repos/blastem: zlib/trees.c comparison

comparison zlib/trees.c @ 2690:9ef72ee5c0b0

Update vendored zlib to 1.3.1

author	Michael Pavone <pavone@retrodev.com>
date	Sun, 15 Jun 2025 15:39:33 -0700
parents	00d788dac91a
children

comparison

equal deleted inserted replaced

-:bd6e33de0972
+:9ef72ee5c0b0
 /* trees.c -- output deflated data using Huffman coding
-* Copyright (C) 1995-2017 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
 */
 /*
 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 */
 };
-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.
+*/
-local void tr_static_init OF((void));
+#define put_short(s, w) { \
-local void init_block     OF((deflate_state *s));
+put_byte(s, (uch)((w) & 0xff)); \
-local void pqdownheap     OF((deflate_state *s, ct_data *tree, int k));
+put_byte(s, (uch)((ush)(w) >> 8)); \
-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));
+* Reverse the first len bits of a code, using straightforward code (a faster
-local void send_tree      OF((deflate_state *s, ct_data *tree, int max_code));
+* method would use a table)
-local int  build_bl_tree  OF((deflate_state *s));
+* IN assertion: 1 <= len <= 15
-local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes,
+*/
-int blcodes));
+local unsigned bi_reverse(unsigned code, int len) {
-local void compress_block OF((deflate_state *s, const ct_data *ltree,
+register unsigned res = 0;
-const ct_data *dtree));
+do {
-local int  detect_data_type OF((deflate_state *s));
+res |= code & 1;
-local unsigned bi_reverse OF((unsigned value, int length));
+code >>= 1, res <<= 1;
-local void bi_windup      OF((deflate_state *s));
+} while (--len > 0);
-local void bi_flush       OF((deflate_state *s));
+return res >> 1;
+}
+/* ===========================================================================
+* 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
 #  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 */
 { 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.
-*/
-#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(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 */
-{
 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))
+* (16 - bi_valid) bits from value, leaving (width - (16 - bi_valid))
 * unused bits in value.
 */
 if (s->bi_valid > (int)Buf_size - length) {
 s->bi_buf |= (ush)value << s->bi_valid;
 put_short(s, s->bi_buf);
 /* the arguments must not have side effects */
 /* ===========================================================================
 * 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 */
 int bits;     /* bit counter */
 int length;   /* length value */
 /* 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++) {
+for (n = 0; n < (1 << extra_lbits[code]); n++) {
 _length_code[length++] = (uch)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:
 */
-_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++) {
+for (n = 0; n < (1 << extra_dbits[code]); n++) {
 _dist_code[dist++] = (uch)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++) {
+for (n = 0; n < (1 << (extra_dbits[code] - 7)); n++) {
 _dist_code[256 + dist++] = (uch)code;
 }
 }
-Assert (dist == 256, "tr_static_init: 256+dist != 512");
+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]++;
 #  endif
 #endif /* defined(GEN_TREES_H) || !defined(STDC) */
 }
 /* ===========================================================================
-* Genererate the file trees.h describing the static trees.
+* Generate 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" : ", "))
+((i) % (width) == (width) - 1 ? ",\n" : ", "))
-void gen_trees_header()
+void gen_trees_header(void) {
-{
 FILE *header = fopen("trees.h", "w");
 int i;
 Assert (header != NULL, "Can't open trees.h");
 fprintf(header,
 fclose(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)
+void ZLIB_INTERNAL _tr_init(deflate_state *s) {
-deflate_state *s;
-{
 tr_static_init();
 s->l_desc.dyn_tree = s->dyn_ltree;
 s->l_desc.stat_desc = &static_l_desc;
 /* Initialize the first block of the first file: */
 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->last_lit = s->matches = 0;
-}
 #define SMALLEST 1
 /* Index within the heap array of least frequent node in the Huffman tree */
 /* ===========================================================================
 * 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
 * when the heap property is re-established (each father smaller than its
 * two sons).
 */
-local void pqdownheap(s, tree, k)
+local void pqdownheap(deflate_state *s, ct_data *tree, int k) {
-deflate_state *s;
-ct_data *tree;  /* the tree to restore */
-int k;               /* node to move down */
-{
 int v = s->heap[k];
 int j = k << 1;  /* left son of k */
 while (j <= s->heap_len) {
 /* Set j to the smallest of the two sons: */
 if (j < s->heap_len &&
-smaller(tree, s->heap[j+1], s->heap[j], s->depth)) {
+smaller(tree, s->heap[j + 1], s->heap[j], s->depth)) {
 j++;
 }
 /* Exit if v is smaller than both sons */
 if (smaller(tree, v, s->heap[j], s->depth)) break;
 * OUT assertions: the field len is set to the optimal bit length, the
 *     array bl_count contains the frequencies for each bit length.
 *     The length opt_len is updated; static_len is also updated if stree is
 *     not null.
 */
-local void gen_bitlen(s, desc)
+local void gen_bitlen(deflate_state *s, tree_desc *desc) {
-deflate_state *s;
-tree_desc *desc;    /* the tree descriptor */
-{
 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;
 /* 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++) {
+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];
+if (n >= base) xbits = extra[n - base];
 f = tree[n].Freq;
 s->opt_len += (ulg)f * (unsigned)(bits + xbits);
 if (stree) s->static_len += (ulg)f * (unsigned)(stree[n].Len + xbits);
 }
 if (overflow == 0) return;
 Tracev((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;
+bits = max_length - 1;
 while (s->bl_count[bits] == 0) bits--;
-s->bl_count[bits]--;      /* move one leaf down the tree */
+s->bl_count[bits]--;        /* move one leaf down the tree */
-s->bl_count[bits+1] += 2; /* move one overflow item as its brother */
+s->bl_count[bits + 1] += 2; /* move one overflow item as its brother */
 s->bl_count[max_length]--;
 /* The brother of the overflow item also moves one step up,
 * but this does not affect bl_count[max_length]
 */
 overflow -= 2;
 n--;
 }
 }
 }
-/* ===========================================================================
+#ifdef DUMP_BL_TREE
-* Generate the codes for a given tree and bit counts (which need not be
+#  include <stdio.h>
-* optimal).
+#endif
-* 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));
-}
-}
 /* ===========================================================================
 * Construct one Huffman tree and assigns the code bit strings and lengths.
 * Update the total bit length for the current block.
 * IN assertion: the field freq is set for all tree elements.
 * OUT assertions: the fields len and code are set to the optimal bit length
 *     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)
+local void build_tree(deflate_state *s, tree_desc *desc) {
-deflate_state *s;
-tree_desc *desc; /* the tree descriptor */
-{
 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 */
 /* 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[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++) {
 s->opt_len--; if (stree) s->static_len -= stree[node].Len;
 /* 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,
+/* 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
 /* ===========================================================================
 * 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)
+local void scan_tree(deflate_state *s, ct_data *tree, int max_code) {
-deflate_state *s;
-ct_data *tree;   /* the tree to be scanned */
-int max_code;    /* and its largest code of non zero frequency */
-{
 int n;                     /* iterates over all tree elements */
 int prevlen = -1;          /* last emitted length */
 int curlen;                /* length of current code */
 int nextlen = tree[0].Len; /* length of next 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 */
+tree[max_code + 1].Len = (ush)0xffff; /* guard */
 for (n = 0; n <= max_code; n++) {
-curlen = nextlen; nextlen = tree[n+1].Len;
+curlen = nextlen; nextlen = tree[n + 1].Len;
 if (++count < max_count && curlen == nextlen) {
 continue;
 } else if (count < min_count) {
 s->bl_tree[curlen].Freq += count;
 } else if (curlen != 0) {
 /* ===========================================================================
 * Send a literal or distance tree in compressed form, using the codes in
 * bl_tree.
 */
-local void send_tree (s, tree, max_code)
+local void send_tree(deflate_state *s, ct_data *tree, int max_code) {
-deflate_state *s;
-ct_data *tree; /* the tree to be scanned */
-int max_code;       /* and its largest code of non zero frequency */
-{
 int n;                     /* iterates over all tree elements */
 int prevlen = -1;          /* last emitted length */
 int curlen;                /* length of current code */
 int nextlen = tree[0].Len; /* length of next 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 */
+/* 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;
+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);
+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);
+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);
+send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count - 11, 7);
 }
 count = 0; prevlen = curlen;
 if (nextlen == 0) {
 max_count = 138, min_count = 3;
 } else if (curlen == nextlen) {
 /* ===========================================================================
 * 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)
+local int build_bl_tree(deflate_state *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
+/* opt_len now includes the length of the tree representations, except the
-* the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
+* 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.)
 */
 for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) {
 if (s->bl_tree[bl_order[max_blindex]].Len != 0) break;
 }
 /* Update opt_len to include the bit length tree and counts */
-s->opt_len += 3*((ulg)max_blindex+1) + 5+5+4;
+s->opt_len += 3*((ulg)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.
 * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
 */
-local void send_all_trees(s, lcodes, dcodes, blcodes)
+local void send_all_trees(deflate_state *s, int lcodes, int dcodes,
-deflate_state *s;
+int 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");
 Tracev((stderr, "\nbl counts: "));
-send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */
+send_bits(s, lcodes - 257, 5);  /* not +255 as stated in appnote.txt */
-send_bits(s, dcodes-1,   5);
+send_bits(s, dcodes - 1,   5);
-send_bits(s, blcodes-4,  4); /* not -3 as stated in appnote.txt */
+send_bits(s, blcodes - 4,  4);  /* not -3 as stated in appnote.txt */
 for (rank = 0; rank < blcodes; rank++) {
 Tracev((stderr, "\nbl code %2d ", bl_order[rank]));
 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 */
+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 */
+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
 */
-void ZLIB_INTERNAL _tr_stored_block(s, buf, stored_len, last)
+void ZLIB_INTERNAL _tr_stored_block(deflate_state *s, charf *buf,
-deflate_state *s;
+ulg stored_len, int last) {
-charf *buf;       /* input block */
+send_bits(s, (STORED_BLOCK<<1) + last, 3);  /* send block type */
-ulg stored_len;   /* length of input block */
-int last;         /* one if this is the last block for a file */
-{
-send_bits(s, (STORED_BLOCK<<1)+last, 3);    /* send block type */
 bi_windup(s);        /* align on byte boundary */
 put_short(s, (ush)stored_len);
 put_short(s, (ush)~stored_len);
-zmemcpy(s->pending_buf + s->pending, (Bytef *)buf, stored_len);
+if (stored_len)
+zmemcpy(s->pending_buf + s->pending, (Bytef *)buf, stored_len);
 s->pending += stored_len;
 #ifdef ZLIB_DEBUG
 s->compressed_len = (s->compressed_len + 3 + 7) & (ulg)~7L;
 s->compressed_len += (stored_len + 4) << 3;
 s->bits_sent += 2*16;
-s->bits_sent += stored_len<<3;
+s->bits_sent += stored_len << 3;
 #endif
 }
 /* ===========================================================================
 * Flush the bits in the bit buffer to pending output (leaves at most 7 bits)
 */
-void ZLIB_INTERNAL _tr_flush_bits(s)
+void ZLIB_INTERNAL _tr_flush_bits(deflate_state *s) {
-deflate_state *s;
-{
 bi_flush(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)
+void ZLIB_INTERNAL _tr_align(deflate_state *s) {
-deflate_state *s;
-{
 send_bits(s, STATIC_TREES<<1, 3);
 send_code(s, END_BLOCK, static_ltree);
 #ifdef ZLIB_DEBUG
 s->compressed_len += 10L; /* 3 for block type, 7 for EOB */
 #endif
 bi_flush(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)
+void ZLIB_INTERNAL _tr_flush_block(deflate_state *s, charf *buf,
-deflate_state *s;
+ulg stored_len, int last) {
-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 */
-{
 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) {
 * 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;
+opt_lenb = (s->opt_len + 3 + 7) >> 3;
-static_lenb = (s->static_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));
+s->sym_next / 3));
-if (static_lenb <= opt_lenb) opt_lenb = static_lenb;
+#ifndef FORCE_STATIC
+if (static_lenb <= opt_lenb || s->strategy == Z_FIXED)
+#endif
+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
-if (stored_len+4 <= opt_lenb && buf != (char*)0) {
+if (stored_len + 4 <= opt_lenb && buf != (char*)0) {
 /* 4: two words for the lengths */
 #endif
 /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
 * Otherwise we can't have processed more than WSIZE input bytes since
 * the last block flush, because compression would have been
 * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
 * transform a block into a stored block.
 */
 _tr_stored_block(s, buf, stored_len, last);
-#ifdef FORCE_STATIC
+} else if (static_lenb == opt_lenb) {
-} else if (static_lenb >= 0) { /* force static trees */
+send_bits(s, (STATIC_TREES<<1) + last, 3);
-#else
-} else if (s->strategy == Z_FIXED || static_lenb == opt_lenb) {
-#endif
-send_bits(s, (STATIC_TREES<<1)+last, 3);
 compress_block(s, (const ct_data *)static_ltree,
 (const ct_data *)static_dtree);
 #ifdef ZLIB_DEBUG
 s->compressed_len += 3 + s->static_len;
 #endif
 } else {
-send_bits(s, (DYN_TREES<<1)+last, 3);
+send_bits(s, (DYN_TREES<<1) + last, 3);
-send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1,
+send_all_trees(s, s->l_desc.max_code + 1, s->d_desc.max_code + 1,
-max_blindex+1);
+max_blindex + 1);
 compress_block(s, (const ct_data *)s->dyn_ltree,
 (const ct_data *)s->dyn_dtree);
 #ifdef ZLIB_DEBUG
 s->compressed_len += 3 + s->opt_len;
 #endif
 bi_windup(s);
 #ifdef ZLIB_DEBUG
 s->compressed_len += 7;  /* align on byte boundary */
 #endif
 }
-Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3,
+Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len >> 3,
-s->compressed_len-7*last));
+s->compressed_len - 7*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)
+int ZLIB_INTERNAL _tr_tally(deflate_state *s, unsigned dist, unsigned lc) {
-deflate_state *s;
+#ifdef LIT_MEM
-unsigned dist;  /* distance of matched string */
+s->d_buf[s->sym_next] = (ush)dist;
-unsigned lc;    /* match length-MIN_MATCH or unmatched char (if dist==0) */
+s->l_buf[s->sym_next++] = (uch)lc;
-{
+#else
-s->d_buf[s->last_lit] = (ush)dist;
+s->sym_buf[s->sym_next++] = (uch)dist;
-s->l_buf[s->last_lit++] = (uch)lc;
+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++;
 } else {
 s->matches++;
 dist--;             /* dist = match distance - 1 */
 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_ltree[_length_code[lc] + LITERALS + 1].Freq++;
 s->dyn_dtree[d_code(dist)].Freq++;
 }
+return (s->sym_next == s->sym_end);
-#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) {
-/* 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);
-int dcode;
-for (dcode = 0; dcode < D_CODES; dcode++) {
-out_length += (ulg)s->dyn_dtree[dcode].Freq *
-(5L+extra_dbits[dcode]);
-}
-out_length >>= 3;
-Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ",
-s->last_lit, in_length, out_length,
-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
-* 64K-1 bytes.
-*/
-}
-/* ===========================================================================
-* 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 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++];
-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 the 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 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);
-}
-/* ===========================================================================
-* 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
-*       "black list" (0..6, 14..25, 28..31).
-*    b) There is at least one printable character belonging to the
-*       "white 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;
-{
-/* black_mask is the bit mask of black-listed bytes
-* set bits 0..6, 14..25, and 28..31
-* 0xf3ffc07f = binary 11110011111111111100000001111111
-*/
-unsigned long black_mask = 0xf3ffc07fUL;
-int n;
-/* Check for non-textual ("black-listed") bytes. */
-for (n = 0; n <= 31; n++, black_mask >>= 1)
-if ((black_mask & 1) && (s->dyn_ltree[n].Freq != 0))
-return Z_BINARY;
-/* Check for textual ("white-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 "black-listed" or "white-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
-}

Mercurial > repos > blastem

comparison zlib/trees.c @ 2690:9ef72ee5c0b0