Gzip 1.1

1 files changed, 369 insertions, 0 deletions

diff --git a/gnu/usr.bin/gzip/unlzw.c b/gnu/usr.bin/gzip/unlzw.c
new file mode 100644
index 0000000..0687c1b
--- /dev/null
+++ b/gnu/usr.bin/gzip/unlzw.c
@@ -0,0 +1,369 @@
+/* unlzw.c -- decompress files in LZW format.
+ * The code in this file is directly derived from the public domain 'compress'
+ * written by Spencer Thomas, Joe Orost, James Woods, Jim McKie, Steve Davies,
+ * Ken Turkowski, Dave Mack and Peter Jannesen.
+ *
+ * This is a temporary version which will be rewritten in some future version
+ * to accommodate in-memory decompression.
+ */
+
+#ifndef lint
+static char rcsid[] = "$Id: unlzw.c,v 0.13 1993/05/27 10:32:55 jloup Exp $";
+#endif
+
+#include <stdio.h>
+#include <sys/types.h>
+
+#include "tailor.h"
+
+#ifdef HAVE_UNISTD_H
+#  include <unistd.h>
+#endif
+#ifndef NO_FCNTL_H
+#  include <fcntl.h>
+#endif
+
+#include "gzip.h"
+#include "lzw.h"
+
+typedef	unsigned char	char_type;
+typedef          long   code_int;
+typedef unsigned long 	count_int;
+typedef unsigned short	count_short;
+typedef unsigned long 	cmp_code_int;
+
+#define MAXCODE(n)	(1L << (n))
+    
+#ifndef	REGISTERS
+#	define	REGISTERS	2
+#endif
+#define	REG1	
+#define	REG2	
+#define	REG3	
+#define	REG4	
+#define	REG5	
+#define	REG6	
+#define	REG7	
+#define	REG8	
+#define	REG9	
+#define	REG10
+#define	REG11	
+#define	REG12	
+#define	REG13
+#define	REG14
+#define	REG15
+#define	REG16
+#if REGISTERS >= 1
+#	undef	REG1
+#	define	REG1	register
+#endif
+#if REGISTERS >= 2
+#	undef	REG2
+#	define	REG2	register
+#endif
+#if REGISTERS >= 3
+#	undef	REG3
+#	define	REG3	register
+#endif
+#if REGISTERS >= 4
+#	undef	REG4
+#	define	REG4	register
+#endif
+#if REGISTERS >= 5
+#	undef	REG5
+#	define	REG5	register
+#endif
+#if REGISTERS >= 6
+#	undef	REG6
+#	define	REG6	register
+#endif
+#if REGISTERS >= 7
+#	undef	REG7
+#	define	REG7	register
+#endif
+#if REGISTERS >= 8
+#	undef	REG8
+#	define	REG8	register
+#endif
+#if REGISTERS >= 9
+#	undef	REG9
+#	define	REG9	register
+#endif
+#if REGISTERS >= 10
+#	undef	REG10
+#	define	REG10	register
+#endif
+#if REGISTERS >= 11
+#	undef	REG11
+#	define	REG11	register
+#endif
+#if REGISTERS >= 12
+#	undef	REG12
+#	define	REG12	register
+#endif
+#if REGISTERS >= 13
+#	undef	REG13
+#	define	REG13	register
+#endif
+#if REGISTERS >= 14
+#	undef	REG14
+#	define	REG14	register
+#endif
+#if REGISTERS >= 15
+#	undef	REG15
+#	define	REG15	register
+#endif
+#if REGISTERS >= 16
+#	undef	REG16
+#	define	REG16	register
+#endif
+    
+#ifndef	BYTEORDER
+#	define	BYTEORDER	0000
+#endif
+	
+#ifndef	NOALLIGN
+#	define	NOALLIGN	0
+#endif
+
+
+union	bytes {
+    long  word;
+    struct {
+#if BYTEORDER == 4321
+	char_type	b1;
+	char_type	b2;
+	char_type	b3;
+	char_type	b4;
+#else
+#if BYTEORDER == 1234
+	char_type	b4;
+	char_type	b3;
+	char_type	b2;
+	char_type	b1;
+#else
+#	undef	BYTEORDER
+	int  dummy;
+#endif
+#endif
+    } bytes;
+};
+
+#if BYTEORDER == 4321 && NOALLIGN == 1
+#  define input(b,o,c,n,m){ \
+     (c) = (*(long *)(&(b)[(o)>>3])>>((o)&0x7))&(m); \
+     (o) += (n); \
+   }
+#else
+#  define input(b,o,c,n,m){ \
+     REG1 char_type *p = &(b)[(o)>>3]; \
+     (c) = ((((long)(p[0]))|((long)(p[1])<<8)| \
+     ((long)(p[2])<<16))>>((o)&0x7))&(m); \
+     (o) += (n); \
+   }
+#endif
+
+#ifndef MAXSEG_64K
+   /* DECLARE(ush, tab_prefix, (1<<BITS)); -- prefix code */
+#  define tab_prefixof(i) tab_prefix[i]
+#  define clear_tab_prefixof()	memzero(tab_prefix, 256);
+#else
+   /* DECLARE(ush, tab_prefix0, (1<<(BITS-1)); -- prefix for even codes */
+   /* DECLARE(ush, tab_prefix1, (1<<(BITS-1)); -- prefix for odd  codes */
+   ush *tab_prefix[2];
+#  define tab_prefixof(i) tab_prefix[(i)&1][(i)>>1]
+#  define clear_tab_prefixof()	\
+      memzero(tab_prefix0, 128), \
+      memzero(tab_prefix1, 128);
+#endif
+#define de_stack        ((char_type *)(&d_buf[DIST_BUFSIZE-1]))
+#define tab_suffixof(i) tab_suffix[i]
+
+int block_mode = BLOCK_MODE; /* block compress mode -C compatible with 2.0 */
+
+/* ============================================================================
+ * Decompress in to out.  This routine adapts to the codes in the
+ * file building the "string" table on-the-fly; requiring no table to
+ * be stored in the compressed file.
+ * IN assertions: the buffer inbuf contains already the beginning of
+ *   the compressed data, from offsets iptr to insize-1 included.
+ *   The magic header has already been checked and skipped.
+ *   bytes_in and bytes_out have been initialized.
+ */
+int unlzw(in, out) 
+    int in, out;    /* input and output file descriptors */
+{
+    REG2   char_type  *stackp;
+    REG3   code_int   code;
+    REG4   int        finchar;
+    REG5   code_int   oldcode;
+    REG6   code_int   incode;
+    REG7   long       inbits;
+    REG8   long       posbits;
+    REG9   int        outpos;
+/*  REG10  int        insize; (global) */
+    REG11  unsigned   bitmask;
+    REG12  code_int   free_ent;
+    REG13  code_int   maxcode;
+    REG14  code_int   maxmaxcode;
+    REG15  int        n_bits;
+    REG16  int        rsize;
+    
+#ifdef MAXSEG_64K
+    tab_prefix[0] = tab_prefix0;
+    tab_prefix[1] = tab_prefix1;
+#endif
+    maxbits = get_byte();
+    block_mode = maxbits & BLOCK_MODE;
+    if ((maxbits & LZW_RESERVED) != 0) {
+	WARN((stderr, "\n%s: %s: warning, unknown flags 0x%x\n",
+	      progname, ifname, maxbits & LZW_RESERVED));
+    }
+    maxbits &= BIT_MASK;
+    maxmaxcode = MAXCODE(maxbits);
+    
+    if (maxbits > BITS) {
+	fprintf(stderr,
+		"\n%s: %s: compressed with %d bits, can only handle %d bits\n",
+		progname, ifname, maxbits, BITS);
+	exit_code = ERROR;
+	return ERROR;
+    }
+    rsize = insize;
+    maxcode = MAXCODE(n_bits = INIT_BITS)-1;
+    bitmask = (1<<n_bits)-1;
+    oldcode = -1;
+    finchar = 0;
+    outpos = 0;
+    posbits = inptr<<3;
+
+    free_ent = ((block_mode) ? FIRST : 256);
+    
+    clear_tab_prefixof(); /* Initialize the first 256 entries in the table. */
+    
+    for (code = 255 ; code >= 0 ; --code) {
+	tab_suffixof(code) = (char_type)code;
+    }
+    do {
+	REG1 int i;
+	int  e;
+	int  o;
+	
+    resetbuf:
+	e = insize-(o = (posbits>>3));
+	
+	for (i = 0 ; i < e ; ++i) {
+	    inbuf[i] = inbuf[i+o];
+	}
+	insize = e;
+	posbits = 0;
+	
+	if (insize < INBUF_EXTRA) {
+	    if ((rsize = read(in, (char*)inbuf+insize, INBUFSIZ)) == EOF) {
+		read_error();
+	    }
+	    insize += rsize;
+	}
+	inbits = ((rsize != 0) ? ((long)insize - insize%n_bits)<<3 : 
+		  ((long)insize<<3)-(n_bits-1));
+	
+	while (inbits > posbits) {
+	    if (free_ent > maxcode) {
+		posbits = ((posbits-1) +
+			   ((n_bits<<3)-(posbits-1+(n_bits<<3))%(n_bits<<3)));
+		++n_bits;
+		if (n_bits == maxbits) {
+		    maxcode = maxmaxcode;
+		} else {
+		    maxcode = MAXCODE(n_bits)-1;
+		}
+		bitmask = (1<<n_bits)-1;
+		goto resetbuf;
+	    }
+	    input(inbuf,posbits,code,n_bits,bitmask);
+	    
+	    if (oldcode == -1) {
+		outbuf[outpos++] = (char_type)(finchar = (int)(oldcode=code));
+		continue;
+	    }
+	    if (code == CLEAR && block_mode) {
+		clear_tab_prefixof();
+		free_ent = FIRST - 1;
+		posbits = ((posbits-1) +
+			   ((n_bits<<3)-(posbits-1+(n_bits<<3))%(n_bits<<3)));
+		maxcode = MAXCODE(n_bits = INIT_BITS)-1;
+		bitmask = (1<<n_bits)-1;
+		goto resetbuf;
+	    }
+	    incode = code;
+	    stackp = de_stack;
+	    
+	    if (code >= free_ent) { /* Special case for KwKwK string. */
+		if (code > free_ent) {
+#ifdef DEBUG		    
+		    char_type *p;
+
+		    posbits -= n_bits;
+		    p = &inbuf[posbits>>3];
+		    fprintf(stderr,
+			    "code:%ld free_ent:%ld n_bits:%d insize:%u\n",
+			    code, free_ent, n_bits, insize);
+		    fprintf(stderr,
+			    "posbits:%ld inbuf:%02X %02X %02X %02X %02X\n",
+			    posbits, p[-1],p[0],p[1],p[2],p[3]);
+#endif
+		    if (!test && outpos > 0) {
+			write_buf(out, outbuf, outpos);
+		    }
+		    error("corrupt input. Use zcat to recover some data.");
+		}
+		*--stackp = (char_type)finchar;
+		code = oldcode;
+	    }
+
+	    while ((cmp_code_int)code >= (cmp_code_int)256) {
+		/* Generate output characters in reverse order */
+		*--stackp = tab_suffixof(code);
+		code = tab_prefixof(code);
+	    }
+	    *--stackp =	(char_type)(finchar = tab_suffixof(code));
+	    
+	    /* And put them out in forward order */
+	    {
+		REG1 int	i;
+	    
+		if (outpos+(i = (de_stack-stackp)) >= OUTBUFSIZ) {
+		    do {
+			if (i > OUTBUFSIZ-outpos) i = OUTBUFSIZ-outpos;
+
+			if (i > 0) {
+			    memcpy(outbuf+outpos, stackp, i);
+			    outpos += i;
+			}
+			if (outpos >= OUTBUFSIZ) {
+			    if (!test) write_buf(out, outbuf, outpos);
+			    outpos = 0;
+			}
+			stackp+= i;
+		    } while ((i = (de_stack-stackp)) > 0);
+		} else {
+		    memcpy(outbuf+outpos, stackp, i);
+		    outpos += i;
+		}
+	    }
+
+	    if ((code = free_ent) < maxmaxcode) { /* Generate the new entry. */
+
+		tab_prefixof(code) = (unsigned short)oldcode;
+		tab_suffixof(code) = (char_type)finchar;
+		free_ent = code+1;
+	    } 
+	    oldcode = incode;	/* Remember previous code.	*/
+	}
+	bytes_in += rsize;
+
+    } while (rsize != 0);
+    
+    if (!test && outpos > 0) write_buf(out, outbuf, outpos);
+    return OK;
+}