/* deflate.c -- compress data using the deflation algorithm
- Copyright (C) 1999, 2006, 2009-2010 Free Software Foundation, Inc.
+ Copyright (C) 1999, 2006, 2009-2015 Free Software Foundation, Inc.
Copyright (C) 1992-1993 Jean-loup Gailly
This program is free software; you can redistribute it and/or modify
/* 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 */
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] = {
/* ===========================================================================
* 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).
*/
compr_level = pack_level;
/* Initialize the hash table. */
-#if defined(MAXSEG_64K) && HASH_BITS == 15
+#if defined MAXSEG_64K && HASH_BITS == 15
for (j = 0; j < HASH_SIZE; j++) head[j] = NIL;
#else
memzero((char*)head, HASH_SIZE*sizeof(*head));
* 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 */
/* Skip to next match if the match length cannot increase
* or if the match length is less than 2:
*/
-#if (defined(UNALIGNED_OK) && MAX_MATCH == 258)
+#if defined UNALIGNED_OK && MAX_MATCH == 258
/* This code assumes sizeof(unsigned short) == 2. Do not use
* UNALIGNED_OK if your compiler uses a different size.
*/
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;
}