/* deflate.c -- compress data using the deflation algorithm
- Copyright (C) 1999, 2006 Free Software Foundation, Inc.
+ Copyright (C) 1999, 2006, 2009-2012 Free Software Foundation, Inc.
Copyright (C) 1992-1993 Jean-loup Gailly
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2, or (at your option)
+ the Free Software Foundation; either version 3, or (at your option)
any later version.
This program is distributed in the hope that it will be useful,
#include "gzip.h"
#include "lzw.h" /* just for consistency checking */
-#ifdef RCSID
-static char rcsid[] = "$Id: deflate.c,v 1.5 2006/12/07 23:53:00 eggert Exp $";
-#endif
-
/* ===========================================================================
* Configuration parameters
*/
/* Matches of length 3 are discarded if their distance exceeds TOO_FAR */
#ifndef RSYNC_WIN
-# define RSYNC_WIN 4096
+# define RSYNC_WIN 8192
#endif
/* Size of rsync window, must be < MAX_DIST */
-#define RSYNC_SUM_MATCH(sum) ((sum) % RSYNC_WIN == 0)
+#define RSYNC_SUM_MATCH(sum) (((sum) & (RSYNC_WIN - 1)) == 0)
/* Whether window sum matches magic value */
/* ===========================================================================
/* DECLARE(Pos, head, 1<<HASH_BITS); */
/* Heads of the hash chains or NIL. */
-ulg window_size = (ulg)2*WSIZE;
+static ulg window_size = (ulg)2*WSIZE;
/* window size, 2*WSIZE except for MMAP or BIG_MEM, where it is the
* input file length plus MIN_LOOKAHEAD.
*/
* H_SHIFT * MIN_MATCH >= HASH_BITS
*/
-unsigned int near prev_length;
+ unsigned int near prev_length;
/* Length of the best match at previous step. Matches not greater than this
* are discarded. This is used in the lazy match evaluation.
*/
local int eofile; /* flag set at end of input file */
local unsigned lookahead; /* number of valid bytes ahead in window */
-unsigned near max_chain_length;
+ unsigned max_chain_length;
/* To speed up deflation, hash chains are never searched beyond this length.
* A higher limit improves compression ratio but degrades the speed.
*/
local int compr_level;
/* compression level (1..9) */
-unsigned near good_match;
+unsigned good_match;
/* Use a faster search when the previous match is longer than this */
local ulg rsync_sum; /* rolling sum of rsync window */
ush max_chain;
} config;
+#ifdef ASMV
+# define static_unless_ASMV
+#else
+# define static_unless_ASMV static
+#endif
+
#ifdef FULL_SEARCH
# define nice_match MAX_MATCH
#else
- int near nice_match; /* Stop searching when current match exceeds this */
+ /* Stop searching when current match exceeds this */
+ static_unless_ASMV int nice_match;
#endif
local config configuration_table[10] = {
* meaning.
*/
-#define EQUAL 0
-/* result of memcmp for equal strings */
-
/* ===========================================================================
* Prototypes for local functions.
*/
-local void fill_window OF((void));
-local off_t deflate_fast OF((void));
+local void fill_window (void);
+local off_t deflate_fast (void);
- int longest_match OF((IPos cur_match));
#ifdef ASMV
- void match_init OF((void)); /* asm code initialization */
+ int longest_match (IPos cur_match);
+ void match_init (void); /* asm code initialization */
#endif
#ifdef DEBUG
-local void check_match OF((IPos start, IPos match, int length));
+local void check_match (IPos start, IPos match, int length);
#endif
/* ===========================================================================
* Update a hash value with the given input byte
- * IN assertion: all calls to to UPDATE_HASH are made with consecutive
+ * IN assertion: all calls to UPDATE_HASH are made with consecutive
* input characters, so that a running hash key can be computed from the
* previous key instead of complete recalculation each time.
*/
* Insert string s in the dictionary and set match_head to the previous head
* of the hash chain (the most recent string with same hash key). Return
* the previous length of the hash chain.
- * IN assertion: all calls to to INSERT_STRING are made with consecutive
+ * IN assertion: all calls to INSERT_STRING are made with consecutive
* input characters and the first MIN_MATCH bytes of s are valid
* (except for the last MIN_MATCH-1 bytes of the input file).
*/
strstart = 0;
block_start = 0L;
+ rsync_chunk_end = 0xFFFFFFFFUL;
#ifdef ASMV
match_init(); /* initialize the asm code */
#endif
lookahead = read_buf((char*)window,
- sizeof(int) <= 2 ? (unsigned)WSIZE : 2*WSIZE);
+ sizeof(int) <= 2 ? (unsigned)WSIZE : 2*WSIZE);
if (lookahead == 0 || lookahead == (unsigned)EOF) {
eofile = 1, lookahead = 0;
* match.s. The code is functionally equivalent, so you can use the C version
* if desired.
*/
-int longest_match(cur_match)
- IPos cur_match; /* current match */
+static int
+longest_match(IPos cur_match)
{
unsigned chain_length = max_chain_length; /* max hash chain length */
register uch *scan = window + strstart; /* current string */
#endif
}
} while ((cur_match = prev[cur_match & WMASK]) > limit
- && --chain_length != 0);
+ && --chain_length != 0);
return best_len;
}
{
/* check that the match is indeed a match */
if (memcmp((char*)window + match,
- (char*)window + start, length) != EQUAL) {
+ (char*)window + start, length) != 0) {
fprintf(stderr,
" start %d, match %d, length %d\n",
start, match, length);
n = read_buf((char*)window+strstart+lookahead, more);
if (n == 0 || n == (unsigned)EOF) {
eofile = 1;
+ /* Don't let garbage pollute the dictionary. */
+ memzero (window + strstart + lookahead, MIN_MATCH - 1);
} else {
lookahead += n;
}
*/
#define FLUSH_BLOCK(eof) \
flush_block(block_start >= 0L ? (char*)&window[(unsigned)block_start] : \
- (char*)NULL, (long)strstart - block_start, flush-1, (eof))
+ (char*)NULL, (long)strstart - block_start, (eof))
/* ===========================================================================
* Processes a new input file and return its compressed length. This
local off_t deflate_fast()
{
IPos hash_head; /* head of the hash chain */
- int flush; /* set if current block must be flushed, 2=>and padded */
+ int flush; /* set if current block must be flushed */
unsigned match_length = 0; /* length of best match */
prev_length = MIN_MATCH-1;
* At this point we have always match_length < MIN_MATCH
*/
if (hash_head != NIL && strstart - hash_head <= MAX_DIST
- && strstart <= window_size - MIN_LOOKAHEAD) {
+ && strstart <= window_size - MIN_LOOKAHEAD) {
/* To simplify the code, we prevent matches with the string
* of window index 0 (in particular we have to avoid a match
* of the string with itself at the start of the input file).
* the next lookahead bytes will be emitted as literals.
*/
} while (--match_length != 0);
- strstart++;
+ strstart++;
} else {
- strstart += match_length;
- match_length = 0;
- ins_h = window[strstart];
- UPDATE_HASH(ins_h, window[strstart+1]);
+ strstart += match_length;
+ match_length = 0;
+ ins_h = window[strstart];
+ UPDATE_HASH(ins_h, window[strstart+1]);
#if MIN_MATCH != 3
Call UPDATE_HASH() MIN_MATCH-3 more times
#endif
flush = ct_tally (0, window[strstart]);
RSYNC_ROLL(strstart, 1);
lookahead--;
- strstart++;
+ strstart++;
+ }
+ if (rsync && strstart > rsync_chunk_end) {
+ ush attr = 0; /* ascii/binary flag */
+
+ flush = 1;
+ /* Reset huffman tree */
+ ct_init(&attr, &method);
+ rsync_chunk_end = 0xFFFFFFFFUL;
}
- if (rsync && strstart > rsync_chunk_end) {
- rsync_chunk_end = 0xFFFFFFFFUL;
- flush = 2;
- }
if (flush) FLUSH_BLOCK(0), block_start = strstart;
/* Make sure that we always have enough lookahead, except
strstart++;
if (rsync && strstart > rsync_chunk_end) {
+ ush attr = 0; /* ascii/binary flag */
+
+ /* Reset huffman tree */
+ ct_init(&attr, &method);
rsync_chunk_end = 0xFFFFFFFFUL;
- flush = 2;
+ flush = 1;
}
if (flush) FLUSH_BLOCK(0), block_start = strstart;
} else if (match_available) {
Tracevv((stderr,"%c",window[strstart-1]));
flush = ct_tally (0, window[strstart-1]);
if (rsync && strstart > rsync_chunk_end) {
+ ush attr = 0; /* ascii/binary flag */
+
+ /* Reset huffman tree */
+ ct_init(&attr, &method);
rsync_chunk_end = 0xFFFFFFFFUL;
- flush = 2;
+
+ flush = 1;
}
if (flush) FLUSH_BLOCK(0), block_start = strstart;
RSYNC_ROLL(strstart, 1);
* the next step to decide.
*/
if (rsync && strstart > rsync_chunk_end) {
+ ush attr = 0; /* ascii/binary flag */
+
/* Reset huffman tree */
+ ct_init(&attr, &method);
rsync_chunk_end = 0xFFFFFFFFUL;
- flush = 2;
+
FLUSH_BLOCK(0), block_start = strstart;
}
match_available = 1;
projects / debian / gzip / blobdiff