diff options
Diffstat (limited to 'dep/src/zlib/trees.c')
| -rw-r--r-- | dep/src/zlib/trees.c | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/dep/src/zlib/trees.c b/dep/src/zlib/trees.c index 5e1908f51ff..395e4e16814 100644 --- a/dep/src/zlib/trees.c +++ b/dep/src/zlib/trees.c @@ -2,6 +2,7 @@ * Copyright (C) 1995-2005 Jean-loup Gailly * For conditions of distribution and use, see copyright notice in zlib.h */ + /* * ALGORITHM * @@ -27,70 +28,96 @@ * Algorithms, p290. * Addison-Wesley, 1983. ISBN 0-201-06672-6. */ + /* @(#) $Id$ */ + /* #define GEN_TREES_H */ + #include "deflate.h" + #ifdef DEBUG # 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 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 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 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 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. */ + #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. */ + #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 * The codes 286 and 287 are needed to build a canonical tree (see _tr_init * below). */ + local ct_data static_dtree[D_CODES]; /* The static distance tree. (Actually a trivial tree since all codes use * 5 bits.) */ + 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. */ + 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) */ + #else # include "trees.h" #endif /* GEN_TREES_H */ + struct static_tree_desc_s { const ct_data *static_tree; /* static tree or NULL */ const intf *extra_bits; /* extra bits for each code or NULL */ @@ -98,15 +125,20 @@ struct static_tree_desc_s { 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 = {(const ct_data *)0, extra_blbits, 0, BL_CODES, MAX_BL_BITS}; + /* =========================================================================== * Local (static) routines in this file. */ + local void tr_static_init OF((void)); local void init_block OF((deflate_state *s)); local void pqdownheap OF((deflate_state *s, ct_data *tree, int k)); @@ -126,17 +158,21 @@ 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)); + #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 (z_verbose>2) fprintf(stderr,"\ncd %3d ",(c)); \ send_bits(s, tree[c].Code, tree[c].Len); } #endif + /* =========================================================================== * Output a short LSB first on the stream. * IN assertion: there is enough room in pendingBuf. @@ -145,12 +181,14 @@ local void gen_trees_header OF((void)); 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 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 */ @@ -159,6 +197,7 @@ local void send_bits(s, value, length) Tracevv((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. @@ -174,6 +213,7 @@ local void send_bits(s, value, length) } } #else /* !DEBUG */ + #define send_bits(s, value, length) \ { int len = length;\ if (s->bi_valid > (int)Buf_size - len) {\ @@ -189,7 +229,9 @@ local void send_bits(s, value, length) } #endif /* DEBUG */ + /* the arguments must not have side effects */ + /* =========================================================================== * Initialize the various 'constant' tables. */ @@ -204,13 +246,16 @@ local void tr_static_init() int dist; /* distance index */ ush 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: */ 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; + /* Initialize the mapping length (0..255) -> length code (0..28) */ length = 0; for (code = 0; code < LENGTH_CODES-1; code++) { @@ -225,6 +270,7 @@ local void tr_static_init() * 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++) { @@ -242,6 +288,7 @@ local void tr_static_init() } } 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; @@ -254,17 +301,20 @@ local void tr_static_init() * 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) || !defined(STDC) */ } + /* =========================================================================== * Genererate the file trees.h describing the static trees. */ @@ -272,49 +322,60 @@ local void tr_static_init() # 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. */ @@ -322,12 +383,16 @@ void _tr_init(s) deflate_state *s; { tr_static_init(); + 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 */ @@ -335,9 +400,11 @@ void _tr_init(s) s->compressed_len = 0L; s->bits_sent = 0L; #endif + /* Initialize the first block of the first file: */ init_block(s); } + /* =========================================================================== * Initialize a new block. */ @@ -345,17 +412,21 @@ 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. @@ -366,6 +437,7 @@ local void init_block(s) 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. @@ -373,6 +445,7 @@ local void init_block(s) #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 @@ -394,13 +467,16 @@ local void pqdownheap(s, tree, k) } /* 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. @@ -427,18 +503,23 @@ local void gen_bitlen(s, desc) 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]; @@ -447,8 +528,10 @@ local void gen_bitlen(s, desc) 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; @@ -461,6 +544,7 @@ local void gen_bitlen(s, desc) */ 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 @@ -481,6 +565,7 @@ local void gen_bitlen(s, desc) } } } + /* =========================================================================== * Generate the codes for a given tree and bit counts (which need not be * optimal). @@ -498,6 +583,7 @@ local void gen_codes (tree, max_code, bl_count) 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. */ @@ -510,15 +596,18 @@ local void gen_codes (tree, max_code, bl_count) 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); + Tracecv(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. @@ -537,11 +626,13 @@ local void build_tree(s, desc) 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; @@ -550,6 +641,7 @@ local void build_tree(s, desc) 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 @@ -563,10 +655,12 @@ local void build_tree(s, desc) /* 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. */ @@ -574,8 +668,10 @@ local void build_tree(s, desc) 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)((s->depth[n] >= s->depth[m] ? @@ -590,15 +686,20 @@ local void build_tree(s, desc) /* 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. @@ -615,8 +716,10 @@ local void scan_tree (s, tree, max_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) { @@ -641,6 +744,7 @@ local void scan_tree (s, tree, max_code) } } } + /* =========================================================================== * Send a literal or distance tree in compressed form, using the codes in * bl_tree. @@ -657,22 +761,27 @@ local void send_tree (s, tree, max_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); } @@ -686,6 +795,7 @@ local void send_tree (s, tree, max_code) } } } + /* =========================================================================== * Construct the Huffman tree for the bit lengths and return the index in * bl_order of the last bit length code to send. @@ -694,14 +804,17 @@ 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.) @@ -713,8 +826,10 @@ local int build_bl_tree(s) 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. @@ -725,6 +840,7 @@ local void send_all_trees(s, lcodes, dcodes, blcodes) 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"); @@ -737,11 +853,14 @@ local void send_all_trees(s, lcodes, dcodes, blcodes) 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 */ @@ -758,6 +877,7 @@ void _tr_stored_block(s, buf, stored_len, eof) #endif copy_block(s, buf, (unsigned)stored_len, 1); /* with header */ } + /* =========================================================================== * Send one empty static block to give enough lookahead for inflate. * This takes 10 bits, of which 7 may remain in the bit buffer. @@ -793,6 +913,7 @@ void _tr_align(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. @@ -805,36 +926,46 @@ void _tr_flush_block(s, buf, stored_len, eof) { ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */ int max_blindex = 0; /* index of last bit length code of non zero freq */ + /* Build the Huffman trees unless a stored block is forced */ if (s->level > 0) { + /* Check if the file is binary or text */ if (stored_len > 0 && s->strm->data_type == Z_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 the block lengths 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; + } else { Assert(buf != (char*)0, "lost buf"); opt_lenb = static_lenb = stored_len + 5; /* force a stored block */ } + #ifdef FORCE_STORED if (buf != (char*)0) { /* force stored block */ #else @@ -848,6 +979,7 @@ void _tr_flush_block(s, buf, stored_len, eof) * transform a block into a stored block. */ _tr_stored_block(s, buf, stored_len, eof); + #ifdef FORCE_STATIC } else if (static_lenb >= 0) { /* force static trees */ #else @@ -872,6 +1004,7 @@ void _tr_flush_block(s, buf, stored_len, eof) * and uLong implemented on 32 bits. */ init_block(s); + if (eof) { bi_windup(s); #ifdef DEBUG @@ -881,6 +1014,7 @@ void _tr_flush_block(s, buf, stored_len, eof) Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3, s->compressed_len-7*eof)); } + /* =========================================================================== * Save the match info and tally the frequency counts. Return true if * the current block must be flushed. @@ -902,9 +1036,11 @@ int _tr_tally (s, dist, lc) Assert((ush)dist < (ush)MAX_DIST(s) && (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_dtree[d_code(dist)].Freq++; } + #ifdef TRUNCATE_BLOCK /* Try to guess if it is profitable to stop the current block here */ if ((s->last_lit & 0x1fff) == 0 && s->level > 2) { @@ -929,6 +1065,7 @@ int _tr_tally (s, dist, lc) * 64K-1 bytes. */ } + /* =========================================================================== * Send the block data compressed using the given Huffman trees */ @@ -942,6 +1079,7 @@ local void compress_block(s, ltree, dtree) 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++]; @@ -960,6 +1098,7 @@ local void compress_block(s, ltree, dtree) 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) { @@ -967,13 +1106,17 @@ local void compress_block(s, ltree, dtree) 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((uInt)(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 BINARY or TEXT, using a crude approximation: * set it to Z_TEXT if all symbols are either printable characters (33 to 255) @@ -984,6 +1127,7 @@ local void set_data_type(s) deflate_state *s; { int n; + for (n = 0; n < 9; n++) if (s->dyn_ltree[n].Freq != 0) break; @@ -993,6 +1137,7 @@ local void set_data_type(s) break; s->strm->data_type = (n == 32) ? Z_TEXT : Z_BINARY; } + /* =========================================================================== * Reverse the first len bits of a code, using straightforward code (a faster * method would use a table) @@ -1009,6 +1154,7 @@ local unsigned bi_reverse(code, len) } while (--len > 0); return res >> 1; } + /* =========================================================================== * Flush the bit buffer, keeping at most 7 bits in it. */ @@ -1025,6 +1171,7 @@ local void bi_flush(s) s->bi_valid -= 8; } } + /* =========================================================================== * Flush the bit buffer and align the output on a byte boundary */ @@ -1042,6 +1189,7 @@ local void bi_windup(s) s->bits_sent = (s->bits_sent+7) & ~7; #endif } + /* =========================================================================== * Copy a stored block, storing first the length and its * one's complement if requested. @@ -1054,6 +1202,7 @@ local void copy_block(s, buf, len, header) { 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); |