/* deflate.c -- compress data using the deflation algorithm * Copyright (C) 1995-2016 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 "zbuild.h" #include "deflate.h" #include "deflate_p.h" #include "match_p.h" #include "functable.h" const char zng_deflate_copyright[] = " deflate 1.2.11.f Copyright 1995-2016 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. */ /* =========================================================================== * Architecture-specific hooks. */ #ifdef S390_DFLTCC_DEFLATE # include "arch/s390/dfltcc_deflate.h" #else /* Memory management for the deflate state. Useful for allocating arch-specific extension blocks. */ # define ZALLOC_STATE(strm, items, size) ZALLOC(strm, items, size) # define ZFREE_STATE(strm, addr) ZFREE(strm, addr) # define ZCOPY_STATE(dst, src, size) memcpy(dst, src, size) /* Memory management for the window. Useful for allocation the aligned window. */ # define ZALLOC_WINDOW(strm, items, size) ZALLOC(strm, items, size) # define TRY_FREE_WINDOW(strm, addr) TRY_FREE(strm, addr) /* Invoked at the beginning of deflateSetDictionary(). Useful for checking arch-specific window data. */ # define DEFLATE_SET_DICTIONARY_HOOK(strm, dict, dict_len) do {} while (0) /* Invoked at the beginning of deflateGetDictionary(). Useful for adjusting arch-specific window data. */ # define DEFLATE_GET_DICTIONARY_HOOK(strm, dict, dict_len) do {} while (0) /* Invoked at the end of deflateResetKeep(). Useful for initializing arch-specific extension blocks. */ # define DEFLATE_RESET_KEEP_HOOK(strm) do {} while (0) /* Invoked at the beginning of deflateParams(). Useful for updating arch-specific compression parameters. */ # define DEFLATE_PARAMS_HOOK(strm, level, strategy) do {} while (0) /* Adjusts the upper bound on compressed data length based on compression parameters and uncompressed data length. * Useful when arch-specific deflation code behaves differently than regular zlib-ng algorithms. */ # define DEFLATE_BOUND_ADJUST_COMPLEN(strm, complen, sourceLen) do {} while (0) /* Returns whether an optimistic upper bound on compressed data length should *not* be used. * Useful when arch-specific deflation code behaves differently than regular zlib-ng algorithms. */ # define DEFLATE_NEED_CONSERVATIVE_BOUND(strm) 0 /* Invoked for each deflate() call. Useful for plugging arch-specific deflation code. */ # define DEFLATE_HOOK(strm, flush, bstate) 0 /* Returns whether zlib-ng should compute a checksum. Set to 0 if arch-specific deflation code already does that. */ # define DEFLATE_NEED_CHECKSUM(strm) 1 /* Returns whether reproducibility parameter can be set to a given value. */ # define DEFLATE_CAN_SET_REPRODUCIBLE(strm, reproducible) 1 #endif /* =========================================================================== * Function prototypes. */ typedef block_state (*compress_func) (deflate_state *s, int flush); /* Compression function. Returns the block state after the call. */ static int deflateStateCheck (PREFIX3(stream) *strm); static block_state deflate_stored (deflate_state *s, int flush); ZLIB_INTERNAL block_state deflate_fast (deflate_state *s, int flush); ZLIB_INTERNAL block_state deflate_quick (deflate_state *s, int flush); #ifndef NO_MEDIUM_STRATEGY ZLIB_INTERNAL block_state deflate_medium (deflate_state *s, int flush); #endif ZLIB_INTERNAL block_state deflate_slow (deflate_state *s, int flush); static block_state deflate_rle (deflate_state *s, int flush); static block_state deflate_huff (deflate_state *s, int flush); static void lm_init (deflate_state *s); ZLIB_INTERNAL unsigned read_buf (PREFIX3(stream) *strm, unsigned char *buf, unsigned size); extern void crc_reset(deflate_state *const s); #ifdef X86_PCLMULQDQ_CRC extern void crc_finalize(deflate_state *const s); #endif extern void copy_with_crc(PREFIX3(stream) *strm, unsigned char *dst, unsigned 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; static 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 NO_MEDIUM_STRATEGY /* 4 */ {4, 4, 16, 16, deflate_slow}, /* lazy matches */ /* 5 */ {8, 16, 32, 32, deflate_slow}, /* 6 */ {8, 16, 128, 128, deflate_slow}, #else /* 4 */ {4, 4, 16, 16, deflate_medium}, /* lazy matches */ /* 5 */ {8, 16, 32, 32, deflate_medium}, /* 6 */ {8, 16, 128, 128, deflate_medium}, #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. */ /* 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) do { \ s->head[s->hash_size - 1] = NIL; \ memset((unsigned char *)s->head, 0, (unsigned)(s->hash_size - 1) * sizeof(*s->head)); \ } while (0) /* =========================================================================== * Slide the hash table when sliding the window down (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. */ ZLIB_INTERNAL void slide_hash_c(deflate_state *s) { unsigned n; Pos *p; unsigned int wsize = s->w_size; 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 */ } /* ========================================================================= */ int ZEXPORT PREFIX(deflateInit_)(PREFIX3(stream) *strm, int level, const char *version, int stream_size) { return PREFIX(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 PREFIX(deflateInit2_)(PREFIX3(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[] = PREFIX2(VERSION); #if defined(X86_CPUID) x86_check_features(); #elif defined(ARM_GETAUXVAL) arm_check_features(); #endif if (version == NULL || version[0] != my_version[0] || stream_size != sizeof(PREFIX3(stream))) { return Z_VERSION_ERROR; } if (strm == NULL) return Z_STREAM_ERROR; strm->msg = NULL; if (strm->zalloc == NULL) { strm->zalloc = zng_calloc; strm->opaque = NULL; } if (strm->zfree == NULL) strm->zfree = zng_cfree; 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 || (windowBits == 8 && wrap != 1)) { 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_STATE(strm, 1, sizeof(deflate_state)); if (s == NULL) return Z_MEM_ERROR; strm->state = (struct internal_state *)s; s->strm = strm; s->status = INIT_STATE; /* to pass state test in deflateReset() */ s->wrap = wrap; s->gzhead = NULL; s->w_bits = (unsigned int)windowBits; s->w_size = 1 << s->w_bits; s->w_mask = s->w_size - 1; #ifdef X86_SSE42_CRC_HASH if (x86_cpu_has_sse42) s->hash_bits = (unsigned int)15; else #endif s->hash_bits = (unsigned int)memLevel + 7; s->hash_size = 1 << s->hash_bits; s->hash_mask = s->hash_size - 1; #if !defined(__x86_64__) && !defined(_M_X64) && !defined(__i386) && !defined(_M_IX86) s->hash_shift = ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH); #endif #ifdef X86_PCLMULQDQ_CRC window_padding = 8; #endif s->window = (unsigned char *) ZALLOC_WINDOW(strm, s->w_size + window_padding, 2*sizeof(unsigned char)); s->prev = (Pos *) ZALLOC(strm, s->w_size, sizeof(Pos)); memset(s->prev, 0, 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 */ /* We overlay pending_buf and sym_buf. This works since the average size * for length/distance pairs over any compressed block is assured to be 31 * bits or less. * * Analysis: The longest fixed codes are a length code of 8 bits plus 5 * extra bits, for lengths 131 to 257. The longest fixed distance codes are * 5 bits plus 13 extra bits, for distances 16385 to 32768. The longest * possible fixed-codes length/distance pair is then 31 bits total. * * sym_buf starts one-fourth of the way into pending_buf. So there are * three bytes in sym_buf for every four bytes in pending_buf. Each symbol * in sym_buf is three bytes -- two for the distance and one for the * literal/length. As each symbol is consumed, the pointer to the next * sym_buf value to read moves forward three bytes. From that symbol, up to * 31 bits are written to pending_buf. The closest the written pending_buf * bits gets to the next sym_buf symbol to read is just before the last * code is written. At that time, 31*(n-2) bits have been written, just * after 24*(n-2) bits have been consumed from sym_buf. sym_buf starts at * 8*n bits into pending_buf. (Note that the symbol buffer fills when n-1 * symbols are written.) The closest the writing gets to what is unread is * then n+14 bits. Here n is lit_bufsize, which is 16384 by default, and * can range from 128 to 32768. * * Therefore, at a minimum, there are 142 bits of space between what is * written and what is read in the overlain buffers, so the symbols cannot * be overwritten by the compressed data. That space is actually 139 bits, * due to the three-bit fixed-code block header. * * That covers the case where either Z_FIXED is specified, forcing fixed * codes, or when the use of fixed codes is chosen, because that choice * results in a smaller compressed block than dynamic codes. That latter * condition then assures that the above analysis also covers all dynamic * blocks. A dynamic-code block will only be chosen to be emitted if it has * fewer bits than a fixed-code block would for the same set of symbols. * Therefore its average symbol length is assured to be less than 31. So * the compressed data for a dynamic block also cannot overwrite the * symbols from which it is being constructed. */ s->pending_buf = (unsigned char *) ZALLOC(strm, s->lit_bufsize, 4); s->pending_buf_size = (unsigned long)s->lit_bufsize * 4; if (s->window == NULL || s->prev == NULL || s->head == NULL || s->pending_buf == NULL) { s->status = FINISH_STATE; strm->msg = ERR_MSG(Z_MEM_ERROR); PREFIX(deflateEnd)(strm); return Z_MEM_ERROR; } s->sym_buf = s->pending_buf + s->lit_bufsize; s->sym_end = (s->lit_bufsize - 1) * 3; /* We avoid equality with lit_bufsize*3 because of wraparound at 64K * on 16 bit machines and because stored blocks are restricted to * 64K-1 bytes. */ s->level = level; s->strategy = strategy; s->method = (unsigned char)method; s->block_open = 0; s->reproducible = 0; return PREFIX(deflateReset)(strm); } /* ========================================================================= * Check for a valid deflate stream state. Return 0 if ok, 1 if not. */ static int deflateStateCheck (PREFIX3(stream) *strm) { deflate_state *s; if (strm == NULL || strm->zalloc == (alloc_func)0 || strm->zfree == (free_func)0) return 1; s = strm->state; if (s == NULL || s->strm != strm || (s->status != INIT_STATE && #ifdef GZIP s->status != GZIP_STATE && #endif s->status != EXTRA_STATE && s->status != NAME_STATE && s->status != COMMENT_STATE && s->status != HCRC_STATE && s->status != BUSY_STATE && s->status != FINISH_STATE)) return 1; return 0; } /* ========================================================================= */ int ZEXPORT PREFIX(deflateSetDictionary)(PREFIX3(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 (deflateStateCheck(strm) || dictionary == 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 = functable.adler32(strm->adler, dictionary, dictLength); DEFLATE_SET_DICTIONARY_HOOK(strm, dictionary, dictLength); /* hook for IBM Z DFLTCC */ 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; functable.fill_window(s); while (s->lookahead >= MIN_MATCH) { str = s->strstart; n = s->lookahead - (MIN_MATCH-1); functable.insert_string(s, str, n); s->strstart = str + n; s->lookahead = MIN_MATCH-1; functable.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 PREFIX(deflateGetDictionary)(PREFIX3(stream) *strm, unsigned char *dictionary, unsigned int *dictLength) { deflate_state *s; unsigned int len; if (deflateStateCheck(strm)) return Z_STREAM_ERROR; DEFLATE_GET_DICTIONARY_HOOK(strm, dictionary, dictLength); /* hook for IBM Z DFLTCC */ s = strm->state; len = s->strstart + s->lookahead; if (len > s->w_size) len = s->w_size; if (dictionary != NULL && len) memcpy(dictionary, s->window + s->strstart + s->lookahead - len, len); if (dictLength != NULL) *dictLength = len; return Z_OK; } /* ========================================================================= */ int ZEXPORT PREFIX(deflateResetKeep)(PREFIX3(stream) *strm) { deflate_state *s; if (deflateStateCheck(strm)) { return Z_STREAM_ERROR; } strm->total_in = strm->total_out = 0; strm->msg = 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 = #ifdef GZIP s->wrap == 2 ? GZIP_STATE : #endif INIT_STATE; #ifdef GZIP if (s->wrap == 2) crc_reset(s); else #endif strm->adler = functable.adler32(0L, NULL, 0); s->last_flush = -2; zng_tr_init(s); DEFLATE_RESET_KEEP_HOOK(strm); /* hook for IBM Z DFLTCC */ return Z_OK; } /* ========================================================================= */ int ZEXPORT PREFIX(deflateReset)(PREFIX3(stream) *strm) { int ret; ret = PREFIX(deflateResetKeep)(strm); if (ret == Z_OK) lm_init(strm->state); return ret; } /* ========================================================================= */ int ZEXPORT PREFIX(deflateSetHeader)(PREFIX3(stream) *strm, PREFIX(gz_headerp) head) { if (deflateStateCheck(strm) || strm->state->wrap != 2) return Z_STREAM_ERROR; strm->state->gzhead = head; return Z_OK; } /* ========================================================================= */ int ZEXPORT PREFIX(deflatePending)(PREFIX3(stream) *strm, uint32_t *pending, int *bits) { if (deflateStateCheck(strm)) return Z_STREAM_ERROR; if (pending != NULL) *pending = strm->state->pending; if (bits != NULL) *bits = strm->state->bi_valid; return Z_OK; } /* ========================================================================= */ int ZEXPORT PREFIX(deflatePrime)(PREFIX3(stream) *strm, int bits, int value) { deflate_state *s; int put; if (deflateStateCheck(strm)) return Z_STREAM_ERROR; s = strm->state; if (bits < 0 || bits > BIT_BUF_SIZE || s->sym_buf < s->pending_out + ((BIT_BUF_SIZE + 7) >> 3)) return Z_BUF_ERROR; do { put = BIT_BUF_SIZE - s->bi_valid; if (put > bits) put = bits; s->bi_buf |= (uint32_t)((value & ((1 << put) - 1)) << s->bi_valid); s->bi_valid += put; zng_tr_flush_bits(s); value >>= put; bits -= put; } while (bits); return Z_OK; } /* ========================================================================= */ int ZEXPORT PREFIX(deflateParams)(PREFIX3(stream) *strm, int level, int strategy) { deflate_state *s; compress_func func; if (deflateStateCheck(strm)) 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; } DEFLATE_PARAMS_HOOK(strm, level, strategy); /* hook for IBM Z DFLTCC */ func = configuration_table[s->level].func; if ((strategy != s->strategy || func != configuration_table[level].func) && s->last_flush != -2) { /* Flush the last buffer: */ int err = PREFIX(deflate)(strm, Z_BLOCK); if (err == Z_STREAM_ERROR) return err; if (strm->avail_in || (s->strstart - s->block_start) + s->lookahead) return Z_BUF_ERROR; } if (s->level != level) { if (s->level == 0 && s->matches != 0) { if (s->matches == 1) { functable.slide_hash(s); } else { CLEAR_HASH(s); } s->matches = 0; } 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 Z_OK; } /* ========================================================================= */ int ZEXPORT PREFIX(deflateTune)(PREFIX3(stream) *strm, int good_length, int max_lazy, int nice_length, int max_chain) { deflate_state *s; if (deflateStateCheck(strm)) return Z_STREAM_ERROR; s = strm->state; s->good_match = (unsigned int)good_length; s->max_lazy_match = (unsigned int)max_lazy; s->nice_match = nice_length; s->max_chain_length = (unsigned int)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 PREFIX(deflateBound)(PREFIX3(stream) *strm, unsigned long sourceLen) { deflate_state *s; unsigned long complen, wraplen; /* conservative upper bound for compressed data */ complen = sourceLen + ((sourceLen + 7) >> 3) + ((sourceLen + 63) >> 6) + 5; DEFLATE_BOUND_ADJUST_COMPLEN(strm, complen, sourceLen); /* hook for IBM Z DFLTCC */ /* if can't get parameters, return conservative bound plus zlib wrapper */ if (deflateStateCheck(strm)) 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; #ifdef GZIP case 2: /* gzip wrapper */ wraplen = 18; if (s->gzhead != NULL) { /* user-supplied gzip header */ unsigned char *str; if (s->gzhead->extra != NULL) { wraplen += 2 + s->gzhead->extra_len; } str = s->gzhead->name; if (str != NULL) { do { wraplen++; } while (*str++); } str = s->gzhead->comment; if (str != NULL) { do { wraplen++; } while (*str++); } if (s->gzhead->hcrc) wraplen += 2; } break; #endif default: /* for compiler happiness */ wraplen = 6; } /* if not default parameters, return conservative bound */ if (DEFLATE_NEED_CONSERVATIVE_BOUND(strm) || /* hook for IBM Z DFLTCC */ 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; } /* ========================================================================= * Flush as much pending output as possible. All deflate() output, except for * some deflate_stored() 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(PREFIX3(stream) *strm) { uint32_t len; deflate_state *s = strm->state; zng_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; } } /* =========================================================================== * Update the header CRC with the bytes s->pending_buf[beg..s->pending - 1]. */ #define HCRC_UPDATE(beg) \ do { \ if (s->gzhead->hcrc && s->pending > (beg)) \ strm->adler = PREFIX(crc32)(strm->adler, s->pending_buf + (beg), s->pending - (beg)); \ } while (0) /* ========================================================================= */ int ZEXPORT PREFIX(deflate)(PREFIX3(stream) *strm, int flush) { int old_flush; /* value of flush param for previous deflate call */ deflate_state *s; if (deflateStateCheck(strm) || flush > Z_BLOCK || flush < 0) { return Z_STREAM_ERROR; } s = strm->state; if (strm->next_out == NULL || (strm->avail_in != 0 && strm->next_in == 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); old_flush = s->last_flush; s->last_flush = flush; /* 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); } /* Write the header */ if (s->status == INIT_STATE && s->wrap == 0) s->status = BUSY_STATE; if (s->status == INIT_STATE) { /* zlib header */ 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); put_short_msb(s, header); /* Save the adler32 of the preset dictionary: */ if (s->strstart != 0) { put_uint32_msb(s, strm->adler); } strm->adler = functable.adler32(0L, NULL, 0); s->status = BUSY_STATE; /* Compression must start with an empty pending buffer */ flush_pending(strm); if (s->pending != 0) { s->last_flush = -1; return Z_OK; } } #ifdef GZIP if (s->status == GZIP_STATE) { /* gzip header */ crc_reset(s); put_byte(s, 31); put_byte(s, 139); put_byte(s, 8); if (s->gzhead == NULL) { put_uint32(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; /* Compression must start with an empty pending buffer */ flush_pending(strm); if (s->pending != 0) { s->last_flush = -1; return Z_OK; } } else { put_byte(s, (s->gzhead->text ? 1 : 0) + (s->gzhead->hcrc ? 2 : 0) + (s->gzhead->extra == NULL ? 0 : 4) + (s->gzhead->name == NULL ? 0 : 8) + (s->gzhead->comment == NULL ? 0 : 16) ); put_uint32(s, s->gzhead->time); 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 != NULL) { put_short(s, s->gzhead->extra_len); } if (s->gzhead->hcrc) strm->adler = PREFIX(crc32)(strm->adler, s->pending_buf, s->pending); s->gzindex = 0; s->status = EXTRA_STATE; } } if (s->status == EXTRA_STATE) { if (s->gzhead->extra != NULL) { uint32_t beg = s->pending; /* start of bytes to update crc */ uint32_t left = (s->gzhead->extra_len & 0xffff) - s->gzindex; while (s->pending + left > s->pending_buf_size) { uint32_t copy = s->pending_buf_size - s->pending; memcpy(s->pending_buf + s->pending, s->gzhead->extra + s->gzindex, copy); s->pending = s->pending_buf_size; HCRC_UPDATE(beg); s->gzindex += copy; flush_pending(strm); if (s->pending != 0) { s->last_flush = -1; return Z_OK; } beg = 0; left -= copy; } memcpy(s->pending_buf + s->pending, s->gzhead->extra + s->gzindex, left); s->pending += left; HCRC_UPDATE(beg); s->gzindex = 0; } s->status = NAME_STATE; } if (s->status == NAME_STATE) { if (s->gzhead->name != NULL) { uint32_t beg = s->pending; /* start of bytes to update crc */ unsigned char val; do { if (s->pending == s->pending_buf_size) { HCRC_UPDATE(beg); flush_pending(strm); if (s->pending != 0) { s->last_flush = -1; return Z_OK; } beg = 0; } val = s->gzhead->name[s->gzindex++]; put_byte(s, val); } while (val != 0); HCRC_UPDATE(beg); s->gzindex = 0; } s->status = COMMENT_STATE; } if (s->status == COMMENT_STATE) { if (s->gzhead->comment != NULL) { uint32_t beg = s->pending; /* start of bytes to update crc */ unsigned char val; do { if (s->pending == s->pending_buf_size) { HCRC_UPDATE(beg); flush_pending(strm); if (s->pending != 0) { s->last_flush = -1; return Z_OK; } beg = 0; } val = s->gzhead->comment[s->gzindex++]; put_byte(s, val); } while (val != 0); HCRC_UPDATE(beg); } 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 != 0) { s->last_flush = -1; return Z_OK; } } put_short(s, (uint16_t)strm->adler); crc_reset(s); } s->status = BUSY_STATE; /* Compression must start with an empty pending buffer */ flush_pending(strm); if (s->pending != 0) { s->last_flush = -1; return Z_OK; } } #endif /* 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; bstate = DEFLATE_HOOK(strm, flush, &bstate) ? bstate : /* hook for IBM Z DFLTCC */ s->level == 0 ? deflate_stored(s, flush) : s->strategy == Z_HUFFMAN_ONLY ? deflate_huff(s, flush) : s->strategy == Z_RLE ? deflate_rle(s, flush) : #ifdef X86_QUICK_STRATEGY (s->level == 1 && !x86_cpu_has_sse42) ? deflate_fast(s, flush) : #endif (*(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) { zng_tr_align(s); } else if (flush != Z_BLOCK) { /* FULL_FLUSH or SYNC_FLUSH */ zng_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; } } } if (flush != Z_FINISH) return Z_OK; if (s->wrap <= 0) return Z_STREAM_END; /* Write the trailer */ #ifdef GZIP if (s->wrap == 2) { # ifdef X86_PCLMULQDQ_CRC crc_finalize(s); # endif put_uint32(s, strm->adler); put_uint32(s, strm->total_in); } else #endif { put_uint32_msb(s, 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 PREFIX(deflateEnd)(PREFIX3(stream) *strm) { int status; if (deflateStateCheck(strm)) return Z_STREAM_ERROR; status = strm->state->status; /* 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_WINDOW(strm, strm->state->window); ZFREE_STATE(strm, strm->state); strm->state = NULL; return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK; } /* ========================================================================= * Copy the source state to the destination state. */ int ZEXPORT PREFIX(deflateCopy)(PREFIX3(stream) *dest, PREFIX3(stream) *source) { deflate_state *ds; deflate_state *ss; if (deflateStateCheck(source) || dest == NULL) { return Z_STREAM_ERROR; } ss = source->state; memcpy((void *)dest, (void *)source, sizeof(PREFIX3(stream))); ds = (deflate_state *) ZALLOC_STATE(dest, 1, sizeof(deflate_state)); if (ds == NULL) return Z_MEM_ERROR; dest->state = (struct internal_state *) ds; ZCOPY_STATE((void *)ds, (void *)ss, sizeof(deflate_state)); ds->strm = dest; ds->window = (unsigned char *) ZALLOC_WINDOW(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)); ds->pending_buf = (unsigned char *) ZALLOC(dest, ds->lit_bufsize, 4); if (ds->window == NULL || ds->prev == NULL || ds->head == NULL || ds->pending_buf == NULL) { PREFIX(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->sym_buf = ds->pending_buf + 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 unsigned read_buf(PREFIX3(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; if (!DEFLATE_NEED_CHECKSUM(strm)) { memcpy(buf, strm->next_in, len); } else #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 = functable.adler32(strm->adler, buf, len); } strm->next_in += len; strm->total_in += len; return len; } /* =========================================================================== * Initialize the "longest match" routines for a new zlib stream */ static 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->match_start = 0; s->ins_h = 0; } #ifdef ZLIB_DEBUG #define EQUAL 0 /* result of memcmp for equal strings */ /* =========================================================================== * 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 /* ZLIB_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). */ void ZLIB_INTERNAL fill_window_c(deflate_state *s) { unsigned n; 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 - more); s->match_start -= wsize; s->strstart -= wsize; /* we now have strstart >= MAX_DIST */ s->block_start -= (long) wsize; if (s->insert > s->strstart) s->insert = s->strstart; functable.slide_hash(s); 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) functable.insert_string(s, str + 2 - MIN_MATCH, 1); #if MIN_MATCH != 3 #error Call insert_string() MIN_MATCH-3 more times while (s->insert) { functable.insert_string(s, str, 1); str++; s->insert--; if (s->lookahead + s->insert < MIN_MATCH) break; } #else unsigned int count; if (UNLIKELY(s->lookahead == 1)) { count = s->insert - 1; } else { count = s->insert; } functable.insert_string(s,str,count); s->insert -= count; #endif } /* 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. * * In case deflateParams() is used to later switch to a non-zero compression * level, s->matches (otherwise unused when storing) keeps track of the number * of hash table slides to perform. If s->matches is 1, then one hash table * slide will be done when switching. If s->matches is 2, the maximum value * allowed here, then the hash table will be cleared, since two or more slides * is the same as a clear. * * deflate_stored() is written to minimize the number of times an input byte is * copied. It is most efficient with large input and output buffers, which * maximizes the opportunites to have a single copy from next_in to next_out. */ static block_state deflate_stored(deflate_state *s, int flush) { /* Smallest worthy block size when not flushing or finishing. By default * this is 32K. This can be as small as 507 bytes for memLevel == 1. For * large input and output buffers, the stored block size will be larger. */ unsigned min_block = MIN(s->pending_buf_size - 5, s->w_size); /* Copy as many min_block or larger stored blocks directly to next_out as * possible. If flushing, copy the remaining available input to next_out as * stored blocks, if there is enough space. */ unsigned len, left, have, last = 0; unsigned used = s->strm->avail_in; do { /* Set len to the maximum size block that we can copy directly with the * available input data and output space. Set left to how much of that * would be copied from what's left in the window. */ len = MAX_STORED; /* maximum deflate stored block length */ have = (s->bi_valid + 42) >> 3; /* number of header bytes */ if (s->strm->avail_out < have) /* need room for header */ break; /* maximum stored block length that will fit in avail_out: */ have = s->strm->avail_out - have; left = s->strstart - s->block_start; /* bytes left in window */ if (len > (unsigned long)left + s->strm->avail_in) len = left + s->strm->avail_in; /* limit len to the input */ if (len > have) len = have; /* limit len to the output */ /* If the stored block would be less than min_block in length, or if * unable to copy all of the available input when flushing, then try * copying to the window and the pending buffer instead. Also don't * write an empty block when flushing -- deflate() does that. */ if (len < min_block && ((len == 0 && flush != Z_FINISH) || flush == Z_NO_FLUSH || len != left + s->strm->avail_in)) break; /* Make a dummy stored block in pending to get the header bytes, * including any pending bits. This also updates the debugging counts. */ last = flush == Z_FINISH && len == left + s->strm->avail_in ? 1 : 0; zng_tr_stored_block(s, (char *)0, 0L, last); /* Replace the lengths in the dummy stored block with len. */ s->pending_buf[s->pending - 4] = len; s->pending_buf[s->pending - 3] = len >> 8; s->pending_buf[s->pending - 2] = ~len; s->pending_buf[s->pending - 1] = ~len >> 8; /* Write the stored block header bytes. */ flush_pending(s->strm); #ifdef ZLIB_DEBUG /* Update debugging counts for the data about to be copied. */ s->compressed_len += len << 3; s->bits_sent += len << 3; #endif /* Copy uncompressed bytes from the window to next_out. */ if (left) { if (left > len) left = len; memcpy(s->strm->next_out, s->window + s->block_start, left); s->strm->next_out += left; s->strm->avail_out -= left; s->strm->total_out += left; s->block_start += left; len -= left; } /* Copy uncompressed bytes directly from next_in to next_out, updating * the check value. */ if (len) { read_buf(s->strm, s->strm->next_out, len); s->strm->next_out += len; s->strm->avail_out -= len; s->strm->total_out += len; } } while (last == 0); /* Update the sliding window with the last s->w_size bytes of the copied * data, or append all of the copied data to the existing window if less * than s->w_size bytes were copied. Also update the number of bytes to * insert in the hash tables, in the event that deflateParams() switches to * a non-zero compression level. */ used -= s->strm->avail_in; /* number of input bytes directly copied */ if (used) { /* If any input was used, then no unused input remains in the window, * therefore s->block_start == s->strstart. */ if (used >= s->w_size) { /* supplant the previous history */ s->matches = 2; /* clear hash */ memcpy(s->window, s->strm->next_in - s->w_size, s->w_size); s->strstart = s->w_size; s->insert = s->strstart; } else { if (s->window_size - s->strstart <= used) { /* Slide the window down. */ s->strstart -= s->w_size; memcpy(s->window, s->window + s->w_size, s->strstart); if (s->matches < 2) s->matches++; /* add a pending slide_hash() */ if (s->insert > s->strstart) s->insert = s->strstart; } memcpy(s->window + s->strstart, s->strm->next_in - used, used); s->strstart += used; s->insert += MIN(used, s->w_size - s->insert); } s->block_start = s->strstart; } if (s->high_water < s->strstart) s->high_water = s->strstart; /* If the last block was written to next_out, then done. */ if (last) return finish_done; /* If flushing and all input has been consumed, then done. */ if (flush != Z_NO_FLUSH && flush != Z_FINISH && s->strm->avail_in == 0 && (long)s->strstart == s->block_start) return block_done; /* Fill the window with any remaining input. */ have = s->window_size - s->strstart; if (s->strm->avail_in > have && s->block_start >= (long)s->w_size) { /* Slide the window down. */ s->block_start -= s->w_size; s->strstart -= s->w_size; memcpy(s->window, s->window + s->w_size, s->strstart); if (s->matches < 2) s->matches++; /* add a pending slide_hash() */ have += s->w_size; /* more space now */ if (s->insert > s->strstart) s->insert = s->strstart; } if (have > s->strm->avail_in) have = s->strm->avail_in; if (have) { read_buf(s->strm, s->window + s->strstart, have); s->strstart += have; s->insert += MIN(have, s->w_size - s->insert); } if (s->high_water < s->strstart) s->high_water = s->strstart; /* There was not enough avail_out to write a complete worthy or flushed * stored block to next_out. Write a stored block to pending instead, if we * have enough input for a worthy block, or if flushing and there is enough * room for the remaining input as a stored block in the pending buffer. */ have = (s->bi_valid + 42) >> 3; /* number of header bytes */ /* maximum stored block length that will fit in pending: */ have = MIN(s->pending_buf_size - have, MAX_STORED); min_block = MIN(have, s->w_size); left = s->strstart - s->block_start; if (left >= min_block || ((left || flush == Z_FINISH) && flush != Z_NO_FLUSH && s->strm->avail_in == 0 && left <= have)) { len = MIN(left, have); last = flush == Z_FINISH && s->strm->avail_in == 0 && len == left ? 1 : 0; zng_tr_stored_block(s, (char *)s->window + s->block_start, len, last); s->block_start += len; flush_pending(s->strm); } /* We've done all we can with the available input and output. */ return last ? finish_started : need_more; } /* =========================================================================== * 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.) */ static 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) { functable.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 - (unsigned 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); zng_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])); zng_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->sym_next) 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.) */ static 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) { functable.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])); zng_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->sym_next) FLUSH_BLOCK(s, 0); return block_done; } #ifndef ZLIB_COMPAT /* ========================================================================= * Checks whether buffer size is sufficient and whether this parameter is a duplicate. */ static int deflateSetParamPre(zng_deflate_param_value **out, size_t min_size, zng_deflate_param_value *param) { int buf_error = param->size < min_size; if (*out != NULL) { (*out)->status = Z_BUF_ERROR; buf_error = 1; } *out = param; return buf_error; } /* ========================================================================= */ int ZEXPORT zng_deflateSetParams(zng_stream *strm, zng_deflate_param_value *params, size_t count) { size_t i; deflate_state *s; zng_deflate_param_value *new_level = NULL; zng_deflate_param_value *new_strategy = NULL; zng_deflate_param_value *new_reproducible = NULL; int param_buf_error; int version_error = 0; int buf_error = 0; int stream_error = 0; int ret; int val; /* Initialize the statuses. */ for (i = 0; i < count; i++) params[i].status = Z_OK; /* Check whether the stream state is consistent. */ if (deflateStateCheck(strm)) return Z_STREAM_ERROR; s = strm->state; /* Check buffer sizes and detect duplicates. */ for (i = 0; i < count; i++) { switch (params[i].param) { case Z_DEFLATE_LEVEL: param_buf_error = deflateSetParamPre(&new_level, sizeof(int), ¶ms[i]); break; case Z_DEFLATE_STRATEGY: param_buf_error = deflateSetParamPre(&new_strategy, sizeof(int), ¶ms[i]); break; case Z_DEFLATE_REPRODUCIBLE: param_buf_error = deflateSetParamPre(&new_reproducible, sizeof(int), ¶ms[i]); break; default: params[i].status = Z_VERSION_ERROR; version_error = 1; param_buf_error = 0; break; } if (param_buf_error) { params[i].status = Z_BUF_ERROR; buf_error = 1; } } /* Exit early if small buffers or duplicates are detected. */ if (buf_error) return Z_BUF_ERROR; /* Apply changes, remember if there were errors. */ if (new_level != NULL || new_strategy != NULL) { ret = PREFIX(deflateParams)(strm, new_level == NULL ? s->level : *(int *)new_level->buf, new_strategy == NULL ? s->strategy : *(int *)new_strategy->buf); if (ret != Z_OK) { if (new_level != NULL) new_level->status = Z_STREAM_ERROR; if (new_strategy != NULL) new_strategy->status = Z_STREAM_ERROR; stream_error = 1; } } if (new_reproducible != NULL) { val = *(int *)new_reproducible->buf; if (DEFLATE_CAN_SET_REPRODUCIBLE(strm, val)) s->reproducible = val; else { new_reproducible->status = Z_STREAM_ERROR; stream_error = 1; } } /* Report version errors only if there are no real errors. */ return stream_error ? Z_STREAM_ERROR : (version_error ? Z_VERSION_ERROR : Z_OK); } /* ========================================================================= */ int ZEXPORT zng_deflateGetParams(zng_stream *strm, zng_deflate_param_value *params, size_t count) { deflate_state *s; size_t i; int buf_error = 0; int version_error = 0; /* Initialize the statuses. */ for (i = 0; i < count; i++) params[i].status = Z_OK; /* Check whether the stream state is consistent. */ if (deflateStateCheck(strm)) return Z_STREAM_ERROR; s = strm->state; for (i = 0; i < count; i++) { switch (params[i].param) { case Z_DEFLATE_LEVEL: if (params[i].size < sizeof(int)) params[i].status = Z_BUF_ERROR; else *(int *)params[i].buf = s->level; break; case Z_DEFLATE_STRATEGY: if (params[i].size < sizeof(int)) params[i].status = Z_BUF_ERROR; else *(int *)params[i].buf = s->strategy; break; case Z_DEFLATE_REPRODUCIBLE: if (params[i].size < sizeof(int)) params[i].status = Z_BUF_ERROR; else *(int *)params[i].buf = s->reproducible; break; default: params[i].status = Z_VERSION_ERROR; version_error = 1; break; } if (params[i].status == Z_BUF_ERROR) buf_error = 1; } return buf_error ? Z_BUF_ERROR : (version_error ? Z_VERSION_ERROR : Z_OK); } #endif