diff options
| -rw-r--r-- | cpukit/zlib/deflate.c | 268 | ||||
| -rw-r--r-- | cpukit/zlib/deflate.h | 17 | ||||
| -rw-r--r-- | cpukit/zlib/trees.c | 82 |
3 files changed, 250 insertions, 117 deletions
diff --git a/cpukit/zlib/deflate.c b/cpukit/zlib/deflate.c index 29ce1f64a5..fcd698cc62 100644 --- a/cpukit/zlib/deflate.c +++ b/cpukit/zlib/deflate.c @@ -1,5 +1,5 @@ /* deflate.c -- compress data using the deflation algorithm - * Copyright (C) 1995-2005 Jean-loup Gailly. + * Copyright (C) 1995-2010 Jean-loup Gailly and Mark Adler * For conditions of distribution and use, see copyright notice in zlib.h */ @@ -52,7 +52,7 @@ #include "deflate.h" const char deflate_copyright[] = - " deflate 1.2.3 Copyright 1995-2005 Jean-loup Gailly "; + " deflate 1.2.4 Copyright 1995-2010 Jean-loup Gailly and Mark Adler "; /* If you use the zlib library in a product, an acknowledgment is welcome in the documentation of your product. If for some reason you cannot @@ -79,19 +79,18 @@ local block_state deflate_fast OF((deflate_state *s, int flush)); #ifndef FASTEST local block_state deflate_slow OF((deflate_state *s, int flush)); #endif +local block_state deflate_rle OF((deflate_state *s, int flush)); +local block_state deflate_huff OF((deflate_state *s, int flush)); local void lm_init OF((deflate_state *s)); local void putShortMSB OF((deflate_state *s, uInt b)); local void flush_pending OF((z_streamp strm)); local int read_buf OF((z_streamp strm, Bytef *buf, unsigned size)); -#ifndef FASTEST #ifdef ASMV void match_init OF((void)); /* asm code initialization */ uInt longest_match OF((deflate_state *s, IPos cur_match)); #else local uInt longest_match OF((deflate_state *s, IPos cur_match)); #endif -#endif -local uInt longest_match_fast OF((deflate_state *s, IPos cur_match)); #ifdef DEBUG local void check_match OF((deflate_state *s, IPos start, IPos match, @@ -110,11 +109,6 @@ local void check_match OF((deflate_state *s, IPos start, IPos match, #endif /* Matches of length 3 are discarded if their distance exceeds TOO_FAR */ -#define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1) -/* Minimum amount of lookahead, except at the end of the input file. - * See deflate.c for comments about the MIN_MATCH+1. - */ - /* Values for max_lazy_match, good_match and max_chain_length, depending on * the desired pack level (0..9). The values given below have been tuned to * exclude worst case performance for pathological files. Better values may be @@ -288,6 +282,8 @@ int ZEXPORT deflateInit2_(strm, level, method, windowBits, memLevel, strategy, s->prev = (Posf *) ZALLOC(strm, s->w_size, sizeof(Pos)); s->head = (Posf *) ZALLOC(strm, s->hash_size, sizeof(Pos)); + s->high_water = 0; /* nothing written to s->window yet */ + s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */ overlay = (ushf *) ZALLOC(strm, s->lit_bufsize, sizeof(ush)+2); @@ -332,8 +328,8 @@ int ZEXPORT deflateSetDictionary (strm, dictionary, dictLength) strm->adler = adler32(strm->adler, dictionary, dictLength); if (length < MIN_MATCH) return Z_OK; - if (length > MAX_DIST(s)) { - length = MAX_DIST(s); + if (length > s->w_size) { + length = s->w_size; dictionary += dictLength - length; /* use the tail of the dictionary */ } zmemcpy(s->window, dictionary, length); @@ -435,9 +431,10 @@ int ZEXPORT deflateParams(strm, level, strategy) } func = configuration_table[s->level].func; - if (func != configuration_table[level].func && strm->total_in != 0) { + if ((strategy != s->strategy || func != configuration_table[level].func) && + strm->total_in != 0) { /* Flush the last buffer: */ - err = deflate(strm, Z_PARTIAL_FLUSH); + err = deflate(strm, Z_BLOCK); } if (s->level != level) { s->level = level; @@ -481,33 +478,66 @@ int ZEXPORT deflateTune(strm, good_length, max_lazy, nice_length, max_chain) * resulting from using fixed blocks instead of stored blocks, which deflate * can emit on compressed data for some combinations of the parameters. * - * This function could be more sophisticated to provide closer upper bounds - * for every combination of windowBits and memLevel, as well as wrap. - * But even the conservative upper bound of about 14% expansion does not - * seem onerous for output buffer allocation. + * This function could be more sophisticated to provide closer upper bounds for + * every combination of windowBits and memLevel. But even the conservative + * upper bound of about 14% expansion does not seem onerous for output buffer + * allocation. */ uLong ZEXPORT deflateBound(strm, sourceLen) z_streamp strm; uLong sourceLen; { deflate_state *s; - uLong destLen; + uLong complen, wraplen; + Bytef *str; - /* conservative upper bound */ - destLen = sourceLen + - ((sourceLen + 7) >> 3) + ((sourceLen + 63) >> 6) + 11; + /* conservative upper bound for compressed data */ + complen = sourceLen + + ((sourceLen + 7) >> 3) + ((sourceLen + 63) >> 6) + 5; - /* if can't get parameters, return conservative bound */ + /* if can't get parameters, return conservative bound plus zlib wrapper */ if (strm == Z_NULL || strm->state == Z_NULL) - return destLen; + return complen + 6; - /* if not default parameters, return conservative bound */ + /* compute wrapper length */ s = strm->state; + switch (s->wrap) { + case 0: /* raw deflate */ + wraplen = 0; + break; + case 1: /* zlib wrapper */ + wraplen = 6 + (s->strstart ? 4 : 0); + break; + case 2: /* gzip wrapper */ + wraplen = 18; + if (s->gzhead != Z_NULL) { /* user-supplied gzip header */ + if (s->gzhead->extra != Z_NULL) + wraplen += 2 + s->gzhead->extra_len; + str = s->gzhead->name; + if (str != Z_NULL) + do { + wraplen++; + } while (*str++); + str = s->gzhead->comment; + if (str != Z_NULL) + do { + wraplen++; + } while (*str++); + if (s->gzhead->hcrc) + wraplen += 2; + } + break; + default: /* for compiler happiness */ + wraplen = 6; + } + + /* if not default parameters, return conservative bound */ if (s->w_bits != 15 || s->hash_bits != 8 + 7) - return destLen; + return complen + wraplen; /* default settings: return tight bound for that case */ - return compressBound(sourceLen); + return sourceLen + (sourceLen >> 12) + (sourceLen >> 14) + + (sourceLen >> 25) + 13 - 6 + wraplen; } /* ========================================================================= @@ -557,7 +587,7 @@ int ZEXPORT deflate (strm, flush) deflate_state *s; if (strm == Z_NULL || strm->state == Z_NULL || - flush > Z_FINISH || flush < 0) { + flush > Z_BLOCK || flush < 0) { return Z_STREAM_ERROR; } s = strm->state; @@ -581,7 +611,7 @@ int ZEXPORT deflate (strm, flush) put_byte(s, 31); put_byte(s, 139); put_byte(s, 8); - if (s->gzhead == NULL) { + if (s->gzhead == Z_NULL) { put_byte(s, 0); put_byte(s, 0); put_byte(s, 0); @@ -608,7 +638,7 @@ int ZEXPORT deflate (strm, flush) (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2 ? 4 : 0)); put_byte(s, s->gzhead->os & 0xff); - if (s->gzhead->extra != NULL) { + if (s->gzhead->extra != Z_NULL) { put_byte(s, s->gzhead->extra_len & 0xff); put_byte(s, (s->gzhead->extra_len >> 8) & 0xff); } @@ -650,7 +680,7 @@ int ZEXPORT deflate (strm, flush) } #ifdef GZIP if (s->status == EXTRA_STATE) { - if (s->gzhead->extra != NULL) { + if (s->gzhead->extra != Z_NULL) { uInt beg = s->pending; /* start of bytes to update crc */ while (s->gzindex < (s->gzhead->extra_len & 0xffff)) { @@ -678,7 +708,7 @@ int ZEXPORT deflate (strm, flush) s->status = NAME_STATE; } if (s->status == NAME_STATE) { - if (s->gzhead->name != NULL) { + if (s->gzhead->name != Z_NULL) { uInt beg = s->pending; /* start of bytes to update crc */ int val; @@ -709,7 +739,7 @@ int ZEXPORT deflate (strm, flush) s->status = COMMENT_STATE; } if (s->status == COMMENT_STATE) { - if (s->gzhead->comment != NULL) { + if (s->gzhead->comment != Z_NULL) { uInt beg = s->pending; /* start of bytes to update crc */ int val; @@ -787,7 +817,9 @@ int ZEXPORT deflate (strm, flush) (flush != Z_NO_FLUSH && s->status != FINISH_STATE)) { block_state bstate; - bstate = (*(configuration_table[s->level].func))(s, flush); + bstate = s->strategy == Z_HUFFMAN_ONLY ? deflate_huff(s, flush) : + (s->strategy == Z_RLE ? deflate_rle(s, flush) : + (*(configuration_table[s->level].func))(s, flush)); if (bstate == finish_started || bstate == finish_done) { s->status = FINISH_STATE; @@ -808,13 +840,17 @@ int ZEXPORT deflate (strm, flush) if (bstate == block_done) { if (flush == Z_PARTIAL_FLUSH) { _tr_align(s); - } else { /* FULL_FLUSH or SYNC_FLUSH */ + } else if (flush != Z_BLOCK) { /* FULL_FLUSH or SYNC_FLUSH */ _tr_stored_block(s, (char*)0, 0L, 0); /* For a full flush, this empty block will be recognized * as a special marker by inflate_sync(). */ if (flush == Z_FULL_FLUSH) { CLEAR_HASH(s); /* forget history */ + if (s->lookahead == 0) { + s->strstart = 0; + s->block_start = 0L; + } } } flush_pending(strm); @@ -1167,12 +1203,13 @@ local uInt longest_match(s, cur_match) return s->lookahead; } #endif /* ASMV */ -#endif /* FASTEST */ + +#else /* FASTEST */ /* --------------------------------------------------------------------------- - * Optimized version for level == 1 or strategy == Z_RLE only + * Optimized version for FASTEST only */ -local uInt longest_match_fast(s, cur_match) +local uInt longest_match(s, cur_match) deflate_state *s; IPos cur_match; /* current match */ { @@ -1225,6 +1262,8 @@ local uInt longest_match_fast(s, cur_match) return (uInt)len <= s->lookahead ? (uInt)len : s->lookahead; } +#endif /* FASTEST */ + #ifdef DEBUG /* =========================================================================== * Check that the match at match_start is indeed a match. @@ -1303,7 +1342,6 @@ local void fill_window(s) later. (Using level 0 permanently is not an optimal usage of zlib, so we don't care about this pathological case.) */ - /* %%% avoid this when Z_RLE */ n = s->hash_size; p = &s->head[n]; do { @@ -1355,27 +1393,61 @@ local void fill_window(s) */ } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0); + + /* If the WIN_INIT bytes after the end of the current data have never been + * written, then zero those bytes in order to avoid memory check reports of + * the use of uninitialized (or uninitialised as Julian writes) bytes by + * the longest match routines. Update the high water mark for the next + * time through here. WIN_INIT is set to MAX_MATCH since the longest match + * routines allow scanning to strstart + MAX_MATCH, ignoring lookahead. + */ + if (s->high_water < s->window_size) { + ulg curr = s->strstart + (ulg)(s->lookahead); + ulg init; + + if (s->high_water < curr) { + /* Previous high water mark below current data -- zero WIN_INIT + * bytes or up to end of window, whichever is less. + */ + init = s->window_size - curr; + if (init > WIN_INIT) + init = WIN_INIT; + zmemzero(s->window + curr, (unsigned)init); + s->high_water = curr + init; + } + else if (s->high_water < (ulg)curr + WIN_INIT) { + /* High water mark at or above current data, but below current data + * plus WIN_INIT -- zero out to current data plus WIN_INIT, or up + * to end of window, whichever is less. + */ + init = (ulg)curr + WIN_INIT - s->high_water; + if (init > s->window_size - s->high_water) + init = s->window_size - s->high_water; + zmemzero(s->window + s->high_water, (unsigned)init); + s->high_water += init; + } + } } /* =========================================================================== * Flush the current block, with given end-of-file flag. * IN assertion: strstart is set to the end of the current match. */ -#define FLUSH_BLOCK_ONLY(s, eof) { \ +#define FLUSH_BLOCK_ONLY(s, last) { \ _tr_flush_block(s, (s->block_start >= 0L ? \ (charf *)&s->window[(unsigned)s->block_start] : \ (charf *)Z_NULL), \ (ulg)((long)s->strstart - s->block_start), \ - (eof)); \ + (last)); \ s->block_start = s->strstart; \ flush_pending(s->strm); \ Tracev((stderr,"[FLUSH]")); \ } /* Same but force premature exit if necessary. */ -#define FLUSH_BLOCK(s, eof) { \ - FLUSH_BLOCK_ONLY(s, eof); \ - if (s->strm->avail_out == 0) return (eof) ? finish_started : need_more; \ +#define FLUSH_BLOCK(s, last) { \ + FLUSH_BLOCK_ONLY(s, last); \ + if (s->strm->avail_out == 0) return (last) ? finish_started : need_more; \ } /* =========================================================================== @@ -1449,7 +1521,7 @@ local block_state deflate_fast(s, flush) deflate_state *s; int flush; { - IPos hash_head = NIL; /* head of the hash chain */ + IPos hash_head; /* head of the hash chain */ int bflush; /* set if current block must be flushed */ for (;;) { @@ -1469,6 +1541,7 @@ local block_state deflate_fast(s, flush) /* Insert the string window[strstart .. strstart+2] in the * dictionary, and set hash_head to the head of the hash chain: */ + hash_head = NIL; if (s->lookahead >= MIN_MATCH) { INSERT_STRING(s, s->strstart, hash_head); } @@ -1481,19 +1554,8 @@ local block_state deflate_fast(s, flush) * of window index 0 (in particular we have to avoid a match * of the string with itself at the start of the input file). */ -#ifdef FASTEST - if ((s->strategy != Z_HUFFMAN_ONLY && s->strategy != Z_RLE) || - (s->strategy == Z_RLE && s->strstart - hash_head == 1)) { - s->match_length = longest_match_fast (s, hash_head); - } -#else - if (s->strategy != Z_HUFFMAN_ONLY && s->strategy != Z_RLE) { - s->match_length = longest_match (s, hash_head); - } else if (s->strategy == Z_RLE && s->strstart - hash_head == 1) { - s->match_length = longest_match_fast (s, hash_head); - } -#endif - /* longest_match() or longest_match_fast() sets match_start */ + s->match_length = longest_match (s, hash_head); + /* longest_match() sets match_start */ } if (s->match_length >= MIN_MATCH) { check_match(s, s->strstart, s->match_start, s->match_length); @@ -1555,7 +1617,7 @@ local block_state deflate_slow(s, flush) deflate_state *s; int flush; { - IPos hash_head = NIL; /* head of hash chain */ + IPos hash_head; /* head of hash chain */ int bflush; /* set if current block must be flushed */ /* Process the input block. */ @@ -1576,6 +1638,7 @@ local block_state deflate_slow(s, flush) /* Insert the string window[strstart .. strstart+2] in the * dictionary, and set hash_head to the head of the hash chain: */ + hash_head = NIL; if (s->lookahead >= MIN_MATCH) { INSERT_STRING(s, s->strstart, hash_head); } @@ -1591,12 +1654,8 @@ local block_state deflate_slow(s, flush) * of window index 0 (in particular we have to avoid a match * of the string with itself at the start of the input file). */ - if (s->strategy != Z_HUFFMAN_ONLY && s->strategy != Z_RLE) { - s->match_length = longest_match (s, hash_head); - } else if (s->strategy == Z_RLE && s->strstart - hash_head == 1) { - s->match_length = longest_match_fast (s, hash_head); - } - /* longest_match() or longest_match_fast() sets match_start */ + s->match_length = longest_match (s, hash_head); + /* longest_match() sets match_start */ if (s->match_length <= 5 && (s->strategy == Z_FILTERED #if TOO_FAR <= 32767 @@ -1674,7 +1733,6 @@ local block_state deflate_slow(s, flush) } #endif /* FASTEST */ -#if 0 /* =========================================================================== * For Z_RLE, simply look for runs of bytes, generate matches only of distance * one. Do not maintain a hash table. (It will be regenerated if this run of @@ -1684,11 +1742,9 @@ local block_state deflate_rle(s, flush) deflate_state *s; int flush; { - int bflush; /* set if current block must be flushed */ - uInt run; /* length of run */ - uInt max; /* maximum length of run */ - uInt prev; /* byte at distance one to match */ - Bytef *scan; /* scan for end of run */ + int bflush; /* set if current block must be flushed */ + uInt prev; /* byte at distance one to match */ + Bytef *scan, *strend; /* scan goes up to strend for length of run */ for (;;) { /* Make sure that we always have enough lookahead, except @@ -1704,23 +1760,33 @@ local block_state deflate_rle(s, flush) } /* See how many times the previous byte repeats */ - run = 0; - if (s->strstart > 0) { /* if there is a previous byte, that is */ - max = s->lookahead < MAX_MATCH ? s->lookahead : MAX_MATCH; + s->match_length = 0; + if (s->lookahead >= MIN_MATCH && s->strstart > 0) { scan = s->window + s->strstart - 1; - prev = *scan++; - do { - if (*scan++ != prev) - break; - } while (++run < max); + prev = *scan; + if (prev == *++scan && prev == *++scan && prev == *++scan) { + strend = s->window + s->strstart + MAX_MATCH; + do { + } while (prev == *++scan && prev == *++scan && + prev == *++scan && prev == *++scan && + prev == *++scan && prev == *++scan && + prev == *++scan && prev == *++scan && + scan < strend); + s->match_length = MAX_MATCH - (int)(strend - scan); + if (s->match_length > s->lookahead) + s->match_length = s->lookahead; + } } /* Emit match if have run of MIN_MATCH or longer, else emit literal */ - if (run >= MIN_MATCH) { - check_match(s, s->strstart, s->strstart - 1, run); - _tr_tally_dist(s, 1, run - MIN_MATCH, bflush); - s->lookahead -= run; - s->strstart += run; + if (s->match_length >= MIN_MATCH) { + check_match(s, s->strstart, s->strstart - 1, s->match_length); + + _tr_tally_dist(s, 1, s->match_length - MIN_MATCH, bflush); + + s->lookahead -= s->match_length; + s->strstart += s->match_length; + s->match_length = 0; } else { /* No match, output a literal byte */ Tracevv((stderr,"%c", s->window[s->strstart])); @@ -1733,4 +1799,36 @@ local block_state deflate_rle(s, flush) FLUSH_BLOCK(s, flush == Z_FINISH); return flush == Z_FINISH ? finish_done : block_done; } -#endif + +/* =========================================================================== + * For Z_HUFFMAN_ONLY, do not look for matches. Do not maintain a hash table. + * (It will be regenerated if this run of deflate switches away from Huffman.) + */ +local block_state deflate_huff(s, flush) + deflate_state *s; + int flush; +{ + int bflush; /* set if current block must be flushed */ + + for (;;) { + /* Make sure that we have a literal to write. */ + if (s->lookahead == 0) { + fill_window(s); + if (s->lookahead == 0) { + if (flush == Z_NO_FLUSH) + return need_more; + break; /* flush the current block */ + } + } + + /* Output a literal byte */ + s->match_length = 0; + Tracevv((stderr,"%c", s->window[s->strstart])); + _tr_tally_lit (s, s->window[s->strstart], bflush); + s->lookahead--; + s->strstart++; + if (bflush) FLUSH_BLOCK(s, 0); + } + FLUSH_BLOCK(s, flush == Z_FINISH); + return flush == Z_FINISH ? finish_done : block_done; +} diff --git a/cpukit/zlib/deflate.h b/cpukit/zlib/deflate.h index 05a5ab3a2c..f53deba852 100644 --- a/cpukit/zlib/deflate.h +++ b/cpukit/zlib/deflate.h @@ -1,5 +1,5 @@ /* deflate.h -- internal compression state - * Copyright (C) 1995-2004 Jean-loup Gailly + * Copyright (C) 1995-2009 Jean-loup Gailly * For conditions of distribution and use, see copyright notice in zlib.h */ @@ -260,6 +260,13 @@ typedef struct internal_state { * are always zero. */ + ulg high_water; + /* High water mark offset in window for initialized bytes -- bytes above + * this are set to zero in order to avoid memory check warnings when + * longest match routines access bytes past the input. This is then + * updated to the new high water mark. + */ + } FAR deflate_state; /* Output a byte on the stream. @@ -278,14 +285,18 @@ typedef struct internal_state { * distances are limited to MAX_DIST instead of WSIZE. */ +#define WIN_INIT MAX_MATCH +/* Number of bytes after end of data in window to initialize in order to avoid + memory checker errors from longest match routines */ + /* in trees.c */ void _tr_init OF((deflate_state *s)); int _tr_tally OF((deflate_state *s, unsigned dist, unsigned lc)); void _tr_flush_block OF((deflate_state *s, charf *buf, ulg stored_len, - int eof)); + int last)); void _tr_align OF((deflate_state *s)); void _tr_stored_block OF((deflate_state *s, charf *buf, ulg stored_len, - int eof)); + int last)); #define d_code(dist) \ ((dist) < 256 ? _dist_code[dist] : _dist_code[256+((dist)>>7)]) diff --git a/cpukit/zlib/trees.c b/cpukit/zlib/trees.c index 395e4e1681..1a6e997ac0 100644 --- a/cpukit/zlib/trees.c +++ b/cpukit/zlib/trees.c @@ -1,5 +1,6 @@ /* trees.c -- output deflated data using Huffman coding - * Copyright (C) 1995-2005 Jean-loup Gailly + * Copyright (C) 1995-2009 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; @@ -864,13 +867,13 @@ local void send_all_trees(s, lcodes, dcodes, blcodes) /* =========================================================================== * Send a stored block */ -void _tr_stored_block(s, buf, stored_len, eof) +void _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; @@ -918,11 +921,11 @@ 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 _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 +934,8 @@ 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 +981,20 @@ 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); @@ -1005,14 +1008,14 @@ 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)); } /* =========================================================================== @@ -1118,24 +1121,45 @@ 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; } /* =========================================================================== |