diff options
Diffstat (limited to 'src/3rdparty/zlib/src/trees.c')
| -rw-r--r-- | src/3rdparty/zlib/src/trees.c | 542 |
1 files changed, 239 insertions, 303 deletions
diff --git a/src/3rdparty/zlib/src/trees.c b/src/3rdparty/zlib/src/trees.c index 5f305c4722..6a523ef34e 100644 --- a/src/3rdparty/zlib/src/trees.c +++ b/src/3rdparty/zlib/src/trees.c @@ -1,5 +1,5 @@ /* trees.c -- output deflated data using Huffman coding - * Copyright (C) 1995-2021 Jean-loup Gailly + * Copyright (C) 1995-2024 Jean-loup Gailly * detect_data_type() function provided freely by Cosmin Truta, 2006 * For conditions of distribution and use, see copyright notice in zlib.h */ @@ -122,39 +122,116 @@ struct static_tree_desc_s { int max_length; /* max bit length for the codes */ }; -local const static_tree_desc static_l_desc = +#ifdef NO_INIT_GLOBAL_POINTERS +# define TCONST +#else +# define TCONST const +#endif + +local TCONST static_tree_desc static_l_desc = {static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS}; -local const static_tree_desc static_d_desc = +local TCONST static_tree_desc static_d_desc = {static_dtree, extra_dbits, 0, D_CODES, MAX_BITS}; -local const static_tree_desc static_bl_desc = +local TCONST static_tree_desc static_bl_desc = {(const ct_data *)0, extra_blbits, 0, BL_CODES, MAX_BL_BITS}; /* =========================================================================== - * Local (static) routines in this file. + * 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)); \ +} + +/* =========================================================================== + * 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(unsigned code, int len) { + register unsigned res = 0; + do { + res |= code & 1; + code >>= 1, res <<= 1; + } while (--len > 0); + return res >> 1; +} -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)); -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, const ct_data *ltree, - const ct_data *dtree)); -local int detect_data_type OF((deflate_state *s)); -local unsigned bi_reverse OF((unsigned code, int len)); -local void bi_windup OF((deflate_state *s)); -local void bi_flush OF((deflate_state *s)); +/* =========================================================================== + * Flush the bit buffer, keeping at most 7 bits in it. + */ +local void bi_flush(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(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 ZLIB_DEBUG + s->bits_sent = (s->bits_sent + 7) & ~7; +#endif +} + +/* =========================================================================== + * 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(ct_data *tree, int max_code, ushf *bl_count) { + ush next_code[MAX_BITS+1]; /* next code value for each bit length */ + unsigned 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++) { + code = (code + bl_count[bits - 1]) << 1; + next_code[bits] = (ush)code; + } + /* 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 = (ush)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)); + } +} #ifdef GEN_TREES_H -local void gen_trees_header OF((void)); +local void gen_trees_header(void); #endif #ifndef ZLIB_DEBUG @@ -168,26 +245,11 @@ local void gen_trees_header OF((void)); #endif /* =========================================================================== - * 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 ZLIB_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 */ - int length; /* number of bits */ -{ +local void send_bits(deflate_state *s, int value, int length) { Tracevv((stderr," l %2d v %4x ", length, value)); Assert(length > 0 && length <= 15, "invalid length"); s->bits_sent += (ulg)length; @@ -229,8 +291,7 @@ local void send_bits(s, value, length) /* =========================================================================== * Initialize the various 'constant' tables. */ -local void tr_static_init() -{ +local void tr_static_init(void) { #if defined(GEN_TREES_H) || !defined(STDC) static int static_init_done = 0; int n; /* iterates over tree elements */ @@ -323,8 +384,7 @@ local void tr_static_init() ((i) == (last)? "\n};\n\n" : \ ((i) % (width) == (width) - 1 ? ",\n" : ", ")) -void gen_trees_header() -{ +void gen_trees_header(void) { FILE *header = fopen("trees.h", "w"); int i; @@ -374,11 +434,25 @@ void gen_trees_header() #endif /* GEN_TREES_H */ /* =========================================================================== + * Initialize a new block. + */ +local void init_block(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->sym_next = s->matches = 0; +} + +/* =========================================================================== * Initialize the tree data structures for a new zlib stream. */ -void ZLIB_INTERNAL _tr_init(s) - deflate_state *s; -{ +void ZLIB_INTERNAL _tr_init(deflate_state *s) { tr_static_init(); s->l_desc.dyn_tree = s->dyn_ltree; @@ -401,24 +475,6 @@ void ZLIB_INTERNAL _tr_init(s) 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->sym_next = s->matches = 0; -} - #define SMALLEST 1 /* Index within the heap array of least frequent node in the Huffman tree */ @@ -448,11 +504,7 @@ local void init_block(s) * 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 */ -{ +local void pqdownheap(deflate_state *s, ct_data *tree, int k) { int v = s->heap[k]; int j = k << 1; /* left son of k */ while (j <= s->heap_len) { @@ -483,10 +535,7 @@ local void pqdownheap(s, tree, k) * 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 */ -{ +local void gen_bitlen(deflate_state *s, tree_desc *desc) { ct_data *tree = desc->dyn_tree; int max_code = desc->max_code; const ct_data *stree = desc->stat_desc->static_tree; @@ -561,48 +610,9 @@ local void gen_bitlen(s, desc) } } -/* =========================================================================== - * 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 */ - unsigned 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++) { - code = (code + bl_count[bits - 1]) << 1; - next_code[bits] = (ush)code; - } - /* 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 = (ush)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)); - } -} +#ifdef DUMP_BL_TREE +# include <stdio.h> +#endif /* =========================================================================== * Construct one Huffman tree and assigns the code bit strings and lengths. @@ -612,10 +622,7 @@ local void gen_codes(tree, max_code, bl_count) * 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 */ -{ +local void build_tree(deflate_state *s, tree_desc *desc) { ct_data *tree = desc->dyn_tree; const ct_data *stree = desc->stat_desc->static_tree; int elems = desc->stat_desc->elems; @@ -700,11 +707,7 @@ local void build_tree(s, desc) * 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 */ -{ +local void scan_tree(deflate_state *s, ct_data *tree, int max_code) { int n; /* iterates over all tree elements */ int prevlen = -1; /* last emitted length */ int curlen; /* length of current code */ @@ -745,11 +748,7 @@ local void scan_tree(s, tree, max_code) * 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 */ -{ +local void send_tree(deflate_state *s, ct_data *tree, int max_code) { int n; /* iterates over all tree elements */ int prevlen = -1; /* last emitted length */ int curlen; /* length of current code */ @@ -796,9 +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. */ -local int build_bl_tree(s) - deflate_state *s; -{ +local int build_bl_tree(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 */ @@ -831,10 +828,8 @@ local int build_bl_tree(s) * 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 */ -{ +local void send_all_trees(deflate_state *s, int lcodes, int dcodes, + int blcodes) { int rank; /* index in bl_order */ Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes"); @@ -860,12 +855,8 @@ local void send_all_trees(s, lcodes, dcodes, blcodes) /* =========================================================================== * Send a stored block */ -void ZLIB_INTERNAL _tr_stored_block(s, buf, stored_len, last) - deflate_state *s; - charf *buf; /* input block */ - ulg stored_len; /* length of input block */ - int last; /* one if this is the last block for a file */ -{ +void ZLIB_INTERNAL _tr_stored_block(deflate_state *s, charf *buf, + ulg stored_len, int last) { send_bits(s, (STORED_BLOCK<<1) + last, 3); /* send block type */ bi_windup(s); /* align on byte boundary */ put_short(s, (ush)stored_len); @@ -884,9 +875,7 @@ void ZLIB_INTERNAL _tr_stored_block(s, buf, stored_len, last) /* =========================================================================== * Flush the bits in the bit buffer to pending output (leaves at most 7 bits) */ -void ZLIB_INTERNAL _tr_flush_bits(s) - deflate_state *s; -{ +void ZLIB_INTERNAL _tr_flush_bits(deflate_state *s) { bi_flush(s); } @@ -894,9 +883,7 @@ void ZLIB_INTERNAL _tr_flush_bits(s) * Send one empty static block to give enough lookahead for inflate. * This takes 10 bits, of which 7 may remain in the bit buffer. */ -void ZLIB_INTERNAL _tr_align(s) - deflate_state *s; -{ +void ZLIB_INTERNAL _tr_align(deflate_state *s) { send_bits(s, STATIC_TREES<<1, 3); send_code(s, END_BLOCK, static_ltree); #ifdef ZLIB_DEBUG @@ -906,15 +893,107 @@ void ZLIB_INTERNAL _tr_align(s) } /* =========================================================================== + * Send the block data compressed using the given Huffman trees + */ +local void compress_block(deflate_state *s, const ct_data *ltree, + const ct_data *dtree) { + unsigned dist; /* distance of matched string */ + int lc; /* match length or unmatched char (if dist == 0) */ + unsigned sx = 0; /* running index in symbol buffers */ + unsigned code; /* the code to send */ + int extra; /* number of extra bits to send */ + + if (s->sym_next != 0) do { +#ifdef LIT_MEM + dist = s->d_buf[sx]; + lc = s->l_buf[sx++]; +#else + dist = s->sym_buf[sx++] & 0xff; + dist += (unsigned)(s->sym_buf[sx++] & 0xff) << 8; + lc = s->sym_buf[sx++]; +#endif + 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 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 -= (unsigned)base_dist[code]; + send_bits(s, dist, extra); /* send the extra distance bits */ + } + } /* literal or match pair ? */ + + /* Check for no overlay of pending_buf on needed symbols */ +#ifdef LIT_MEM + Assert(s->pending < 2 * (s->lit_bufsize + sx), "pendingBuf overflow"); +#else + Assert(s->pending < s->lit_bufsize + sx, "pendingBuf overflow"); +#endif + + } while (sx < s->sym_next); + + send_code(s, END_BLOCK, ltree); +} + +/* =========================================================================== + * Check if the data type is TEXT or BINARY, using the following algorithm: + * - TEXT if the two conditions below are satisfied: + * a) There are no non-portable control characters belonging to the + * "block list" (0..6, 14..25, 28..31). + * b) There is at least one printable character belonging to the + * "allow list" (9 {TAB}, 10 {LF}, 13 {CR}, 32..255). + * - BINARY otherwise. + * - The following partially-portable control characters form a + * "gray list" that is ignored in this detection algorithm: + * (7 {BEL}, 8 {BS}, 11 {VT}, 12 {FF}, 26 {SUB}, 27 {ESC}). + * IN assertion: the fields Freq of dyn_ltree are set. + */ +local int detect_data_type(deflate_state *s) { + /* block_mask is the bit mask of block-listed bytes + * set bits 0..6, 14..25, and 28..31 + * 0xf3ffc07f = binary 11110011111111111100000001111111 + */ + unsigned long block_mask = 0xf3ffc07fUL; + int n; + + /* Check for non-textual ("block-listed") bytes. */ + for (n = 0; n <= 31; n++, block_mask >>= 1) + if ((block_mask & 1) && (s->dyn_ltree[n].Freq != 0)) + return Z_BINARY; + + /* Check for textual ("allow-listed") bytes. */ + if (s->dyn_ltree[9].Freq != 0 || s->dyn_ltree[10].Freq != 0 + || s->dyn_ltree[13].Freq != 0) + return Z_TEXT; + for (n = 32; n < LITERALS; n++) + if (s->dyn_ltree[n].Freq != 0) + return Z_TEXT; + + /* There are no "block-listed" or "allow-listed" bytes: + * this stream either is empty or has tolerated ("gray-listed") bytes only. + */ + return Z_BINARY; +} + +/* =========================================================================== * Determine the best encoding for the current block: dynamic trees, static * trees or store, and write out the encoded block. */ -void ZLIB_INTERNAL _tr_flush_block(s, buf, stored_len, last) - deflate_state *s; - charf *buf; /* input block, or NULL if too old */ - ulg stored_len; /* length of input block */ - int last; /* one if this is the last block for a file */ -{ +void ZLIB_INTERNAL _tr_flush_block(deflate_state *s, charf *buf, + ulg stored_len, int last) { 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 */ @@ -1011,14 +1090,15 @@ void ZLIB_INTERNAL _tr_flush_block(s, buf, stored_len, last) * Save the match info and tally the frequency counts. Return true if * the current block must be flushed. */ -int ZLIB_INTERNAL _tr_tally(s, dist, lc) - deflate_state *s; - unsigned dist; /* distance of matched string */ - unsigned lc; /* match length - MIN_MATCH or unmatched char (dist==0) */ -{ +int ZLIB_INTERNAL _tr_tally(deflate_state *s, unsigned dist, unsigned lc) { +#ifdef LIT_MEM + s->d_buf[s->sym_next] = (ush)dist; + s->l_buf[s->sym_next++] = (uch)lc; +#else s->sym_buf[s->sym_next++] = (uch)dist; s->sym_buf[s->sym_next++] = (uch)(dist >> 8); s->sym_buf[s->sym_next++] = (uch)lc; +#endif if (dist == 0) { /* lc is the unmatched char */ s->dyn_ltree[lc].Freq++; @@ -1035,147 +1115,3 @@ int ZLIB_INTERNAL _tr_tally(s, dist, lc) } return (s->sym_next == s->sym_end); } - -/* =========================================================================== - * Send the block data compressed using the given Huffman trees - */ -local void compress_block(s, ltree, dtree) - deflate_state *s; - const ct_data *ltree; /* literal tree */ - const ct_data *dtree; /* distance tree */ -{ - unsigned dist; /* distance of matched string */ - int lc; /* match length or unmatched char (if dist == 0) */ - unsigned sx = 0; /* running index in sym_buf */ - unsigned code; /* the code to send */ - int extra; /* number of extra bits to send */ - - if (s->sym_next != 0) do { - dist = s->sym_buf[sx++] & 0xff; - dist += (unsigned)(s->sym_buf[sx++] & 0xff) << 8; - lc = s->sym_buf[sx++]; - 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 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 -= (unsigned)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 sym_buf is ok: */ - Assert(s->pending < s->lit_bufsize + sx, "pendingBuf overflow"); - - } while (sx < s->sym_next); - - send_code(s, END_BLOCK, ltree); -} - -/* =========================================================================== - * Check if the data type is TEXT or BINARY, using the following algorithm: - * - TEXT if the two conditions below are satisfied: - * a) There are no non-portable control characters belonging to the - * "block list" (0..6, 14..25, 28..31). - * b) There is at least one printable character belonging to the - * "allow list" (9 {TAB}, 10 {LF}, 13 {CR}, 32..255). - * - BINARY otherwise. - * - The following partially-portable control characters form a - * "gray list" that is ignored in this detection algorithm: - * (7 {BEL}, 8 {BS}, 11 {VT}, 12 {FF}, 26 {SUB}, 27 {ESC}). - * IN assertion: the fields Freq of dyn_ltree are set. - */ -local int detect_data_type(s) - deflate_state *s; -{ - /* block_mask is the bit mask of block-listed bytes - * set bits 0..6, 14..25, and 28..31 - * 0xf3ffc07f = binary 11110011111111111100000001111111 - */ - unsigned long block_mask = 0xf3ffc07fUL; - int n; - - /* Check for non-textual ("block-listed") bytes. */ - for (n = 0; n <= 31; n++, block_mask >>= 1) - if ((block_mask & 1) && (s->dyn_ltree[n].Freq != 0)) - return Z_BINARY; - - /* Check for textual ("allow-listed") bytes. */ - if (s->dyn_ltree[9].Freq != 0 || s->dyn_ltree[10].Freq != 0 - || s->dyn_ltree[13].Freq != 0) - return Z_TEXT; - for (n = 32; n < LITERALS; n++) - if (s->dyn_ltree[n].Freq != 0) - return Z_TEXT; - - /* There are no "block-listed" or "allow-listed" bytes: - * this stream either is empty or has tolerated ("gray-listed") bytes only. - */ - return Z_BINARY; -} - -/* =========================================================================== - * 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 ZLIB_DEBUG - s->bits_sent = (s->bits_sent + 7) & ~7; -#endif -} |