/* deflate.c -- compress data using the deflation algorithm * Copyright (C) 1995-2013 Jean-loup Gailly and Mark Adler * For conditions of distribution and use, see copyright notice in zlib.h */ /* * ALGORITHM * * The "deflation" process depends on being able to identify portions * of the input text which are identical to earlier input (within a * sliding window trailing behind the input currently being processed). * * The most straightforward technique turns out to be the fastest for * most input files: try all possible matches and select the longest. * The key feature of this algorithm is that insertions into the string * dictionary are very simple and thus fast, and deletions are avoided * completely. Insertions are performed at each input character, whereas * string matches are performed only when the previous match ends. So it * is preferable to spend more time in matches to allow very fast string * insertions and avoid deletions. The matching algorithm for small * strings is inspired from that of Rabin & Karp. A brute force approach * is used to find longer strings when a small match has been found. * A similar algorithm is used in comic (by Jan-Mark Wams) and freeze * (by Leonid Broukhis). * A previous version of this file used a more sophisticated algorithm * (by Fiala and Greene) which is guaranteed to run in linear amortized * time, but has a larger average cost, uses more memory and is patented. * However the F&G algorithm may be faster for some highly redundant * files if the parameter max_chain_length (described below) is too large. * * ACKNOWLEDGEMENTS * * The idea of lazy evaluation of matches is due to Jan-Mark Wams, and * I found it in 'freeze' written by Leonid Broukhis. * Thanks to many people for bug reports and testing. * * REFERENCES * * Deutsch, L.P.,"DEFLATE Compressed Data Format Specification". * Available in http://tools.ietf.org/html/rfc1951 * * A description of the Rabin and Karp algorithm is given in the book * "Algorithms" by R. Sedgewick, Addison-Wesley, p252. * * Fiala,E.R., and Greene,D.H. * Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595 * */ /* @(#) $Id$ */ #include "deflate.h" #include "deflate_p.h" #include "match.h" const char deflate_copyright[] = " deflate 1.2.8.f Copyright 1995-2013 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 include such an acknowledgment, I would appreciate that you keep this copyright string in the executable of your product. */ /* =========================================================================== * Function prototypes. */ typedef block_state (*compress_func) (deflate_state *s, int flush); /* Compression function. Returns the block state after the call. */ void fill_window (deflate_state *s); local block_state deflate_stored (deflate_state *s, int flush); block_state deflate_fast (deflate_state *s, int flush); block_state deflate_quick (deflate_state *s, int flush); #ifdef MEDIUM_STRATEGY block_state deflate_medium (deflate_state *s, int flush); #endif block_state deflate_slow (deflate_state *s, int flush); local block_state deflate_rle (deflate_state *s, int flush); local block_state deflate_huff (deflate_state *s, int flush); local void lm_init (deflate_state *s); local void putShortMSB (deflate_state *s, uint16_t b); ZLIB_INTERNAL void flush_pending (z_stream *strm); ZLIB_INTERNAL int read_buf (z_stream *strm, unsigned char *buf, unsigned size); extern void crc_reset(deflate_state *const s); extern void crc_finalize(deflate_state *const s); extern void copy_with_crc(z_stream *strm, unsigned char *dst, long size); /* =========================================================================== * Local data */ #define NIL 0 /* Tail of hash chains */ /* 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 * found for specific files. */ typedef struct config_s { uint16_t good_length; /* reduce lazy search above this match length */ uint16_t max_lazy; /* do not perform lazy search above this match length */ uint16_t nice_length; /* quit search above this match length */ uint16_t max_chain; compress_func func; } config; local const config configuration_table[10] = { /* good lazy nice chain */ /* 0 */ {0, 0, 0, 0, deflate_stored}, /* store only */ #ifdef X86_QUICK_STRATEGY /* 1 */ {4, 4, 8, 4, deflate_quick}, /* 2 */ {4, 4, 8, 4, deflate_fast}, /* max speed, no lazy matches */ #else /* 1 */ {4, 4, 8, 4, deflate_fast}, /* max speed, no lazy matches */ /* 2 */ {4, 5, 16, 8, deflate_fast}, #endif /* 3 */ {4, 6, 32, 32, deflate_fast}, #ifdef MEDIUM_STRATEGY /* 4 */ {4, 4, 16, 16, deflate_medium}, /* lazy matches */ /* 5 */ {8, 16, 32, 32, deflate_medium}, /* 6 */ {8, 16, 128, 128, deflate_medium}, #else /* 4 */ {4, 4, 16, 16, deflate_slow}, /* lazy matches */ /* 5 */ {8, 16, 32, 32, deflate_slow}, /* 6 */ {8, 16, 128, 128, deflate_slow}, #endif /* 7 */ {8, 32, 128, 256, deflate_slow}, /* 8 */ {32, 128, 258, 1024, deflate_slow}, /* 9 */ {32, 258, 258, 4096, deflate_slow}}; /* max compression */ /* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4 * For deflate_fast() (levels <= 3) good is ignored and lazy has a different * meaning. */ #define EQUAL 0 /* result of memcmp for equal strings */ /* rank Z_BLOCK between Z_NO_FLUSH and Z_PARTIAL_FLUSH */ #define RANK(f) (((f) * 2) - ((f) > 4 ? 9 : 0)) /* =========================================================================== * Initialize the hash table (avoiding 64K overflow for 16 bit systems). * prev[] will be initialized on the fly. */ #define CLEAR_HASH(s) \ s->head[s->hash_size-1] = NIL; \ memset((unsigned char *)s->head, 0, (unsigned)(s->hash_size-1)*sizeof(*s->head)); /* ========================================================================= */ int ZEXPORT deflateInit_(z_stream *strm, int level, const char *version, int stream_size) { return deflateInit2_(strm, level, Z_DEFLATED, MAX_WBITS, DEF_MEM_LEVEL, Z_DEFAULT_STRATEGY, version, stream_size); /* Todo: ignore strm->next_in if we use it as window */ } /* ========================================================================= */ int ZEXPORT deflateInit2_(z_stream *strm, int level, int method, int windowBits, int memLevel, int strategy, const char *version, int stream_size) { unsigned window_padding = 0; deflate_state *s; int wrap = 1; static const char my_version[] = ZLIB_VERSION; uint16_t *overlay; /* We overlay pending_buf and d_buf+l_buf. This works since the average * output size for (length,distance) codes is <= 24 bits. */ #if defined(X86_SSE2_FILL_WINDOW) || defined(X86_SSE4_2_CRC_HASH) x86_check_features(); #endif if (version == Z_NULL || version[0] != my_version[0] || stream_size != sizeof(z_stream)) { return Z_VERSION_ERROR; } if (strm == Z_NULL) return Z_STREAM_ERROR; strm->msg = Z_NULL; if (strm->zalloc == (alloc_func)0) { strm->zalloc = zcalloc; strm->opaque = NULL; } if (strm->zfree == (free_func)0) strm->zfree = zcfree; if (level == Z_DEFAULT_COMPRESSION) level = 6; if (windowBits < 0) { /* suppress zlib wrapper */ wrap = 0; windowBits = -windowBits; #ifdef GZIP } else if (windowBits > 15) { wrap = 2; /* write gzip wrapper instead */ windowBits -= 16; #endif } if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != Z_DEFLATED || windowBits < 8 || windowBits > 15 || level < 0 || level > 9 || strategy < 0 || strategy > Z_FIXED) { return Z_STREAM_ERROR; } if (windowBits == 8) windowBits = 9; /* until 256-byte window bug fixed */ #ifdef X86_QUICK_STRATEGY if (level == 1) windowBits = 13; #endif s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state)); if (s == Z_NULL) return Z_MEM_ERROR; strm->state = (struct internal_state *)s; s->strm = strm; s->wrap = wrap; s->gzhead = Z_NULL; s->w_bits = windowBits; s->w_size = 1 << s->w_bits; s->w_mask = s->w_size - 1; #ifdef X86_SSE4_2_CRC_HASH if (x86_cpu_has_sse42) s->hash_bits = 15; else #endif s->hash_bits = memLevel + 7; s->hash_size = 1 << s->hash_bits; s->hash_mask = s->hash_size - 1; s->hash_shift = ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH); #ifdef X86_PCLMULQDQ_CRC window_padding = 8; #endif s->window = (unsigned char *) ZALLOC(strm, s->w_size + window_padding, 2*sizeof(unsigned char)); s->prev = (Pos *) ZALLOC(strm, s->w_size, sizeof(Pos)); s->head = (Pos *) 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 = (uint16_t *) ZALLOC(strm, s->lit_bufsize, sizeof(uint16_t)+2); s->pending_buf = (unsigned char *) overlay; s->pending_buf_size = (unsigned long)s->lit_bufsize * (sizeof(uint16_t)+2L); if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL || s->pending_buf == Z_NULL) { s->status = FINISH_STATE; strm->msg = ERR_MSG(Z_MEM_ERROR); deflateEnd(strm); return Z_MEM_ERROR; } s->d_buf = overlay + s->lit_bufsize/sizeof(uint16_t); s->l_buf = s->pending_buf + (1+sizeof(uint16_t))*s->lit_bufsize; s->level = level; s->strategy = strategy; s->method = (unsigned char)method; return deflateReset(strm); } /* ========================================================================= */ int ZEXPORT deflateSetDictionary(z_stream *strm, const unsigned char *dictionary, unsigned int dictLength) { deflate_state *s; unsigned int str, n; int wrap; uint32_t avail; const unsigned char *next; if (strm == Z_NULL || strm->state == Z_NULL || dictionary == Z_NULL) return Z_STREAM_ERROR; s = strm->state; wrap = s->wrap; if (wrap == 2 || (wrap == 1 && s->status != INIT_STATE) || s->lookahead) return Z_STREAM_ERROR; /* when using zlib wrappers, compute Adler-32 for provided dictionary */ if (wrap == 1) strm->adler = adler32(strm->adler, dictionary, dictLength); s->wrap = 0; /* avoid computing Adler-32 in read_buf */ /* if dictionary would fill window, just replace the history */ if (dictLength >= s->w_size) { if (wrap == 0) { /* already empty otherwise */ CLEAR_HASH(s); s->strstart = 0; s->block_start = 0L; s->insert = 0; } dictionary += dictLength - s->w_size; /* use the tail */ dictLength = s->w_size; } /* insert dictionary into window and hash */ avail = strm->avail_in; next = strm->next_in; strm->avail_in = dictLength; strm->next_in = (const unsigned char *)dictionary; fill_window(s); while (s->lookahead >= MIN_MATCH) { str = s->strstart; n = s->lookahead - (MIN_MATCH-1); bulk_insert_str(s, str, n); s->strstart = str + n; s->lookahead = MIN_MATCH-1; fill_window(s); } s->strstart += s->lookahead; s->block_start = (long)s->strstart; s->insert = s->lookahead; s->lookahead = 0; s->match_length = s->prev_length = MIN_MATCH-1; s->match_available = 0; strm->next_in = next; strm->avail_in = avail; s->wrap = wrap; return Z_OK; } /* ========================================================================= */ int ZEXPORT deflateResetKeep(z_stream *strm) { deflate_state *s; if (strm == Z_NULL || strm->state == Z_NULL || strm->zalloc == (alloc_func)0 || strm->zfree == (free_func)0) { return Z_STREAM_ERROR; } strm->total_in = strm->total_out = 0; strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */ strm->data_type = Z_UNKNOWN; s = (deflate_state *)strm->state; s->pending = 0; s->pending_out = s->pending_buf; if (s->wrap < 0) { s->wrap = -s->wrap; /* was made negative by deflate(..., Z_FINISH); */ } s->status = s->wrap ? INIT_STATE : BUSY_STATE; #ifdef GZIP strm->adler = s->wrap == 2 ? crc32(0L, Z_NULL, 0) : adler32(0L, Z_NULL, 0); #else strm->adler = adler32(0L, Z_NULL, 0); #endif s->last_flush = Z_NO_FLUSH; _tr_init(s); return Z_OK; } /* ========================================================================= */ int ZEXPORT deflateReset(z_stream *strm) { int ret; ret = deflateResetKeep(strm); if (ret == Z_OK) lm_init(strm->state); return ret; } /* ========================================================================= */ int ZEXPORT deflateSetHeader(z_stream *strm, gz_headerp head) { if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; if (strm->state->wrap != 2) return Z_STREAM_ERROR; strm->state->gzhead = head; return Z_OK; } /* ========================================================================= */ int ZEXPORT deflatePending(z_stream *strm, uint32_t *pending, int *bits) { if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; if (pending != Z_NULL) *pending = strm->state->pending; if (bits != Z_NULL) *bits = strm->state->bi_valid; return Z_OK; } /* ========================================================================= */ int ZEXPORT deflatePrime(z_stream *strm, int bits, int value) { deflate_state *s; int put; if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; s = strm->state; if ((unsigned char *)(s->d_buf) < s->pending_out + ((Buf_size + 7) >> 3)) return Z_BUF_ERROR; do { put = Buf_size - s->bi_valid; if (put > bits) put = bits; s->bi_buf |= (uint16_t)((value & ((1 << put) - 1)) << s->bi_valid); s->bi_valid += put; _tr_flush_bits(s); value >>= put; bits -= put; } while (bits); return Z_OK; } /* ========================================================================= */ int ZEXPORT deflateParams(z_stream *strm, int level, int strategy) { deflate_state *s; compress_func func; int err = Z_OK; if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; s = strm->state; if (level == Z_DEFAULT_COMPRESSION) level = 6; if (level < 0 || level > 9 || strategy < 0 || strategy > Z_FIXED) { return Z_STREAM_ERROR; } func = configuration_table[s->level].func; if ((strategy != s->strategy || func != configuration_table[level].func)) { /* Flush the last buffer: */ err = deflate(strm, Z_BLOCK); if (err == Z_BUF_ERROR && s->pending == 0) err = Z_OK; } if (s->level != level) { s->level = level; s->max_lazy_match = configuration_table[level].max_lazy; s->good_match = configuration_table[level].good_length; s->nice_match = configuration_table[level].nice_length; s->max_chain_length = configuration_table[level].max_chain; } s->strategy = strategy; return err; } /* ========================================================================= */ int ZEXPORT deflateTune(z_stream *strm, int good_length, int max_lazy, int nice_length, int max_chain) { deflate_state *s; if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; s = strm->state; s->good_match = good_length; s->max_lazy_match = max_lazy; s->nice_match = nice_length; s->max_chain_length = max_chain; return Z_OK; } /* ========================================================================= * For the default windowBits of 15 and memLevel of 8, this function returns * a close to exact, as well as small, upper bound on the compressed size. * They are coded as constants here for a reason--if the #define's are * changed, then this function needs to be changed as well. The return * value for 15 and 8 only works for those exact settings. * * For any setting other than those defaults for windowBits and memLevel, * the value returned is a conservative worst case for the maximum expansion * 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. But even the conservative * upper bound of about 14% expansion does not seem onerous for output buffer * allocation. */ unsigned long ZEXPORT deflateBound(z_stream *strm, unsigned long sourceLen) { deflate_state *s; unsigned long complen, wraplen; unsigned char *str; /* conservative upper bound for compressed data */ complen = sourceLen + ((sourceLen + 7) >> 3) + ((sourceLen + 63) >> 6) + 5; /* if can't get parameters, return conservative bound plus zlib wrapper */ if (strm == Z_NULL || strm->state == Z_NULL) return complen + 6; /* 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 complen + wraplen; /* default settings: return tight bound for that case */ return sourceLen + (sourceLen >> 12) + (sourceLen >> 14) + (sourceLen >> 25) + 13 - 6 + wraplen; } /* ========================================================================= * Put a short in the pending buffer. The 16-bit value is put in MSB order. * IN assertion: the stream state is correct and there is enough room in * pending_buf. */ local void putShortMSB(deflate_state *s, uint16_t b) { put_byte(s, (unsigned char)(b >> 8)); put_byte(s, (unsigned char)(b & 0xff)); } /* ========================================================================= * Flush as much pending output as possible. All deflate() output goes * through this function so some applications may wish to modify it * to avoid allocating a large strm->next_out buffer and copying into it. * (See also read_buf()). */ ZLIB_INTERNAL void flush_pending(z_stream *strm) { uint32_t len; deflate_state *s = strm->state; _tr_flush_bits(s); len = s->pending; if (len > strm->avail_out) len = strm->avail_out; if (len == 0) return; memcpy(strm->next_out, s->pending_out, len); strm->next_out += len; s->pending_out += len; strm->total_out += len; strm->avail_out -= len; s->pending -= len; if (s->pending == 0) { s->pending_out = s->pending_buf; } } /* ========================================================================= */ int ZEXPORT deflate(z_stream *strm, int flush) { int old_flush; /* value of flush param for previous deflate call */ deflate_state *s; if (strm == Z_NULL || strm->state == Z_NULL || flush > Z_BLOCK || flush < 0) { return Z_STREAM_ERROR; } s = strm->state; if (strm->next_out == Z_NULL || (strm->avail_in != 0 && strm->next_in == Z_NULL) || (s->status == FINISH_STATE && flush != Z_FINISH)) { ERR_RETURN(strm, Z_STREAM_ERROR); } if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR); s->strm = strm; /* just in case */ old_flush = s->last_flush; s->last_flush = flush; /* Write the header */ if (s->status == INIT_STATE) { #ifdef GZIP if (s->wrap == 2) { crc_reset(s); put_byte(s, 31); put_byte(s, 139); put_byte(s, 8); if (s->gzhead == Z_NULL) { put_byte(s, 0); put_byte(s, 0); put_byte(s, 0); put_byte(s, 0); put_byte(s, 0); put_byte(s, s->level == 9 ? 2 : (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2 ? 4 : 0)); put_byte(s, OS_CODE); s->status = BUSY_STATE; } else { put_byte(s, (s->gzhead->text ? 1 : 0) + (s->gzhead->hcrc ? 2 : 0) + (s->gzhead->extra == Z_NULL ? 0 : 4) + (s->gzhead->name == Z_NULL ? 0 : 8) + (s->gzhead->comment == Z_NULL ? 0 : 16) ); put_byte(s, (unsigned char)(s->gzhead->time & 0xff)); put_byte(s, (unsigned char)((s->gzhead->time >> 8) & 0xff)); put_byte(s, (unsigned char)((s->gzhead->time >> 16) & 0xff)); put_byte(s, (unsigned char)((s->gzhead->time >> 24) & 0xff)); put_byte(s, s->level == 9 ? 2 : (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2 ? 4 : 0)); put_byte(s, s->gzhead->os & 0xff); if (s->gzhead->extra != Z_NULL) { put_byte(s, s->gzhead->extra_len & 0xff); put_byte(s, (s->gzhead->extra_len >> 8) & 0xff); } if (s->gzhead->hcrc) strm->adler = crc32(strm->adler, s->pending_buf, s->pending); s->gzindex = 0; s->status = EXTRA_STATE; } } else #endif { unsigned int header = (Z_DEFLATED + ((s->w_bits-8) << 4)) << 8; unsigned int level_flags; if (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2) level_flags = 0; else if (s->level < 6) level_flags = 1; else if (s->level == 6) level_flags = 2; else level_flags = 3; header |= (level_flags << 6); if (s->strstart != 0) header |= PRESET_DICT; header += 31 - (header % 31); s->status = BUSY_STATE; putShortMSB(s, header); /* Save the adler32 of the preset dictionary: */ if (s->strstart != 0) { putShortMSB(s, (uint16_t)(strm->adler >> 16)); putShortMSB(s, (uint16_t)strm->adler); } strm->adler = adler32(0L, Z_NULL, 0); } } #ifdef GZIP if (s->status == EXTRA_STATE) { if (s->gzhead->extra != Z_NULL) { uint32_t beg = s->pending; /* start of bytes to update crc */ while (s->gzindex < (s->gzhead->extra_len & 0xffff)) { if (s->pending == s->pending_buf_size) { if (s->gzhead->hcrc && s->pending > beg) strm->adler = crc32(strm->adler, s->pending_buf + beg, s->pending - beg); flush_pending(strm); beg = s->pending; if (s->pending == s->pending_buf_size) break; } put_byte(s, s->gzhead->extra[s->gzindex]); s->gzindex++; } if (s->gzhead->hcrc && s->pending > beg) strm->adler = crc32(strm->adler, s->pending_buf + beg, s->pending - beg); if (s->gzindex == s->gzhead->extra_len) { s->gzindex = 0; s->status = NAME_STATE; } } else { s->status = NAME_STATE; } } if (s->status == NAME_STATE) { if (s->gzhead->name != Z_NULL) { uint32_t beg = s->pending; /* start of bytes to update crc */ int val; do { if (s->pending == s->pending_buf_size) { if (s->gzhead->hcrc && s->pending > beg) strm->adler = crc32(strm->adler, s->pending_buf + beg, s->pending - beg); flush_pending(strm); beg = s->pending; if (s->pending == s->pending_buf_size) { val = 1; break; } } val = s->gzhead->name[s->gzindex++]; put_byte(s, val); } while (val != 0); if (s->gzhead->hcrc && s->pending > beg) strm->adler = crc32(strm->adler, s->pending_buf + beg, s->pending - beg); if (val == 0) { s->gzindex = 0; s->status = COMMENT_STATE; } } else { s->status = COMMENT_STATE; } } if (s->status == COMMENT_STATE) { if (s->gzhead->comment != Z_NULL) { uint32_t beg = s->pending; /* start of bytes to update crc */ int val; do { if (s->pending == s->pending_buf_size) { if (s->gzhead->hcrc && s->pending > beg) strm->adler = crc32(strm->adler, s->pending_buf + beg, s->pending - beg); flush_pending(strm); beg = s->pending; if (s->pending == s->pending_buf_size) { val = 1; break; } } val = s->gzhead->comment[s->gzindex++]; put_byte(s, val); } while (val != 0); if (s->gzhead->hcrc && s->pending > beg) strm->adler = crc32(strm->adler, s->pending_buf + beg, s->pending - beg); if (val == 0) s->status = HCRC_STATE; } else { s->status = HCRC_STATE; } } if (s->status == HCRC_STATE) { if (s->gzhead->hcrc) { if (s->pending + 2 > s->pending_buf_size) flush_pending(strm); if (s->pending + 2 <= s->pending_buf_size) { put_byte(s, (unsigned char)(strm->adler & 0xff)); put_byte(s, (unsigned char)((strm->adler >> 8) & 0xff)); strm->adler = crc32(0L, Z_NULL, 0); s->status = BUSY_STATE; } } else { s->status = BUSY_STATE; } } #endif /* Flush as much pending output as possible */ if (s->pending != 0) { flush_pending(strm); if (strm->avail_out == 0) { /* Since avail_out is 0, deflate will be called again with * more output space, but possibly with both pending and * avail_in equal to zero. There won't be anything to do, * but this is not an error situation so make sure we * return OK instead of BUF_ERROR at next call of deflate: */ s->last_flush = -1; return Z_OK; } /* Make sure there is something to do and avoid duplicate consecutive * flushes. For repeated and useless calls with Z_FINISH, we keep * returning Z_STREAM_END instead of Z_BUF_ERROR. */ } else if (strm->avail_in == 0 && RANK(flush) <= RANK(old_flush) && flush != Z_FINISH) { ERR_RETURN(strm, Z_BUF_ERROR); } /* User must not provide more input after the first FINISH: */ if (s->status == FINISH_STATE && strm->avail_in != 0) { ERR_RETURN(strm, Z_BUF_ERROR); } /* Start a new block or continue the current one. */ if (strm->avail_in != 0 || s->lookahead != 0 || (flush != Z_NO_FLUSH && s->status != FINISH_STATE)) { block_state bstate; #ifdef X86_QUICK_STRATEGY if (s->level == 1 && !x86_cpu_has_sse42) bstate = s->strategy == Z_HUFFMAN_ONLY ? deflate_huff(s, flush) : (s->strategy == Z_RLE ? deflate_rle(s, flush) : deflate_fast(s, flush)); else #endif 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; } if (bstate == need_more || bstate == finish_started) { if (strm->avail_out == 0) { s->last_flush = -1; /* avoid BUF_ERROR next call, see above */ } return Z_OK; /* If flush != Z_NO_FLUSH && avail_out == 0, the next call * of deflate should use the same flush parameter to make sure * that the flush is complete. So we don't have to output an * empty block here, this will be done at next call. This also * ensures that for a very small output buffer, we emit at most * one empty block. */ } if (bstate == block_done) { if (flush == Z_PARTIAL_FLUSH) { _tr_align(s); } 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; s->insert = 0; } } } flush_pending(strm); if (strm->avail_out == 0) { s->last_flush = -1; /* avoid BUF_ERROR at next call, see above */ return Z_OK; } } } Assert(strm->avail_out > 0, "bug2"); if (flush != Z_FINISH) return Z_OK; if (s->wrap <= 0) return Z_STREAM_END; /* Write the trailer */ #ifdef GZIP if (s->wrap == 2) { crc_finalize(s); put_byte(s, (unsigned char)(strm->adler & 0xff)); put_byte(s, (unsigned char)((strm->adler >> 8) & 0xff)); put_byte(s, (unsigned char)((strm->adler >> 16) & 0xff)); put_byte(s, (unsigned char)((strm->adler >> 24) & 0xff)); put_byte(s, (unsigned char)(strm->total_in & 0xff)); put_byte(s, (unsigned char)((strm->total_in >> 8) & 0xff)); put_byte(s, (unsigned char)((strm->total_in >> 16) & 0xff)); put_byte(s, (unsigned char)((strm->total_in >> 24) & 0xff)); } else #endif { putShortMSB(s, (uint16_t)(strm->adler >> 16)); putShortMSB(s, (uint16_t)strm->adler); } flush_pending(strm); /* If avail_out is zero, the application will call deflate again * to flush the rest. */ if (s->wrap > 0) s->wrap = -s->wrap; /* write the trailer only once! */ return s->pending != 0 ? Z_OK : Z_STREAM_END; } /* ========================================================================= */ int ZEXPORT deflateEnd(z_stream *strm) { int status; if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; status = strm->state->status; if (status != INIT_STATE && status != EXTRA_STATE && status != NAME_STATE && status != COMMENT_STATE && status != HCRC_STATE && status != BUSY_STATE && status != FINISH_STATE) { return Z_STREAM_ERROR; } /* Deallocate in reverse order of allocations: */ TRY_FREE(strm, strm->state->pending_buf); TRY_FREE(strm, strm->state->head); TRY_FREE(strm, strm->state->prev); TRY_FREE(strm, strm->state->window); ZFREE(strm, strm->state); strm->state = Z_NULL; return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK; } /* ========================================================================= * Copy the source state to the destination state. */ int ZEXPORT deflateCopy(z_stream *dest, z_stream *source) { deflate_state *ds; deflate_state *ss; uint16_t *overlay; if (source == Z_NULL || dest == Z_NULL || source->state == Z_NULL) { return Z_STREAM_ERROR; } ss = source->state; memcpy((void *)dest, (void *)source, sizeof(z_stream)); ds = (deflate_state *) ZALLOC(dest, 1, sizeof(deflate_state)); if (ds == Z_NULL) return Z_MEM_ERROR; dest->state = (struct internal_state *) ds; memcpy((void *)ds, (void *)ss, sizeof(deflate_state)); ds->strm = dest; ds->window = (unsigned char *) ZALLOC(dest, ds->w_size, 2*sizeof(unsigned char)); ds->prev = (Pos *) ZALLOC(dest, ds->w_size, sizeof(Pos)); ds->head = (Pos *) ZALLOC(dest, ds->hash_size, sizeof(Pos)); overlay = (uint16_t *) ZALLOC(dest, ds->lit_bufsize, sizeof(uint16_t)+2); ds->pending_buf = (unsigned char *) overlay; if (ds->window == Z_NULL || ds->prev == Z_NULL || ds->head == Z_NULL || ds->pending_buf == Z_NULL) { deflateEnd(dest); return Z_MEM_ERROR; } memcpy(ds->window, ss->window, ds->w_size * 2 * sizeof(unsigned char)); memcpy((void *)ds->prev, (void *)ss->prev, ds->w_size * sizeof(Pos)); memcpy((void *)ds->head, (void *)ss->head, ds->hash_size * sizeof(Pos)); memcpy(ds->pending_buf, ss->pending_buf, (unsigned int)ds->pending_buf_size); ds->pending_out = ds->pending_buf + (ss->pending_out - ss->pending_buf); ds->d_buf = overlay + ds->lit_bufsize/sizeof(uint16_t); ds->l_buf = ds->pending_buf + (1+sizeof(uint16_t))*ds->lit_bufsize; ds->l_desc.dyn_tree = ds->dyn_ltree; ds->d_desc.dyn_tree = ds->dyn_dtree; ds->bl_desc.dyn_tree = ds->bl_tree; return Z_OK; } /* =========================================================================== * Read a new buffer from the current input stream, update the adler32 * and total number of bytes read. All deflate() input goes through * this function so some applications may wish to modify it to avoid * allocating a large strm->next_in buffer and copying from it. * (See also flush_pending()). */ ZLIB_INTERNAL int read_buf(z_stream *strm, unsigned char *buf, unsigned size) { uint32_t len = strm->avail_in; if (len > size) len = size; if (len == 0) return 0; strm->avail_in -= len; #ifdef GZIP if (strm->state->wrap == 2) copy_with_crc(strm, buf, len); else #endif { memcpy(buf, strm->next_in, len); if (strm->state->wrap == 1) strm->adler = adler32(strm->adler, buf, len); } strm->next_in += len; strm->total_in += len; return (int)len; } /* =========================================================================== * Initialize the "longest match" routines for a new zlib stream */ local void lm_init(deflate_state *s) { s->window_size = (unsigned long)2L*s->w_size; CLEAR_HASH(s); /* Set the default configuration parameters: */ s->max_lazy_match = configuration_table[s->level].max_lazy; s->good_match = configuration_table[s->level].good_length; s->nice_match = configuration_table[s->level].nice_length; s->max_chain_length = configuration_table[s->level].max_chain; s->strstart = 0; s->block_start = 0L; s->lookahead = 0; s->insert = 0; s->match_length = s->prev_length = MIN_MATCH-1; s->match_available = 0; s->ins_h = 0; } #ifdef DEBUG /* =========================================================================== * Check that the match at match_start is indeed a match. */ void check_match(deflate_state *s, IPos start, IPos match, int length) { /* check that the match is indeed a match */ if (memcmp(s->window + match, s->window + start, length) != EQUAL) { fprintf(stderr, " start %u, match %u, length %d\n", start, match, length); do { fprintf(stderr, "%c%c", s->window[match++], s->window[start++]); } while (--length != 0); z_error("invalid match"); } if (z_verbose > 1) { fprintf(stderr, "\\[%u,%d]", start-match, length); do { putc(s->window[start++], stderr); } while (--length != 0); } } #else # define check_match(s, start, match, length) #endif /* DEBUG */ /* =========================================================================== * Fill the window when the lookahead becomes insufficient. * Updates strstart and lookahead. * * IN assertion: lookahead < MIN_LOOKAHEAD * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD * At least one byte has been read, or avail_in == 0; reads are * performed for at least two bytes (required for the zip translate_eol * option -- not supported here). */ #ifdef X86_SSE2_FILL_WINDOW extern void fill_window_sse(deflate_state *s); #endif void fill_window_c(deflate_state *s); void fill_window(deflate_state *s) { #ifdef X86_SSE2_FILL_WINDOW # ifndef X86_NOCHECK_SSE2 if (x86_cpu_has_sse2) { # endif fill_window_sse(s); # ifndef X86_NOCHECK_SSE2 } else { fill_window_c(s); } # endif #else fill_window_c(s); #endif } void fill_window_c(deflate_state *s) { register unsigned n; register Pos *p; unsigned more; /* Amount of free space at the end of the window. */ unsigned int wsize = s->w_size; Assert(s->lookahead < MIN_LOOKAHEAD, "already enough lookahead"); do { more = (unsigned)(s->window_size -(unsigned long)s->lookahead -(unsigned long)s->strstart); /* If the window is almost full and there is insufficient lookahead, * move the upper half to the lower one to make room in the upper half. */ if (s->strstart >= wsize+MAX_DIST(s)) { memcpy(s->window, s->window+wsize, (unsigned)wsize); s->match_start -= wsize; s->strstart -= wsize; /* we now have strstart >= MAX_DIST */ s->block_start -= (long) wsize; /* Slide the hash table (could be avoided with 32 bit values at the expense of memory usage). We slide even when level == 0 to keep the hash table consistent if we switch back to level > 0 later. (Using level 0 permanently is not an optimal usage of zlib, so we don't care about this pathological case.) */ n = s->hash_size; p = &s->head[n]; #ifdef NOT_TWEAK_COMPILER do { unsigned m; m = *--p; *p = (Pos)(m >= wsize ? m-wsize : NIL); } while (--n); #else /* As of I make this change, gcc (4.8.*) isn't able to vectorize * this hot loop using saturated-subtraction on x86-64 architecture. * To avoid this defect, we can change the loop such that * o. the pointer advance forward, and * o. demote the variable 'm' to be local to the loop, and * choose type "Pos" (instead of 'unsigned int') for the * variable to avoid unncessary zero-extension. */ { unsigned int i; Pos *q = p - n; for (i = 0; i < n; i++) { Pos m = *q; Pos t = wsize; *q++ = (Pos)(m >= t ? m-t: NIL); } } #endif /* NOT_TWEAK_COMPILER */ n = wsize; p = &s->prev[n]; #ifdef NOT_TWEAK_COMPILER do { unsigned m; m = *--p; *p = (Pos)(m >= wsize ? m-wsize : NIL); /* If n is not on any hash chain, prev[n] is garbage but * its value will never be used. */ } while (--n); #else { unsigned int i; Pos *q = p - n; for (i = 0; i < n; i++) { Pos m = *q; Pos t = wsize; *q++ = (Pos)(m >= t ? m-t: NIL); } } #endif /* NOT_TWEAK_COMPILER */ more += wsize; } if (s->strm->avail_in == 0) break; /* If there was no sliding: * strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 && * more == window_size - lookahead - strstart * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1) * => more >= window_size - 2*WSIZE + 2 * In the BIG_MEM or MMAP case (not yet supported), * window_size == input_size + MIN_LOOKAHEAD && * strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD. * Otherwise, window_size == 2*WSIZE so more >= 2. * If there was sliding, more >= WSIZE. So in all cases, more >= 2. */ Assert(more >= 2, "more < 2"); n = read_buf(s->strm, s->window + s->strstart + s->lookahead, more); s->lookahead += n; /* Initialize the hash value now that we have some input: */ if (s->lookahead + s->insert >= MIN_MATCH) { unsigned int str = s->strstart - s->insert; s->ins_h = s->window[str]; if (str >= 1) UPDATE_HASH(s, s->ins_h, str + 1 - (MIN_MATCH-1)); #if MIN_MATCH != 3 Call UPDATE_HASH() MIN_MATCH-3 more times #endif while (s->insert) { UPDATE_HASH(s, s->ins_h, str); s->prev[str & s->w_mask] = s->head[s->ins_h]; s->head[s->ins_h] = (Pos)str; str++; s->insert--; if (s->lookahead + s->insert < MIN_MATCH) break; } } /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage, * but this is not important since only literal bytes will be emitted. */ } 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) { unsigned long curr = s->strstart + (unsigned long)(s->lookahead); unsigned long 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; memset(s->window + curr, 0, (unsigned)init); s->high_water = curr + init; } else if (s->high_water < (unsigned long)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 = (unsigned long)curr + WIN_INIT - s->high_water; if (init > s->window_size - s->high_water) init = s->window_size - s->high_water; memset(s->window + s->high_water, 0, (unsigned)init); s->high_water += init; } } Assert((unsigned long)s->strstart <= s->window_size - MIN_LOOKAHEAD, "not enough room for search"); } /* =========================================================================== * Copy without compression as much as possible from the input stream, return * the current block state. * This function does not insert new strings in the dictionary since * uncompressible data is probably not useful. This function is used * only for the level=0 compression option. * NOTE: this function should be optimized to avoid extra copying from * window to pending_buf. */ local block_state deflate_stored(deflate_state *s, int flush) { /* Stored blocks are limited to 0xffff bytes, pending_buf is limited * to pending_buf_size, and each stored block has a 5 byte header: */ unsigned long max_block_size = 0xffff; unsigned long max_start; if (max_block_size > s->pending_buf_size - 5) { max_block_size = (uint32_t)(s->pending_buf_size - 5); } /* Copy as much as possible from input to output: */ for (;;) { /* Fill the window as much as possible: */ if (s->lookahead <= 1) { Assert(s->strstart < s->w_size+MAX_DIST(s) || s->block_start >= (long)s->w_size, "slide too late"); fill_window(s); if (s->lookahead == 0 && flush == Z_NO_FLUSH) return need_more; if (s->lookahead == 0) break; /* flush the current block */ } Assert(s->block_start >= 0L, "block gone"); s->strstart += s->lookahead; s->lookahead = 0; /* Emit a stored block if pending_buf will be full: */ max_start = s->block_start + max_block_size; if (s->strstart == 0 || (unsigned long)s->strstart >= max_start) { /* strstart == 0 is possible when wraparound on 16-bit machine */ s->lookahead = (unsigned int)(s->strstart - max_start); s->strstart = (unsigned int)max_start; FLUSH_BLOCK(s, 0); } /* Flush if we may have to slide, otherwise block_start may become * negative and the data will be gone: */ if (s->strstart - (unsigned int)s->block_start >= MAX_DIST(s)) { FLUSH_BLOCK(s, 0); } } s->insert = 0; if (flush == Z_FINISH) { FLUSH_BLOCK(s, 1); return finish_done; } if ((long)s->strstart > s->block_start) FLUSH_BLOCK(s, 0); return block_done; } /* =========================================================================== * 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 * deflate switches away from Z_RLE.) */ local block_state deflate_rle(deflate_state *s, int flush) { int bflush; /* set if current block must be flushed */ unsigned int prev; /* byte at distance one to match */ unsigned char *scan, *strend; /* scan goes up to strend for length of run */ for (;;) { /* Make sure that we always have enough lookahead, except * at the end of the input file. We need MAX_MATCH bytes * for the longest run, plus one for the unrolled loop. */ if (s->lookahead <= MAX_MATCH) { fill_window(s); if (s->lookahead <= MAX_MATCH && flush == Z_NO_FLUSH) { return need_more; } if (s->lookahead == 0) break; /* flush the current block */ } /* See how many times the previous byte repeats */ s->match_length = 0; if (s->lookahead >= MIN_MATCH && s->strstart > 0) { scan = s->window + s->strstart - 1; 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; } Assert(scan <= s->window+(unsigned int)(s->window_size-1), "wild scan"); } /* Emit match if have run of MIN_MATCH or longer, else emit literal */ 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])); _tr_tally_lit(s, s->window[s->strstart], bflush); s->lookahead--; s->strstart++; } if (bflush) FLUSH_BLOCK(s, 0); } s->insert = 0; if (flush == Z_FINISH) { FLUSH_BLOCK(s, 1); return finish_done; } if (s->last_lit) FLUSH_BLOCK(s, 0); return block_done; } /* =========================================================================== * 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(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); } s->insert = 0; if (flush == Z_FINISH) { FLUSH_BLOCK(s, 1); return finish_done; } if (s->last_lit) FLUSH_BLOCK(s, 0); return block_done; }