X-Git-Url: https://git.gag.com/?a=blobdiff_plain;f=deflate.c;h=f0f23940ac9d0c891877105ebc803d508483987d;hb=b6def44c57e9b31b98b7766c8916531a4db9fd27;hp=0950391ee88ba44a67a36ce4f1b14c87f79ebaa3;hpb=802f4f397f6823422798c944b833b112af37ce14;p=debian%2Fgzip diff --git a/deflate.c b/deflate.c index 0950391..f0f2394 100644 --- a/deflate.c +++ b/deflate.c @@ -1,6 +1,6 @@ /* deflate.c -- compress data using the deflation algorithm - Copyright (C) 1999, 2006, 2009-2010 Free Software Foundation, Inc. + Copyright (C) 1999, 2006, 2009-2013 Free Software Foundation, Inc. Copyright (C) 1992-1993 Jean-loup Gailly This program is free software; you can redistribute it and/or modify @@ -161,7 +161,7 @@ typedef unsigned IPos; /* DECLARE(Pos, head, 1<= 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. */ @@ -190,7 +190,7 @@ unsigned int near prev_length; 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. */ @@ -209,7 +209,7 @@ local unsigned int max_lazy_match; 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 */ @@ -226,10 +226,17 @@ typedef struct config { 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] = { @@ -254,21 +261,21 @@ 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. */ @@ -278,7 +285,7 @@ local void check_match OF((IPos start, IPos match, int length)); * 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). */ @@ -329,7 +336,7 @@ void lm_init (pack_level, flags) #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; @@ -361,8 +368,8 @@ void lm_init (pack_level, flags) * 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 */ @@ -481,7 +488,7 @@ int longest_match(cur_match) #endif } } while ((cur_match = prev[cur_match & WMASK]) > limit - && --chain_length != 0); + && --chain_length != 0); return best_len; } @@ -564,6 +571,8 @@ local void fill_window() 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; } @@ -601,7 +610,7 @@ local off_t deflate_fast() * 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). @@ -617,7 +626,7 @@ local off_t deflate_fast() lookahead -= match_length; - /* Insert new strings in the hash table only if the match length + /* Insert new strings in the hash table only if the match length * is not too large. This saves time but degrades compression. */ if (match_length <= max_insert_length) { @@ -631,12 +640,12 @@ local off_t deflate_fast() * 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 @@ -646,7 +655,7 @@ local off_t deflate_fast() Tracevv((stderr,"%c",window[strstart])); flush = ct_tally (0, window[strstart]); lookahead--; - strstart++; + strstart++; } if (flush) FLUSH_BLOCK(0), block_start = strstart;