAHEAD) {
+            fill_window(s);
+            if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) return 1;
+
+            if (s->lookahead == 0) break; /* flush the current block */
+        }
+
+        /* Insert the string window[strstart .. strstart+2] in the
+         * dictionary, and set hash_head to the head of the hash chain:
+         */
+        if (s->lookahead >= MIN_MATCH) {
+            INSERT_STRING(s, s->strstart, hash_head);
+        }
+
+        /* Find the longest match, discarding those <= prev_length.
+         * At this point we have always match_length < MIN_MATCH
+         */
+        if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) {
+            /* To simplify the code, we prevent matches with the string
+             * of window index 0 (in particular we have to avoid a match
+             * of the string with itself at the start of the input file).
+             */
+            if (s->strategy != Z_HUFFMAN_ONLY) {
+                s->match_length = longest_match (s, hash_head);
+            }
+            /* longest_match() sets match_start */
+
+            if (s->match_length > s->lookahead) s->match_length = s->lookahead;
+        }
+        if (s->match_length >= MIN_MATCH) {
+            check_match(s, s->strstart, s->match_start, s->match_length);
+
+            bflush = ct_tally(s, s->strstart - s->match_start,
+                              s->match_length - MIN_MATCH);
+
+            s->lookahead -= s->match_length;
+
+            /* Insert new strings in the hash table only if the match length
+             * is not too large. This saves time but degrades compression.
+             */
+            if (s->match_length <= s->max_insert_length &&
+                s->lookahead >= MIN_MATCH) {
+                s->match_length--; /* string at strstart already in hash table */
+                do {
+                    s->strstart++;
+                    INSERT_STRING(s, s->strstart, hash_head);
+                    /* strstart never exceeds WSIZE-MAX_MATCH, so there are
+                     * always MIN_MATCH bytes ahead.
+                     */
+                } while (--s->match_length != 0);
+                s->strstart++; 
+            } else {
+                s->strstart += s->match_length;
+                s->match_length = 0;
+                s->ins_h = s->window[s->strstart];
+                UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
+#if MIN_MATCH != 3
+                Call UPDATE_HASH() MIN_MATCH-3 more times
+#endif
+                /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not
+                 * matter since it will be recomputed at next deflate call.
+                 */
+            }
+        } else {
+            /* No match, output a literal byte */
+            Tracevv((stderr,"%c", s->window[s->strstart]));
+            bflush = ct_tally (s, 0, s->window[s->strstart]);
+            s->lookahead--;
+            s->strstart++; 
+        }
+        if (bflush) FLUSH_BLOCK(s, Z_NO_FLUSH);
+    }
+    FLUSH_BLOCK(s, flush);
+    return 0; /* normal exit */
+}
+
+/* ===========================================================================
+ * Same as above, but achieves better compression. We use a lazy
+ * evaluation for matches: a match is finally adopted only if there is
+ * no better match at the next window position.
+ */
+local int deflate_slow(s, flush)
+    deflate_state *s;
+    int flush;
+{
+    IPos hash_head = NIL;    /* head of hash chain */
+    int bflush;              /* set if current block must be flushed */
+
+    /* Process the input block. */
+    for (;;) {
+        /* Make sure that we always have enough lookahead, except
+         * at the end of the input file. We need MAX_MATCH bytes
+         * for the next match, plus MIN_MATCH bytes to insert the
+         * string following the next match.
+         */
+        if (s->lookahead < MIN_LOOKAHEAD) {
+            fill_window(s);
+            if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) return 1;
+
+            if (s->lookahead == 0) break; /* flush the current block */
+        }
+
+        /* Insert the string window[strstart .. strstart+2] in the
+         * dictionary, and set hash_head to the head of the hash chain:
+         */
+        if (s->lookahead >= MIN_MATCH) {
+            INSERT_STRING(s, s->strstart, hash_head);
+        }
+
+        /* Find the longest match, discarding those <= prev_length.
+         */
+        s->prev_length = s->match_length, s->prev_match = s->match_start;
+        s->match_length = MIN_MATCH-1;
+
+        if (hash_head != NIL && s->prev_length < s->max_lazy_match &&
+            s->strstart - hash_head <= MAX_DIST(s)) {
+            /* To simplify the code, we prevent matches with the string
+             * of window index 0 (in particular we have to avoid a match
+             * of the string with itself at the start of the input file).
+             */
+            if (s->strategy != Z_HUFFMAN_ONLY) {
+                s->match_length = longest_match (s, hash_head);
+            }
+            /* longest_match() sets match_start */
+            if (s->match_length > s->lookahead) s->match_length = s->lookahead;
+
+            if (s->match_length <= 5 && (s->strategy == Z_FILTERED ||
+                 (s->match_length == MIN_MATCH &&
+                  s->strstart - s->match_start > TOO_FAR))) {
+
+                /* If prev_match is also MIN_MATCH, match_start is garbage
+                 * but we will ignore the current match anyway.
+                 */
+                s->match_length = MIN_MATCH-1;
+            }
+        }
+        /* If there was a match at the previous step and the current
+         * match is not better, output the previous match:
+         */
+        if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) {
+            uInt max_insert = s->strstart + s->lookahead - MIN_MATCH;
+            /* Do not insert strings in hash table beyond this. */
+
+            check_match(s, s->strstart-1, s->prev_match, s->prev_length);
+
+            bflush = ct_tally(s, s->strstart -1 - s->prev_match,
+                              s->prev_length - MIN_MATCH);
+
+            /* Insert in hash table all strings up to the end of the match.
+             * strstart-1 and strstart are already inserted. If there is not
+             * enough lookahead, the last two strings are not inserted in
+             * the hash table.
+             */
+            s->lookahead -= s->prev_length-1;
+            s->prev_length -= 2;
+            do {
+                if (++s->strstart <= max_insert) {
+                    INSERT_STRING(s, s->strstart, hash_head);
+                }
+            } while (--s->prev_length != 0);
+            s->match_available = 0;
+            s->match_length = MIN_MATCH-1;
+            s->strstart++;
+
+            if (bflush) FLUSH_BLOCK(s, Z_NO_FLUSH);
+
+        } else if (s->match_available) {
+            /* If there was no match at the previous position, output a
+             * single literal. If there was a match but the current match
+             * is longer, truncate the previous match to a single literal.
+             */
+            Tracevv((stderr,"%c", s->window[s->strstart-1]));
+            if (ct_tally (s, 0, s->window[s->strstart-1])) {
+                FLUSH_BLOCK_ONLY(s, Z_NO_FLUSH);
+            }
+            s->strstart++;
+            s->lookahead--;
+            if (s->strm->avail_out == 0) return 1;
+        } else {
+            /* There is no previous match to compare with, wait for
+             * the next step to decide.
+             */
+            s->match_available = 1;
+            s->strstart++;
+            s->lookahead--;
+        }
+    }
+    Assert (flush != Z_NO_FLUSH, "no flush?");
+    if (s->match_available) {
+        Tracevv((stderr,"%c", s->window[s->strstart-1]));
+        ct_tally (s, 0, s->window[s->strstart-1]);
+        s->match_available = 0;
+    }
+    FLUSH_BLOCK(s, flush);
+    return 0;
+}
+
+
+/*+++++*/
+/* trees.c -- output deflated data using Huffman coding
+ * Copyright (C) 1995 Jean-loup Gailly
+ * For conditions of distribution and use, see copyright notice in zlib.h 
+ */
+
+/*
+ *  ALGORITHM
+ *
+ *      The "deflation" process uses several Huffman trees. The more
+ *      common source values are represented by shorter bit sequences.
+ *
+ *      Each code tree is stored in a compressed form which is itself
+ * a Huffman encoding of the lengths of all the code strings (in
+ * ascending order by source values).  The actual code strings are
+ * reconstructed from the lengths in the inflate process, as described
+ * in the deflate specification.
+ *
+ *  REFERENCES
+ *
+ *      Deutsch, L.P.,"'Deflate' Compressed Data Format Specification".
+ *      Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc
+ *
+ *      Storer, James A.
+ *          Data Compression:  Methods and Theory, pp. 49-50.
+ *          Computer Science Press, 1988.  ISBN 0-7167-8156-5.
+ *
+ *      Sedgewick, R.
+ *          Algorithms, p290.
+ *          Addison-Wesley, 1983. ISBN 0-201-06672-6.
+ */
+
+/* From: trees.c,v 1.5 1995/05/03 17:27:12 jloup Exp */
+
+#ifdef DEBUG_ZLIB
+#  include <ctype.h>
+#endif
+
+/* ===========================================================================
+ * Constants
+ */
+
+#define MAX_BL_BITS 7
+/* Bit length codes must not exceed MAX_BL_BITS bits */
+
+#define END_BLOCK 256
+/* end of block literal code */
+
+#define REP_3_6      16
+/* repeat previous bit length 3-6 times (2 bits of repeat count) */
+
+#define REPZ_3_10    17
+/* repeat a zero length 3-10 times  (3 bits of repeat count) */
+
+#define REPZ_11_138  18
+/* repeat a zero length 11-138 times  (7 bits of repeat count) */
+
+local int extra_lbits[LENGTH_CODES] /* extra bits for each length code */
+   = {0,0,0,0,0,0,0,0,1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,4,5,5,5,5,0};
+
+local int extra_dbits[D_CODES] /* extra bits for each distance code */
+   = {0,0,0,0,1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,13,13};
+
+local int extra_blbits[BL_CODES]/* extra bits for each bit length code */
+   = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7};
+
+local uch bl_order[BL_CODES]
+   = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15};
+/* The lengths of the bit length codes are sent in order of decreasing
+ * probability, to avoid transmitting the lengths for unused bit length codes.
+ */
+
+#define Buf_size (8 * 2*sizeof(char))
+/* Number of bits used within bi_buf. (bi_buf might be implemented on
+ * more than 16 bits on some systems.)
+ */
+
+/* ===========================================================================
+ * Local data. These are initialized only once.
+ * To do: initialize at compile time to be completely reentrant. ???
+ */
+
+local ct_data static_ltree[L_CODES+2];
+/* The static literal tree. Since the bit lengths are imposed, there is no
+ * need for the L_CODES extra codes used during heap construction. However
+ * The codes 286 and 287 are needed to build a canonical tree (see ct_init
+ * below).
+ */
+
+local ct_data static_dtree[D_CODES];
+/* The static distance tree. (Actually a trivial tree since all codes use
+ * 5 bits.)
+ */
+
+local uch dist_code[512];
+/* distance codes. The first 256 values correspond to the distances
+ * 3 .. 258, the last 256 values correspond to the top 8 bits of
+ * the 15 bit distances.
+ */
+
+local uch length_code[MAX_MATCH-MIN_MATCH+1];
+/* length code for each normalized match length (0 == MIN_MATCH) */
+
+local int base_length[LENGTH_CODES];
+/* First normalized length for each code (0 = MIN_MATCH) */
+
+local int base_dist[D_CODES];
+/* First normalized distance for each code (0 = distance of 1) */
+
+struct static_tree_desc_s {
+    ct_data *static_tree;        /* static tree or NULL */
+    intf    *extra_bits;         /* extra bits for each code or NULL */
+    int     extra_base;          /* base index for extra_bits */
+    int     elems;               /* max number of elements in the tree */
+    int     max_length;          /* max bit length for the codes */
+};
+
+local static_tree_desc  static_l_desc =
+{static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS};
+
+local static_tree_desc  static_d_desc =
+{static_dtree, extra_dbits, 0,          D_CODES, MAX_BITS};
+
+local static_tree_desc  static_bl_desc =
+{(ct_data *)0, extra_blbits, 0,      BL_CODES, MAX_BL_BITS};
+
+/* ===========================================================================
+ * Local (static) routines in this file.
+ */
+
+local void ct_static_init OF((void));
+local void init_block     OF((deflate_state *s));
+local void pqdownheap     OF((deflate_state *s, ct_data *tree, int k));
+local void gen_bitlen     OF((deflate_state *s, tree_desc *desc));
+local void gen_codes      OF((ct_data *tree, int max_code, ushf *bl_count));
+local void build_tree     OF((deflate_state *s, tree_desc *desc));
+local void scan_tree      OF((deflate_state *s, ct_data *tree, int max_code));
+local void send_tree      OF((deflate_state *s, ct_data *tree, int max_code));
+local int  build_bl_tree  OF((deflate_state *s));
+local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes,
+                              int blcodes));
+local void compress_block OF((deflate_state *s, ct_data *ltree,
+                              ct_data *dtree));
+local void set_data_type  OF((deflate_state *s));
+local unsigned bi_reverse OF((unsigned value, int length));
+local void bi_windup      OF((deflate_state *s));
+local void bi_flush       OF((deflate_state *s));
+local void copy_block     OF((deflate_state *s, charf *buf, unsigned len,
+                              int header));
+
+#ifndef DEBUG_ZLIB
+#  define send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len)
+   /* Send a code of the given tree. c and tree must not have side effects */
+
+#else /* DEBUG_ZLIB */
+#  define send_code(s, c, tree) \
+     { if (verbose>1) fprintf(stderr,"\ncd %3d ",(c)); \
+       send_bits(s, tree[c].Code, tree[c].Len); }
+#endif
+
+#define d_code(dist) \
+   ((dist) < 256 ? dist_code[dist] : dist_code[256+((dist)>>7)])
+/* Mapping from a distance to a distance code. dist is the distance - 1 and
+ * must not have side effects. dist_code[256] and dist_code[257] are never
+ * used.
+ */
+
+/* ===========================================================================
+ * Output a short LSB first on the stream.
+ * IN assertion: there is enough room in pendingBuf.
+ */
+#define put_short(s, w) { \
+    put_byte(s, (uch)((w) & 0xff)); \
+    put_byte(s, (uch)((ush)(w) >> 8)); \
+}
+
+/* ===========================================================================
+ * Send a value on a given number of bits.
+ * IN assertion: length <= 16 and value fits in length bits.
+ */
+#ifdef DEBUG_ZLIB
+local void send_bits      OF((deflate_state *s, int value, int length));
+
+local void send_bits(s, value, length)
+    deflate_state *s;
+    int value;  /* value to send */
+    int length; /* number of bits */
+{
+    Tracev((stderr," l %2d v %4x ", length, value));
+    Assert(length > 0 && length <= 15, "invalid length");
+    s->bits_sent += (ulg)length;
+
+    /* If not enough room in bi_buf, use (valid) bits from bi_buf and
+     * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid))
+     * unused bits in value.
+     */
+    if (s->bi_valid > (int)Buf_size - length) {
+        s->bi_buf |= (value << s->bi_valid);
+        put_short(s, s->bi_buf);
+        s->bi_buf = (ush)value >> (Buf_size - s->bi_valid);
+        s->bi_valid += length - Buf_size;
+    } else {
+        s->bi_buf |= value << s->bi_valid;
+        s->bi_valid += length;
+    }
+}
+#else /* !DEBUG_ZLIB */
+
+#define send_bits(s, value, length) \
+{ int len = length;\
+  if (s->bi_valid > (int)Buf_size - len) {\
+    int val = value;\
+    s->bi_buf |= (val << s->bi_valid);\
+    put_short(s, s->bi_buf);\
+    s->bi_buf = (ush)val >> (Buf_size - s->bi_valid);\
+    s->bi_valid += len - Buf_size;\
+  } else {\
+    s->bi_buf |= (value) << s->bi_valid;\
+    s->bi_valid += len;\
+  }\
+}
+#endif /* DEBUG_ZLIB */
+
+
+#define MAX(a,b) (a >= b ? a : b)
+/* the arguments must not have side effects */
+
+/* ===========================================================================
+ * Initialize the various 'constant' tables.
+ * To do: do this at compile time.
+ */
+local void ct_static_init()
+{
+    int n;        /* iterates over tree elements */
+    int bits;     /* bit counter */
+    int length;   /* length value */
+    int code;     /* code value */
+    int dist;     /* distance index */
+    ush bl_count[MAX_BITS+1];
+    /* number of codes at each bit length for an optimal tree */
+
+    /* Initialize the mapping length (0..255) -> length code (0..28) */
+    length = 0;
+    for (code = 0; code < LENGTH_CODES-1; code++) {
+        base_length[code] = length;
+        for (n = 0; n < (1<<extra_lbits[code]); n++) {
+            length_code[length++] = (uch)code;
+        }
+    }
+    Assert (length == 256, "ct_static_init: length != 256");
+    /* Note that the length 255 (match length 258) can be represented
+     * in two different ways: code 284 + 5 bits or code 285, so we
+     * overwrite length_code[255] to use the best encoding:
+     */
+    length_code[length-1] = (uch)code;
+
+    /* Initialize the mapping dist (0..32K) -> dist code (0..29) */
+    dist = 0;
+    for (code = 0 ; code < 16; code++) {
+        base_dist[code] = dist;
+        for (n = 0; n < (1<<extra_dbits[code]); n++) {
+            dist_code[dist++] = (uch)code;
+        }
+    }
+    Assert (dist == 256, "ct_static_init: dist != 256");
+    dist >>= 7; /* from now on, all distances are divided by 128 */
+    for ( ; code < D_CODES; code++) {
+        base_dist[code] = dist << 7;
+        for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) {
+            dist_code[256 + dist++] = (uch)code;
+        }
+    }
+    Assert (dist == 256, "ct_static_init: 256+dist != 512");
+
+    /* Construct the codes of the static literal tree */
+    for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0;
+    n = 0;
+    while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++;
+    while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++;
+    while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++;
+    while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++;
+    /* Codes 286 and 287 do not exist, but we must include them in the
+     * tree construction to get a canonical Huffman tree (longest code
+     * all ones)
+     */
+    gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count);
+
+    /* The static distance tree is trivial: */
+    for (n = 0; n < D_CODES; n++) {
+        static_dtree[n].Len = 5;
+        static_dtree[n].Code = bi_reverse(n, 5);
+    }
+}
+
+/* ===========================================================================
+ * Initialize the tree data structures for a new zlib stream.
+ */
+local void ct_init(s)
+    deflate_state *s;
+{
+    if (static_dtree[0].Len == 0) {
+        ct_static_init();              /* To do: at compile time */
+    }
+
+    s->compressed_len = 0L;
+
+    s->l_desc.dyn_tree = s->dyn_ltree;
+    s->l_desc.stat_desc = &static_l_desc;
+
+    s->d_desc.dyn_tree = s->dyn_dtree;
+    s->d_desc.stat_desc = &static_d_desc;
+
+    s->bl_desc.dyn_tree = s->bl_tree;
+    s->bl_desc.stat_desc = &static_bl_desc;
+
+    s->bi_buf = 0;
+    s->bi_valid = 0;
+    s->last_eob_len = 8; /* enough lookahead for inflate */
+#ifdef DEBUG_ZLIB
+    s->bits_sent = 0L;
+#endif
+    s->blocks_in_packet = 0;
+
+    /* Initialize the first block of the first file: */
+    init_block(s);
+}
+
+/* ===========================================================================
+ * Initialize a new block.
+ */
+local void init_block(s)
+    deflate_state *s;
+{
+    int n; /* iterates over tree elements */
+
+    /* Initialize the trees. */
+    for (n = 0; n < L_CODES;  n++) s->dyn_ltree[n].Freq = 0;
+    for (n = 0; n < D_CODES;  n++) s->dyn_dtree[n].Freq = 0;
+    for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0;
+
+    s->dyn_ltree[END_BLOCK].Freq = 1;
+    s->opt_len = s->static_len = 0L;
+    s->last_lit = s->matches = 0;
+}
+
+#define SMALLEST 1
+/* Index within the heap array of least frequent node in the Huffman tree */
+
+
+/* ===========================================================================
+ * Remove the smallest element from the heap and recreate the heap with
+ * one less element. Updates heap and heap_len.
+ */
+#define pqremove(s, tree, top) \
+{\
+    top = s->heap[SMALLEST]; \
+    s->heap[SMALLEST] = s->heap[s->heap_len--]; \
+    pqdownheap(s, tree, SMALLEST); \
+}
+
+/* ===========================================================================
+ * Compares to subtrees, using the tree depth as tie breaker when
+ * the subtrees have equal frequency. This minimizes the worst case length.
+ */
+#define smaller(tree, n, m, depth) \
+   (tree[n].Freq < tree[m].Freq || \
+   (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m]))
+
+/* ===========================================================================
+ * Restore the heap property by moving down the tree starting at node k,
+ * exchanging a node with the smallest of its two sons if necessary, stopping
+ * when the heap property is re-established (each father smaller than its
+ * two sons).
+ */
+local void pqdownheap(s, tree, k)
+    deflate_state *s;
+    ct_data *tree;  /* the tree to restore */
+    int k;               /* node to move down */
+{
+    int v = s->heap[k];
+    int j = k << 1;  /* left son of k */
+    while (j <= s->heap_len) {
+        /* Set j to the smallest of the two sons: */
+        if (j < s->heap_len &&
+            smaller(tree, s->heap[j+1], s->heap[j], s->depth)) {
+            j++;
+        }
+        /* Exit if v is smaller than both sons */
+        if (smaller(tree, v, s->heap[j], s->depth)) break;
+
+        /* Exchange v with the smallest son */
+        s->heap[k] = s->heap[j];  k = j;
+
+        /* And continue down the tree, setting j to the left son of k */
+        j <<= 1;
+    }
+    s->heap[k] = v;
+}
+
+/* ===========================================================================
+ * Compute the optimal bit lengths for a tree and update the total bit length
+ * for the current block.
+ * IN assertion: the fields freq and dad are set, heap[heap_max] and
+ *    above are the tree nodes sorted by increasing frequency.
+ * OUT assertions: the field len is set to the optimal bit length, the
+ *     array bl_count contains the frequencies for each bit length.
+ *     The length opt_len is updated; static_len is also updated if stree is
+ *     not null.
+ */
+local void gen_bitlen(s, desc)
+    deflate_state *s;
+    tree_desc *desc;    /* the tree descriptor */
+{
+    ct_data *tree  = desc->dyn_tree;
+    int max_code   = desc->max_code;
+    ct_data *stree = desc->stat_desc->static_tree;
+    intf *extra    = desc->stat_desc->extra_bits;
+    int base       = desc->stat_desc->extra_base;
+    int max_length = desc->stat_desc->max_length;
+    int h;              /* heap index */
+    int n, m;           /* iterate over the tree elements */
+    int bits;           /* bit length */
+    int xbits;          /* extra bits */
+    ush f;              /* frequency */
+    int overflow = 0;   /* number of elements with bit length too large */
+
+    for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0;
+
+    /* In a first pass, compute the optimal bit lengths (which may
+     * overflow in the case of the bit length tree).
+     */
+    tree[s->heap[s->heap_max]].Len = 0; /* root of the heap */
+
+    for (h = s->heap_max+1; h < HEAP_SIZE; h++) {
+        n = s->heap[h];
+        bits = tree[tree[n].Dad].Len + 1;
+        if (bits > max_length) bits = max_length, overflow++;
+        tree[n].Len = (ush)bits;
+        /* We overwrite tree[n].Dad which is no longer needed */
+
+        if (n > max_code) continue; /* not a leaf node */
+
+        s->bl_count[bits]++;
+        xbits = 0;
+        if (n >= base) xbits = extra[n-base];
+        f = tree[n].Freq;
+        s->opt_len += (ulg)f * (bits + xbits);
+        if (stree) s->static_len += (ulg)f * (stree[n].Len + xbits);
+    }
+    if (overflow == 0) return;
+
+    Trace((stderr,"\nbit length overflow\n"));
+    /* This happens for example on obj2 and pic of the Calgary corpus */
+
+    /* Find the first bit length which could increase: */
+    do {
+        bits = max_length-1;
+        while (s->bl_count[bits] == 0) bits--;
+        s->bl_count[bits]--;      /* move one leaf down the tree */
+        s->bl_count[bits+1] += 2; /* move one overflow item as its brother */
+        s->bl_count[max_length]--;
+        /* The brother of the overflow item also moves one step up,
+         * but this does not affect bl_count[max_length]
+         */
+        overflow -= 2;
+    } while (overflow > 0);
+
+    /* Now recompute all bit lengths, scanning in increasing frequency.
+     * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all
+     * lengths instead of fixing only the wrong ones. This idea is taken
+     * from 'ar' written by Haruhiko Okumura.)
+     */
+    for (bits = max_length; bits != 0; bits--) {
+        n = s->bl_count[bits];
+        while (n != 0) {
+            m = s->heap[--h];
+            if (m > max_code) continue;
+            if (tree[m].Len != (unsigned) bits) {
+                Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits));
+                s->opt_len += ((long)bits - (long)tree[m].Len)
+                              *(long)tree[m].Freq;
+                tree[m].Len = (ush)bits;
+            }
+            n--;
+        }
+    }
+}
+
+/* ===========================================================================
+ * Generate the codes for a given tree and bit counts (which need not be
+ * optimal).
+ * IN assertion: the array bl_count contains the bit length statistics for
+ * the given tree and the field len is set for all tree elements.
+ * OUT assertion: the field code is set for all tree elements of non
+ *     zero code length.
+ */
+local void gen_codes (tree, max_code, bl_count)
+    ct_data *tree;             /* the tree to decorate */
+    int max_code;              /* largest code with non zero frequency */
+    ushf *bl_count;            /* number of codes at each bit length */
+{
+    ush next_code[MAX_BITS+1]; /* next code value for each bit length */
+    ush code = 0;              /* running code value */
+    int bits;                  /* bit index */
+    int n;                     /* code index */
+
+    /* The distribution counts are first used to generate the code values
+     * without bit reversal.
+     */
+    for (bits = 1; bits <= MAX_BITS; bits++) {
+        next_code[bits] = code = (code + bl_count[bits-1]) << 1;
+    }
+    /* Check that the bit counts in bl_count are consistent. The last code
+     * must be all ones.
+     */
+    Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1,
+            "inconsistent bit counts");
+    Tracev((stderr,"\ngen_codes: max_code %d ", max_code));
+
+    for (n = 0;  n <= max_code; n++) {
+        int len = tree[n].Len;
+        if (len == 0) continue;
+        /* Now reverse the bits */
+        tree[n].Code = bi_reverse(next_code[len]++, len);
+
+        Tracec(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ",
+             n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1));
+    }
+}
+
+/* ===========================================================================
+ * Construct one Huffman tree and assigns the code bit strings and lengths.
+ * Update the total bit length for the current block.
+ * IN assertion: the field freq is set for all tree elements.
+ * OUT assertions: the fields len and code are set to the optimal bit length
+ *     and corresponding code. The length opt_len is updated; static_len is
+ *     also updated if stree is not null. The field max_code is set.
+ */
+local void build_tree(s, desc)
+    deflate_state *s;
+    tree_desc *desc; /* the tree descriptor */
+{
+    ct_data *tree   = desc->dyn_tree;
+    ct_data *stree  = desc->stat_desc->static_tree;
+    int elems       = desc->stat_desc->elems;
+    int n, m;          /* iterate over heap elements */
+    int max_code = -1; /* largest code with non zero frequency */
+    int node;          /* new node being created */
+
+    /* Construct the initial heap, with least frequent element in
+     * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
+     * heap[0] is not used.
+     */
+    s->heap_len = 0, s->heap_max = HEAP_SIZE;
+
+    for (n = 0; n < elems; n++) {
+        if (tree[n].Freq != 0) {
+            s->heap[++(s->heap_len)] = max_code = n;
+            s->depth[n] = 0;
+        } else {
+            tree[n].Len = 0;
+        }
+    }
+
+    /* The pkzip format requires that at least one distance code exists,
+     * and that at least one bit should be sent even if there is only one
+     * possible code. So to avoid special checks later on we force at least
+     * two codes of non zero frequency.
+     */
+    while (s->heap_len < 2) {
+        node = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0);
+        tree[node].Freq = 1;
+        s->depth[node] = 0;
+        s->opt_len--; if (stree) s->static_len -= stree[node].Len;
+        /* node is 0 or 1 so it does not have extra bits */
+    }
+    desc->max_code = max_code;
+
+    /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
+     * establish sub-heaps of increasing lengths:
+     */
+    for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n);
+
+    /* Construct the Huffman tree by repeatedly combining the least two
+     * frequent nodes.
+     */
+    node = elems;              /* next internal node of the tree */
+    do {
+        pqremove(s, tree, n);  /* n = node of least frequency */
+        m = s->heap[SMALLEST]; /* m = node of next least frequency */
+
+        s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */
+        s->heap[--(s->heap_max)] = m;
+
+        /* Create a new node father of n and m */
+        tree[node].Freq = tree[n].Freq + tree[m].Freq;
+        s->depth[node] = (uch) (MAX(s->depth[n], s->depth[m]) + 1);
+        tree[n].Dad = tree[m].Dad = (ush)node;
+#ifdef DUMP_BL_TREE
+        if (tree == s->bl_tree) {
+            fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)",
+                    node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq);
+        }
+#endif
+        /* and insert the new node in the heap */
+        s->heap[SMALLEST] = node++;
+        pqdownheap(s, tree, SMALLEST);
+
+    } while (s->heap_len >= 2);
+
+    s->heap[--(s->heap_max)] = s->heap[SMALLEST];
+
+    /* At this point, the fields freq and dad are set. We can now
+     * generate the bit lengths.
+     */
+    gen_bitlen(s, (tree_desc *)desc);
+
+    /* The field len is now set, we can generate the bit codes */
+    gen_codes ((ct_data *)tree, max_code, s->bl_count);
+}
+
+/* ===========================================================================
+ * Scan a literal or distance tree to determine the frequencies of the codes
+ * in the bit length tree.
+ */
+local void scan_tree (s, tree, max_code)
+    deflate_state *s;
+    ct_data *tree;   /* the tree to be scanned */
+    int max_code;    /* and its largest code of non zero frequency */
+{
+    int n;                     /* iterates over all tree elements */
+    int prevlen = -1;          /* last emitted length */
+    int curlen;                /* length of current code */
+    int nextlen = tree[0].Len; /* length of next code */
+    int count = 0;             /* repeat count of the current code */
+    int max_count = 7;         /* max repeat count */
+    int min_count = 4;         /* min repeat count */
+
+    if (nextlen == 0) max_count = 138, min_count = 3;
+    tree[max_code+1].Len = (ush)0xffff; /* guard */
+
+    for (n = 0; n <= max_code; n++) {
+        curlen = nextlen; nextlen = tree[n+1].Len;
+        if (++count < max_count && curlen == nextlen) {
+            continue;
+        } else if (count < min_count) {
+            s->bl_tree[curlen].Freq += count;
+        } else if (curlen != 0) {
+            if (curlen != prevlen) s->bl_tree[curlen].Freq++;
+            s->bl_tree[REP_3_6].Freq++;
+        } else if (count <= 10) {
+            s->bl_tree[REPZ_3_10].Freq++;
+        } else {
+            s->bl_tree[REPZ_11_138].Freq++;
+        }
+        count = 0; prevlen = curlen;
+        if (nextlen == 0) {
+            max_count = 138, min_count = 3;
+        } else if (curlen == nextlen) {
+            max_count = 6, min_count = 3;
+        } else {
+            max_count = 7, min_count = 4;
+        }
+    }
+}
+
+/* ===========================================================================
+ * Send a literal or distance tree in compressed form, using the codes in
+ * bl_tree.
+ */
+local void send_tree (s, tree, max_code)
+    deflate_state *s;
+    ct_data *tree; /* the tree to be scanned */
+    int max_code;       /* and its largest code of non zero frequency */
+{
+    int n;                     /* iterates over all tree elements */
+    int prevlen = -1;          /* last emitted length */
+    int curlen;                /* length of current code */
+    int nextlen = tree[0].Len; /* length of next code */
+    int count = 0;             /* repeat count of the current code */
+    int max_count = 7;         /* max repeat count */
+    int min_count = 4;         /* min repeat count */
+
+    /* tree[max_code+1].Len = -1; */  /* guard already set */
+    if (nextlen == 0) max_count = 138, min_count = 3;
+
+    for (n = 0; n <= max_code; n++) {
+        curlen = nextlen; nextlen = tree[n+1].Len;
+        if (++count < max_count && curlen == nextlen) {
+            continue;
+        } else if (count < min_count) {
+            do { send_code(s, curlen, s->bl_tree); } while (--count != 0);
+
+        } else if (curlen != 0) {
+            if (curlen != prevlen) {
+                send_code(s, curlen, s->bl_tree); count--;
+            }
+            Assert(count >= 3 && count <= 6, " 3_6?");
+            send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2);
+
+        } else if (count <= 10) {
+            send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3);
+
+        } else {
+            send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7);
+        }
+        count = 0; prevlen = curlen;
+        if (nextlen == 0) {
+            max_count = 138, min_count = 3;
+        } else if (curlen == nextlen) {
+            max_count = 6, min_count = 3;
+        } else {
+            max_count = 7, min_count = 4;
+        }
+    }
+}
+
+/* ===========================================================================
+ * Construct the Huffman tree for the bit lengths and return the index in
+ * bl_order of the last bit length code to send.
+ */
+local int build_bl_tree(s)
+    deflate_state *s;
+{
+    int max_blindex;  /* index of last bit length code of non zero freq */
+
+    /* Determine the bit length frequencies for literal and distance trees */
+    scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code);
+    scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code);
+
+    /* Build the bit length tree: */
+    build_tree(s, (tree_desc *)(&(s->bl_desc)));
+    /* opt_len now includes the length of the tree representations, except
+     * the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
+     */
+
+    /* Determine the number of bit length codes to send. The pkzip format
+     * requires that at least 4 bit length codes be sent. (appnote.txt says
+     * 3 but the actual value used is 4.)
+     */
+    for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) {
+        if (s->bl_tree[bl_order[max_blindex]].Len != 0) break;
+    }
+    /* Update opt_len to include the bit length tree and counts */
+    s->opt_len += 3*(max_blindex+1) + 5+5+4;
+    Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld",
+            s->opt_len, s->static_len));
+
+    return max_blindex;
+}
+
+/* ===========================================================================
+ * Send the header for a block using dynamic Huffman trees: the counts, the
+ * lengths of the bit length codes, the literal tree and the distance tree.
+ * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
+ */
+local void send_all_trees(s, lcodes, dcodes, blcodes)
+    deflate_state *s;
+    int lcodes, dcodes, blcodes; /* number of codes for each tree */
+{
+    int rank;                    /* index in bl_order */
+
+    Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes");
+    Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES,
+            "too many codes");
+    Tracev((stderr, "\nbl counts: "));
+    send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */
+    send_bits(s, dcodes-1,   5);
+    send_bits(s, blcodes-4,  4); /* not -3 as stated in appnote.txt */
+    for (rank = 0; rank < blcodes; rank++) {
+        Tracev((stderr, "\nbl code %2d ", bl_order[rank]));
+        send_bits(s, s->bl_tree[bl_order[rank]].Len, 3);
+    }
+    Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent));
+
+    send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */
+    Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent));
+
+    send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */
+    Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent));
+}
+
+/* ===========================================================================
+ * Send a stored block
+ */
+local void ct_stored_block(s, buf, stored_len, eof)
+    deflate_state *s;
+    charf *buf;       /* input block */
+    ulg stored_len;   /* length of input block */
+    int eof;          /* true if this is the last block for a file */
+{
+    send_bits(s, (STORED_BLOCK<<1)+eof, 3);  /* send block type */
+    s->compressed_len = (s->compressed_len + 3 + 7) & ~7L;
+    s->compressed_len += (stored_len + 4) << 3;
+
+    copy_block(s, buf, (unsigned)stored_len, 1); /* with header */
+}
+
+/* Send just the `stored block' type code without any length bytes or data.
+ */
+local void ct_stored_type_only(s)
+    deflate_state *s;
+{
+    send_bits(s, (STORED_BLOCK << 1), 3);
+    bi_windup(s);
+    s->compressed_len = (s->compressed_len + 3) & ~7L;
+}
+
+
+/* ===========================================================================
+ * Send one empty static block to give enough lookahead for inflate.
+ * This takes 10 bits, of which 7 may remain in the bit buffer.
+ * The current inflate code requires 9 bits of lookahead. If the EOB
+ * code for the previous block was coded on 5 bits or less, inflate
+ * may have only 5+3 bits of lookahead to decode this EOB.
+ * (There are no problems if the previous block is stored or fixed.)
+ */
+local void ct_align(s)
+    deflate_state *s;
+{
+    send_bits(s, STATIC_TREES<<1, 3);
+    send_code(s, END_BLOCK, static_ltree);
+    s->compressed_len += 10L; /* 3 for block type, 7 for EOB */
+    bi_flush(s);
+    /* Of the 10 bits for the empty block, we have already sent
+     * (10 - bi_valid) bits. The lookahead for the EOB of the previous
+     * block was thus its length plus what we have just sent.
+     */
+    if (s->last_eob_len + 10 - s->bi_valid < 9) {
+        send_bits(s, STATIC_TREES<<1, 3);
+        send_code(s, END_BLOCK, static_ltree);
+        s->compressed_len += 10L;
+        bi_flush(s);
+    }
+    s->last_eob_len = 7;
+}
+
+/* ===========================================================================
+ * Determine the best encoding for the current block: dynamic trees, static
+ * trees or store, and output the encoded block to the zip file. This function
+ * returns the total compressed length for the file so far.
+ */
+local ulg ct_flush_block(s, buf, stored_len, flush)
+    deflate_state *s;
+    charf *buf;       /* input block, or NULL if too old */
+    ulg stored_len;   /* length of input block */
+    int flush;        /* Z_FINISH if this is the last block for a file */
+{
+    ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */
+    int max_blindex;  /* index of last bit length code of non zero freq */
+    int eof = flush == Z_FINISH;
+
+    ++s->blocks_in_packet;
+
+    /* Check if the file is ascii or binary */
+    if (s->data_type == UNKNOWN) set_data_type(s);
+
+    /* Construct the literal and distance trees */
+    build_tree(s, (tree_desc *)(&(s->l_desc)));
+    Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len,
+            s->static_len));
+
+    build_tree(s, (tree_desc *)(&(s->d_desc)));
+    Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len,
+            s->static_len));
+    /* At this point, opt_len and static_len are the total bit lengths of
+     * the compressed block data, excluding the tree representations.
+     */
+
+    /* Build the bit length tree for the above two trees, and get the index
+     * in bl_order of the last bit length code to send.
+     */
+    max_blindex = build_bl_tree(s);
+
+    /* Determine the best encoding. Compute first the block length in bytes */
+    opt_lenb = (s->opt_len+3+7)>>3;
+    static_lenb = (s->static_len+3+7)>>3;
+
+    Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ",
+            opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len,
+            s->last_lit));
+
+    if (static_lenb <= opt_lenb) opt_lenb = static_lenb;
+
+    /* If compression failed and this is the first and last block,
+     * and if the .zip file can be seeked (to rewrite the local header),
+     * the whole file is transformed into a stored file:
+     */
+#ifdef STORED_FILE_OK
+#  ifdef FORCE_STORED_FILE
+    if (eof && compressed_len == 0L) /* force stored file */
+#  else
+    if (stored_len <= opt_lenb && eof && s->compressed_len==0L && seekable())
+#  endif
+    {
+        /* Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there: */
+        if (buf == (charf*)0) error ("block vanished");
+
+        copy_block(buf, (unsigned)stored_len, 0); /* without header */
+        s->compressed_len = stored_len << 3;
+        s->method = STORED;
+    } else
+#endif /* STORED_FILE_OK */
+
+    /* For Z_PACKET_FLUSH, if we don't achieve the required minimum
+     * compression, and this block contains all the data since the last
+     * time we used Z_PACKET_FLUSH, then just omit this block completely
+     * from the output.
+     */
+    if (flush == Z_PACKET_FLUSH && s->blocks_in_packet == 1
+	&& opt_lenb > stored_len - s->minCompr) {
+	s->blocks_in_packet = 0;
+	/* output nothing */
+    } else
+
+#ifdef FORCE_STORED
+    if (buf != (char*)0) /* force stored block */
+#else
+    if (stored_len+4 <= opt_lenb && buf != (char*)0)
+                       /* 4: two words for the lengths */
+#endif
+    {
+        /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
+         * Otherwise we can't have processed more than WSIZE input bytes since
+         * the last block flush, because compression would have been
+         * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
+         * transform a block into a stored block.
+         */
+        ct_stored_block(s, buf, stored_len, eof);
+    } else
+
+#ifdef FORCE_STATIC
+    if (static_lenb >= 0) /* force static trees */
+#else
+    if (static_lenb == opt_lenb)
+#endif
+    {
+        send_bits(s, (STATIC_TREES<<1)+eof, 3);
+        compress_block(s, (ct_data *)static_ltree, (ct_data *)static_dtree);
+        s->compressed_len += 3 + s->static_len;
+    } else {
+        send_bits(s, (DYN_TREES<<1)+eof, 3);
+        send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1,
+                       max_blindex+1);
+        compress_block(s, (ct_data *)s->dyn_ltree, (ct_data *)s->dyn_dtree);
+        s->compressed_len += 3 + s->opt_len;
+    }
+    Assert (s->compressed_len == s->bits_sent, "bad compressed size");
+    init_block(s);
+
+    if (eof) {
+        bi_windup(s);
+        s->compressed_len += 7;  /* align on byte boundary */
+    }
+    Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3,
+           s->compressed_len-7*eof));
+
+    return s->compressed_len >> 3;
+}
+
+/* ===========================================================================
+ * Save the match info and tally the frequency counts. Return true if
+ * the current block must be flushed.
+ */
+local int ct_tally (s, dist, lc)
+    deflate_state *s;
+    int dist;  /* distance of matched string */
+    int lc;    /* match length-MIN_MATCH or unmatched char (if dist==0) */
+{
+    s->d_buf[s->last_lit] = (ush)dist;
+    s->l_buf[s->last_lit++] = (uch)lc;
+    if (dist == 0) {
+        /* lc is the unmatched char */
+        s->dyn_ltree[lc].Freq++;
+    } else {
+        s->matches++;
+        /* Here, lc is the match length - MIN_MATCH */
+        dist--;             /* dist = match distance - 1 */
+        Assert((ush)dist < (ush)MAX_DIST(s) &&
+               (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) &&
+               (ush)d_code(dist) < (ush)D_CODES,  "ct_tally: bad match");
+
+        s->dyn_ltree[length_code[lc]+LITERALS+1].Freq++;
+        s->dyn_dtree[d_code(dist)].Freq++;
+    }
+
+    /* Try to guess if it is profitable to stop the current block here */
+    if (s->level > 2 && (s->last_lit & 0xfff) == 0) {
+        /* Compute an upper bound for the compressed length */
+        ulg out_length = (ulg)s->last_lit*8L;
+        ulg in_length = (ulg)s->strstart - s->block_start;
+        int dcode;
+        for (dcode = 0; dcode < D_CODES; dcode++) {
+            out_length += (ulg)s->dyn_dtree[dcode].Freq *
+                (5L+extra_dbits[dcode]);
+        }
+        out_length >>= 3;
+        Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ",
+               s->last_lit, in_length, out_length,
+               100L - out_length*100L/in_length));
+        if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1;
+    }
+    return (s->last_lit == s->lit_bufsize-1);
+    /* We avoid equality with lit_bufsize because of wraparound at 64K
+     * on 16 bit machines and because stored blocks are restricted to
+     * 64K-1 bytes.
+     */
+}
+
+/* ===========================================================================
+ * Send the block data compressed using the given Huffman trees
+ */
+local void compress_block(s, ltree, dtree)
+    deflate_state *s;
+    ct_data *ltree; /* literal tree */
+    ct_data *dtree; /* distance tree */
+{
+    unsigned dist;      /* distance of matched string */
+    int lc;             /* match length or unmatched char (if dist == 0) */
+    unsigned lx = 0;    /* running index in l_buf */
+    unsigned code;      /* the code to send */
+    int extra;          /* number of extra bits to send */
+
+    if (s->last_lit != 0) do {
+        dist = s->d_buf[lx];
+        lc = s->l_buf[lx++];
+        if (dist == 0) {
+            send_code(s, lc, ltree); /* send a literal byte */
+            Tracecv(isgraph(lc), (stderr," '%c' ", lc));
+        } else {
+            /* Here, lc is the match length - MIN_MATCH */
+            code = length_code[lc];
+            send_code(s, code+LITERALS+1, ltree); /* send the length code */
+            extra = extra_lbits[code];
+            if (extra != 0) {
+                lc -= base_length[code];
+                send_bits(s, lc, extra);       /* send the extra length bits */
+            }
+            dist--; /* dist is now the match distance - 1 */
+            code = d_code(dist);
+            Assert (code < D_CODES, "bad d_code");
+
+            send_code(s, code, dtree);       /* send the distance code */
+            extra = extra_dbits[code];
+            if (extra != 0) {
+                dist -= base_dist[code];
+                send_bits(s, dist, extra);   /* send the extra distance bits */
+            }
+        } /* literal or match pair ? */
+
+        /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */
+        Assert(s->pending < s->lit_bufsize + 2*lx, "pendingBuf overflow");
+
+    } while (lx < s->last_lit);
+
+    send_code(s, END_BLOCK, ltree);
+    s->last_eob_len = ltree[END_BLOCK].Len;
+}
+
+/* ===========================================================================
+ * Set the data type to ASCII or Z_BINARY, using a crude approximation:
+ * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise.
+ * IN assertion: the fields freq of dyn_ltree are set and the total of all
+ * frequencies does not exceed 64K (to fit in an int on 16 bit machines).
+ */
+local void set_data_type(s)
+    deflate_state *s;
+{
+    int n = 0;
+    unsigned ascii_freq = 0;
+    unsigned bin_freq = 0;
+    while (n < 7)        bin_freq += s->dyn_ltree[n++].Freq;
+    while (n < 128)    ascii_freq += s->dyn_ltree[n++].Freq;
+    while (n < LITERALS) bin_freq += s->dyn_ltree[n++].Freq;
+    s->data_type = (Byte)(bin_freq > (ascii_freq >> 2) ? Z_BINARY : ASCII);
+}
+
+/* ===========================================================================
+ * Reverse the first len bits of a code, using straightforward code (a faster
+ * method would use a table)
+ * IN assertion: 1 <= len <= 15
+ */
+local unsigned bi_reverse(code, len)
+    unsigned code; /* the value to invert */
+    int len;       /* its bit length */
+{
+    register unsigned res = 0;
+    do {
+        res |= code & 1;
+        code >>= 1, res <<= 1;
+    } while (--len > 0);
+    return res >> 1;
+}
+
+/* ===========================================================================
+ * Flush the bit buffer, keeping at most 7 bits in it.
+ */
+local void bi_flush(s)
+    deflate_state *s;
+{
+    if (s->bi_valid == 16) {
+        put_short(s, s->bi_buf);
+        s->bi_buf = 0;
+        s->bi_valid = 0;
+    } else if (s->bi_valid >= 8) {
+        put_byte(s, (Byte)s->bi_buf);
+        s->bi_buf >>= 8;
+        s->bi_valid -= 8;
+    }
+}
+
+/* ===========================================================================
+ * Flush the bit buffer and align the output on a byte boundary
+ */
+local void bi_windup(s)
+    deflate_state *s;
+{
+    if (s->bi_valid > 8) {
+        put_short(s, s->bi_buf);
+    } else if (s->bi_valid > 0) {
+        put_byte(s, (Byte)s->bi_buf);
+    }
+    s->bi_buf = 0;
+    s->bi_valid = 0;
+#ifdef DEBUG_ZLIB
+    s->bits_sent = (s->bits_sent+7) & ~7;
+#endif
+}
+
+/* ===========================================================================
+ * Copy a stored block, storing first the length and its
+ * one's complement if requested.
+ */
+local void copy_block(s, buf, len, header)
+    deflate_state *s;
+    charf    *buf;    /* the input data */
+    unsigned len;     /* its length */
+    int      header;  /* true if block header must be written */
+{
+    bi_windup(s);        /* align on byte boundary */
+    s->last_eob_len = 8; /* enough lookahead for inflate */
+
+    if (header) {
+        put_short(s, (ush)len);   
+        put_short(s, (ush)~len);
+#ifdef DEBUG_ZLIB
+        s->bits_sent += 2*16;
+#endif
+    }
+#ifdef DEBUG_ZLIB
+    s->bits_sent += (ulg)len<<3;
+#endif
+    while (len--) {
+        put_byte(s, *buf++);
+    }
+}
+
+
+/*+++++*/
+/* infblock.h -- header to use infblock.c
+ * Copyright (C) 1995 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h 
+ */
+
+/* WARNING: this file should *not* be used by applications. It is
+   part of the implementation of the compression library and is
+   subject to change. Applications should only use zlib.h.
+ */
+
+struct inflate_blocks_state;
+typedef struct inflate_blocks_state FAR inflate_blocks_statef;
+
+local inflate_blocks_statef * inflate_blocks_new OF((
+    z_stream *z,
+    check_func c,               /* check function */
+    uInt w));                   /* window size */
+
+local int inflate_blocks OF((
+    inflate_blocks_statef *,
+    z_stream *,
+    int));                      /* initial return code */
+
+local void inflate_blocks_reset OF((
+    inflate_blocks_statef *,
+    z_stream *,
+    uLongf *));                  /* check value on output */
+
+local int inflate_blocks_free OF((
+    inflate_blocks_statef *,
+    z_stream *,
+    uLongf *));                  /* check value on output */
+
+local int inflate_addhistory OF((
+    inflate_blocks_statef *,
+    z_stream *));
+
+local int inflate_packet_flush OF((
+    inflate_blocks_statef *));
+
+/*+++++*/
+/* inftrees.h -- header to use inftrees.c
+ * Copyright (C) 1995 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h 
+ */
+
+/* WARNING: this file should *not* be used by applications. It is
+   part of the implementation of the compression library and is
+   subject to change. Applications should only use zlib.h.
+ */
+
+/* Huffman code lookup table entry--this entry is four bytes for machines
+   that have 16-bit pointers (e.g. PC's in the small or medium model). */
+
+typedef struct inflate_huft_s FAR inflate_huft;
+
+struct inflate_huft_s {
+  union {
+    struct {
+      Byte Exop;        /* number of extra bits or operation */
+      Byte Bits;        /* number of bits in this code or subcode */
+    } what;
+    uInt Nalloc;	/* number of these allocated here */
+    Bytef *pad;         /* pad structure to a power of 2 (4 bytes for */
+  } word;               /*  16-bit, 8 bytes for 32-bit machines) */
+  union {
+    uInt Base;          /* literal, length base, or distance base */
+    inflate_huft *Next; /* pointer to next level of table */
+  } more;
+};
+
+#ifdef DEBUG_ZLIB
+  local uInt inflate_hufts;
+#endif
+
+local int inflate_trees_bits OF((
+    uIntf *,                    /* 19 code lengths */
+    uIntf *,                    /* bits tree desired/actual depth */
+    inflate_huft * FAR *,       /* bits tree result */
+    z_stream *));               /* for zalloc, zfree functions */
+
+local int inflate_trees_dynamic OF((
+    uInt,                       /* number of literal/length codes */
+    uInt,                       /* number of distance codes */
+    uIntf *,                    /* that many (total) code lengths */
+    uIntf *,                    /* literal desired/actual bit depth */
+    uIntf *,                    /* distance desired/actual bit depth */
+    inflate_huft * FAR *,       /* literal/length tree result */
+    inflate_huft * FAR *,       /* distance tree result */
+    z_stream *));               /* for zalloc, zfree functions */
+
+local int inflate_trees_fixed OF((
+    uIntf *,                    /* literal desired/actual bit depth */
+    uIntf *,                    /* distance desired/actual bit depth */
+    inflate_huft * FAR *,       /* literal/length tree result */
+    inflate_huft * FAR *));     /* distance tree result */
+
+local int inflate_trees_free OF((
+    inflate_huft *,             /* tables to free */
+    z_stream *));               /* for zfree function */
+
+
+/*+++++*/
+/* infcodes.h -- header to use infcodes.c
+ * Copyright (C) 1995 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h 
+ */
+
+/* WARNING: this file should *not* be used by applications. It is
+   part of the implementation of the compression library and is
+   subject to change. Applications should only use zlib.h.
+ */
+
+struct inflate_codes_state;
+typedef struct inflate_codes_state FAR inflate_codes_statef;
+
+local inflate_codes_statef *inflate_codes_new OF((
+    uInt, uInt,
+    inflate_huft *, inflate_huft *,
+    z_stream *));
+
+local int inflate_codes OF((
+    inflate_blocks_statef *,
+    z_stream *,
+    int));
+
+local void inflate_codes_free OF((
+    inflate_codes_statef *,
+    z_stream *));
+
+
+/*+++++*/
+/* inflate.c -- zlib interface to inflate modules
+ * Copyright (C) 1995 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h 
+ */
+
+/* inflate private state */
+struct internal_state {
+
+  /* mode */
+  enum {
+      METHOD,   /* waiting for method byte */
+      FLAG,     /* waiting for flag byte */
+      BLOCKS,   /* decompressing blocks */
+      CHECK4,   /* four check bytes to go */
+      CHECK3,   /* three check bytes to go */
+      CHECK2,   /* two check bytes to go */
+      CHECK1,   /* one check byte to go */
+      DONE,     /* finished check, done */
+      BAD}      /* got an error--stay here */
+    mode;               /* current inflate mode */
+
+  /* mode dependent information */
+  union {
+    uInt method;        /* if FLAGS, method byte */
+    struct {
+      uLong was;                /* computed check value */
+      uLong need;               /* stream check value */
+    } check;            /* if CHECK, check values to compare */
+    uInt marker;        /* if BAD, inflateSync's marker bytes count */
+  } sub;        /* submode */
+
+  /* mode independent information */
+  int  nowrap;          /* flag for no wrapper */
+  uInt wbits;           /* log2(window size)  (8..15, defaults to 15) */
+  inflate_blocks_statef 
+    *blocks;            /* current inflate_blocks state */
+
+};
+
+
+int inflateReset(z)
+z_stream *z;
+{
+  uLong c;
+
+  if (z == Z_NULL || z->state == Z_NULL)
+    return Z_STREAM_ERROR;
+  z->total_in = z->total_out = 0;
+  z->msg = Z_NULL;
+  z->state->mode = z->state->nowrap ? BLOCKS : METHOD;
+  inflate_blocks_reset(z->state->blocks, z, &c);
+  Trace((stderr, "inflate: reset\n"));
+  return Z_OK;
+}
+
+
+int inflateEnd(z)
+z_stream *z;
+{
+  uLong c;
+
+  if (z == Z_NULL || z->state == Z_NULL || z->zfree == Z_NULL)
+    return Z_STREAM_ERROR;
+  if (z->state->blocks != Z_NULL)
+    inflate_blocks_free(z->state->blocks, z, &c);
+  ZFREE(z, z->state, sizeof(struct internal_state));
+  z->state = Z_NULL;
+  Trace((stderr, "inflate: end\n"));
+  return Z_OK;
+}
+
+
+int inflateInit2(z, w)
+z_stream *z;
+int w;
+{
+  /* initialize state */
+  if (z == Z_NULL)
+    return Z_STREAM_ERROR;
+/*  if (z->zalloc == Z_NULL) z->zalloc = zcalloc; */
+/*  if (z->zfree == Z_NULL) z->zfree = zcfree; */
+  if ((z->state = (struct internal_state FAR *)
+       ZALLOC_INIT(z,1,sizeof(struct internal_state))) == Z_NULL)
+    return Z_MEM_ERROR;
+  z->state->blocks = Z_NULL;
+
+  /* handle undocumented nowrap option (no zlib header or check) */
+  z->state->nowrap = 0;
+  if (w < 0)
+  {
+    w = - w;
+    z->state->nowrap = 1;
+  }
+
+  /* set window size */
+  if (w < 8 || w > 15)
+  {
+    inflateEnd(z);
+    return Z_STREAM_ERROR;
+  }
+  z->state->wbits = (uInt)w;
+
+  /* create inflate_blocks state */
+  if ((z->state->blocks =
+       inflate_blocks_new(z, z->state->nowrap ? Z_NULL : adler32, 1 << w))
+      == Z_NULL)
+  {
+    inflateEnd(z);
+    return Z_MEM_ERROR;
+  }
+  Trace((stderr, "inflate: allocated\n"));
+
+  /* reset state */
+  inflateReset(z);
+  return Z_OK;
+}
+
+
+int inflateInit(z)
+z_stream *z;
+{
+  return inflateInit2(z, DEF_WBITS);
+}
+
+
+#define NEEDBYTE {if(z->avail_in==0)goto empty;r=Z_OK;}
+#define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++)
+
+int inflate(z, f)
+z_stream *z;
+int f;
+{
+  int r;
+  uInt b;
+
+  if (z == Z_NULL || z->next_in == Z_NULL)
+    return Z_STREAM_ERROR;
+  r = Z_BUF_ERROR;
+  while (1) switch (z->state->mode)
+  {
+    case METHOD:
+      NEEDBYTE
+      if (((z->state->sub.method = NEXTBYTE) & 0xf) != DEFLATED)
+      {
+        z->state->mode = BAD;
+        z->msg = "unknown compression method";
+        z->state->sub.marker = 5;       /* can't try inflateSync */
+        break;
+      }
+      if ((z->state->sub.method >> 4) + 8 > z->state->wbits)
+      {
+        z->state->mode = BAD;
+        z->msg = "invalid window size";
+        z->state->sub.marker = 5;       /* can't try inflateSync */
+        break;
+      }
+      z->state->mode = FLAG;
+    case FLAG:
+      NEEDBYTE
+      if ((b = NEXTBYTE) & 0x20)
+      {
+        z->state->mode = BAD;
+        z->msg = "invalid reserved bit";
+        z->state->sub.marker = 5;       /* can't try inflateSync */
+        break;
+      }
+      if (((z->state->sub.method << 8) + b) % 31)
+      {
+        z->state->mode = BAD;
+        z->msg = "incorrect header check";
+        z->state->sub.marker = 5;       /* can't try inflateSync */
+        break;
+      }
+      Trace((stderr, "inflate: zlib header ok\n"));
+      z->state->mode = BLOCKS;
+    case BLOCKS:
+      r = inflate_blocks(z->state->blocks, z, r);
+      if (f == Z_PACKET_FLUSH && z->avail_in == 0 && z->avail_out != 0)
+	  r = inflate_packet_flush(z->state->blocks);
+      if (r == Z_DATA_ERROR)
+      {
+        z->state->mode = BAD;
+        z->state->sub.marker = 0;       /* can try inflateSync */
+        break;
+      }
+      if (r != Z_STREAM_END)
+        return r;
+      r = Z_OK;
+      inflate_blocks_reset(z->state->blocks, z, &z->state->sub.check.was);
+      if (z->state->nowrap)
+      {
+        z->state->mode = DONE;
+        break;
+      }
+      z->state->mode = CHECK4;
+    case CHECK4:
+      NEEDBYTE
+      z->state->sub.check.need = (uLong)NEXTBYTE << 24;
+      z->state->mode = CHECK3;
+    case CHECK3:
+      NEEDBYTE
+      z->state->sub.check.need += (uLong)NEXTBYTE << 16;
+      z->state->mode = CHECK2;
+    case CHECK2:
+      NEEDBYTE
+      z->state->sub.check.need += (uLong)NEXTBYTE << 8;
+      z->state->mode = CHECK1;
+    case CHECK1:
+      NEEDBYTE
+      z->state->sub.check.need += (uLong)NEXTBYTE;
+
+      if (z->state->sub.check.was != z->state->sub.check.need)
+      {
+        z->state->mode = BAD;
+        z->msg = "incorrect data check";
+        z->state->sub.marker = 5;       /* can't try inflateSync */
+        break;
+      }
+      Trace((stderr, "inflate: zlib check ok\n"));
+      z->state->mode = DONE;
+    case DONE:
+      return Z_STREAM_END;
+    case BAD:
+      return Z_DATA_ERROR;
+    default:
+      return Z_STREAM_ERROR;
+  }
+
+ empty:
+  if (f != Z_PACKET_FLUSH)
+    return r;
+  z->state->mode = BAD;
+  z->state->sub.marker = 0;       /* can try inflateSync */
+  return Z_DATA_ERROR;
+}
+
+/*
+ * This subroutine adds the data at next_in/avail_in to the output history
+ * without performing any output.  The output buffer must be "caught up";
+ * i.e. no pending output (hence s->read equals s->write), and the state must
+ * be BLOCKS (i.e. we should be willing to see the start of a series of
+ * BLOCKS).  On exit, the output will also be caught up, and the checksum
+ * will have been updated if need be.
+ */
+
+int inflateIncomp(z)
+z_stream *z;
+{
+    if (z->state->mode != BLOCKS)
+	return Z_DATA_ERROR;
+    return inflate_addhistory(z->state->blocks, z);
+}
+
+
+int inflateSync(z)
+z_stream *z;
+{
+  uInt n;       /* number of bytes to look at */
+  Bytef *p;     /* pointer to bytes */
+  uInt m;       /* number of marker bytes found in a row */
+  uLong r, w;   /* temporaries to save total_in and total_out */
+
+  /* set up */
+  if (z == Z_NULL || z->state == Z_NULL)
+    return Z_STREAM_ERROR;
+  if (z->state->mode != BAD)
+  {
+    z->state->mode = BAD;
+    z->state->sub.marker = 0;
+  }
+  if ((n = z->avail_in) == 0)
+    return Z_BUF_ERROR;
+  p = z->next_in;
+  m = z->state->sub.marker;
+
+  /* search */
+  while (n && m < 4)
+  {
+    if (*p == (Byte)(m < 2 ? 0 : 0xff))
+      m++;
+    else if (*p)
+      m = 0;
+    else
+      m = 4 - m;
+    p++, n--;
+  }
+
+  /* restore */
+  z->total_in += p - z->next_in;
+  z->next_in = p;
+  z->avail_in = n;
+  z->state->sub.marker = m;
+
+  /* return no joy or set up to restart on a new block */
+  if (m != 4)
+    return Z_DATA_ERROR;
+  r = z->total_in;  w = z->total_out;
+  inflateReset(z);
+  z->total_in = r;  z->total_out = w;
+  z->state->mode = BLOCKS;
+  return Z_OK;
+}
+
+#undef NEEDBYTE
+#undef NEXTBYTE
+
+/*+++++*/
+/* infutil.h -- types and macros common to blocks and codes
+ * Copyright (C) 1995 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h 
+ */
+
+/* WARNING: this file should *not* be used by applications. It is
+   part of the implementation of the compression library and is
+   subject to change. Applications should only use zlib.h.
+ */
+
+/* inflate blocks semi-private state */
+struct inflate_blocks_state {
+
+  /* mode */
+  enum {
+      TYPE,     /* get type bits (3, including end bit) */
+      LENS,     /* get lengths for stored */
+      STORED,   /* processing stored block */
+      TABLE,    /* get table lengths */
+      BTREE,    /* get bit lengths tree for a dynamic block */
+      DTREE,    /* get length, distance trees for a dynamic block */
+      CODES,    /* processing fixed or dynamic block */
+      DRY,      /* output remaining window bytes */
+      DONEB,     /* finished last block, done */
+      BADB}      /* got a data error--stuck here */
+    mode;               /* current inflate_block mode */
+
+  /* mode dependent information */
+  union {
+    uInt left;          /* if STORED, bytes left to copy */
+    struct {
+      uInt table;               /* table lengths (14 bits) */
+      uInt index;               /* index into blens (or border) */
+      uIntf *blens;             /* bit lengths of codes */
+      uInt bb;                  /* bit length tree depth */
+      inflate_huft *tb;         /* bit length decoding tree */
+      int nblens;		/* # elements allocated at blens */
+    } trees;            /* if DTREE, decoding info for trees */
+    struct {
+      inflate_huft *tl, *td;    /* trees to free */
+      inflate_codes_statef 
+         *codes;
+    } decode;           /* if CODES, current state */
+  } sub;                /* submode */
+  uInt last;            /* true if this block is the last block */
+
+  /* mode independent information */
+  uInt bitk;            /* bits in bit buffer */
+  uLong bitb;           /* bit buffer */
+  Bytef *window;        /* sliding window */
+  Bytef *end;           /* one byte after sliding window */
+  Bytef *read;          /* window read pointer */
+  Bytef *write;         /* window write pointer */
+  check_func checkfn;   /* check function */
+  uLong check;          /* check on output */
+
+};
+
+
+/* defines for inflate input/output */
+/*   update pointers and return */
+#define UPDBITS {s->bitb=b;s->bitk=k;}
+#define UPDIN {z->avail_in=n;z->total_in+=p-z->next_in;z->next_in=p;}
+#define UPDOUT {s->write=q;}
+#define UPDATE {UPDBITS UPDIN UPDOUT}
+#define LEAVE {UPDATE return inflate_flush(s,z,r);}
+/*   get bytes and bits */
+#define LOADIN {p=z->next_in;n=z->avail_in;b=s->bitb;k=s->bitk;}
+#define NEEDBYTE {if(n)r=Z_OK;else LEAVE}
+#define NEXTBYTE (n--,*p++)
+#define NEEDBITS(j) {while(k<(j)){NEEDBYTE;b|=((uLong)NEXTBYTE)<<k;k+=8;}}
+#define DUMPBITS(j) {b>>=(j);k-=(j);}
+/*   output bytes */
+#define WAVAIL (q<s->read?s->read-q-1:s->end-q)
+#define LOADOUT {q=s->write;m=WAVAIL;}
+#define WRAP {if(q==s->end&&s->read!=s->window){q=s->window;m=WAVAIL;}}
+#define FLUSH {UPDOUT r=inflate_flush(s,z,r); LOADOUT}
+#define NEEDOUT {if(m==0){WRAP if(m==0){FLUSH WRAP if(m==0) LEAVE}}r=Z_OK;}
+#define OUTBYTE(a) {*q++=(Byte)(a);m--;}
+/*   load local pointers */
+#define LOAD {LOADIN LOADOUT}
+
+/* And'ing with mask[n] masks the lower n bits */
+local uInt inflate_mask[] = {
+    0x0000,
+    0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
+    0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
+};
+
+/* copy as much as possible from the sliding window to the output area */
+local int inflate_flush OF((
+    inflate_blocks_statef *,
+    z_stream *,
+    int));
+
+/*+++++*/
+/* inffast.h -- header to use inffast.c
+ * Copyright (C) 1995 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h 
+ */
+
+/* WARNING: this file should *not* be used by applications. It is
+   part of the implementation of the compression library and is
+   subject to change. Applications should only use zlib.h.
+ */
+
+local int inflate_fast OF((
+    uInt,
+    uInt,
+    inflate_huft *,
+    inflate_huft *,
+    inflate_blocks_statef *,
+    z_stream *));
+
+
+/*+++++*/
+/* infblock.c -- interpret and process block types to last block
+ * Copyright (C) 1995 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h 
+ */
+
+/* Table for deflate from PKZIP's appnote.txt. */
+local uInt border[] = { /* Order of the bit length code lengths */
+        16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
+
+/*
+   Notes beyond the 1.93a appnote.txt:
+
+   1. Distance pointers never point before the beginning of the output
+      stream.
+   2. Distance pointers can point back across blocks, up to 32k away.
+   3. There is an implied maximum of 7 bits for the bit length table and
+      15 bits for the actual data.
+   4. If only one code exists, then it is encoded using one bit.  (Zero
+      would be more efficient, but perhaps a little confusing.)  If two
+      codes exist, they are coded using one bit each (0 and 1).
+   5. There is no way of sending zero distance codes--a dummy must be
+      sent if there are none.  (History: a pre 2.0 version of PKZIP would
+      store blocks with no distance codes, but this was discovered to be
+      too harsh a criterion.)  Valid only for 1.93a.  2.04c does allow
+      zero distance codes, which is sent as one code of zero bits in
+      length.
+   6. There are up to 286 literal/length codes.  Code 256 represents the
+      end-of-block.  Note however that the static length tree defines
+      288 codes just to fill out the Huffman codes.  Codes 286 and 287
+      cannot be used though, since there is no length base or extra bits
+      defined for them.  Similarily, there are up to 30 distance codes.
+      However, static trees define 32 codes (all 5 bits) to fill out the
+      Huffman codes, but the last two had better not show up in the data.
+   7. Unzip can check dynamic Huffman blocks for complete code sets.
+      The exception is that a single code would not be complete (see #4).
+   8. The five bits following the block type is really the number of
+      literal codes sent minus 257.
+   9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits
+      (1+6+6).  Therefore, to output three times the length, you output
+      three codes (1+1+1), whereas to output four times the same length,
+      you only need two codes (1+3).  Hmm.
+  10. In the tree reconstruction algorithm, Code = Code + Increment
+      only if BitLength(i) is not zero.  (Pretty obvious.)
+  11. Correction: 4 Bits: # of Bit Length codes - 4     (4 - 19)
+  12. Note: length code 284 can represent 227-258, but length code 285
+      really is 258.  The last length deserves its own, short code
+      since it gets used a lot in very redundant files.  The length
+      258 is special since 258 - 3 (the min match length) is 255.
+  13. The literal/length and distance code bit lengths are read as a
+      single stream of lengths.  It is possible (and advantageous) for
+      a repeat code (16, 17, or 18) to go across the boundary between
+      the two sets of lengths.
+ */
+
+
+local void inflate_blocks_reset(s, z, c)
+inflate_blocks_statef *s;
+z_stream *z;
+uLongf *c;
+{
+  if (s->checkfn != Z_NULL)
+    *c = s->check;
+  if (s->mode == BTREE || s->mode == DTREE)
+    ZFREE(z, s->sub.trees.blens, s->sub.trees.nblens * sizeof(uInt));
+  if (s->mode == CODES)
+  {
+    inflate_codes_free(s->sub.decode.codes, z);
+    inflate_trees_free(s->sub.decode.td, z);
+    inflate_trees_free(s->sub.decode.tl, z);
+  }
+  s->mode = TYPE;
+  s->bitk = 0;
+  s->bitb = 0;
+  s->read = s->write = s->window;
+  if (s->checkfn != Z_NULL)
+    s->check = (*s->checkfn)(0L, Z_NULL, 0);
+  Trace((stderr, "inflate:   blocks reset\n"));
+}
+
+
+local inflate_blocks_statef *inflate_blocks_new(z, c, w)
+z_stream *z;
+check_func c;
+uInt w;
+{
+  inflate_blocks_statef *s;
+
+  if ((s = (inflate_blocks_statef *)ZALLOC_INIT
+       (z,1,sizeof(struct inflate_blocks_state))) == Z_NULL)
+    return s;
+  if ((s->window = (Bytef *)ZALLOC_INIT(z, 1, w)) == Z_NULL)
+  {
+    ZFREE(z, s, sizeof(struct inflate_blocks_state));
+    return Z_NULL;
+  }
+  s->end = s->window + w;
+  s->checkfn = c;
+  s->mode = TYPE;
+  Trace((stderr, "inflate:   blocks allocated\n"));
+  inflate_blocks_reset(s, z, &s->check);
+  return s;
+}
+
+
+local int inflate_blocks(s, z, r)
+inflate_blocks_statef *s;
+z_stream *z;
+int r;
+{
+  uInt t;               /* temporary storage */
+  uLong b;              /* bit buffer */
+  uInt k;               /* bits in bit buffer */
+  Bytef *p;             /* input data pointer */
+  uInt n;               /* bytes available there */
+  Bytef *q;             /* output window write pointer */
+  uInt m;               /* bytes to end of window or read pointer */
+
+  /* copy input/output information to locals (UPDATE macro restores) */
+  LOAD
+
+  /* process input based on current state */
+  while (1) switch (s->mode)
+  {
+    case TYPE:
+      NEEDBITS(3)
+      t = (uInt)b & 7;
+      s->last = t & 1;
+      switch (t >> 1)
+      {
+        case 0:                         /* stored */
+          Trace((stderr, "inflate:     stored block%s\n",
+                 s->last ? " (last)" : ""));
+          DUMPBITS(3)
+          t = k & 7;                    /* go to byte boundary */
+          DUMPBITS(t)
+          s->mode = LENS;               /* get length of stored block */
+          break;
+        case 1:                         /* fixed */
+          Trace((stderr, "inflate:     fixed codes block%s\n",
+                 s->last ? " (last)" : ""));
+          {
+            uInt bl, bd;
+            inflate_huft *tl, *td;
+
+            inflate_trees_fixed(&bl, &bd, &tl, &td);
+            s->sub.decode.codes = inflate_codes_new(bl, bd, tl, td, z);
+            if (s->sub.decode.codes == Z_NULL)
+            {
+              r = Z_MEM_ERROR;
+              LEAVE
+            }
+            s->sub.decode.tl = Z_NULL;  /* don't try to free these */
+            s->sub.decode.td = Z_NULL;
+          }
+          DUMPBITS(3)
+          s->mode = CODES;
+          break;
+        case 2:                         /* dynamic */
+          Trace((stderr, "inflate:     dynamic codes block%s\n",
+                 s->last ? " (last)" : ""));
+          DUMPBITS(3)
+          s->mode = TABLE;
+          break;
+        case 3:                         /* illegal */
+          DUMPBITS(3)
+          s->mode = BADB;
+          z->msg = "invalid block type";
+          r = Z_DATA_ERROR;
+          LEAVE
+      }
+      break;
+    case LENS:
+      NEEDBITS(32)
+      if (((~b) >> 16) != (b & 0xffff))
+      {
+        s->mode = BADB;
+        z->msg = "invalid stored block lengths";
+        r = Z_DATA_ERROR;
+        LEAVE
+      }
+      s->sub.left = (uInt)b & 0xffff;
+      b = k = 0;                      /* dump bits */
+      Tracev((stderr, "inflate:       stored length %u\n", s->sub.left));
+      s->mode = s->sub.left ? STORED : TYPE;
+      break;
+    case STORED:
+      if (n == 0)
+        LEAVE
+      NEEDOUT
+      t = s->sub.left;
+      if (t > n) t = n;
+      if (t > m) t = m;
+      zmemcpy(q, p, t);
+      p += t;  n -= t;
+      q += t;  m -= t;
+      if ((s->sub.left -= t) != 0)
+        break;
+      Tracev((stderr, "inflate:       stored end, %lu total out\n",
+              z->total_out + (q >= s->read ? q - s->read :
+              (s->end - s->read) + (q - s->window))));
+      s->mode = s->last ? DRY : TYPE;
+      break;
+    case TABLE:
+      NEEDBITS(14)
+      s->sub.trees.table = t = (uInt)b & 0x3fff;
+#ifndef PKZIP_BUG_WORKAROUND
+      if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29)
+      {
+        s->mode = BADB;
+        z->msg = "too many length or distance symbols";
+        r = Z_DATA_ERROR;
+        LEAVE
+      }
+#endif
+      t = 258 + (t & 0x1f) + ((t >> 5) & 0x1f);
+      if (t < 19)
+        t = 19;
+      if ((s->sub.trees.blens = (uIntf*)ZALLOC(z, t, sizeof(uInt))) == Z_NULL)
+      {
+        r = Z_MEM_ERROR;
+        LEAVE
+      }
+      s->sub.trees.nblens = t;
+      DUMPBITS(14)
+      s->sub.trees.index = 0;
+      Tracev((stderr, "inflate:       table sizes ok\n"));
+      s->mode = BTREE;
+    case BTREE:
+      while (s->sub.trees.index < 4 + (s->sub.trees.table >> 10))
+      {
+        NEEDBITS(3)
+        s->sub.trees.blens[border[s->sub.trees.index++]] = (uInt)b & 7;
+        DUMPBITS(3)
+      }
+      while (s->sub.trees.index < 19)
+        s->sub.trees.blens[border[s->sub.trees.index++]] = 0;
+      s->sub.trees.bb = 7;
+      t = inflate_trees_bits(s->sub.trees.blens, &s->sub.trees.bb,
+                             &s->sub.trees.tb, z);
+      if (t != Z_OK)
+      {
+        r = t;
+        if (r == Z_DATA_ERROR)
+          s->mode = BADB;
+        LEAVE
+      }
+      s->sub.trees.index = 0;
+      Tracev((stderr, "inflate:       bits tree ok\n"));
+      s->mode = DTREE;
+    case DTREE:
+      while (t = s->sub.trees.table,
+             s->sub.trees.index < 258 + (t & 0x1f) + ((t >> 5) & 0x1f))
+      {
+        inflate_huft *h;
+        uInt i, j, c;
+
+        t = s->sub.trees.bb;
+        NEEDBITS(t)
+        h = s->sub.trees.tb + ((uInt)b & inflate_mask[t]);
+        t = h->word.what.Bits;
+        c = h->more.Base;
+        if (c < 16)
+        {
+          DUMPBITS(t)
+          s->sub.trees.blens[s->sub.trees.index++] = c;
+        }
+        else /* c == 16..18 */
+        {
+          i = c == 18 ? 7 : c - 14;
+          j = c == 18 ? 11 : 3;
+          NEEDBITS(t + i)
+          DUMPBITS(t)
+          j += (uInt)b & inflate_mask[i];
+          DUMPBITS(i)
+          i = s->sub.trees.index;
+          t = s->sub.trees.table;
+          if (i + j > 258 + (t & 0x1f) + ((t >> 5) & 0x1f) ||
+              (c == 16 && i < 1))
+          {
+            s->mode = BADB;
+            z->msg = "invalid bit length repeat";
+            r = Z_DATA_ERROR;
+            LEAVE
+          }
+          c = c == 16 ? s->sub.trees.blens[i - 1] : 0;
+          do {
+            s->sub.trees.blens[i++] = c;
+          } while (--j);
+          s->sub.trees.index = i;
+        }
+      }
+      inflate_trees_free(s->sub.trees.tb, z);
+      s->sub.trees.tb = Z_NULL;
+      {
+        uInt bl, bd;
+        inflate_huft *tl, *td;
+        inflate_codes_statef *c;
+
+        bl = 9;         /* must be <= 9 for lookahead assumptions */
+        bd = 6;         /* must be <= 9 for lookahead assumptions */
+        t = s->sub.trees.table;
+        t = inflate_trees_dynamic(257 + (t & 0x1f), 1 + ((t >> 5) & 0x1f),
+                                  s->sub.trees.blens, &bl, &bd, &tl, &td, z);
+        if (t != Z_OK)
+        {
+          if (t == (uInt)Z_DATA_ERROR)
+            s->mode = BADB;
+          r = t;
+          LEAVE
+        }
+        Tracev((stderr, "inflate:       trees ok\n"));
+        if ((c = inflate_codes_new(bl, bd, tl, td, z)) == Z_NULL)
+        {
+          inflate_trees_free(td, z);
+          inflate_trees_free(tl, z);
+          r = Z_MEM_ERROR;
+          LEAVE
+        }
+        ZFREE(z, s->sub.trees.blens, s->sub.trees.nblens * sizeof(uInt));
+        s->sub.decode.codes = c;
+        s->sub.decode.tl = tl;
+        s->sub.decode.td = td;
+      }
+      s->mode = CODES;
+    case CODES:
+      UPDATE
+      if ((r = inflate_codes(s, z, r)) != Z_STREAM_END)
+        return inflate_flush(s, z, r);
+      r = Z_OK;
+      inflate_codes_free(s->sub.decode.codes, z);
+      inflate_trees_free(s->sub.decode.td, z);
+      inflate_trees_free(s->sub.decode.tl, z);
+      LOAD
+      Tracev((stderr, "inflate:       codes end, %lu total out\n",
+              z->total_out + (q >= s->read ? q - s->read :
+              (s->end - s->read) + (q - s->window))));
+      if (!s->last)
+      {
+        s->mode = TYPE;
+        break;
+      }
+      if (k > 7)              /* return unused byte, if any */
+      {
+        Assert(k < 16, "inflate_codes grabbed too many bytes")
+        k -= 8;
+        n++;
+        p--;                    /* can always return one */
+      }
+      s->mode = DRY;
+    case DRY:
+      FLUSH
+      if (s->read != s->write)
+        LEAVE
+      s->mode = DONEB;
+    case DONEB:
+      r = Z_STREAM_END;
+      LEAVE
+    case BADB:
+      r = Z_DATA_ERROR;
+      LEAVE
+    default:
+      r = Z_STREAM_ERROR;
+      LEAVE
+  }
+}
+
+
+local int inflate_blocks_free(s, z, c)
+inflate_blocks_statef *s;
+z_stream *z;
+uLongf *c;
+{
+  inflate_blocks_reset(s, z, c);
+  ZFREE(z, s->window, s->end - s->window);
+  ZFREE(z, s, sizeof(struct inflate_blocks_state));
+  Trace((stderr, "inflate:   blocks freed\n"));
+  return Z_OK;
+}
+
+/*
+ * This subroutine adds the data at next_in/avail_in to the output history
+ * without performing any output.  The output buffer must be "caught up";
+ * i.e. no pending output (hence s->read equals s->write), and the state must
+ * be BLOCKS (i.e. we should be willing to see the start of a series of
+ * BLOCKS).  On exit, the output will also be caught up, and the checksum
+ * will have been updated if need be.
+ */
+local int inflate_addhistory(s, z)
+inflate_blocks_statef *s;
+z_stream *z;
+{
+    uLong b;              /* bit buffer */  /* NOT USED HERE */
+    uInt k;               /* bits in bit buffer */ /* NOT USED HERE */
+    uInt t;               /* temporary storage */
+    Bytef *p;             /* input data pointer */
+    uInt n;               /* bytes available there */
+    Bytef *q;             /* output window write pointer */
+    uInt m;               /* bytes to end of window or read pointer */
+
+    if (s->read != s->write)
+	return Z_STREAM_ERROR;
+    if (s->mode != TYPE)
+	return Z_DATA_ERROR;
+
+    /* we're ready to rock */
+    LOAD
+    /* while there is input ready, copy to output buffer, moving
+     * pointers as needed.
+     */
+    while (n) {
+	t = n;  /* how many to do */
+	/* is there room until end of buffer? */
+	if (t > m) t = m;
+	/* update check information */
+	if (s->checkfn != Z_NULL)
+	    s->check = (*s->checkfn)(s->check, q, t);
+	zmemcpy(q, p, t);
+	q += t;
+	p += t;
+	n -= t;
+	z->total_out += t;
+	s->read = q;    /* drag read pointer forward */
+/*      WRAP  */ 	/* expand WRAP macro by hand to handle s->read */
+	if (q == s->end) {
+	    s->read = q = s->window;
+	    m = WAVAIL;
+	}
+    }
+    UPDATE
+    return Z_OK;
+}
+
+
+/*
+ * At the end of a Deflate-compressed PPP packet, we expect to have seen
+ * a `stored' block type value but not the (zero) length bytes.
+ */
+local int inflate_packet_flush(s)
+    inflate_blocks_statef *s;
+{
+    if (s->mode != LENS)
+	return Z_DATA_ERROR;
+    s->mode = TYPE;
+    return Z_OK;
+}
+
+
+/*+++++*/
+/* inftrees.c -- generate Huffman trees for efficient decoding
+ * Copyright (C) 1995 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h 
+ */
+
+/* simplify the use of the inflate_huft type with some defines */
+#define base more.Base
+#define next more.Next
+#define exop word.what.Exop
+#define bits word.what.Bits
+
+
+local int huft_build OF((
+    uIntf *,            /* code lengths in bits */
+    uInt,               /* number of codes */
+    uInt,               /* number of "simple" codes */
+    uIntf *,            /* list of base values for non-simple codes */
+    uIntf *,            /* list of extra bits for non-simple codes */
+    inflate_huft * FAR*,/* result: starting table */
+    uIntf *,            /* maximum lookup bits (returns actual) */
+    z_stream *));       /* for zalloc function */
+
+local voidpf falloc OF((
+    voidpf,             /* opaque pointer (not used) */
+    uInt,               /* number of items */
+    uInt));             /* size of item */
+
+local void ffree OF((
+    voidpf q,           /* opaque pointer (not used) */
+    voidpf p,           /* what to free (not used) */
+    uInt n));		/* number of bytes (not used) */
+
+/* Tables for deflate from PKZIP's appnote.txt. */
+local uInt cplens[] = { /* Copy lengths for literal codes 257..285 */
+        3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
+        35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0};
+        /* actually lengths - 2; also see note #13 above about 258 */
+local uInt cplext[] = { /* Extra bits for literal codes 257..285 */
+        0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
+        3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 192, 192}; /* 192==invalid */
+local uInt cpdist[] = { /* Copy offsets for distance codes 0..29 */
+        1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
+        257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
+        8193, 12289, 16385, 24577};
+local uInt cpdext[] = { /* Extra bits for distance codes */
+        0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
+        7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
+        12, 12, 13, 13};
+
+/*
+   Huffman code decoding is performed using a multi-level table lookup.
+   The fastest way to decode is to simply build a lookup table whose
+   size is determined by the longest code.  However, the time it takes
+   to build this table can also be a factor if the data being decoded
+   is not very long.  The most common codes are necessarily the
+   shortest codes, so those codes dominate the decoding time, and hence
+   the speed.  The idea is you can have a shorter table that decodes the
+   shorter, more probable codes, and then point to subsidiary tables for
+   the longer codes.  The time it costs to decode the longer codes is
+   then traded against the time it takes to make longer tables.
+
+   This results of this trade are in the variables lbits and dbits
+   below.  lbits is the number of bits the first level table for literal/
+   length codes can decode in one step, and dbits is the same thing for
+   the distance codes.  Subsequent tables are also less than or equal to
+   those sizes.  These values may be adjusted either when all of the
+   codes are shorter than that, in which case the longest code length in
+   bits is used, or when the shortest code is *longer* than the requested
+   table size, in which case the length of the shortest code in bits is
+   used.
+
+   There are two different values for the two tables, since they code a
+   different number of possibilities each.  The literal/length table
+   codes 286 possible values, or in a flat code, a little over eight
+   bits.  The distance table codes 30 possible values, or a little less
+   than five bits, flat.  The optimum values for speed end up being
+   about one bit more than those, so lbits is 8+1 and dbits is 5+1.
+   The optimum values may differ though from machine to machine, and
+   possibly even between compilers.  Your mileage may vary.
+ */
+
+
+/* If BMAX needs to be larger than 16, then h and x[] should be uLong. */
+#define BMAX 15         /* maximum bit length of any code */
+#define N_MAX 288       /* maximum number of codes in any set */
+
+#ifdef DEBUG_ZLIB
+  uInt inflate_hufts;
+#endif
+
+local int huft_build(b, n, s, d, e, t, m, zs)
+uIntf *b;               /* code lengths in bits (all assumed <= BMAX) */
+uInt n;                 /* number of codes (assumed <= N_MAX) */
+uInt s;                 /* number of simple-valued codes (0..s-1) */
+uIntf *d;               /* list of base values for non-simple codes */
+uIntf *e;               /* list of extra bits for non-simple codes */  
+inflate_huft * FAR *t;  /* result: starting table */
+uIntf *m;               /* maximum lookup bits, returns actual */
+z_stream *zs;           /* for zalloc function */
+/* Given a list of code lengths and a maximum table size, make a set of
+   tables to decode that set of codes.  Return Z_OK on success, Z_BUF_ERROR
+   if the given code set is incomplete (the tables are still built in this
+   case), Z_DATA_ERROR if the input is invalid (all zero length codes or an
+   over-subscribed set of lengths), or Z_MEM_ERROR if not enough memory. */
+{
+
+  uInt a;                       /* counter for codes of length k */
+  uInt c[BMAX+1];               /* bit length count table */
+  uInt f;                       /* i repeats in table every f entries */
+  int g;                        /* maximum code length */
+  int h;                        /* table level */
+  register uInt i;              /* counter, current code */
+  register uInt j;              /* counter */
+  register int k;               /* number of bits in current code */
+  int l;                        /* bits per table (returned in m) */
+  register uIntf *p;            /* pointer into c[], b[], or v[] */
+  inflate_huft *q;              /* points to current table */
+  struct inflate_huft_s r;      /* table entry for structure assignment */
+  inflate_huft *u[BMAX];        /* table stack */
+  uInt v[N_MAX];                /* values in order of bit length */
+  register int w;               /* bits before this table == (l * h) */
+  uInt x[BMAX+1];               /* bit offsets, then code stack */
+  uIntf *xp;                    /* pointer into x */
+  int y;                        /* number of dummy codes added */
+  uInt z;                       /* number of entries in current table */
+
+
+  /* Generate counts for each bit length */
+  p = c;
+#define C0 *p++ = 0;
+#define C2 C0 C0 C0 C0
+#define C4 C2 C2 C2 C2
+  C4                            /* clear c[]--assume BMAX+1 is 16 */
+  p = b;  i = n;
+  do {
+    c[*p++]++;                  /* assume all entries <= BMAX */
+  } while (--i);
+  if (c[0] == n)                /* null input--all zero length codes */
+  {
+    *t = (inflate_huft *)Z_NULL;
+    *m = 0;
+    return Z_OK;
+  }
+
+
+  /* Find minimum and maximum length, bound *m by those */
+  l = *m;
+  for (j = 1; j <= BMAX; j++)
+    if (c[j])
+      break;
+  k = j;                        /* minimum code length */
+  if ((uInt)l < j)
+    l = j;
+  for (i = BMAX; i; i--)
+    if (c[i])
+      break;
+  g = i;                        /* maximum code length */
+  if ((uInt)l > i)
+    l = i;
+  *m = l;
+
+
+  /* Adjust last length count to fill out codes, if needed */
+  for (y = 1 << j; j < i; j++, y <<= 1)
+    if ((y -= c[j]) < 0)
+      return Z_DATA_ERROR;
+  if ((y -= c[i]) < 0)
+    return Z_DATA_ERROR;
+  c[i] += y;
+
+
+  /* Generate starting offsets into the value table for each length */
+  x[1] = j = 0;
+  p = c + 1;  xp = x + 2;
+  while (--i) {                 /* note that i == g from above */
+    *xp++ = (j += *p++);
+  }
+
+
+  /* Make a table of values in order of bit lengths */
+  p = b;  i = 0;
+  do {
+    if ((j = *p++) != 0)
+      v[x[j]++] = i;
+  } while (++i < n);
+
+
+  /* Generate the Huffman codes and for each, make the table entries */
+  x[0] = i = 0;                 /* first Huffman code is zero */
+  p = v;                        /* grab values in bit order */
+  h = -1;                       /* no tables yet--level -1 */
+  w = -l;                       /* bits decoded == (l * h) */
+  u[0] = (inflate_huft *)Z_NULL;        /* just to keep compilers happy */
+  q = (inflate_huft *)Z_NULL;   /* ditto */
+  z = 0;                        /* ditto */
+
+  /* go through the bit lengths (k already is bits in shortest code) */
+  for (; k <= g; k++)
+  {
+    a = c[k];
+    while (a--)
+    {
+      /* here i is the Huffman code of length k bits for value *p */
+      /* make tables up to required level */
+      while (k > w + l)
+      {
+        h++;
+        w += l;                 /* previous table always l bits */
+
+        /* compute minimum size table less than or equal to l bits */
+        z = (z = g - w) > (uInt)l ? l : z;      /* table size upper limit */
+        if ((f = 1 << (j = k - w)) > a + 1)     /* try a k-w bit table */
+        {                       /* too few codes for k-w bit table */
+          f -= a + 1;           /* deduct codes from patterns left */
+          xp = c + k;
+          if (j < z)
+            while (++j < z)     /* try smaller tables up to z bits */
+            {
+              if ((f <<= 1) <= *++xp)
+                break;          /* enough codes to use up j bits */
+              f -= *xp;         /* else deduct codes from patterns */
+            }
+        }
+        z = 1 << j;             /* table entries for j-bit table */
+
+        /* allocate and link in new table */
+        if ((q = (inflate_huft *)ZALLOC
+             (zs,z + 1,sizeof(inflate_huft))) == Z_NULL)
+        {
+          if (h)
+            inflate_trees_free(u[0], zs);
+          return Z_MEM_ERROR;   /* not enough memory */
+        }
+	q->word.Nalloc = z + 1;
+#ifdef DEBUG_ZLIB
+        inflate_hufts += z + 1;
+#endif
+        *t = q + 1;             /* link to list for huft_free() */
+        *(t = &(q->next)) = Z_NULL;
+        u[h] = ++q;             /* table starts after link */
+
+        /* connect to last table, if there is one */
+        if (h)
+        {
+          x[h] = i;             /* save pattern for backing up */
+          r.bits = (Byte)l;     /* bits to dump before this table */
+          r.exop = (Byte)j;     /* bits in this table */
+          r.next = q;           /* pointer to this table */
+          j = i >> (w - l);     /* (get around Turbo C bug) */
+          u[h-1][j] = r;        /* connect to last table */
+        }
+      }
+
+      /* set up table entry in r */
+      r.bits = (Byte)(k - w);
+      if (p >= v + n)
+        r.exop = 128 + 64;      /* out of values--invalid code */
+      else if (*p < s)
+      {
+        r.exop = (Byte)(*p < 256 ? 0 : 32 + 64);     /* 256 is end-of-block */
+        r.base = *p++;          /* simple code is just the value */
+      }
+      else
+      {
+        r.exop = (Byte)e[*p - s] + 16 + 64; /* non-simple--look up in lists */
+        r.base = d[*p++ - s];
+      }
+
+      /* fill code-like entries with r */
+      f = 1 << (k - w);
+      for (j = i >> w; j < z; j += f)
+        q[j] = r;
+
+      /* backwards increment the k-bit code i */
+      for (j = 1 << (k - 1); i & j; j >>= 1)
+        i ^= j;
+      i ^= j;
+
+      /* backup over finished tables */
+      while ((i & ((1 << w) - 1)) != x[h])
+      {
+        h--;                    /* don't need to update q */
+        w -= l;
+      }
+    }
+  }
+
+
+  /* Return Z_BUF_ERROR if we were given an incomplete table */
+  return y != 0 && g != 1 ? Z_BUF_ERROR : Z_OK;
+}
+
+
+local int inflate_trees_bits(c, bb, tb, z)
+uIntf *c;               /* 19 code lengths */
+uIntf *bb;              /* bits tree desired/actual depth */
+inflate_huft * FAR *tb; /* bits tree result */
+z_stream *z;            /* for zfree function */
+{
+  int r;
+
+  r = huft_build(c, 19, 19, (uIntf*)Z_NULL, (uIntf*)Z_NULL, tb, bb, z);
+  if (r == Z_DATA_ERROR)
+    z->msg = "oversubscribed dynamic bit lengths tree";
+  else if (r == Z_BUF_ERROR)
+  {
+    inflate_trees_free(*tb, z);
+    z->msg = "incomplete dynamic bit lengths tree";
+    r = Z_DATA_ERROR;
+  }
+  return r;
+}
+
+
+local int inflate_trees_dynamic(nl, nd, c, bl, bd, tl, td, z)
+uInt nl;                /* number of literal/length codes */
+uInt nd;                /* number of distance codes */
+uIntf *c;               /* that many (total) code lengths */
+uIntf *bl;              /* literal desired/actual bit depth */
+uIntf *bd;              /* distance desired/actual bit depth */
+inflate_huft * FAR *tl; /* literal/length tree result */
+inflate_huft * FAR *td; /* distance tree result */
+z_stream *z;            /* for zfree function */
+{
+  int r;
+
+  /* build literal/length tree */
+  if ((r = huft_build(c, nl, 257, cplens, cplext, tl, bl, z)) != Z_OK)
+  {
+    if (r == Z_DATA_ERROR)
+      z->msg = "oversubscribed literal/length tree";
+    else if (r == Z_BUF_ERROR)
+    {
+      inflate_trees_free(*tl, z);
+      z->msg = "incomplete literal/length tree";
+      r = Z_DATA_ERROR;
+    }
+    return r;
+  }
+
+  /* build distance tree */
+  if ((r = huft_build(c + nl, nd, 0, cpdist, cpdext, td, bd, z)) != Z_OK)
+  {
+    if (r == Z_DATA_ERROR)
+      z->msg = "oversubscribed literal/length tree";
+    else if (r == Z_BUF_ERROR) {
+#ifdef PKZIP_BUG_WORKAROUND
+      r = Z_OK;
+    }
+#else
+      inflate_trees_free(*td, z);
+      z->msg = "incomplete literal/length tree";
+      r = Z_DATA_ERROR;
+    }
+    inflate_trees_free(*tl, z);
+    return r;
+#endif
+  }
+
+  /* done */
+  return Z_OK;
+}
+
+
+/* build fixed tables only once--keep them here */
+local int fixed_lock = 0;
+local int fixed_built = 0;
+#define FIXEDH 530      /* number of hufts used by fixed tables */
+local uInt fixed_left = FIXEDH;
+local inflate_huft fixed_mem[FIXEDH];
+local uInt fixed_bl;
+local uInt fixed_bd;
+local inflate_huft *fixed_tl;
+local inflate_huft *fixed_td;
+
+
+local voidpf falloc(q, n, s)
+voidpf q;        /* opaque pointer (not used) */
+uInt n;         /* number of items */
+uInt s;         /* size of item */
+{
+  Assert(s == sizeof(inflate_huft) && n <= fixed_left,
+         "inflate_trees falloc overflow");
+  if (q) s++; /* to make some compilers happy */
+  fixed_left -= n;
+  return (voidpf)(fixed_mem + fixed_left);
+}
+
+
+local void ffree(q, p, n)
+voidpf q;
+voidpf p;
+uInt n;
+{
+  Assert(0, "inflate_trees ffree called!");
+  if (q) q = p; /* to make some compilers happy */
+}
+
+
+local int inflate_trees_fixed(bl, bd, tl, td)
+uIntf *bl;               /* literal desired/actual bit depth */
+uIntf *bd;               /* distance desired/actual bit depth */
+inflate_huft * FAR *tl;  /* literal/length tree result */
+inflate_huft * FAR *td;  /* distance tree result */
+{
+  /* build fixed tables if not built already--lock out other instances */
+  while (++fixed_lock > 1)
+    fixed_lock--;
+  if (!fixed_built)
+  {
+    int k;              /* temporary variable */
+    unsigned c[288];    /* length list for huft_build */
+    z_stream z;         /* for falloc function */
+
+    /* set up fake z_stream for memory routines */
+    z.zalloc = falloc;
+    z.zfree = ffree;
+    z.opaque = Z_NULL;
+
+    /* literal table */
+    for (k = 0; k < 144; k++)
+      c[k] = 8;
+    for (; k < 256; k++)
+      c[k] = 9;
+    for (; k < 280; k++)
+      c[k] = 7;
+    for (; k < 288; k++)
+      c[k] = 8;
+    fixed_bl = 7;
+    huft_build(c, 288, 257, cplens, cplext, &fixed_tl, &fixed_bl, &z);
+
+    /* distance table */
+    for (k = 0; k < 30; k++)
+      c[k] = 5;
+    fixed_bd = 5;
+    huft_build(c, 30, 0, cpdist, cpdext, &fixed_td, &fixed_bd, &z);
+
+    /* done */
+    fixed_built = 1;
+  }
+  fixed_lock--;
+  *bl = fixed_bl;
+  *bd = fixed_bd;
+  *tl = fixed_tl;
+  *td = fixed_td;
+  return Z_OK;
+}
+
+
+local int inflate_trees_free(t, z)
+inflate_huft *t;        /* table to free */
+z_stream *z;            /* for zfree function */
+/* Free the malloc'ed tables built by huft_build(), which makes a linked
+   list of the tables it made, with the links in a dummy first entry of
+   each table. */
+{
+  register inflate_huft *p, *q;
+
+  /* Go through linked list, freeing from the malloced (t[-1]) address. */
+  p = t;
+  while (p != Z_NULL)
+  {
+    q = (--p)->next;
+    ZFREE(z, p, p->word.Nalloc * sizeof(inflate_huft));
+    p = q;
+  } 
+  return Z_OK;
+}
+
+/*+++++*/
+/* infcodes.c -- process literals and length/distance pairs
+ * Copyright (C) 1995 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h 
+ */
+
+/* simplify the use of the inflate_huft type with some defines */
+#define base more.Base
+#define next more.Next
+#define exop word.what.Exop
+#define bits word.what.Bits
+
+/* inflate codes private state */
+struct inflate_codes_state {
+
+  /* mode */
+  enum {        /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
+      START,    /* x: set up for LEN */
+      LEN,      /* i: get length/literal/eob next */
+      LENEXT,   /* i: getting length extra (have base) */
+      DIST,     /* i: get distance next */
+      DISTEXT,  /* i: getting distance extra */
+      COPY,     /* o: copying bytes in window, waiting for space */
+      LIT,      /* o: got literal, waiting for output space */
+      WASH,     /* o: got eob, possibly still output waiting */
+      END,      /* x: got eob and all data flushed */
+      BADCODE}  /* x: got error */
+    mode;               /* current inflate_codes mode */
+
+  /* mode dependent information */
+  uInt len;
+  union {
+    struct {
+      inflate_huft *tree;       /* pointer into tree */
+      uInt need;                /* bits needed */
+    } code;             /* if LEN or DIST, where in tree */
+    uInt lit;           /* if LIT, literal */
+    struct {
+      uInt get;                 /* bits to get for extra */
+      uInt dist;                /* distance back to copy from */
+    } copy;             /* if EXT or COPY, where and how much */
+  } sub;                /* submode */
+
+  /* mode independent information */
+  Byte lbits;           /* ltree bits decoded per branch */
+  Byte dbits;           /* dtree bits decoder per branch */
+  inflate_huft *ltree;          /* literal/length/eob tree */
+  inflate_huft *dtree;          /* distance tree */
+
+};
+
+
+local inflate_codes_statef *inflate_codes_new(bl, bd, tl, td, z)
+uInt bl, bd;
+inflate_huft *tl, *td;
+z_stream *z;
+{
+  inflate_codes_statef *c;
+
+  if ((c = (inflate_codes_statef *)
+       ZALLOC(z,1,sizeof(struct inflate_codes_state))) != Z_NULL)
+  {
+    c->mode = START;
+    c->lbits = (Byte)bl;
+    c->dbits = (Byte)bd;
+    c->ltree = tl;
+    c->dtree = td;
+    Tracev((stderr, "inflate:       codes new\n"));
+  }
+  return c;
+}
+
+
+local int inflate_codes(s, z, r)
+inflate_blocks_statef *s;
+z_stream *z;
+int r;
+{
+  uInt j;               /* temporary storage */
+  inflate_huft *t;      /* temporary pointer */
+  uInt e;               /* extra bits or operation */
+  uLong b;              /* bit buffer */
+  uInt k;               /* bits in bit buffer */
+  Bytef *p;             /* input data pointer */
+  uInt n;               /* bytes available there */
+  Bytef *q;             /* output window write pointer */
+  uInt m;               /* bytes to end of window or read pointer */
+  Bytef *f;             /* pointer to copy strings from */
+  inflate_codes_statef *c = s->sub.decode.codes;  /* codes state */
+
+  /* copy input/output information to locals (UPDATE macro restores) */
+  LOAD
+
+  /* process input and output based on current state */
+  while (1) switch (c->mode)
+  {             /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
+    case START:         /* x: set up for LEN */
+#ifndef SLOW
+      if (m >= 258 && n >= 10)
+      {
+        UPDATE
+        r = inflate_fast(c->lbits, c->dbits, c->ltree, c->dtree, s, z);
+        LOAD
+        if (r != Z_OK)
+        {
+          c->mode = r == Z_STREAM_END ? WASH : BADCODE;
+          break;
+        }
+      }
+#endif /* !SLOW */
+      c->sub.code.need = c->lbits;
+      c->sub.code.tree = c->ltree;
+      c->mode = LEN;
+    case LEN:           /* i: get length/literal/eob next */
+      j = c->sub.code.need;
+      NEEDBITS(j)
+      t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
+      DUMPBITS(t->bits)
+      e = (uInt)(t->exop);
+      if (e == 0)               /* literal */
+      {
+        c->sub.lit = t->base;
+        Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
+                 "inflate:         literal '%c'\n" :
+                 "inflate:         literal 0x%02x\n", t->base));
+        c->mode = LIT;
+        break;
+      }
+      if (e & 16)               /* length */
+      {
+        c->sub.copy.get = e & 15;
+        c->len = t->base;
+        c->mode = LENEXT;
+        break;
+      }
+      if ((e & 64) == 0)        /* next table */
+      {
+        c->sub.code.need = e;
+        c->sub.code.tree = t->next;
+        break;
+      }
+      if (e & 32)               /* end of block */
+      {
+        Tracevv((stderr, "inflate:         end of block\n"));
+        c->mode = WASH;
+        break;
+      }
+      c->mode = BADCODE;        /* invalid code */
+      z->msg = "invalid literal/length code";
+      r = Z_DATA_ERROR;
+      LEAVE
+    case LENEXT:        /* i: getting length extra (have base) */
+      j = c->sub.copy.get;
+      NEEDBITS(j)
+      c->len += (uInt)b & inflate_mask[j];
+      DUMPBITS(j)
+      c->sub.code.need = c->dbits;
+      c->sub.code.tree = c->dtree;
+      Tracevv((stderr, "inflate:         length %u\n", c->len));
+      c->mode = DIST;
+    case DIST:          /* i: get distance next */
+      j = c->sub.code.need;
+      NEEDBITS(j)
+      t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
+      DUMPBITS(t->bits)
+      e = (uInt)(t->exop);
+      if (e & 16)               /* distance */
+      {
+        c->sub.copy.get = e & 15;
+        c->sub.copy.dist = t->base;
+        c->mode = DISTEXT;
+        break;
+      }
+      if ((e & 64) == 0)        /* next table */
+      {
+        c->sub.code.need = e;
+        c->sub.code.tree = t->next;
+        break;
+      }
+      c->mode = BADCODE;        /* invalid code */
+      z->msg = "invalid distance code";
+      r = Z_DATA_ERROR;
+      LEAVE
+    case DISTEXT:       /* i: getting distance extra */
+      j = c->sub.copy.get;
+      NEEDBITS(j)
+      c->sub.copy.dist += (uInt)b & inflate_mask[j];
+      DUMPBITS(j)
+      Tracevv((stderr, "inflate:         distance %u\n", c->sub.copy.dist));
+      c->mode = COPY;
+    case COPY:          /* o: copying bytes in window, waiting for space */
+#ifndef __TURBOC__ /* Turbo C bug for following expression */
+      f = (uInt)(q - s->window) < c->sub.copy.dist ?
+          s->end - (c->sub.copy.dist - (q - s->window)) :
+          q - c->sub.copy.dist;
+#else
+      f = q - c->sub.copy.dist;
+      if ((uInt)(q - s->window) < c->sub.copy.dist)
+        f = s->end - (c->sub.copy.dist - (q - s->window));
+#endif
+      while (c->len)
+      {
+        NEEDOUT
+        OUTBYTE(*f++)
+        if (f == s->end)
+          f = s->window;
+        c->len--;
+      }
+      c->mode = START;
+      break;
+    case LIT:           /* o: got literal, waiting for output space */
+      NEEDOUT
+      OUTBYTE(c->sub.lit)
+      c->mode = START;
+      break;
+    case WASH:          /* o: got eob, possibly more output */
+      FLUSH
+      if (s->read != s->write)
+        LEAVE
+      c->mode = END;
+    case END:
+      r = Z_STREAM_END;
+      LEAVE
+    case BADCODE:       /* x: got error */
+      r = Z_DATA_ERROR;
+      LEAVE
+    default:
+      r = Z_STREAM_ERROR;
+      LEAVE
+  }
+}
+
+
+local void inflate_codes_free(c, z)
+inflate_codes_statef *c;
+z_stream *z;
+{
+  ZFREE(z, c, sizeof(struct inflate_codes_state));
+  Tracev((stderr, "inflate:       codes free\n"));
+}
+
+/*+++++*/
+/* inflate_util.c -- data and routines common to blocks and codes
+ * Copyright (C) 1995 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h 
+ */
+
+/* copy as much as possible from the sliding window to the output area */
+local int inflate_flush(s, z, r)
+inflate_blocks_statef *s;
+z_stream *z;
+int r;
+{
+  uInt n;
+  Bytef *p, *q;
+
+  /* local copies of source and destination pointers */
+  p = z->next_out;
+  q = s->read;
+
+  /* compute number of bytes to copy as far as end of window */
+  n = (uInt)((q <= s->write ? s->write : s->end) - q);
+  if (n > z->avail_out) n = z->avail_out;
+  if (n && r == Z_BUF_ERROR) r = Z_OK;
+
+  /* update counters */
+  z->avail_out -= n;
+  z->total_out += n;
+
+  /* update check information */
+  if (s->checkfn != Z_NULL)
+    s->check = (*s->checkfn)(s->check, q, n);
+
+  /* copy as far as end of window */
+  if (p != NULL) {
+    zmemcpy(p, q, n);
+    p += n;
+  }
+  q += n;
+
+  /* see if more to copy at beginning of window */
+  if (q == s->end)
+  {
+    /* wrap pointers */
+    q = s->window;
+    if (s->write == s->end)
+      s->write = s->window;
+
+    /* compute bytes to copy */
+    n = (uInt)(s->write - q);
+    if (n > z->avail_out) n = z->avail_out;
+    if (n && r == Z_BUF_ERROR) r = Z_OK;
+
+    /* update counters */
+    z->avail_out -= n;
+    z->total_out += n;
+
+    /* update check information */
+    if (s->checkfn != Z_NULL)
+      s->check = (*s->checkfn)(s->check, q, n);
+
+    /* copy */
+    if (p != NULL) {
+      zmemcpy(p, q, n);
+      p += n;
+    }
+    q += n;
+  }
+
+  /* update pointers */
+  z->next_out = p;
+  s->read = q;
+
+  /* done */
+  return r;
+}
+
+
+/*+++++*/
+/* inffast.c -- process literals and length/distance pairs fast
+ * Copyright (C) 1995 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h 
+ */
+
+/* simplify the use of the inflate_huft type with some defines */
+#define base more.Base
+#define next more.Next
+#define exop word.what.Exop
+#define bits word.what.Bits
+
+/* macros for bit input with no checking and for returning unused bytes */
+#define GRABBITS(j) {while(k<(j)){b|=((uLong)NEXTBYTE)<<k;k+=8;}}
+#define UNGRAB {n+=(c=k>>3);p-=c;k&=7;}
+
+/* Called with number of bytes left to write in window at least 258
+   (the maximum string length) and number of input bytes available
+   at least ten.  The ten bytes are six bytes for the longest length/
+   distance pair plus four bytes for overloading the bit buffer. */
+
+local int inflate_fast(bl, bd, tl, td, s, z)
+uInt bl, bd;
+inflate_huft *tl, *td;
+inflate_blocks_statef *s;
+z_stream *z;
+{
+  inflate_huft *t;      /* temporary pointer */
+  uInt e;               /* extra bits or operation */
+  uLong b;              /* bit buffer */
+  uInt k;               /* bits in bit buffer */
+  Bytef *p;             /* input data pointer */
+  uInt n;               /* bytes available there */
+  Bytef *q;             /* output window write pointer */
+  uInt m;               /* bytes to end of window or read pointer */
+  uInt ml;              /* mask for literal/length tree */
+  uInt md;              /* mask for distance tree */
+  uInt c;               /* bytes to copy */
+  uInt d;               /* distance back to copy from */
+  Bytef *r;             /* copy source pointer */
+
+  /* load input, output, bit values */
+  LOAD
+
+  /* initialize masks */
+  ml = inflate_mask[bl];
+  md = inflate_mask[bd];
+
+  /* do until not enough input or output space for fast loop */
+  do {                          /* assume called with m >= 258 && n >= 10 */
+    /* get literal/length code */
+    GRABBITS(20)                /* max bits for literal/length code */
+    if ((e = (t = tl + ((uInt)b & ml))->exop) == 0)
+    {
+      DUMPBITS(t->bits)
+      Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
+                "inflate:         * literal '%c'\n" :
+                "inflate:         * literal 0x%02x\n", t->base));
+      *q++ = (Byte)t->base;
+      m--;
+      continue;
+    }
+    do {
+      DUMPBITS(t->bits)
+      if (e & 16)
+      {
+        /* get extra bits for length */
+        e &= 15;
+        c = t->base + ((uInt)b & inflate_mask[e]);
+        DUMPBITS(e)
+        Tracevv((stderr, "inflate:         * length %u\n", c));
+
+        /* decode distance base of block to copy */
+        GRABBITS(15);           /* max bits for distance code */
+        e = (t = td + ((uInt)b & md))->exop;
+        do {
+          DUMPBITS(t->bits)
+          if (e & 16)
+          {
+            /* get extra bits to add to distance base */
+            e &= 15;
+            GRABBITS(e)         /* get extra bits (up to 13) */
+            d = t->base + ((uInt)b & inflate_mask[e]);
+            DUMPBITS(e)
+            Tracevv((stderr, "inflate:         * distance %u\n", d));
+
+            /* do the copy */
+            m -= c;
+            if ((uInt)(q - s->window) >= d)     /* offset before dest */
+            {                                   /*  just copy */
+              r = q - d;
+              *q++ = *r++;  c--;        /* minimum count is three, */
+              *q++ = *r++;  c--;        /*  so unroll loop a little */
+            }
+            else                        /* else offset after destination */
+            {
+              e = d - (q - s->window);  /* bytes from offset to end */
+              r = s->end - e;           /* pointer to offset */
+              if (c > e)                /* if source crosses, */
+              {
+                c -= e;                 /* copy to end of window */
+                do {
+                  *q++ = *r++;
+                } while (--e);
+                r = s->window;          /* copy rest from start of window */
+              }
+            }
+            do {                        /* copy all or what's left */
+              *q++ = *r++;
+            } while (--c);
+            break;
+          }
+          else if ((e & 64) == 0)
+            e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop;
+          else
+          {
+            z->msg = "invalid distance code";
+            UNGRAB
+            UPDATE
+            return Z_DATA_ERROR;
+          }
+        } while (1);
+        break;
+      }
+      if ((e & 64) == 0)
+      {
+        if ((e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop) == 0)
+        {
+          DUMPBITS(t->bits)
+          Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
+                    "inflate:         * literal '%c'\n" :
+                    "inflate:         * literal 0x%02x\n", t->base));
+          *q++ = (Byte)t->base;
+          m--;
+          break;
+        }
+      }
+      else if (e & 32)
+      {
+        Tracevv((stderr, "inflate:         * end of block\n"));
+        UNGRAB
+        UPDATE
+        return Z_STREAM_END;
+      }
+      else
+      {
+        z->msg = "invalid literal/length code";
+        UNGRAB
+        UPDATE
+        return Z_DATA_ERROR;
+      }
+    } while (1);
+  } while (m >= 258 && n >= 10);
+
+  /* not enough input or output--restore pointers and return */
+  UNGRAB
+  UPDATE
+  return Z_OK;
+}
+
+
+/*+++++*/
+/* zutil.c -- target dependent utility functions for the compression library
+ * Copyright (C) 1995 Jean-loup Gailly.
+ * For conditions of distribution and use, see copyright notice in zlib.h 
+ */
+
+/* From: zutil.c,v 1.8 1995/05/03 17:27:12 jloup Exp */
+
+char *zlib_version = ZLIB_VERSION;
+
+char *z_errmsg[] = {
+"stream end",          /* Z_STREAM_END    1 */
+"",                    /* Z_OK            0 */
+"file error",          /* Z_ERRNO        (-1) */
+"stream error",        /* Z_STREAM_ERROR (-2) */
+"data error",          /* Z_DATA_ERROR   (-3) */
+"insufficient memory", /* Z_MEM_ERROR    (-4) */
+"buffer error",        /* Z_BUF_ERROR    (-5) */
+""};
+
+
+/*+++++*/
+/* adler32.c -- compute the Adler-32 checksum of a data stream
+ * Copyright (C) 1995 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h 
+ */
+
+/* From: adler32.c,v 1.6 1995/05/03 17:27:08 jloup Exp */
+
+#define BASE 65521L /* largest prime smaller than 65536 */
+#define NMAX 5552
+/* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */
+
+#define DO1(buf)  {s1 += *buf++; s2 += s1;}
+#define DO2(buf)  DO1(buf); DO1(buf);
+#define DO4(buf)  DO2(buf); DO2(buf);
+#define DO8(buf)  DO4(buf); DO4(buf);
+#define DO16(buf) DO8(buf); DO8(buf);
+
+/* ========================================================================= */
+uLong adler32(adler, buf, len)
+    uLong adler;
+    Bytef *buf;
+    uInt len;
+{
+    unsigned long s1 = adler & 0xffff;
+    unsigned long s2 = (adler >> 16) & 0xffff;
+    int k;
+
+    if (buf == Z_NULL) return 1L;
+
+    while (len > 0) {
+        k = len < NMAX ? len : NMAX;
+        len -= k;
+        while (k >= 16) {
+            DO16(buf);
+            k -= 16;
+        }
+        if (k != 0) do {
+            DO1(buf);
+        } while (--k);
+        s1 %= BASE;
+        s2 %= BASE;
+    }
+    return (s2 << 16) | s1;
+}
diff --git a/sys/net/zlib.h b/sys/net/zlib.h
new file mode 100644
index 0000000..864698a
--- /dev/null
+++ b/sys/net/zlib.h
@@ -0,0 +1,643 @@
+/*	$Id: zlib.h,v 1.6 1997/05/22 06:44:40 paulus Exp $	*/
+
+/*
+ * This file is derived from zlib.h and zconf.h from the zlib-0.95
+ * distribution by Jean-loup Gailly and Mark Adler, with some additions
+ * by Paul Mackerras to aid in implementing Deflate compression and
+ * decompression for PPP packets.
+ */
+
+/*
+ *  ==FILEVERSION 970501==
+ *
+ * This marker is used by the Linux installation script to determine
+ * whether an up-to-date version of this file is already installed.
+ */
+
+/* zlib.h -- interface of the 'zlib' general purpose compression library
+  version 0.95, Aug 16th, 1995.
+
+  Copyright (C) 1995 Jean-loup Gailly and Mark Adler
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+
+  Jean-loup Gailly        Mark Adler
+  gzip@prep.ai.mit.edu    madler@alumni.caltech.edu
+ */
+
+#ifndef _ZLIB_H
+#define _ZLIB_H
+
+/* #include "zconf.h" */	/* included directly here */
+
+/* zconf.h -- configuration of the zlib compression library
+ * Copyright (C) 1995 Jean-loup Gailly.
+ * For conditions of distribution and use, see copyright notice in zlib.h 
+ */
+
+/* From: zconf.h,v 1.12 1995/05/03 17:27:12 jloup Exp */
+
+/*
+     The library does not install any signal handler. It is recommended to
+  add at least a handler for SIGSEGV when decompressing; the library checks
+  the consistency of the input data whenever possible but may go nuts
+  for some forms of corrupted input.
+ */
+
+/*
+ * Compile with -DMAXSEG_64K if the alloc function cannot allocate more
+ * than 64k bytes at a time (needed on systems with 16-bit int).
+ * Compile with -DUNALIGNED_OK if it is OK to access shorts or ints
+ * at addresses which are not a multiple of their size.
+ * Under DOS, -DFAR=far or -DFAR=__far may be needed.
+ */
+
+#ifndef STDC
+#  if defined(MSDOS) || defined(__STDC__) || defined(__cplusplus)
+#    define STDC
+#  endif
+#endif
+
+#ifdef	__MWERKS__ /* Metrowerks CodeWarrior declares fileno() in unix.h */
+#  include <unix.h>
+#endif
+
+/* Maximum value for memLevel in deflateInit2 */
+#ifndef MAX_MEM_LEVEL
+#  ifdef MAXSEG_64K
+#    define MAX_MEM_LEVEL 8
+#  else
+#    define MAX_MEM_LEVEL 9
+#  endif
+#endif
+
+#ifndef FAR
+#  define FAR
+#endif
+
+/* Maximum value for windowBits in deflateInit2 and inflateInit2 */
+#ifndef MAX_WBITS
+#  define MAX_WBITS   15 /* 32K LZ77 window */
+#endif
+
+/* The memory requirements for deflate are (in bytes):
+            1 << (windowBits+2)   +  1 << (memLevel+9)
+ that is: 128K for windowBits=15  +  128K for memLevel = 8  (default values)
+ plus a few kilobytes for small objects. For example, if you want to reduce
+ the default memory requirements from 256K to 128K, compile with
+     make CFLAGS="-O -DMAX_WBITS=14 -DMAX_MEM_LEVEL=7"
+ Of course this will generally degrade compression (there's no free lunch).
+
+   The memory requirements for inflate are (in bytes) 1 << windowBits
+ that is, 32K for windowBits=15 (default value) plus a few kilobytes
+ for small objects.
+*/
+
+                        /* Type declarations */
+
+#ifndef OF /* function prototypes */
+#  ifdef STDC
+#    define OF(args)  args
+#  else
+#    define OF(args)  ()
+#  endif
+#endif
+
+typedef unsigned char  Byte;  /* 8 bits */
+typedef unsigned int   uInt;  /* 16 bits or more */
+typedef unsigned long  uLong; /* 32 bits or more */
+
+typedef Byte FAR Bytef;
+typedef char FAR charf;
+typedef int FAR intf;
+typedef uInt FAR uIntf;
+typedef uLong FAR uLongf;
+
+#ifdef STDC
+   typedef void FAR *voidpf;
+   typedef void     *voidp;
+#else
+   typedef Byte FAR *voidpf;
+   typedef Byte     *voidp;
+#endif
+
+/* end of original zconf.h */
+
+#define ZLIB_VERSION "0.95P"
+
+/* 
+     The 'zlib' compression library provides in-memory compression and
+  decompression functions, including integrity checks of the uncompressed
+  data.  This version of the library supports only one compression method
+  (deflation) but other algorithms may be added later and will have the same
+  stream interface.
+
+     For compression the application must provide the output buffer and
+  may optionally provide the input buffer for optimization. For decompression,
+  the application must provide the input buffer and may optionally provide
+  the output buffer for optimization.
+
+     Compression can be done in a single step if the buffers are large
+  enough (for example if an input file is mmap'ed), or can be done by
+  repeated calls of the compression function.  In the latter case, the
+  application must provide more input and/or consume the output
+  (providing more output space) before each call.
+*/
+
+typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size));
+typedef void   (*free_func)  OF((voidpf opaque, voidpf address, uInt nbytes));
+
+struct internal_state;
+
+typedef struct z_stream_s {
+    Bytef    *next_in;  /* next input byte */
+    uInt     avail_in;  /* number of bytes available at next_in */
+    uLong    total_in;  /* total nb of input bytes read so far */
+
+    Bytef    *next_out; /* next output byte should be put there */
+    uInt     avail_out; /* remaining free space at next_out */
+    uLong    total_out; /* total nb of bytes output so far */
+
+    char     *msg;      /* last error message, NULL if no error */
+    struct internal_state FAR *state; /* not visible by applications */
+
+    alloc_func zalloc;  /* used to allocate the internal state */
+    alloc_func zalloc_init;  /* used to allocate the internal state during initialization */
+    free_func  zfree;   /* used to free the internal state */
+    voidp      opaque;  /* private data object passed to zalloc and zfree */
+
+    Byte     data_type; /* best guess about the data type: ascii or binary */
+
+} z_stream;
+
+/*
+   The application must update next_in and avail_in when avail_in has
+   dropped to zero. It must update next_out and avail_out when avail_out
+   has dropped to zero. The application must initialize zalloc, zfree and
+   opaque before calling the init function. All other fields are set by the
+   compression library and must not be updated by the application.
+
+   The opaque value provided by the application will be passed as the first
+   parameter for calls of zalloc and zfree. This can be useful for custom
+   memory management. The compression library attaches no meaning to the
+   opaque value.
+
+   zalloc must return Z_NULL if there is not enough memory for the object.
+   On 16-bit systems, the functions zalloc and zfree must be able to allocate
+   exactly 65536 bytes, but will not be required to allocate more than this
+   if the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS,
+   pointers returned by zalloc for objects of exactly 65536 bytes *must*
+   have their offset normalized to zero. The default allocation function
+   provided by this library ensures this (see zutil.c). To reduce memory
+   requirements and avoid any allocation of 64K objects, at the expense of
+   compression ratio, compile the library with -DMAX_WBITS=14 (see zconf.h).
+
+   The fields total_in and total_out can be used for statistics or
+   progress reports. After compression, total_in holds the total size of
+   the uncompressed data and may be saved for use in the decompressor
+   (particularly if the decompressor wants to decompress everything in
+   a single step).
+*/
+
+                        /* constants */
+
+#define Z_NO_FLUSH      0
+#define Z_PARTIAL_FLUSH 1
+#define Z_FULL_FLUSH    2
+#define Z_SYNC_FLUSH    3 /* experimental: partial_flush + byte align */
+#define Z_FINISH        4
+#define Z_PACKET_FLUSH	5
+/* See deflate() below for the usage of these constants */
+
+#define Z_OK            0
+#define Z_STREAM_END    1
+#define Z_ERRNO        (-1)
+#define Z_STREAM_ERROR (-2)
+#define Z_DATA_ERROR   (-3)
+#define Z_MEM_ERROR    (-4)
+#define Z_BUF_ERROR    (-5)
+/* error codes for the compression/decompression functions */
+
+#define Z_BEST_SPEED             1
+#define Z_BEST_COMPRESSION       9
+#define Z_DEFAULT_COMPRESSION  (-1)
+/* compression levels */
+
+#define Z_FILTERED            1
+#define Z_HUFFMAN_ONLY        2
+#define Z_DEFAULT_STRATEGY    0
+
+#define Z_BINARY   0
+#define Z_ASCII    1
+#define Z_UNKNOWN  2
+/* Used to set the data_type field */
+
+#define Z_NULL  0  /* for initializing zalloc, zfree, opaque */
+
+extern char *zlib_version;
+/* The application can compare zlib_version and ZLIB_VERSION for consistency.
+   If the first character differs, the library code actually used is
+   not compatible with the zlib.h header file used by the application.
+ */
+
+                        /* basic functions */
+
+extern int deflateInit OF((z_stream *strm, int level));
+/* 
+     Initializes the internal stream state for compression. The fields
+   zalloc, zfree and opaque must be initialized before by the caller.
+   If zalloc and zfree are set to Z_NULL, deflateInit updates them to
+   use default allocation functions.
+
+     The compression level must be Z_DEFAULT_COMPRESSION, or between 1 and 9:
+   1 gives best speed, 9 gives best compression. Z_DEFAULT_COMPRESSION requests
+   a default compromise between speed and compression (currently equivalent
+   to level 6).
+
+     deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not
+   enough memory, Z_STREAM_ERROR if level is not a valid compression level.
+   msg is set to null if there is no error message.  deflateInit does not
+   perform any compression: this will be done by deflate().
+*/
+
+
+extern int deflate OF((z_stream *strm, int flush));
+/*
+  Performs one or both of the following actions:
+
+  - Compress more input starting at next_in and update next_in and avail_in
+    accordingly. If not all input can be processed (because there is not
+    enough room in the output buffer), next_in and avail_in are updated and
+    processing will resume at this point for the next call of deflate().
+
+  - Provide more output starting at next_out and update next_out and avail_out
+    accordingly. This action is forced if the parameter flush is non zero.
+    Forcing flush frequently degrades the compression ratio, so this parameter
+    should be set only when necessary (in interactive applications).
+    Some output may be provided even if flush is not set.
+
+  Before the call of deflate(), the application should ensure that at least
+  one of the actions is possible, by providing more input and/or consuming
+  more output, and updating avail_in or avail_out accordingly; avail_out
+  should never be zero before the call. The application can consume the
+  compressed output when it wants, for example when the output buffer is full
+  (avail_out == 0), or after each call of deflate().
+
+    If the parameter flush is set to Z_PARTIAL_FLUSH, the current compression
+  block is terminated and flushed to the output buffer so that the
+  decompressor can get all input data available so far. For method 9, a future
+  variant on method 8, the current block will be flushed but not terminated.
+  If flush is set to Z_FULL_FLUSH, the compression block is terminated, a
+  special marker is output and the compression dictionary is discarded; this
+  is useful to allow the decompressor to synchronize if one compressed block
+  has been damaged (see inflateSync below).  Flushing degrades compression and
+  so should be used only when necessary.  Using Z_FULL_FLUSH too often can
+  seriously degrade the compression. If deflate returns with avail_out == 0,
+  this function must be called again with the same value of the flush
+  parameter and more output space (updated avail_out), until the flush is
+  complete (deflate returns with non-zero avail_out).
+
+    If the parameter flush is set to Z_PACKET_FLUSH, the compression
+  block is terminated, and a zero-length stored block is output,
+  omitting the length bytes (the effect of this is that the 3-bit type
+  code 000 for a stored block is output, and the output is then
+  byte-aligned).  This is designed for use at the end of a PPP packet.
+  In addition, if the current compression block contains all the data
+  since the last Z_PACKET_FLUSH, it is never output as a stored block.
+  If the current compression block output as a static or dynamic block
+  would not be at least `minCompression' bytes smaller than the
+  original data, then nothing is output for that block.  (The type
+  code for the zero-length stored block is still output, resulting in
+  a single zero byte being output for the whole packet.)
+  `MinCompression' is a parameter to deflateInit2, or 0 if deflateInit
+  is used.
+
+    If the parameter flush is set to Z_FINISH, all pending input is processed,
+  all pending output is flushed and deflate returns with Z_STREAM_END if there
+  was enough output space; if deflate returns with Z_OK, this function must be
+  called again with Z_FINISH and more output space (updated avail_out) but no
+  more input data, until it returns with Z_STREAM_END or an error. After
+  deflate has returned Z_STREAM_END, the only possible operations on the
+  stream are deflateReset or deflateEnd.
+  
+    Z_FINISH can be used immediately after deflateInit if all the compression
+  is to be done in a single step. In this case, avail_out must be at least
+  0.1% larger than avail_in plus 12 bytes.  If deflate does not return
+  Z_STREAM_END, then it must be called again as described above.
+
+    deflate() may update data_type if it can make a good guess about
+  the input data type (Z_ASCII or Z_BINARY). In doubt, the data is considered
+  binary. This field is only for information purposes and does not affect
+  the compression algorithm in any manner.
+
+    deflate() returns Z_OK if some progress has been made (more input
+  processed or more output produced), Z_STREAM_END if all input has been
+  consumed and all output has been produced (only when flush is set to
+  Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example
+  if next_in or next_out was NULL), Z_BUF_ERROR if no progress is possible.
+*/
+
+
+extern int deflateEnd OF((z_stream *strm));
+/*
+     All dynamically allocated data structures for this stream are freed.
+   This function discards any unprocessed input and does not flush any
+   pending output.
+
+     deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the
+   stream state was inconsistent. In the error case, msg may be set
+   but then points to a static string (which must not be deallocated).
+*/
+
+
+extern int inflateInit OF((z_stream *strm));
+/* 
+     Initializes the internal stream state for decompression. The fields
+   zalloc and zfree must be initialized before by the caller.  If zalloc and
+   zfree are set to Z_NULL, inflateInit updates them to use default allocation
+   functions.
+
+     inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not
+   enough memory.  msg is set to null if there is no error message.
+   inflateInit does not perform any decompression: this will be done by
+   inflate().
+*/
+
+
+#if defined(__FreeBSD__) && (defined(KERNEL) || defined(_KERNEL))
+#define inflate	inflate_ppp	/* FreeBSD already has an inflate :-( */
+#endif
+
+extern int inflate OF((z_stream *strm, int flush));
+/*
+  Performs one or both of the following actions:
+
+  - Decompress more input starting at next_in and update next_in and avail_in
+    accordingly. If not all input can be processed (because there is not
+    enough room in the output buffer), next_in is updated and processing
+    will resume at this point for the next call of inflate().
+
+  - Provide more output starting at next_out and update next_out and avail_out
+    accordingly.  inflate() always provides as much output as possible
+    (until there is no more input data or no more space in the output buffer).
+
+  Before the call of inflate(), the application should ensure that at least
+  one of the actions is possible, by providing more input and/or consuming
+  more output, and updating the next_* and avail_* values accordingly.
+  The application can consume the uncompressed output when it wants, for
+  example when the output buffer is full (avail_out == 0), or after each
+  call of inflate().
+
+    If the parameter flush is set to Z_PARTIAL_FLUSH or Z_PACKET_FLUSH,
+  inflate flushes as much output as possible to the output buffer. The
+  flushing behavior of inflate is not specified for values of the flush
+  parameter other than Z_PARTIAL_FLUSH, Z_PACKET_FLUSH or Z_FINISH, but the
+  current implementation actually flushes as much output as possible
+  anyway.  For Z_PACKET_FLUSH, inflate checks that once all the input data
+  has been consumed, it is expecting to see the length field of a stored
+  block; if not, it returns Z_DATA_ERROR.
+
+    inflate() should normally be called until it returns Z_STREAM_END or an
+  error. However if all decompression is to be performed in a single step
+  (a single call of inflate), the parameter flush should be set to
+  Z_FINISH. In this case all pending input is processed and all pending
+  output is flushed; avail_out must be large enough to hold all the
+  uncompressed data. (The size of the uncompressed data may have been saved
+  by the compressor for this purpose.) The next operation on this stream must
+  be inflateEnd to deallocate the decompression state. The use of Z_FINISH
+  is never required, but can be used to inform inflate that a faster routine
+  may be used for the single inflate() call.
+
+    inflate() returns Z_OK if some progress has been made (more input
+  processed or more output produced), Z_STREAM_END if the end of the
+  compressed data has been reached and all uncompressed output has been
+  produced, Z_DATA_ERROR if the input data was corrupted, Z_STREAM_ERROR if
+  the stream structure was inconsistent (for example if next_in or next_out
+  was NULL), Z_MEM_ERROR if there was not enough memory, Z_BUF_ERROR if no
+  progress is possible or if there was not enough room in the output buffer
+  when Z_FINISH is used. In the Z_DATA_ERROR case, the application may then
+  call inflateSync to look for a good compression block.  */
+
+
+extern int inflateEnd OF((z_stream *strm));
+/*
+     All dynamically allocated data structures for this stream are freed.
+   This function discards any unprocessed input and does not flush any
+   pending output.
+
+     inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state
+   was inconsistent. In the error case, msg may be set but then points to a
+   static string (which must not be deallocated).
+*/
+
+                        /* advanced functions */
+
+/*
+    The following functions are needed only in some special applications.
+*/
+
+extern int deflateInit2 OF((z_stream *strm,
+                            int  level,
+                            int  method,
+                            int  windowBits,
+                            int  memLevel,
+                            int  strategy,
+			    int  minCompression));
+/*   
+     This is another version of deflateInit with more compression options. The
+   fields next_in, zalloc and zfree must be initialized before by the caller.
+
+     The method parameter is the compression method. It must be 8 in this
+   version of the library. (Method 9 will allow a 64K history buffer and
+   partial block flushes.)
+
+     The windowBits parameter is the base two logarithm of the window size
+   (the size of the history buffer).  It should be in the range 8..15 for this
+   version of the library (the value 16 will be allowed for method 9). Larger
+   values of this parameter result in better compression at the expense of
+   memory usage. The default value is 15 if deflateInit is used instead.
+
+    The memLevel parameter specifies how much memory should be allocated
+   for the internal compression state. memLevel=1 uses minimum memory but
+   is slow and reduces compression ratio; memLevel=9 uses maximum memory
+   for optimal speed. The default value is 8. See zconf.h for total memory
+   usage as a function of windowBits and memLevel.
+
+     The strategy parameter is used to tune the compression algorithm. Use
+   the value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data
+   produced by a filter (or predictor), or Z_HUFFMAN_ONLY to force Huffman
+   encoding only (no string match).  Filtered data consists mostly of small
+   values with a somewhat random distribution. In this case, the
+   compression algorithm is tuned to compress them better. The strategy
+   parameter only affects the compression ratio but not the correctness of
+   the compressed output even if it is not set appropriately.
+
+     The minCompression parameter specifies the minimum reduction in size
+   required for a compressed block to be output when Z_PACKET_FLUSH is
+   used (see the description of deflate above).
+
+     If next_in is not null, the library will use this buffer to hold also
+   some history information; the buffer must either hold the entire input
+   data, or have at least 1<<(windowBits+1) bytes and be writable. If next_in
+   is null, the library will allocate its own history buffer (and leave next_in
+   null). next_out need not be provided here but must be provided by the
+   application for the next call of deflate().
+
+     If the history buffer is provided by the application, next_in must
+   must never be changed by the application since the compressor maintains
+   information inside this buffer from call to call; the application
+   must provide more input only by increasing avail_in. next_in is always
+   reset by the library in this case.
+
+      deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was
+   not enough memory, Z_STREAM_ERROR if a parameter is invalid (such as
+   an invalid method). msg is set to null if there is no error message.
+   deflateInit2 does not perform any compression: this will be done by
+   deflate().
+*/
+                            
+extern int deflateCopy OF((z_stream *dest,
+                           z_stream *source));
+/*
+     Sets the destination stream as a complete copy of the source stream.  If
+   the source stream is using an application-supplied history buffer, a new
+   buffer is allocated for the destination stream.  The compressed output
+   buffer is always application-supplied. It's the responsibility of the
+   application to provide the correct values of next_out and avail_out for the
+   next call of deflate.
+
+     This function is useful when several compression strategies will be
+   tried, for example when there are several ways of pre-processing the input
+   data with a filter. The streams that will be discarded should then be freed
+   by calling deflateEnd.  Note that deflateCopy duplicates the internal
+   compression state which can be quite large, so this strategy is slow and
+   can consume lots of memory.
+
+      deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
+   enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
+   (such as zalloc being NULL). msg is left unchanged in both source and
+   destination.
+*/
+
+extern int deflateReset OF((z_stream *strm));
+/*
+     This function is equivalent to deflateEnd followed by deflateInit,
+   but does not free and reallocate all the internal compression state.
+   The stream will keep the same compression level and any other attributes
+   that may have been set by deflateInit2.
+
+      deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
+   stream state was inconsistent (such as zalloc or state being NULL).
+*/
+
+extern int inflateInit2 OF((z_stream *strm,
+                            int  windowBits));
+/*   
+     This is another version of inflateInit with more compression options. The
+   fields next_out, zalloc and zfree must be initialized before by the caller.
+
+     The windowBits parameter is the base two logarithm of the maximum window
+   size (the size of the history buffer).  It should be in the range 8..15 for
+   this version of the library (the value 16 will be allowed soon). The
+   default value is 15 if inflateInit is used instead. If a compressed stream
+   with a larger window size is given as input, inflate() will return with
+   the error code Z_DATA_ERROR instead of trying to allocate a larger window.
+
+     If next_out is not null, the library will use this buffer for the history
+   buffer; the buffer must either be large enough to hold the entire output
+   data, or have at least 1<<windowBits bytes.  If next_out is null, the
+   library will allocate its own buffer (and leave next_out null). next_in
+   need not be provided here but must be provided by the application for the
+   next call of inflate().
+
+     If the history buffer is provided by the application, next_out must
+   never be changed by the application since the decompressor maintains
+   history information inside this buffer from call to call; the application
+   can only reset next_out to the beginning of the history buffer when
+   avail_out is zero and all output has been consumed.
+
+      inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was
+   not enough memory, Z_STREAM_ERROR if a parameter is invalid (such as
+   windowBits < 8). msg is set to null if there is no error message.
+   inflateInit2 does not perform any decompression: this will be done by
+   inflate().
+*/
+
+extern int inflateSync OF((z_stream *strm));
+/* 
+    Skips invalid compressed data until the special marker (see deflate()
+  above) can be found, or until all available input is skipped. No output
+  is provided.
+
+    inflateSync returns Z_OK if the special marker has been found, Z_BUF_ERROR
+  if no more input was provided, Z_DATA_ERROR if no marker has been found,
+  or Z_STREAM_ERROR if the stream structure was inconsistent. In the success
+  case, the application may save the current current value of total_in which
+  indicates where valid compressed data was found. In the error case, the
+  application may repeatedly call inflateSync, providing more input each time,
+  until success or end of the input data.
+*/
+
+extern int inflateReset OF((z_stream *strm));
+/*
+     This function is equivalent to inflateEnd followed by inflateInit,
+   but does not free and reallocate all the internal decompression state.
+   The stream will keep attributes that may have been set by inflateInit2.
+
+      inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
+   stream state was inconsistent (such as zalloc or state being NULL).
+*/
+
+extern int inflateIncomp OF((z_stream *strm));
+/*
+     This function adds the data at next_in (avail_in bytes) to the output
+   history without performing any output.  There must be no pending output,
+   and the decompressor must be expecting to see the start of a block.
+   Calling this function is equivalent to decompressing a stored block
+   containing the data at next_in (except that the data is not output).
+*/
+
+                        /* checksum functions */
+
+/*
+     This function is not related to compression but is exported
+   anyway because it might be useful in applications using the
+   compression library.
+*/
+
+extern uLong adler32 OF((uLong adler, Bytef *buf, uInt len));
+
+/*
+     Update a running Adler-32 checksum with the bytes buf[0..len-1] and
+   return the updated checksum. If buf is NULL, this function returns
+   the required initial value for the checksum.
+   An Adler-32 checksum is almost as reliable as a CRC32 but can be computed
+   much faster. Usage example:
+
+     uLong adler = adler32(0L, Z_NULL, 0);
+
+     while (read_buffer(buffer, length) != EOF) {
+       adler = adler32(adler, buffer, length);
+     }
+     if (adler != original_adler) error();
+*/
+
+#ifndef _Z_UTIL_H
+    struct internal_state {int dummy;}; /* hack for buggy compilers */
+#endif
+
+#endif /* _ZLIB_H */