diff options
Diffstat (limited to 'trees.c')
| -rw-r--r-- | trees.c | 220 |
1 files changed, 3 insertions, 217 deletions
@@ -32,42 +32,15 @@ /* @(#) $Id$ */ -/* #define GEN_TREES_H */ - #include "zbuild.h" #include "deflate.h" +#include "trees_p.h" +#include "trees.h" #ifdef ZLIB_DEBUG # include <ctype.h> #endif -/* =========================================================================== - * Constants - */ - -#define MAX_BL_BITS 7 -/* Bit length codes must not exceed MAX_BL_BITS bits */ - -#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) */ - -static 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}; - -static 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}; - -static 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}; - -static const unsigned char 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. */ @@ -76,42 +49,6 @@ static const unsigned char 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) -/* non ANSI compilers may not accept trees.h */ - -ZLIB_INTERNAL 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 zng_tr_init - * below). - */ - -static ct_data static_dtree[D_CODES]; -/* The static distance tree. (Actually a trivial tree since all codes use - * 5 bits.) - */ - -unsigned char zng_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. - */ - -unsigned char zng_length_code[MAX_MATCH-MIN_MATCH+1]; -/* length code for each normalized match length (0 == MIN_MATCH) */ - -static int base_length[LENGTH_CODES]; -/* First normalized length for each code (0 = MIN_MATCH) */ - -static 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 { const ct_data *static_tree; /* static tree or NULL */ const int *extra_bits; /* extra bits for each code or NULL */ @@ -133,11 +70,9 @@ static const static_tree_desc static_bl_desc = * Local (static) routines in this file. */ -static void tr_static_init (void); static void init_block (deflate_state *s); static void pqdownheap (deflate_state *s, ct_data *tree, int k); static void gen_bitlen (deflate_state *s, tree_desc *desc); -static void gen_codes (ct_data *tree, int max_code, uint16_t *bl_count); static void build_tree (deflate_state *s, tree_desc *desc); static void scan_tree (deflate_state *s, ct_data *tree, int max_code); static void send_tree (deflate_state *s, ct_data *tree, int max_code); @@ -147,159 +82,10 @@ static void compress_block (deflate_state *s, const ct_data *ltree, const ct_d static int detect_data_type (deflate_state *s); static void bi_flush (deflate_state *s); -#ifdef GEN_TREES_H -static void gen_trees_header (void); -#endif - -/* =========================================================================== - * Initialize the various 'constant' tables. - */ -static void tr_static_init(void) { -#if defined(GEN_TREES_H) - static int static_init_done = 0; - int n; /* iterates over tree elements */ - int bits; /* bit counter */ - int length; /* length value */ - int code; /* code value */ - int dist; /* distance index */ - uint16_t bl_count[MAX_BITS+1]; - /* number of codes at each bit length for an optimal tree */ - - if (static_init_done) - return; - - /* For some embedded targets, global variables are not initialized: */ -#ifdef NO_INIT_GLOBAL_POINTERS - static_l_desc.static_tree = static_ltree; - static_l_desc.extra_bits = extra_lbits; - static_d_desc.static_tree = static_dtree; - static_d_desc.extra_bits = extra_dbits; - static_bl_desc.extra_bits = extra_blbits; -#endif - - /* 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++) { - zng_length_code[length++] = (unsigned char)code; - } - } - Assert(length == 256, "tr_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: - */ - zng_length_code[length-1] = (unsigned char)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++) { - zng_dist_code[dist++] = (unsigned char)code; - } - } - Assert(dist == 256, "tr_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++) { - zng_dist_code[256 + dist++] = (unsigned char)code; - } - } - Assert(dist == 256, "tr_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((unsigned)n, 5); - } - static_init_done = 1; - -# ifdef GEN_TREES_H - gen_trees_header(); -# endif -#endif /* defined(GEN_TREES_H) */ -} - -/* =========================================================================== - * Genererate the file trees.h describing the static trees. - */ -#ifdef GEN_TREES_H -# ifndef ZLIB_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, "#ifndef TREES_H_\n"); - fprintf(header, "#define TREES_H_\n\n"); - - fprintf(header, "/* header created automatically with -DGEN_TREES_H */\n\n"); - - fprintf(header, "ZLIB_INTERNAL 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, "static 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 unsigned char ZLIB_INTERNAL zng_dist_code[DIST_CODE_LEN] = {\n"); - for (i = 0; i < DIST_CODE_LEN; i++) { - fprintf(header, "%2u%s", zng_dist_code[i], SEPARATOR(i, DIST_CODE_LEN-1, 20)); - } - - fprintf(header, "const unsigned char ZLIB_INTERNAL zng_length_code[MAX_MATCH-MIN_MATCH+1]= {\n"); - for (i = 0; i < MAX_MATCH-MIN_MATCH+1; i++) { - fprintf(header, "%2u%s", zng_length_code[i], SEPARATOR(i, MAX_MATCH-MIN_MATCH, 20)); - } - - fprintf(header, "static const int base_length[LENGTH_CODES] = {\n"); - for (i = 0; i < LENGTH_CODES; i++) { - fprintf(header, "%d%s", base_length[i], SEPARATOR(i, LENGTH_CODES-1, 20)); - } - - fprintf(header, "static const int base_dist[D_CODES] = {\n"); - for (i = 0; i < D_CODES; i++) { - fprintf(header, "%5d%s", base_dist[i], SEPARATOR(i, D_CODES-1, 10)); - } - - fprintf(header, "#endif /* TREES_H_ */\n"); - fclose(header); -} -#endif /* GEN_TREES_H */ - /* =========================================================================== * Initialize the tree data structures for a new zlib stream. */ void ZLIB_INTERNAL zng_tr_init(deflate_state *s) { - tr_static_init(); - s->l_desc.dyn_tree = s->dyn_ltree; s->l_desc.stat_desc = &static_l_desc; @@ -495,7 +281,7 @@ static void gen_bitlen(deflate_state *s, tree_desc *desc) { * OUT assertion: the field code is set for all tree elements of non * zero code length. */ -static void gen_codes(ct_data *tree, int max_code, uint16_t *bl_count) { +ZLIB_INTERNAL void gen_codes(ct_data *tree, int max_code, uint16_t *bl_count) { /* tree: the tree to decorate */ /* max_code: largest code with non zero frequency */ /* bl_count: number of codes at each bit length */ |