/* deflate.c -- compress data using the deflation algorithm * Copyright (C) 1995-2024 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 https://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 * */ #include "zbuild.h" #include "deflate.h" #include "deflate_p.h" #include "functable.h" /* Avoid conflicts with zlib.h macros */ #ifdef ZLIB_COMPAT # undef deflateInit # undef deflateInit2 #endif const char PREFIX(deflate_copyright)[] = " deflate 1.3.1 Copyright 1995-2024 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" /* DFLTCC instructions require window to be page-aligned */ # define PAD_WINDOW PAD_4096 # define WINDOW_PAD_SIZE 4096 # define HINT_ALIGNED_WINDOW HINT_ALIGNED_4096 #else # define PAD_WINDOW PAD_64 # define WINDOW_PAD_SIZE 64 # define HINT_ALIGNED_WINDOW HINT_ALIGNED_64 /* Adjust the window size for the arch-specific deflate code. */ # define DEFLATE_ADJUST_WINDOW_SIZE(n) (n) /* 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, hook_flush) do {} while (0) /* Returns whether the last deflate(flush) operation did everything it's supposed to do. */ # define DEFLATE_DONE(strm, flush) 1 /* 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. */ static int deflateStateCheck (PREFIX3(stream) *strm); Z_INTERNAL block_state deflate_stored(deflate_state *s, int flush); Z_INTERNAL block_state deflate_fast (deflate_state *s, int flush); Z_INTERNAL block_state deflate_quick (deflate_state *s, int flush); #ifndef NO_MEDIUM_STRATEGY Z_INTERNAL block_state deflate_medium(deflate_state *s, int flush); #endif Z_INTERNAL block_state deflate_slow (deflate_state *s, int flush); Z_INTERNAL block_state deflate_rle (deflate_state *s, int flush); Z_INTERNAL block_state deflate_huff (deflate_state *s, int flush); static void lm_set_level (deflate_state *s, int level); static void lm_init (deflate_state *s); Z_INTERNAL unsigned read_buf (PREFIX3(stream) *strm, unsigned char *buf, unsigned size); /* =========================================================================== * Local data */ /* 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 NO_QUICK_STRATEGY /* 1 */ {4, 4, 8, 4, deflate_fast}, /* max speed, no lazy matches */ /* 2 */ {4, 5, 16, 8, deflate_fast}, #else /* 1 */ {0, 0, 0, 0, deflate_quick}, /* 2 */ {4, 4, 8, 4, deflate_fast}, /* max speed, no lazy matches */ #endif #ifdef NO_MEDIUM_STRATEGY /* 3 */ {4, 6, 32, 32, deflate_fast}, /* 4 */ {4, 4, 16, 16, deflate_slow}, /* lazy matches */ /* 5 */ {8, 16, 32, 32, deflate_slow}, /* 6 */ {8, 16, 128, 128, deflate_slow}, #else /* 3 */ {4, 6, 16, 6, deflate_medium}, /* 4 */ {4, 12, 32, 24, 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 >= STD_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. prev[] will be initialized on the fly. */ #define CLEAR_HASH(s) do { \ memset((unsigned char *)s->head, 0, HASH_SIZE * sizeof(*s->head)); \ } while (0) #ifdef DEF_ALLOC_DEBUG # include # define LOGSZ(name,size) fprintf(stderr, "%s is %d bytes\n", name, size) # define LOGSZP(name,size,loc,pad) fprintf(stderr, "%s is %d bytes, offset %d, padded %d\n", name, size, loc, pad) # define LOGSZPL(name,size,loc,pad) fprintf(stderr, "%s is %d bytes, offset %ld, padded %d\n", name, size, loc, pad) #else # define LOGSZ(name,size) # define LOGSZP(name,size,loc,pad) # define LOGSZPL(name,size,loc,pad) #endif /* =========================================================================== * Allocate a big buffer and divide it up into the various buffers deflate needs. * Handles alignment of allocated buffer and alignment of individual buffers. */ Z_INTERNAL deflate_allocs* alloc_deflate(PREFIX3(stream) *strm, int windowBits, int lit_bufsize) { int curr_size = 0; /* Define sizes */ int window_size = DEFLATE_ADJUST_WINDOW_SIZE((1 << windowBits) * 2); int prev_size = (1 << windowBits) * sizeof(Pos); int head_size = HASH_SIZE * sizeof(Pos); int pending_size = lit_bufsize * LIT_BUFS; int state_size = sizeof(deflate_state); int alloc_size = sizeof(deflate_allocs); /* Calculate relative buffer positions and paddings */ LOGSZP("window", window_size, PAD_WINDOW(curr_size), PADSZ(curr_size,WINDOW_PAD_SIZE)); int window_pos = PAD_WINDOW(curr_size); curr_size = window_pos + window_size; LOGSZP("prev", prev_size, PAD_64(curr_size), PADSZ(curr_size,64)); int prev_pos = PAD_64(curr_size); curr_size = prev_pos + prev_size; LOGSZP("head", head_size, PAD_64(curr_size), PADSZ(curr_size,64)); int head_pos = PAD_64(curr_size); curr_size = head_pos + head_size; LOGSZP("pending", pending_size, PAD_64(curr_size), PADSZ(curr_size,64)); int pending_pos = PAD_64(curr_size); curr_size = pending_pos + pending_size; LOGSZP("state", state_size, PAD_64(curr_size), PADSZ(curr_size,64)); int state_pos = PAD_64(curr_size); curr_size = state_pos + state_size; LOGSZP("alloc", alloc_size, PAD_16(curr_size), PADSZ(curr_size,16)); int alloc_pos = PAD_16(curr_size); curr_size = alloc_pos + alloc_size; /* Add 64-1 or 4096-1 to allow window alignment, and round size of buffer up to multiple of 64 */ int total_size = PAD_64(curr_size + (WINDOW_PAD_SIZE - 1)); /* Allocate buffer, align to 64-byte cacheline, and zerofill the resulting buffer */ char *original_buf = strm->zalloc(strm->opaque, 1, total_size); if (original_buf == NULL) return NULL; char *buff = (char *)HINT_ALIGNED_WINDOW((char *)PAD_WINDOW(original_buf)); LOGSZPL("Buffer alloc", total_size, PADSZ((uintptr_t)original_buf,WINDOW_PAD_SIZE), PADSZ(curr_size,WINDOW_PAD_SIZE)); /* Initialize alloc_bufs */ deflate_allocs *alloc_bufs = (struct deflate_allocs_s *)(buff + alloc_pos); alloc_bufs->buf_start = (char *)original_buf; alloc_bufs->zfree = strm->zfree; /* Assign buffers */ alloc_bufs->window = (unsigned char *)HINT_ALIGNED_WINDOW(buff + window_pos); alloc_bufs->prev = (Pos *)HINT_ALIGNED_64(buff + prev_pos); alloc_bufs->head = (Pos *)HINT_ALIGNED_64(buff + head_pos); alloc_bufs->pending_buf = (unsigned char *)HINT_ALIGNED_64(buff + pending_pos); alloc_bufs->state = (deflate_state *)HINT_ALIGNED_16(buff + state_pos); memset((char *)alloc_bufs->prev, 0, prev_size); return alloc_bufs; } /* =========================================================================== * Free all allocated deflate buffers */ static inline void free_deflate(PREFIX3(stream) *strm) { deflate_state *state = (deflate_state *)strm->state; if (state->alloc_bufs != NULL) { deflate_allocs *alloc_bufs = state->alloc_bufs; alloc_bufs->zfree(strm->opaque, alloc_bufs->buf_start); strm->state = NULL; } } /* =========================================================================== * Initialize deflate state and buffers. * This function is hidden in ZLIB_COMPAT builds. */ int32_t ZNG_CONDEXPORT PREFIX(deflateInit2)(PREFIX3(stream) *strm, int32_t level, int32_t method, int32_t windowBits, int32_t memLevel, int32_t strategy) { /* Todo: ignore strm->next_in if we use it as window */ deflate_state *s; int wrap = 1; /* Initialize functable */ FUNCTABLE_INIT; if (strm == NULL) return Z_STREAM_ERROR; strm->msg = NULL; if (strm->zalloc == NULL) { strm->zalloc = PREFIX(zcalloc); strm->opaque = NULL; } if (strm->zfree == NULL) strm->zfree = PREFIX(zcfree); if (level == Z_DEFAULT_COMPRESSION) level = 6; if (windowBits < 0) { /* suppress zlib wrapper */ wrap = 0; if (windowBits < -MAX_WBITS) return Z_STREAM_ERROR; windowBits = -windowBits; #ifdef GZIP } else if (windowBits > MAX_WBITS) { wrap = 2; /* write gzip wrapper instead */ windowBits -= 16; #endif } if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != Z_DEFLATED || windowBits < MIN_WBITS || windowBits > MAX_WBITS || 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 */ /* Allocate buffers */ int lit_bufsize = 1 << (memLevel + 6); deflate_allocs *alloc_bufs = alloc_deflate(strm, windowBits, lit_bufsize); if (alloc_bufs == NULL) return Z_MEM_ERROR; s = alloc_bufs->state; s->alloc_bufs = alloc_bufs; s->window = alloc_bufs->window; s->prev = alloc_bufs->prev; s->head = alloc_bufs->head; s->pending_buf = alloc_bufs->pending_buf; 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; s->high_water = 0; /* nothing written to s->window yet */ s->lit_bufsize = lit_bufsize; /* 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_size = 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; } #ifdef LIT_MEM s->d_buf = (uint16_t *)(s->pending_buf + (s->lit_bufsize << 1)); s->l_buf = s->pending_buf + (s->lit_bufsize << 2); s->sym_end = s->lit_bufsize - 1; #else s->sym_buf = s->pending_buf + s->lit_bufsize; s->sym_end = (s->lit_bufsize - 1) * 3; #endif /* 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->block_open = 0; s->reproducible = 0; return PREFIX(deflateReset)(strm); } #ifndef ZLIB_COMPAT int32_t Z_EXPORT PREFIX(deflateInit)(PREFIX3(stream) *strm, int32_t level) { return PREFIX(deflateInit2)(strm, level, Z_DEFLATED, MAX_WBITS, DEF_MEM_LEVEL, Z_DEFAULT_STRATEGY); } #endif /* Function used by zlib.h and zlib-ng version 2.0 macros */ int32_t Z_EXPORT PREFIX(deflateInit_)(PREFIX3(stream) *strm, int32_t level, const char *version, int32_t stream_size) { if (CHECK_VER_STSIZE(version, stream_size)) return Z_VERSION_ERROR; return PREFIX(deflateInit2)(strm, level, Z_DEFLATED, MAX_WBITS, DEF_MEM_LEVEL, Z_DEFAULT_STRATEGY); } /* Function used by zlib.h and zlib-ng version 2.0 macros */ int32_t Z_EXPORT PREFIX(deflateInit2_)(PREFIX3(stream) *strm, int32_t level, int32_t method, int32_t windowBits, int32_t memLevel, int32_t strategy, const char *version, int32_t stream_size) { if (CHECK_VER_STSIZE(version, stream_size)) return Z_VERSION_ERROR; return PREFIX(deflateInit2)(strm, level, method, windowBits, memLevel, strategy); } /* ========================================================================= * 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->alloc_bufs == NULL || s->strm != strm || (s->status < INIT_STATE || s->status > MAX_STATE)) return 1; return 0; } /* ========================================================================= */ int32_t Z_EXPORT PREFIX(deflateSetDictionary)(PREFIX3(stream) *strm, const uint8_t *dictionary, uint32_t 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_CALL(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 = 0; 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 = (z_const unsigned char *)dictionary; PREFIX(fill_window)(s); while (s->lookahead >= STD_MIN_MATCH) { str = s->strstart; n = s->lookahead - (STD_MIN_MATCH - 1); s->insert_string(s, str, n); s->strstart = str + n; s->lookahead = STD_MIN_MATCH - 1; PREFIX(fill_window)(s); } s->strstart += s->lookahead; s->block_start = (int)s->strstart; s->insert = s->lookahead; s->lookahead = 0; s->prev_length = 0; s->match_available = 0; strm->next_in = (z_const unsigned char *)next; strm->avail_in = avail; s->wrap = wrap; return Z_OK; } /* ========================================================================= */ int32_t Z_EXPORT PREFIX(deflateGetDictionary)(PREFIX3(stream) *strm, uint8_t *dictionary, uint32_t *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; } /* ========================================================================= */ int32_t Z_EXPORT 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) { strm->adler = FUNCTABLE_CALL(crc32_fold_reset)(&s->crc_fold); } else #endif strm->adler = ADLER32_INITIAL_VALUE; s->last_flush = -2; zng_tr_init(s); DEFLATE_RESET_KEEP_HOOK(strm); /* hook for IBM Z DFLTCC */ return Z_OK; } /* ========================================================================= */ int32_t Z_EXPORT PREFIX(deflateReset)(PREFIX3(stream) *strm) { int ret = PREFIX(deflateResetKeep)(strm); if (ret == Z_OK) lm_init(strm->state); return ret; } /* ========================================================================= */ int32_t Z_EXPORT 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; } /* ========================================================================= */ int32_t Z_EXPORT PREFIX(deflatePending)(PREFIX3(stream) *strm, uint32_t *pending, int32_t *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; } /* ========================================================================= */ int32_t Z_EXPORT PREFIX(deflatePrime)(PREFIX3(stream) *strm, int32_t bits, int32_t value) { deflate_state *s; uint64_t value64 = (uint64_t)value; int32_t put; if (deflateStateCheck(strm)) return Z_STREAM_ERROR; s = strm->state; #ifdef LIT_MEM if (bits < 0 || bits > BIT_BUF_SIZE || (unsigned char *)s->d_buf < s->pending_out + ((BIT_BUF_SIZE + 7) >> 3)) return Z_BUF_ERROR; #else if (bits < 0 || bits > BIT_BUF_SIZE || bits > (int32_t)(sizeof(value) << 3) || s->sym_buf < s->pending_out + ((BIT_BUF_SIZE + 7) >> 3)) return Z_BUF_ERROR; #endif do { put = BIT_BUF_SIZE - s->bi_valid; put = MIN(put, bits); if (s->bi_valid == 0) s->bi_buf = value64; else s->bi_buf |= (value64 & ((UINT64_C(1) << put) - 1)) << s->bi_valid; s->bi_valid += put; zng_tr_flush_bits(s); value64 >>= put; bits -= put; } while (bits); return Z_OK; } /* ========================================================================= */ int32_t Z_EXPORT PREFIX(deflateParams)(PREFIX3(stream) *strm, int32_t level, int32_t strategy) { deflate_state *s; compress_func func; int hook_flush = Z_NO_FLUSH; 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_flush); /* hook for IBM Z DFLTCC */ func = configuration_table[s->level].func; if (((strategy != s->strategy || func != configuration_table[level].func) && s->last_flush != -2) || hook_flush != Z_NO_FLUSH) { /* Flush the last buffer. Use Z_BLOCK mode, unless the hook requests a "stronger" one. */ int flush = RANK(hook_flush) > RANK(Z_BLOCK) ? hook_flush : Z_BLOCK; int err = PREFIX(deflate)(strm, flush); if (err == Z_STREAM_ERROR) return err; if (strm->avail_in || ((int)s->strstart - s->block_start) + s->lookahead || !DEFLATE_DONE(strm, flush)) return Z_BUF_ERROR; } if (s->level != level) { if (s->level == 0 && s->matches != 0) { if (s->matches == 1) { FUNCTABLE_CALL(slide_hash)(s); } else { CLEAR_HASH(s); } s->matches = 0; } lm_set_level(s, level); } s->strategy = strategy; return Z_OK; } /* ========================================================================= */ int32_t Z_EXPORT PREFIX(deflateTune)(PREFIX3(stream) *strm, int32_t good_length, int32_t max_lazy, int32_t nice_length, int32_t 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 Z_EXPORT 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 = ZLIB_WRAPLEN + (s->strstart ? 4 : 0); break; #ifdef GZIP case 2: /* gzip wrapper */ wraplen = GZIP_WRAPLEN; 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 = ZLIB_WRAPLEN; } /* if not default parameters, return conservative bound */ if (DEFLATE_NEED_CONSERVATIVE_BOUND(strm) || /* hook for IBM Z DFLTCC */ s->w_bits != MAX_WBITS || HASH_BITS < 15) { if (s->level == 0) { /* upper bound for stored blocks with length 127 (memLevel == 1) -- ~4% overhead plus a small constant */ complen = sourceLen + (sourceLen >> 5) + (sourceLen >> 7) + (sourceLen >> 11) + 7; } return complen + wraplen; } #ifndef NO_QUICK_STRATEGY return sourceLen /* The source size itself */ + (sourceLen == 0 ? 1 : 0) /* Always at least one byte for any input */ + (sourceLen < 9 ? 1 : 0) /* One extra byte for lengths less than 9 */ + DEFLATE_QUICK_OVERHEAD(sourceLen) /* Source encoding overhead, padded to next full byte */ + DEFLATE_BLOCK_OVERHEAD /* Deflate block overhead bytes */ + wraplen; /* none, zlib or gzip wrapper */ #else return sourceLen + (sourceLen >> 4) + 7 + wraplen; #endif } /* ========================================================================= * 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()). */ Z_INTERNAL void PREFIX(flush_pending)(PREFIX3(stream) *strm) { uint32_t len; deflate_state *s = strm->state; zng_tr_flush_bits(s); len = MIN(s->pending, strm->avail_out); if (len == 0) return; Tracev((stderr, "[FLUSH]")); 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) /* ========================================================================= */ int32_t Z_EXPORT PREFIX(deflate)(PREFIX3(stream) *strm, int32_t flush) { int32_t 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) { PREFIX(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, (uint16_t)header); /* Save the adler32 of the preset dictionary: */ if (s->strstart != 0) put_uint32_msb(s, strm->adler); strm->adler = ADLER32_INITIAL_VALUE; s->status = BUSY_STATE; /* Compression must start with an empty pending buffer */ PREFIX(flush_pending)(strm); if (s->pending != 0) { s->last_flush = -1; return Z_OK; } } #ifdef GZIP if (s->status == GZIP_STATE) { /* gzip header */ FUNCTABLE_CALL(crc32_fold_reset)(&s->crc_fold); 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 */ PREFIX(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, (uint16_t)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; PREFIX(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); PREFIX(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); PREFIX(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) { PREFIX(flush_pending)(strm); if (s->pending != 0) { s->last_flush = -1; return Z_OK; } } put_short(s, (uint16_t)strm->adler); FUNCTABLE_CALL(crc32_fold_reset)(&s->crc_fold); } s->status = BUSY_STATE; /* Compression must start with an empty pending buffer */ PREFIX(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) : (*(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 = 0; s->insert = 0; } } } PREFIX(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; /* Write the trailer */ #ifdef GZIP if (s->wrap == 2) { strm->adler = FUNCTABLE_CALL(crc32_fold_final)(&s->crc_fold); put_uint32(s, strm->adler); put_uint32(s, (uint32_t)strm->total_in); } else #endif { if (s->wrap == 1) put_uint32_msb(s, strm->adler); } PREFIX(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! */ if (s->pending == 0) { Assert(s->bi_valid == 0, "bi_buf not flushed"); return Z_STREAM_END; } return Z_OK; } /* ========================================================================= */ int32_t Z_EXPORT PREFIX(deflateEnd)(PREFIX3(stream) *strm) { if (deflateStateCheck(strm)) return Z_STREAM_ERROR; int32_t status = strm->state->status; /* Free allocated buffers */ free_deflate(strm); return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK; } /* ========================================================================= * Copy the source state to the destination state. */ int32_t Z_EXPORT 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))); deflate_allocs *alloc_bufs = alloc_deflate(dest, ss->w_bits, ss->lit_bufsize); if (alloc_bufs == NULL) return Z_MEM_ERROR; ds = alloc_bufs->state; dest->state = (struct internal_state *) ds; memcpy(ds, ss, sizeof(deflate_state)); ds->strm = dest; ds->alloc_bufs = alloc_bufs; ds->window = alloc_bufs->window; ds->prev = alloc_bufs->prev; ds->head = alloc_bufs->head; ds->pending_buf = alloc_bufs->pending_buf; 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, DEFLATE_ADJUST_WINDOW_SIZE(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, HASH_SIZE * sizeof(Pos)); memcpy(ds->pending_buf, ss->pending_buf, ds->lit_bufsize * LIT_BUFS); ds->pending_out = ds->pending_buf + (ss->pending_out - ss->pending_buf); #ifdef LIT_MEM ds->d_buf = (uint16_t *)(ds->pending_buf + (ds->lit_bufsize << 1)); ds->l_buf = ds->pending_buf + (ds->lit_bufsize << 2); #else ds->sym_buf = ds->pending_buf + ds->lit_bufsize; #endif 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()). */ Z_INTERNAL unsigned PREFIX(read_buf)(PREFIX3(stream) *strm, unsigned char *buf, unsigned size) { uint32_t len = MIN(strm->avail_in, size); if (len == 0) return 0; strm->avail_in -= len; if (!DEFLATE_NEED_CHECKSUM(strm)) { memcpy(buf, strm->next_in, len); #ifdef GZIP } else if (strm->state->wrap == 2) { FUNCTABLE_CALL(crc32_fold_copy)(&strm->state->crc_fold, buf, strm->next_in, len); #endif } else if (strm->state->wrap == 1) { strm->adler = FUNCTABLE_CALL(adler32_fold_copy)(strm->adler, buf, strm->next_in, len); } else { memcpy(buf, strm->next_in, len); } strm->next_in += len; strm->total_in += len; return len; } /* =========================================================================== * Set longest match variables based on level configuration */ static void lm_set_level(deflate_state *s, int 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; /* Use rolling hash for deflate_slow algorithm with level 9. It allows us to * properly lookup different hash chains to speed up longest_match search. Since hashing * method changes depending on the level we cannot put this into functable. */ if (s->max_chain_length > 1024) { s->update_hash = &update_hash_roll; s->insert_string = &insert_string_roll; s->quick_insert_string = &quick_insert_string_roll; } else { s->update_hash = update_hash; s->insert_string = insert_string; s->quick_insert_string = quick_insert_string; } s->level = level; } /* =========================================================================== * Initialize the "longest match" routines for a new zlib stream */ static void lm_init(deflate_state *s) { s->window_size = 2 * s->w_size; CLEAR_HASH(s); /* Set the default configuration parameters: */ lm_set_level(s, s->level); s->strstart = 0; s->block_start = 0; s->lookahead = 0; s->insert = 0; s->prev_length = 0; s->match_available = 0; s->match_start = 0; s->ins_h = 0; } /* =========================================================================== * 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 Z_INTERNAL PREFIX(fill_window)(deflate_state *s) { unsigned n; unsigned int 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 = s->window_size - s->lookahead - 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); if (s->match_start >= wsize) { s->match_start -= wsize; } else { s->match_start = 0; s->prev_length = 0; } s->strstart -= wsize; /* we now have strstart >= MAX_DIST */ s->block_start -= (int)wsize; if (s->insert > s->strstart) s->insert = s->strstart; FUNCTABLE_CALL(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 = PREFIX(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 >= STD_MIN_MATCH) { unsigned int str = s->strstart - s->insert; if (UNLIKELY(s->max_chain_length > 1024)) { s->ins_h = s->update_hash(s->window[str], s->window[str+1]); } else if (str >= 1) { s->quick_insert_string(s, str + 2 - STD_MIN_MATCH); } unsigned int count = s->insert; if (UNLIKELY(s->lookahead == 1)) { count -= 1; } if (count > 0) { s->insert_string(s, str, count); s->insert -= count; } } /* If the whole input has less than STD_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 STD_MAX_MATCH since the longest match * routines allow scanning to strstart + STD_MAX_MATCH, ignoring lookahead. */ if (s->high_water < s->window_size) { unsigned int curr = s->strstart + s->lookahead; unsigned int 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, init); s->high_water = curr + init; } else if (s->high_water < 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 = 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, init); s->high_water += init; } } Assert((unsigned long)s->strstart <= s->window_size - MIN_LOOKAHEAD, "not enough room for search"); } #ifndef ZLIB_COMPAT /* ========================================================================= * Checks whether buffer size is sufficient and whether this parameter is a duplicate. */ static int32_t deflateSetParamPre(zng_deflate_param_value **out, size_t min_size, zng_deflate_param_value *param) { int32_t buf_error = param->size < min_size; if (*out != NULL) { (*out)->status = Z_BUF_ERROR; buf_error = 1; } *out = param; return buf_error; } /* ========================================================================= */ int32_t Z_EXPORT 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; /* 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) { int 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) { int 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); } /* ========================================================================= */ int32_t Z_EXPORT zng_deflateGetParams(zng_stream *strm, zng_deflate_param_value *params, size_t count) { deflate_state *s; size_t i; int32_t buf_error = 0; int32_t 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