summaryrefslogtreecommitdiff
path: root/Modules/zlib/trees.c
diff options
context:
space:
mode:
Diffstat (limited to 'Modules/zlib/trees.c')
-rw-r--r--Modules/zlib/trees.c93
1 files changed, 59 insertions, 34 deletions
diff --git a/Modules/zlib/trees.c b/Modules/zlib/trees.c
index 395e4e1681..56e9bb1c11 100644
--- a/Modules/zlib/trees.c
+++ b/Modules/zlib/trees.c
@@ -1,5 +1,6 @@
/* trees.c -- output deflated data using Huffman coding
- * Copyright (C) 1995-2005 Jean-loup Gailly
+ * Copyright (C) 1995-2010 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
*/
@@ -152,7 +153,7 @@ local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes,
int blcodes));
local void compress_block OF((deflate_state *s, ct_data *ltree,
ct_data *dtree));
-local void set_data_type OF((deflate_state *s));
+local int detect_data_type OF((deflate_state *s));
local unsigned bi_reverse OF((unsigned value, int length));
local void bi_windup OF((deflate_state *s));
local void bi_flush OF((deflate_state *s));
@@ -203,12 +204,12 @@ local void send_bits(s, value, length)
* unused bits in value.
*/
if (s->bi_valid > (int)Buf_size - length) {
- s->bi_buf |= (value << s->bi_valid);
+ s->bi_buf |= (ush)value << s->bi_valid;
put_short(s, s->bi_buf);
s->bi_buf = (ush)value >> (Buf_size - s->bi_valid);
s->bi_valid += length - Buf_size;
} else {
- s->bi_buf |= value << s->bi_valid;
+ s->bi_buf |= (ush)value << s->bi_valid;
s->bi_valid += length;
}
}
@@ -218,12 +219,12 @@ local void send_bits(s, value, length)
{ int len = length;\
if (s->bi_valid > (int)Buf_size - len) {\
int val = value;\
- s->bi_buf |= (val << s->bi_valid);\
+ s->bi_buf |= (ush)val << s->bi_valid;\
put_short(s, s->bi_buf);\
s->bi_buf = (ush)val >> (Buf_size - s->bi_valid);\
s->bi_valid += len - Buf_size;\
} else {\
- s->bi_buf |= (value) << s->bi_valid;\
+ s->bi_buf |= (ush)(value) << s->bi_valid;\
s->bi_valid += len;\
}\
}
@@ -250,11 +251,13 @@ local void tr_static_init()
if (static_init_done) return;
/* For some embedded targets, global variables are not initialized: */
+#ifdef NO_INIT_GLOBAL_POINTERS
static_l_desc.static_tree = static_ltree;
static_l_desc.extra_bits = extra_lbits;
static_d_desc.static_tree = static_dtree;
static_d_desc.extra_bits = extra_dbits;
static_bl_desc.extra_bits = extra_blbits;
+#endif
/* Initialize the mapping length (0..255) -> length code (0..28) */
length = 0;
@@ -348,13 +351,14 @@ void gen_trees_header()
static_dtree[i].Len, SEPARATOR(i, D_CODES-1, 5));
}
- fprintf(header, "const uch _dist_code[DIST_CODE_LEN] = {\n");
+ fprintf(header, "const uch ZLIB_INTERNAL _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");
+ fprintf(header,
+ "const uch ZLIB_INTERNAL _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));
@@ -379,7 +383,7 @@ void gen_trees_header()
/* ===========================================================================
* Initialize the tree data structures for a new zlib stream.
*/
-void _tr_init(s)
+void ZLIB_INTERNAL _tr_init(s)
deflate_state *s;
{
tr_static_init();
@@ -864,13 +868,13 @@ local void send_all_trees(s, lcodes, dcodes, blcodes)
/* ===========================================================================
* Send a stored block
*/
-void _tr_stored_block(s, buf, stored_len, eof)
+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 eof; /* true if this is the last block for a file */
+ int last; /* one if this is the last block for a file */
{
- send_bits(s, (STORED_BLOCK<<1)+eof, 3); /* send block type */
+ send_bits(s, (STORED_BLOCK<<1)+last, 3); /* send block type */
#ifdef DEBUG
s->compressed_len = (s->compressed_len + 3 + 7) & (ulg)~7L;
s->compressed_len += (stored_len + 4) << 3;
@@ -889,7 +893,7 @@ void _tr_stored_block(s, buf, stored_len, eof)
* To simplify the code, we assume the worst case of last real code encoded
* on one bit only.
*/
-void _tr_align(s)
+void ZLIB_INTERNAL _tr_align(s)
deflate_state *s;
{
send_bits(s, STATIC_TREES<<1, 3);
@@ -918,11 +922,11 @@ void _tr_align(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(s, buf, stored_len, eof)
+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 eof; /* true if this is the last block for a file */
+ 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 */
@@ -931,8 +935,8 @@ void _tr_flush_block(s, buf, stored_len, eof)
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);
+ if (s->strm->data_type == Z_UNKNOWN)
+ s->strm->data_type = detect_data_type(s);
/* Construct the literal and distance trees */
build_tree(s, (tree_desc *)(&(s->l_desc)));
@@ -978,20 +982,20 @@ void _tr_flush_block(s, buf, stored_len, eof)
* 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, eof);
+ _tr_stored_block(s, buf, stored_len, last);
#ifdef FORCE_STATIC
} else if (static_lenb >= 0) { /* force static trees */
#else
} else if (s->strategy == Z_FIXED || static_lenb == opt_lenb) {
#endif
- send_bits(s, (STATIC_TREES<<1)+eof, 3);
+ send_bits(s, (STATIC_TREES<<1)+last, 3);
compress_block(s, (ct_data *)static_ltree, (ct_data *)static_dtree);
#ifdef DEBUG
s->compressed_len += 3 + s->static_len;
#endif
} else {
- send_bits(s, (DYN_TREES<<1)+eof, 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,
max_blindex+1);
compress_block(s, (ct_data *)s->dyn_ltree, (ct_data *)s->dyn_dtree);
@@ -1005,21 +1009,21 @@ void _tr_flush_block(s, buf, stored_len, eof)
*/
init_block(s);
- if (eof) {
+ if (last) {
bi_windup(s);
#ifdef DEBUG
s->compressed_len += 7; /* align on byte boundary */
#endif
}
Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3,
- s->compressed_len-7*eof));
+ s->compressed_len-7*last));
}
/* ===========================================================================
* Save the match info and tally the frequency counts. Return true if
* the current block must be flushed.
*/
-int _tr_tally (s, dist, lc)
+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 (if dist==0) */
@@ -1118,24 +1122,45 @@ local void compress_block(s, ltree, dtree)
}
/* ===========================================================================
- * 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.
+ * 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 void set_data_type(s)
+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;
- for (n = 0; n < 9; 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)
- 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;
+ 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;
}
/* ===========================================================================
View Lorry Controller Status