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-rw-r--r--libpng/trees.c247
1 files changed, 131 insertions, 116 deletions
diff --git a/libpng/trees.c b/libpng/trees.c
index 6125d6b..395e4e1 100644
--- a/libpng/trees.c
+++ b/libpng/trees.c
@@ -1,6 +1,6 @@
/* trees.c -- output deflated data using Huffman coding
- * Copyright (C) 1995-2002 Jean-loup Gailly
- * For conditions of distribution and use, see copyright notice in zlib.h
+ * Copyright (C) 1995-2005 Jean-loup Gailly
+ * For conditions of distribution and use, see copyright notice in zlib.h
*/
/*
@@ -189,7 +189,10 @@ local void gen_trees_header OF((void));
#ifdef 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");
@@ -227,13 +230,12 @@ local void send_bits(deflate_state s, int value, int length)
#endif /* DEBUG */
-#define MAX(a,b) (a >= b ? a : b)
/* the arguments must not have side effects */
/* ===========================================================================
* Initialize the various 'constant' tables.
*/
-local void tr_static_init(void)
+local void tr_static_init()
{
#if defined(GEN_TREES_H) || !defined(STDC)
static int static_init_done = 0;
@@ -332,42 +334,42 @@ void gen_trees_header()
Assert (header != NULL, "Can't open trees.h");
fprintf(header,
- "/* header created automatically with -DGEN_TREES_H */\n\n");
+ "/* 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, "{{%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, "{{%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, "%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, "%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, "%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));
+ fprintf(header, "%5u%s", base_dist[i],
+ SEPARATOR(i, D_CODES-1, 10));
}
fclose(header);
@@ -377,7 +379,8 @@ void gen_trees_header()
/* ===========================================================================
* Initialize the tree data structures for a new zlib stream.
*/
-void _tr_init(deflate_state *s)
+void _tr_init(s)
+ deflate_state *s;
{
tr_static_init();
@@ -405,7 +408,8 @@ void _tr_init(deflate_state *s)
/* ===========================================================================
* Initialize a new block.
*/
-local void init_block(deflate_state *s)
+local void init_block(s)
+ deflate_state *s;
{
int n; /* iterates over tree elements */
@@ -448,10 +452,10 @@ local void init_block(deflate_state *s)
* when the heap property is re-established (each father smaller than its
* two sons).
*/
-local void pqdownheap(deflate_state *s, ct_data *tree, int k)
-
- /* the tree to restore */
- /* node to move down */
+local void pqdownheap(s, tree, 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 */
@@ -483,9 +487,9 @@ local void pqdownheap(deflate_state *s, ct_data *tree, int k)
* The length opt_len is updated; static_len is also updated if stree is
* not null.
*/
-local void gen_bitlen(deflate_state *s, tree_desc *desc)
-
- /* the tree descriptor */
+local void gen_bitlen(s, desc)
+ deflate_state *s;
+ tree_desc *desc; /* the tree descriptor */
{
ct_data *tree = desc->dyn_tree;
int max_code = desc->max_code;
@@ -551,7 +555,7 @@ local void gen_bitlen(deflate_state *s, tree_desc *desc)
while (n != 0) {
m = s->heap[--h];
if (m > max_code) continue;
- if (tree[m].Len != (unsigned) bits) {
+ if ((unsigned) tree[m].Len != (unsigned) bits) {
Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits));
s->opt_len += ((long)bits - (long)tree[m].Len)
*(long)tree[m].Freq;
@@ -570,10 +574,10 @@ local 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.
*/
-local void gen_codes (ct_data *tree, int max_code, ushf *bl_count)
- /* the tree to decorate */
- /* largest code with non zero frequency */
- /* number of codes at each bit 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 */
ush code = 0; /* running code value */
@@ -612,9 +616,9 @@ local void gen_codes (ct_data *tree, int max_code, ushf *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(deflate_state *s, tree_desc *desc)
-
- /* the tree descriptor */
+local void build_tree(s, 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;
@@ -670,7 +674,8 @@ local void build_tree(deflate_state *s, tree_desc *desc)
/* Create a new node father of n and m */
tree[node].Freq = tree[n].Freq + tree[m].Freq;
- s->depth[node] = (uch) (MAX(s->depth[n], s->depth[m]) + 1);
+ s->depth[node] = (uch)((s->depth[n] >= s->depth[m] ?
+ s->depth[n] : s->depth[m]) + 1);
tree[n].Dad = tree[m].Dad = (ush)node;
#ifdef DUMP_BL_TREE
if (tree == s->bl_tree) {
@@ -699,10 +704,10 @@ local void build_tree(deflate_state *s, tree_desc *desc)
* Scan a literal or distance tree to determine the frequencies of the codes
* in the bit length tree.
*/
-local void scan_tree (deflate_state *s, ct_data *tree, int max_code)
-
- /* the tree to be scanned */
- /* and its largest code of non zero frequency */
+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 */
{
int n; /* iterates over all tree elements */
int prevlen = -1; /* last emitted length */
@@ -744,10 +749,10 @@ local void scan_tree (deflate_state *s, ct_data *tree, int max_code)
* Send a literal or distance tree in compressed form, using the codes in
* bl_tree.
*/
-local void send_tree (deflate_state *s, ct_data *tree, int max_code)
-
- /* the tree to be scanned */
- /* and its largest code of non zero frequency */
+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 */
{
int n; /* iterates over all tree elements */
int prevlen = -1; /* last emitted length */
@@ -795,7 +800,8 @@ local void send_tree (deflate_state *s, ct_data *tree, int 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(deflate_state *s)
+local int build_bl_tree(s)
+ deflate_state *s;
{
int max_blindex; /* index of last bit length code of non zero freq */
@@ -829,9 +835,9 @@ local int build_bl_tree(deflate_state *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(deflate_state *s, int lcodes, int dcodes, int blcodes)
-
- /* number of codes for each tree */
+local void send_all_trees(s, lcodes, dcodes, blcodes)
+ deflate_state *s;
+ int lcodes, dcodes, blcodes; /* number of codes for each tree */
{
int rank; /* index in bl_order */
@@ -858,11 +864,11 @@ local void send_all_trees(deflate_state *s, int lcodes, int dcodes, int blcodes)
/* ===========================================================================
* Send a stored block
*/
-void _tr_stored_block(deflate_state *s, charf *buf, ulg stored_len, int eof)
-
- /* input block */
- /* length of input block */
- /* true if this is the last block for a file */
+void _tr_stored_block(s, buf, stored_len, eof)
+ deflate_state *s;
+ charf *buf; /* input block */
+ ulg stored_len; /* length of input block */
+ int eof; /* true if this is the last block for a file */
{
send_bits(s, (STORED_BLOCK<<1)+eof, 3); /* send block type */
#ifdef DEBUG
@@ -883,7 +889,8 @@ void _tr_stored_block(deflate_state *s, charf *buf, ulg stored_len, int eof)
* To simplify the code, we assume the worst case of last real code encoded
* on one bit only.
*/
-void _tr_align(deflate_state *s)
+void _tr_align(s)
+ deflate_state *s;
{
send_bits(s, STATIC_TREES<<1, 3);
send_code(s, END_BLOCK, static_ltree);
@@ -911,11 +918,11 @@ void _tr_align(deflate_state *s)
* Determine the best encoding for the current block: dynamic trees, static
* trees or store, and output the encoded block to the zip file.
*/
-void _tr_flush_block(deflate_state *s, charf *buf, ulg stored_len, int eof)
-
- /* input block, or NULL if too old */
- /* length of input block */
- /* true if this is the last block for a file */
+void _tr_flush_block(s, buf, stored_len, eof)
+ deflate_state *s;
+ charf *buf; /* input block, or NULL if too old */
+ ulg stored_len; /* length of input block */
+ int eof; /* true 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 */
@@ -923,39 +930,40 @@ void _tr_flush_block(deflate_state *s, charf *buf, ulg stored_len, int eof)
/* Build the Huffman trees unless a stored block is forced */
if (s->level > 0) {
- /* Check if the file is ascii or binary */
- if (s->data_type == Z_UNKNOWN) set_data_type(s);
+ /* 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));
+ /* 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_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);
+ /* 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 first the block length in bytes*/
- opt_lenb = (s->opt_len+3+7)>>3;
- static_lenb = (s->static_len+3+7)>>3;
+ /* 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));
+ 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;
+ 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 */
+ opt_lenb = static_lenb = stored_len + 5; /* force a stored block */
}
#ifdef FORCE_STORED
@@ -975,7 +983,7 @@ void _tr_flush_block(deflate_state *s, charf *buf, ulg stored_len, int eof)
#ifdef FORCE_STATIC
} else if (static_lenb >= 0) { /* force static trees */
#else
- } else if (static_lenb == opt_lenb) {
+ } else if (s->strategy == Z_FIXED || static_lenb == opt_lenb) {
#endif
send_bits(s, (STATIC_TREES<<1)+eof, 3);
compress_block(s, (ct_data *)static_ltree, (ct_data *)static_dtree);
@@ -1011,10 +1019,10 @@ void _tr_flush_block(deflate_state *s, charf *buf, ulg stored_len, int eof)
* Save the match info and tally the frequency counts. Return true if
* the current block must be flushed.
*/
-int _tr_tally (deflate_state *s, unsigned int dist, unsigned int lc)
-
- /* distance of matched string */
- /* match length-MIN_MATCH or unmatched char (if dist==0) */
+int _tr_tally (s, dist, lc)
+ deflate_state *s;
+ unsigned dist; /* distance of matched string */
+ unsigned lc; /* match length-MIN_MATCH or unmatched char (if dist==0) */
{
s->d_buf[s->last_lit] = (ush)dist;
s->l_buf[s->last_lit++] = (uch)lc;
@@ -1061,10 +1069,10 @@ int _tr_tally (deflate_state *s, unsigned int dist, unsigned int lc)
/* ===========================================================================
* Send the block data compressed using the given Huffman trees
*/
-local void compress_block(deflate_state *s, ct_data *ltree, ct_data *dtree)
-
- /* literal tree */
- /* distance tree */
+local void compress_block(s, ltree, dtree)
+ deflate_state *s;
+ ct_data *ltree; /* literal tree */
+ ct_data *dtree; /* distance tree */
{
unsigned dist; /* distance of matched string */
int lc; /* match length or unmatched char (if dist == 0) */
@@ -1100,7 +1108,8 @@ local void compress_block(deflate_state *s, ct_data *ltree, ct_data *dtree)
} /* literal or match pair ? */
/* Check that the overlay between pending_buf and d_buf+l_buf is ok: */
- Assert(s->pending < s->lit_bufsize + 2*lx, "pendingBuf overflow");
+ Assert((uInt)(s->pending) < s->lit_bufsize + 2*lx,
+ "pendingBuf overflow");
} while (lx < s->last_lit);
@@ -1109,20 +1118,24 @@ local void compress_block(deflate_state *s, ct_data *ltree, ct_data *dtree)
}
/* ===========================================================================
- * Set the data type to ASCII or BINARY, using a crude approximation:
- * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise.
- * IN assertion: the fields freq of dyn_ltree are set and the total of all
- * frequencies does not exceed 64K (to fit in an int on 16 bit machines).
+ * 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)
+ * or white spaces (9 to 13, or 32); or set it to Z_BINARY otherwise.
+ * IN assertion: the fields Freq of dyn_ltree are set.
*/
-local void set_data_type(deflate_state *s)
+local void set_data_type(s)
+ deflate_state *s;
{
- int n = 0;
- unsigned ascii_freq = 0;
- unsigned bin_freq = 0;
- while (n < 7) bin_freq += s->dyn_ltree[n++].Freq;
- while (n < 128) ascii_freq += s->dyn_ltree[n++].Freq;
- while (n < LITERALS) bin_freq += s->dyn_ltree[n++].Freq;
- s->data_type = (Byte)(bin_freq > (ascii_freq >> 2) ? Z_BINARY : Z_ASCII);
+ int n;
+
+ for (n = 0; n < 9; n++)
+ if (s->dyn_ltree[n].Freq != 0)
+ break;
+ if (n == 9)
+ for (n = 14; n < 32; n++)
+ if (s->dyn_ltree[n].Freq != 0)
+ break;
+ s->strm->data_type = (n == 32) ? Z_TEXT : Z_BINARY;
}
/* ===========================================================================
@@ -1130,9 +1143,9 @@ local void set_data_type(deflate_state *s)
* method would use a table)
* IN assertion: 1 <= len <= 15
*/
-local unsigned bi_reverse(unsigned int code, int len)
- /* the value to invert */
- /* its bit length */
+local unsigned bi_reverse(code, len)
+ unsigned code; /* the value to invert */
+ int len; /* its bit length */
{
register unsigned res = 0;
do {
@@ -1145,7 +1158,8 @@ local unsigned bi_reverse(unsigned int code, int len)
/* ===========================================================================
* Flush the bit buffer, keeping at most 7 bits in it.
*/
-local void bi_flush(deflate_state *s)
+local void bi_flush(s)
+ deflate_state *s;
{
if (s->bi_valid == 16) {
put_short(s, s->bi_buf);
@@ -1161,7 +1175,8 @@ local void bi_flush(deflate_state *s)
/* ===========================================================================
* Flush the bit buffer and align the output on a byte boundary
*/
-local void bi_windup(deflate_state *s)
+local void bi_windup(s)
+ deflate_state *s;
{
if (s->bi_valid > 8) {
put_short(s, s->bi_buf);
@@ -1179,17 +1194,17 @@ local void bi_windup(deflate_state *s)
* Copy a stored block, storing first the length and its
* one's complement if requested.
*/
-local void copy_block(deflate_state *s, charf *buf, unsigned int len, int header)
-
- /* the input data */
- /* its length */
- /* true if block header must be written */
+local void copy_block(s, buf, len, header)
+ deflate_state *s;
+ charf *buf; /* the input data */
+ unsigned len; /* its length */
+ int header; /* true if block header must be written */
{
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);
put_short(s, (ush)~len);
#ifdef DEBUG
s->bits_sent += 2*16;
generated by cgit v0.12 at 2024-07-17 15:14:08 (GMT)