diff options
Diffstat (limited to 'lib/libz/trees.c')
-rw-r--r-- | lib/libz/trees.c | 151 |
1 files changed, 113 insertions, 38 deletions
diff --git a/lib/libz/trees.c b/lib/libz/trees.c index a5a8173..2497001 100644 --- a/lib/libz/trees.c +++ b/lib/libz/trees.c @@ -1,5 +1,5 @@ /* trees.c -- output deflated data using Huffman coding - * Copyright (C) 1995-1996 Jean-loup Gailly + * Copyright (C) 1995-1998 Jean-loup Gailly * For conditions of distribution and use, see copyright notice in zlib.h */ @@ -31,6 +31,8 @@ /* $FreeBSD$ */ +/* #define GEN_TREES_H */ + #include "deflate.h" #ifdef DEBUG @@ -56,16 +58,16 @@ #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 */ +local const 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 */ +local const 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 */ +local const 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] +local const 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. @@ -80,6 +82,11 @@ local uch bl_order[BL_CODES] * Local data. These are initialized only once. */ +#define DIST_CODE_LEN 512 /* see definition of array dist_code below */ + +#if defined(GEN_TREES_H) || !defined(STDC) +/* non ANSI compilers may not accept trees.h */ + 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 @@ -92,13 +99,13 @@ local ct_data static_dtree[D_CODES]; * 5 bits.) */ -local uch dist_code[512]; -/* distance codes. The first 256 values correspond to the distances +uch _dist_code[DIST_CODE_LEN]; +/* 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]; +uch _length_code[MAX_MATCH-MIN_MATCH+1]; /* length code for each normalized match length (0 == MIN_MATCH) */ local int base_length[LENGTH_CODES]; @@ -107,9 +114,13 @@ local int base_length[LENGTH_CODES]; local int base_dist[D_CODES]; /* First normalized distance for each code (0 = distance of 1) */ +#else +# include "trees.h" +#endif /* GEN_TREES_H */ + struct static_tree_desc_s { - ct_data *static_tree; /* static tree or NULL */ - intf *extra_bits; /* extra bits for each code or NULL */ + const ct_data *static_tree; /* static tree or NULL */ + const 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 */ @@ -122,7 +133,7 @@ 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}; +{(const ct_data *)0, extra_blbits, 0, BL_CODES, MAX_BL_BITS}; /* =========================================================================== * Local (static) routines in this file. @@ -148,23 +159,20 @@ local void bi_flush OF((deflate_state *s)); local void copy_block OF((deflate_state *s, charf *buf, unsigned len, int header)); +#ifdef GEN_TREES_H +local void gen_trees_header OF((void)); +#endif + #ifndef DEBUG # 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 */ # define send_code(s, c, tree) \ - { if (verbose>2) fprintf(stderr,"\ncd %3d ",(c)); \ + { if (z_verbose>2) 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. @@ -226,12 +234,11 @@ local void send_bits(s, value, length) /* the arguments must not have side effects */ /* =========================================================================== - * Initialize the various 'constant' tables. In a multi-threaded environment, - * this function may be called by two threads concurrently, but this is - * harmless since both invocations do exactly the same thing. + * Initialize the various 'constant' tables. */ local void tr_static_init() { +#if defined(GEN_TREES_H) || !defined(STDC) static int static_init_done = 0; int n; /* iterates over tree elements */ int bits; /* bit counter */ @@ -248,7 +255,7 @@ local void tr_static_init() 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; + _length_code[length++] = (uch)code; } } Assert (length == 256, "tr_static_init: length != 256"); @@ -256,14 +263,14 @@ local void tr_static_init() * 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; + _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; + _dist_code[dist++] = (uch)code; } } Assert (dist == 256, "tr_static_init: dist != 256"); @@ -271,7 +278,7 @@ local void tr_static_init() 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; + _dist_code[256 + dist++] = (uch)code; } } Assert (dist == 256, "tr_static_init: 256+dist != 512"); @@ -295,7 +302,73 @@ local void tr_static_init() static_dtree[n].Code = bi_reverse((unsigned)n, 5); } static_init_done = 1; + +# ifdef GEN_TREES_H + gen_trees_header(); +# endif +#endif /* defined(GEN_TREES_H) || !defined(STDC) */ +} + +/* =========================================================================== + * Genererate the file trees.h describing the static trees. + */ +#ifdef GEN_TREES_H +# ifndef DEBUG +# include <stdio.h> +# endif + +# define SEPARATOR(i, last, width) \ + ((i) == (last)? "\n};\n\n" : \ + ((i) % (width) == (width)-1 ? ",\n" : ", ")) + +void gen_trees_header() +{ + FILE *header = fopen("trees.h", "w"); + int i; + + Assert (header != NULL, "Can't open trees.h"); + fprintf(header, + "/* header created automatically with -DGEN_TREES_H */\n\n"); + + fprintf(header, "local const ct_data static_ltree[L_CODES+2] = {\n"); + for (i = 0; i < L_CODES+2; i++) { + fprintf(header, "{{%3u},{%3u}}%s", static_ltree[i].Code, + static_ltree[i].Len, SEPARATOR(i, L_CODES+1, 5)); + } + + fprintf(header, "local const ct_data static_dtree[D_CODES] = {\n"); + for (i = 0; i < D_CODES; i++) { + fprintf(header, "{{%2u},{%2u}}%s", static_dtree[i].Code, + static_dtree[i].Len, SEPARATOR(i, D_CODES-1, 5)); + } + + fprintf(header, "const uch _dist_code[DIST_CODE_LEN] = {\n"); + for (i = 0; i < DIST_CODE_LEN; i++) { + fprintf(header, "%2u%s", _dist_code[i], + SEPARATOR(i, DIST_CODE_LEN-1, 20)); + } + + fprintf(header, "const uch _length_code[MAX_MATCH-MIN_MATCH+1]= {\n"); + for (i = 0; i < MAX_MATCH-MIN_MATCH+1; i++) { + fprintf(header, "%2u%s", _length_code[i], + SEPARATOR(i, MAX_MATCH-MIN_MATCH, 20)); + } + + fprintf(header, "local const int base_length[LENGTH_CODES] = {\n"); + for (i = 0; i < LENGTH_CODES; i++) { + fprintf(header, "%1u%s", base_length[i], + SEPARATOR(i, LENGTH_CODES-1, 20)); + } + + fprintf(header, "local const int base_dist[D_CODES] = {\n"); + for (i = 0; i < D_CODES; i++) { + fprintf(header, "%5u%s", base_dist[i], + SEPARATOR(i, D_CODES-1, 10)); + } + + fclose(header); } +#endif /* GEN_TREES_H */ /* =========================================================================== * Initialize the tree data structures for a new zlib stream. @@ -413,12 +486,12 @@ 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; + ct_data *tree = desc->dyn_tree; + int max_code = desc->max_code; + const ct_data *stree = desc->stat_desc->static_tree; + const 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 */ @@ -542,9 +615,9 @@ 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; + ct_data *tree = desc->dyn_tree; + const 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 */ @@ -965,12 +1038,13 @@ int _tr_tally (s, dist, lc) (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) && (ush)d_code(dist) < (ush)D_CODES, "_tr_tally: bad match"); - s->dyn_ltree[length_code[lc]+LITERALS+1].Freq++; + s->dyn_ltree[_length_code[lc]+LITERALS+1].Freq++; s->dyn_dtree[d_code(dist)].Freq++; } +#ifdef TRUNCATE_BLOCK /* Try to guess if it is profitable to stop the current block here */ - if (s->level > 2 && (s->last_lit & 0xfff) == 0) { + if ((s->last_lit & 0x1fff) == 0 && s->level > 2) { /* Compute an upper bound for the compressed length */ ulg out_length = (ulg)s->last_lit*8L; ulg in_length = (ulg)((long)s->strstart - s->block_start); @@ -985,6 +1059,7 @@ int _tr_tally (s, dist, lc) 100L - out_length*100L/in_length)); if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1; } +#endif 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 @@ -1014,7 +1089,7 @@ local void compress_block(s, ltree, dtree) Tracecv(isgraph(lc), (stderr," '%c' ", lc)); } else { /* Here, lc is the match length - MIN_MATCH */ - code = length_code[lc]; + code = _length_code[lc]; send_code(s, code+LITERALS+1, ltree); /* send the length code */ extra = extra_lbits[code]; if (extra != 0) { |