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diff --git a/lib/sqfs/comp/zlib/deflate.c b/lib/sqfs/comp/zlib/deflate.c
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-/* deflate.c -- compress data using the deflation algorithm
- * Copyright (C) 1995-2017 Jean-loup Gailly and Mark Adler
- * For conditions of distribution and use, see copyright notice in zlib.h
- */
-
-/*
- * ALGORITHM
- *
- * The "deflation" process depends on being able to identify portions
- * of the input text which are identical to earlier input (within a
- * sliding window trailing behind the input currently being processed).
- *
- * The most straightforward technique turns out to be the fastest for
- * most input files: try all possible matches and select the longest.
- * The key feature of this algorithm is that insertions into the string
- * dictionary are very simple and thus fast, and deletions are avoided
- * completely. Insertions are performed at each input character, whereas
- * string matches are performed only when the previous match ends. So it
- * is preferable to spend more time in matches to allow very fast string
- * insertions and avoid deletions. The matching algorithm for small
- * strings is inspired from that of Rabin & Karp. A brute force approach
- * is used to find longer strings when a small match has been found.
- * A similar algorithm is used in comic (by Jan-Mark Wams) and freeze
- * (by Leonid Broukhis).
- * A previous version of this file used a more sophisticated algorithm
- * (by Fiala and Greene) which is guaranteed to run in linear amortized
- * time, but has a larger average cost, uses more memory and is patented.
- * However the F&G algorithm may be faster for some highly redundant
- * files if the parameter max_chain_length (described below) is too large.
- *
- * ACKNOWLEDGEMENTS
- *
- * The idea of lazy evaluation of matches is due to Jan-Mark Wams, and
- * I found it in 'freeze' written by Leonid Broukhis.
- * Thanks to many people for bug reports and testing.
- *
- * REFERENCES
- *
- * Deutsch, L.P.,"DEFLATE Compressed Data Format Specification".
- * Available in http://tools.ietf.org/html/rfc1951
- *
- * A description of the Rabin and Karp algorithm is given in the book
- * "Algorithms" by R. Sedgewick, Addison-Wesley, p252.
- *
- * Fiala,E.R., and Greene,D.H.
- * Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595
- *
- */
-
-/* @(#) $Id$ */
-
-#include "deflate.h"
-
-/*
- XXX: Not original zlib source code. The following 2 lines were
- commented out by David Oberhollenzer for use in in libsquashfs.
-
-const char deflate_copyright[] =
- " deflate 1.2.11 Copyright 1995-2017 Jean-loup Gailly and Mark Adler ";
-*/
-/*
- If you use the zlib library in a product, an acknowledgment is welcome
- in the documentation of your product. If for some reason you cannot
- include such an acknowledgment, I would appreciate that you keep this
- copyright string in the executable of your product.
- */
-
-/* ===========================================================================
- * Function prototypes.
- */
-typedef enum {
- need_more, /* block not completed, need more input or more output */
- block_done, /* block flush performed */
- finish_started, /* finish started, need only more output at next deflate */
- finish_done /* finish done, accept no more input or output */
-} block_state;
-
-typedef block_state (*compress_func) OF((deflate_state *s, int flush));
-/* Compression function. Returns the block state after the call. */
-
-local int deflateStateCheck OF((z_streamp strm));
-local void slide_hash OF((deflate_state *s));
-local void fill_window OF((deflate_state *s));
-local block_state deflate_stored OF((deflate_state *s, int flush));
-local block_state deflate_fast OF((deflate_state *s, int flush));
-#ifndef FASTEST
-local block_state deflate_slow OF((deflate_state *s, int flush));
-#endif
-local block_state deflate_rle OF((deflate_state *s, int flush));
-local block_state deflate_huff OF((deflate_state *s, int flush));
-local void lm_init OF((deflate_state *s));
-local void putShortMSB OF((deflate_state *s, uInt b));
-local void flush_pending OF((z_streamp strm));
-local unsigned read_buf OF((z_streamp strm, Bytef *buf, unsigned size));
-#ifdef ASMV
-# pragma message("Assembler code may have bugs -- use at your own risk")
- void match_init OF((void)); /* asm code initialization */
- uInt longest_match OF((deflate_state *s, IPos cur_match));
-#else
-local uInt longest_match OF((deflate_state *s, IPos cur_match));
-#endif
-
-#ifdef ZLIB_DEBUG
-local void check_match OF((deflate_state *s, IPos start, IPos match,
- int length));
-#endif
-
-/* ===========================================================================
- * Local data
- */
-
-#define NIL 0
-/* Tail of hash chains */
-
-#ifndef TOO_FAR
-# define TOO_FAR 4096
-#endif
-/* Matches of length 3 are discarded if their distance exceeds TOO_FAR */
-
-/* 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 {
- ush good_length; /* reduce lazy search above this match length */
- ush max_lazy; /* do not perform lazy search above this match length */
- ush nice_length; /* quit search above this match length */
- ush max_chain;
- compress_func func;
-} config;
-
-#ifdef FASTEST
-local const config configuration_table[2] = {
-/* good lazy nice chain */
-/* 0 */ {0, 0, 0, 0, deflate_stored}, /* store only */
-/* 1 */ {4, 4, 8, 4, deflate_fast}}; /* max speed, no lazy matches */
-#else
-local const config configuration_table[10] = {
-/* good lazy nice chain */
-/* 0 */ {0, 0, 0, 0, deflate_stored}, /* store only */
-/* 1 */ {4, 4, 8, 4, deflate_fast}, /* max speed, no lazy matches */
-/* 2 */ {4, 5, 16, 8, deflate_fast},
-/* 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},
-/* 7 */ {8, 32, 128, 256, deflate_slow},
-/* 8 */ {32, 128, 258, 1024, deflate_slow},
-/* 9 */ {32, 258, 258, 4096, deflate_slow}}; /* max compression */
-#endif
-
-/* 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))
-
-/* ===========================================================================
- * Update a hash value with the given input byte
- * IN assertion: all calls to UPDATE_HASH are made with consecutive input
- * characters, so that a running hash key can be computed from the previous
- * key instead of complete recalculation each time.
- */
-#define UPDATE_HASH(s,h,c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask)
-
-
-/* ===========================================================================
- * Insert string str in the dictionary and set match_head to the previous head
- * of the hash chain (the most recent string with same hash key). Return
- * the previous length of the hash chain.
- * If this file is compiled with -DFASTEST, the compression level is forced
- * to 1, and no hash chains are maintained.
- * IN assertion: all calls to INSERT_STRING are made with consecutive input
- * characters and the first MIN_MATCH bytes of str are valid (except for
- * the last MIN_MATCH-1 bytes of the input file).
- */
-#ifdef FASTEST
-#define INSERT_STRING(s, str, match_head) \
- (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
- match_head = s->head[s->ins_h], \
- s->head[s->ins_h] = (Pos)(str))
-#else
-#define INSERT_STRING(s, str, match_head) \
- (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
- match_head = s->prev[(str) & s->w_mask] = s->head[s->ins_h], \
- s->head[s->ins_h] = (Pos)(str))
-#endif
-
-/* ===========================================================================
- * Initialize the hash table (avoiding 64K overflow for 16 bit systems).
- * prev[] will be initialized on the fly.
- */
-#define CLEAR_HASH(s) \
- s->head[s->hash_size-1] = NIL; \
- zmemzero((Bytef *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head));
-
-/* ===========================================================================
- * 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.
- */
-local void slide_hash(s)
- deflate_state *s;
-{
- unsigned n, m;
- Posf *p;
- uInt wsize = s->w_size;
-
- n = s->hash_size;
- p = &s->head[n];
- do {
- m = *--p;
- *p = (Pos)(m >= wsize ? m - wsize : NIL);
- } while (--n);
- n = wsize;
-#ifndef FASTEST
- p = &s->prev[n];
- do {
- 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);
-#endif
-}
-
-/* ========================================================================= */
-int ZEXPORT deflateInit_(strm, level, version, stream_size)
- z_streamp strm;
- int level;
- const char *version;
- int stream_size;
-{
- return deflateInit2_(strm, level, Z_DEFLATED, MAX_WBITS, DEF_MEM_LEVEL,
- Z_DEFAULT_STRATEGY, version, stream_size);
- /* To do: ignore strm->next_in if we use it as window */
-}
-
-/* ========================================================================= */
-int ZEXPORT deflateInit2_(strm, level, method, windowBits, memLevel, strategy,
- version, stream_size)
- z_streamp strm;
- int level;
- int method;
- int windowBits;
- int memLevel;
- int strategy;
- const char *version;
- int stream_size;
-{
- deflate_state *s;
- int wrap = 1;
- static const char my_version[] = ZLIB_VERSION;
-
- ushf *overlay;
- /* We overlay pending_buf and d_buf+l_buf. This works since the average
- * output size for (length,distance) codes is <= 24 bits.
- */
-
- if (version == Z_NULL || version[0] != my_version[0] ||
- stream_size != sizeof(z_stream)) {
- return Z_VERSION_ERROR;
- }
- if (strm == Z_NULL) return Z_STREAM_ERROR;
-
- strm->msg = Z_NULL;
- if (strm->zalloc == (alloc_func)0) {
-#ifdef Z_SOLO
- return Z_STREAM_ERROR;
-#else
- strm->zalloc = zcalloc;
- strm->opaque = (voidpf)0;
-#endif
- }
- if (strm->zfree == (free_func)0)
-#ifdef Z_SOLO
- return Z_STREAM_ERROR;
-#else
- strm->zfree = zcfree;
-#endif
-
-#ifdef FASTEST
- if (level != 0) level = 1;
-#else
- if (level == Z_DEFAULT_COMPRESSION) level = 6;
-#endif
-
- 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 */
- s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state));
- if (s == Z_NULL) return Z_MEM_ERROR;
- strm->state = (struct internal_state FAR *)s;
- s->strm = strm;
- s->status = INIT_STATE; /* to pass state test in deflateReset() */
-
- s->wrap = wrap;
- s->gzhead = Z_NULL;
- s->w_bits = (uInt)windowBits;
- s->w_size = 1 << s->w_bits;
- s->w_mask = s->w_size - 1;
-
- s->hash_bits = (uInt)memLevel + 7;
- s->hash_size = 1 << s->hash_bits;
- s->hash_mask = s->hash_size - 1;
- s->hash_shift = ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH);
-
- s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte));
- s->prev = (Posf *) ZALLOC(strm, s->w_size, sizeof(Pos));
- s->head = (Posf *) ZALLOC(strm, s->hash_size, sizeof(Pos));
-
- s->high_water = 0; /* nothing written to s->window yet */
-
- s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */
-
- overlay = (ushf *) ZALLOC(strm, s->lit_bufsize, sizeof(ush)+2);
- s->pending_buf = (uchf *) overlay;
- s->pending_buf_size = (ulg)s->lit_bufsize * (sizeof(ush)+2L);
-
- if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL ||
- s->pending_buf == Z_NULL) {
- s->status = FINISH_STATE;
- strm->msg = ERR_MSG(Z_MEM_ERROR);
- deflateEnd (strm);
- return Z_MEM_ERROR;
- }
- s->d_buf = overlay + s->lit_bufsize/sizeof(ush);
- s->l_buf = s->pending_buf + (1+sizeof(ush))*s->lit_bufsize;
-
- s->level = level;
- s->strategy = strategy;
- s->method = (Byte)method;
-
- return deflateReset(strm);
-}
-
-/* =========================================================================
- * Check for a valid deflate stream state. Return 0 if ok, 1 if not.
- */
-local int deflateStateCheck (strm)
- z_streamp strm;
-{
- deflate_state *s;
- if (strm == Z_NULL ||
- strm->zalloc == (alloc_func)0 || strm->zfree == (free_func)0)
- return 1;
- s = strm->state;
- if (s == Z_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 deflateSetDictionary (strm, dictionary, dictLength)
- z_streamp strm;
- const Bytef *dictionary;
- uInt dictLength;
-{
- deflate_state *s;
- uInt str, n;
- int wrap;
- unsigned avail;
- z_const unsigned char *next;
-
- if (deflateStateCheck(strm) || dictionary == Z_NULL)
- return Z_STREAM_ERROR;
- s = strm->state;
- wrap = s->wrap;
- if (wrap == 2 || (wrap == 1 && s->status != INIT_STATE) || s->lookahead)
- return Z_STREAM_ERROR;
-
- /* when using zlib wrappers, compute Adler-32 for provided dictionary */
- if (wrap == 1)
- strm->adler = adler32(strm->adler, dictionary, dictLength);
- s->wrap = 0; /* avoid computing Adler-32 in read_buf */
-
- /* if dictionary would fill window, just replace the history */
- if (dictLength >= s->w_size) {
- if (wrap == 0) { /* already empty otherwise */
- CLEAR_HASH(s);
- s->strstart = 0;
- s->block_start = 0L;
- s->insert = 0;
- }
- dictionary += dictLength - s->w_size; /* use the tail */
- dictLength = s->w_size;
- }
-
- /* insert dictionary into window and hash */
- avail = strm->avail_in;
- next = strm->next_in;
- strm->avail_in = dictLength;
- strm->next_in = (z_const Bytef *)dictionary;
- fill_window(s);
- while (s->lookahead >= MIN_MATCH) {
- str = s->strstart;
- n = s->lookahead - (MIN_MATCH-1);
- do {
- UPDATE_HASH(s, s->ins_h, s->window[str + MIN_MATCH-1]);
-#ifndef FASTEST
- s->prev[str & s->w_mask] = s->head[s->ins_h];
-#endif
- s->head[s->ins_h] = (Pos)str;
- str++;
- } while (--n);
- s->strstart = str;
- s->lookahead = MIN_MATCH-1;
- fill_window(s);
- }
- s->strstart += s->lookahead;
- s->block_start = (long)s->strstart;
- s->insert = s->lookahead;
- s->lookahead = 0;
- s->match_length = s->prev_length = MIN_MATCH-1;
- s->match_available = 0;
- strm->next_in = next;
- strm->avail_in = avail;
- s->wrap = wrap;
- return Z_OK;
-}
-
-/* ========================================================================= */
-int ZEXPORT deflateGetDictionary (strm, dictionary, dictLength)
- z_streamp strm;
- Bytef *dictionary;
- uInt *dictLength;
-{
- deflate_state *s;
- uInt len;
-
- if (deflateStateCheck(strm))
- return Z_STREAM_ERROR;
- s = strm->state;
- len = s->strstart + s->lookahead;
- if (len > s->w_size)
- len = s->w_size;
- if (dictionary != Z_NULL && len)
- zmemcpy(dictionary, s->window + s->strstart + s->lookahead - len, len);
- if (dictLength != Z_NULL)
- *dictLength = len;
- return Z_OK;
-}
-
-/* ========================================================================= */
-int ZEXPORT deflateResetKeep (strm)
- z_streamp strm;
-{
- deflate_state *s;
-
- if (deflateStateCheck(strm)) {
- return Z_STREAM_ERROR;
- }
-
- strm->total_in = strm->total_out = 0;
- strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */
- strm->data_type = Z_UNKNOWN;
-
- s = (deflate_state *)strm->state;
- s->pending = 0;
- s->pending_out = s->pending_buf;
-
- if (s->wrap < 0) {
- s->wrap = -s->wrap; /* was made negative by deflate(..., Z_FINISH); */
- }
- s->status =
-#ifdef GZIP
- s->wrap == 2 ? GZIP_STATE :
-#endif
- s->wrap ? INIT_STATE : BUSY_STATE;
- strm->adler =
-#ifdef GZIP
- s->wrap == 2 ? crc32(0L, Z_NULL, 0) :
-#endif
- adler32(0L, Z_NULL, 0);
- s->last_flush = Z_NO_FLUSH;
-
- _tr_init(s);
-
- return Z_OK;
-}
-
-/* ========================================================================= */
-int ZEXPORT deflateReset (strm)
- z_streamp strm;
-{
- int ret;
-
- ret = deflateResetKeep(strm);
- if (ret == Z_OK)
- lm_init(strm->state);
- return ret;
-}
-
-/* ========================================================================= */
-int ZEXPORT deflateSetHeader (strm, head)
- z_streamp strm;
- gz_headerp head;
-{
- if (deflateStateCheck(strm) || strm->state->wrap != 2)
- return Z_STREAM_ERROR;
- strm->state->gzhead = head;
- return Z_OK;
-}
-
-/* ========================================================================= */
-int ZEXPORT deflatePending (strm, pending, bits)
- unsigned *pending;
- int *bits;
- z_streamp strm;
-{
- if (deflateStateCheck(strm)) return Z_STREAM_ERROR;
- if (pending != Z_NULL)
- *pending = strm->state->pending;
- if (bits != Z_NULL)
- *bits = strm->state->bi_valid;
- return Z_OK;
-}
-
-/* ========================================================================= */
-int ZEXPORT deflatePrime (strm, bits, value)
- z_streamp strm;
- int bits;
- int value;
-{
- deflate_state *s;
- int put;
-
- if (deflateStateCheck(strm)) return Z_STREAM_ERROR;
- s = strm->state;
- if ((Bytef *)(s->d_buf) < s->pending_out + ((Buf_size + 7) >> 3))
- return Z_BUF_ERROR;
- do {
- put = Buf_size - s->bi_valid;
- if (put > bits)
- put = bits;
- s->bi_buf |= (ush)((value & ((1 << put) - 1)) << s->bi_valid);
- s->bi_valid += put;
- _tr_flush_bits(s);
- value >>= put;
- bits -= put;
- } while (bits);
- return Z_OK;
-}
-
-/* ========================================================================= */
-int ZEXPORT deflateParams(strm, level, strategy)
- z_streamp strm;
- int level;
- int strategy;
-{
- deflate_state *s;
- compress_func func;
-
- if (deflateStateCheck(strm)) return Z_STREAM_ERROR;
- s = strm->state;
-
-#ifdef FASTEST
- if (level != 0) level = 1;
-#else
- if (level == Z_DEFAULT_COMPRESSION) level = 6;
-#endif
- if (level < 0 || level > 9 || strategy < 0 || strategy > Z_FIXED) {
- return Z_STREAM_ERROR;
- }
- func = configuration_table[s->level].func;
-
- if ((strategy != s->strategy || func != configuration_table[level].func) &&
- s->high_water) {
- /* Flush the last buffer: */
- int err = deflate(strm, Z_BLOCK);
- if (err == Z_STREAM_ERROR)
- return err;
- if (strm->avail_out == 0)
- return Z_BUF_ERROR;
- }
- if (s->level != level) {
- if (s->level == 0 && s->matches != 0) {
- if (s->matches == 1)
- 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 deflateTune(strm, good_length, max_lazy, nice_length, max_chain)
- z_streamp 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 = (uInt)good_length;
- s->max_lazy_match = (uInt)max_lazy;
- s->nice_match = nice_length;
- s->max_chain_length = (uInt)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.
- */
-uLong ZEXPORT deflateBound(strm, sourceLen)
- z_streamp strm;
- uLong sourceLen;
-{
- deflate_state *s;
- uLong complen, wraplen;
-
- /* conservative upper bound for compressed data */
- complen = sourceLen +
- ((sourceLen + 7) >> 3) + ((sourceLen + 63) >> 6) + 5;
-
- /* if can't get parameters, return conservative bound plus zlib wrapper */
- if (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 != Z_NULL) { /* user-supplied gzip header */
- Bytef *str;
- if (s->gzhead->extra != Z_NULL)
- wraplen += 2 + s->gzhead->extra_len;
- str = s->gzhead->name;
- if (str != Z_NULL)
- do {
- wraplen++;
- } while (*str++);
- str = s->gzhead->comment;
- if (str != Z_NULL)
- do {
- wraplen++;
- } while (*str++);
- if (s->gzhead->hcrc)
- wraplen += 2;
- }
- break;
-#endif
- default: /* for compiler happiness */
- wraplen = 6;
- }
-
- /* if not default parameters, return conservative bound */
- if (s->w_bits != 15 || s->hash_bits != 8 + 7)
- return complen + wraplen;
-
- /* default settings: return tight bound for that case */
- return sourceLen + (sourceLen >> 12) + (sourceLen >> 14) +
- (sourceLen >> 25) + 13 - 6 + wraplen;
-}
-
-/* =========================================================================
- * Put a short in the pending buffer. The 16-bit value is put in MSB order.
- * IN assertion: the stream state is correct and there is enough room in
- * pending_buf.
- */
-local void putShortMSB (s, b)
- deflate_state *s;
- uInt b;
-{
- put_byte(s, (Byte)(b >> 8));
- put_byte(s, (Byte)(b & 0xff));
-}
-
-/* =========================================================================
- * 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()).
- */
-local void flush_pending(strm)
- z_streamp strm;
-{
- unsigned len;
- deflate_state *s = strm->state;
-
- _tr_flush_bits(s);
- len = s->pending;
- if (len > strm->avail_out) len = strm->avail_out;
- if (len == 0) return;
-
- zmemcpy(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 = crc32(strm->adler, s->pending_buf + (beg), \
- s->pending - (beg)); \
- } while (0)
-
-/* ========================================================================= */
-int ZEXPORT deflate (strm, flush)
- z_streamp 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 == Z_NULL ||
- (strm->avail_in != 0 && strm->next_in == Z_NULL) ||
- (s->status == FINISH_STATE && flush != Z_FINISH)) {
- ERR_RETURN(strm, Z_STREAM_ERROR);
- }
- if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR);
-
- 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) {
- /* zlib header */
- uInt header = (Z_DEFLATED + ((s->w_bits-8)<<4)) << 8;
- uInt 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);
-
- putShortMSB(s, header);
-
- /* Save the adler32 of the preset dictionary: */
- if (s->strstart != 0) {
- putShortMSB(s, (uInt)(strm->adler >> 16));
- putShortMSB(s, (uInt)(strm->adler & 0xffff));
- }
- strm->adler = adler32(0L, Z_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 */
- strm->adler = crc32(0L, Z_NULL, 0);
- put_byte(s, 31);
- put_byte(s, 139);
- put_byte(s, 8);
- if (s->gzhead == Z_NULL) {
- put_byte(s, 0);
- put_byte(s, 0);
- put_byte(s, 0);
- put_byte(s, 0);
- put_byte(s, 0);
- put_byte(s, s->level == 9 ? 2 :
- (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2 ?
- 4 : 0));
- put_byte(s, OS_CODE);
- s->status = BUSY_STATE;
-
- /* 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 == Z_NULL ? 0 : 4) +
- (s->gzhead->name == Z_NULL ? 0 : 8) +
- (s->gzhead->comment == Z_NULL ? 0 : 16)
- );
- put_byte(s, (Byte)(s->gzhead->time & 0xff));
- put_byte(s, (Byte)((s->gzhead->time >> 8) & 0xff));
- put_byte(s, (Byte)((s->gzhead->time >> 16) & 0xff));
- put_byte(s, (Byte)((s->gzhead->time >> 24) & 0xff));
- put_byte(s, s->level == 9 ? 2 :
- (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2 ?
- 4 : 0));
- put_byte(s, s->gzhead->os & 0xff);
- if (s->gzhead->extra != Z_NULL) {
- put_byte(s, s->gzhead->extra_len & 0xff);
- put_byte(s, (s->gzhead->extra_len >> 8) & 0xff);
- }
- if (s->gzhead->hcrc)
- strm->adler = crc32(strm->adler, s->pending_buf,
- s->pending);
- s->gzindex = 0;
- s->status = EXTRA_STATE;
- }
- }
- if (s->status == EXTRA_STATE) {
- if (s->gzhead->extra != Z_NULL) {
- ulg beg = s->pending; /* start of bytes to update crc */
- uInt left = (s->gzhead->extra_len & 0xffff) - s->gzindex;
- while (s->pending + left > s->pending_buf_size) {
- uInt copy = s->pending_buf_size - s->pending;
- zmemcpy(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;
- }
- zmemcpy(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 != Z_NULL) {
- ulg beg = s->pending; /* start of bytes to update crc */
- int 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 != Z_NULL) {
- ulg beg = s->pending; /* start of bytes to update crc */
- int 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_byte(s, (Byte)(strm->adler & 0xff));
- put_byte(s, (Byte)((strm->adler >> 8) & 0xff));
- strm->adler = crc32(0L, Z_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;
- }
- }
-#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 = 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) {
- _tr_align(s);
- } else if (flush != Z_BLOCK) { /* FULL_FLUSH or SYNC_FLUSH */
- _tr_stored_block(s, (char*)0, 0L, 0);
- /* For a full flush, this empty block will be recognized
- * as a special marker by inflate_sync().
- */
- if (flush == Z_FULL_FLUSH) {
- CLEAR_HASH(s); /* forget history */
- if (s->lookahead == 0) {
- s->strstart = 0;
- s->block_start = 0L;
- s->insert = 0;
- }
- }
- }
- flush_pending(strm);
- if (strm->avail_out == 0) {
- s->last_flush = -1; /* avoid BUF_ERROR at next call, see above */
- return Z_OK;
- }
- }
- }
-
- if (flush != Z_FINISH) return Z_OK;
- if (s->wrap <= 0) return Z_STREAM_END;
-
- /* Write the trailer */
-#ifdef GZIP
- if (s->wrap == 2) {
- put_byte(s, (Byte)(strm->adler & 0xff));
- put_byte(s, (Byte)((strm->adler >> 8) & 0xff));
- put_byte(s, (Byte)((strm->adler >> 16) & 0xff));
- put_byte(s, (Byte)((strm->adler >> 24) & 0xff));
- put_byte(s, (Byte)(strm->total_in & 0xff));
- put_byte(s, (Byte)((strm->total_in >> 8) & 0xff));
- put_byte(s, (Byte)((strm->total_in >> 16) & 0xff));
- put_byte(s, (Byte)((strm->total_in >> 24) & 0xff));
- }
- else
-#endif
- {
- putShortMSB(s, (uInt)(strm->adler >> 16));
- putShortMSB(s, (uInt)(strm->adler & 0xffff));
- }
- flush_pending(strm);
- /* If avail_out is zero, the application will call deflate again
- * to flush the rest.
- */
- if (s->wrap > 0) s->wrap = -s->wrap; /* write the trailer only once! */
- return s->pending != 0 ? Z_OK : Z_STREAM_END;
-}
-
-/* ========================================================================= */
-int ZEXPORT deflateEnd (strm)
- z_streamp 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(strm, strm->state->window);
-
- ZFREE(strm, strm->state);
- strm->state = Z_NULL;
-
- return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK;
-}
-
-/* =========================================================================
- * Copy the source state to the destination state.
- * To simplify the source, this is not supported for 16-bit MSDOS (which
- * doesn't have enough memory anyway to duplicate compression states).
- */
-int ZEXPORT deflateCopy (dest, source)
- z_streamp dest;
- z_streamp source;
-{
-#ifdef MAXSEG_64K
- return Z_STREAM_ERROR;
-#else
- deflate_state *ds;
- deflate_state *ss;
- ushf *overlay;
-
-
- if (deflateStateCheck(source) || dest == Z_NULL) {
- return Z_STREAM_ERROR;
- }
-
- ss = source->state;
-
- zmemcpy((voidpf)dest, (voidpf)source, sizeof(z_stream));
-
- ds = (deflate_state *) ZALLOC(dest, 1, sizeof(deflate_state));
- if (ds == Z_NULL) return Z_MEM_ERROR;
- dest->state = (struct internal_state FAR *) ds;
- zmemcpy((voidpf)ds, (voidpf)ss, sizeof(deflate_state));
- ds->strm = dest;
-
- ds->window = (Bytef *) ZALLOC(dest, ds->w_size, 2*sizeof(Byte));
- ds->prev = (Posf *) ZALLOC(dest, ds->w_size, sizeof(Pos));
- ds->head = (Posf *) ZALLOC(dest, ds->hash_size, sizeof(Pos));
- overlay = (ushf *) ZALLOC(dest, ds->lit_bufsize, sizeof(ush)+2);
- ds->pending_buf = (uchf *) overlay;
-
- if (ds->window == Z_NULL || ds->prev == Z_NULL || ds->head == Z_NULL ||
- ds->pending_buf == Z_NULL) {
- deflateEnd (dest);
- return Z_MEM_ERROR;
- }
- /* following zmemcpy do not work for 16-bit MSDOS */
- zmemcpy(ds->window, ss->window, ds->w_size * 2 * sizeof(Byte));
- zmemcpy((voidpf)ds->prev, (voidpf)ss->prev, ds->w_size * sizeof(Pos));
- zmemcpy((voidpf)ds->head, (voidpf)ss->head, ds->hash_size * sizeof(Pos));
- zmemcpy(ds->pending_buf, ss->pending_buf, (uInt)ds->pending_buf_size);
-
- ds->pending_out = ds->pending_buf + (ss->pending_out - ss->pending_buf);
- ds->d_buf = overlay + ds->lit_bufsize/sizeof(ush);
- ds->l_buf = ds->pending_buf + (1+sizeof(ush))*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;
-#endif /* MAXSEG_64K */
-}
-
-/* ===========================================================================
- * 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()).
- */
-local unsigned read_buf(strm, buf, size)
- z_streamp strm;
- Bytef *buf;
- unsigned size;
-{
- unsigned len = strm->avail_in;
-
- if (len > size) len = size;
- if (len == 0) return 0;
-
- strm->avail_in -= len;
-
- zmemcpy(buf, strm->next_in, len);
- if (strm->state->wrap == 1) {
- strm->adler = adler32(strm->adler, buf, len);
- }
-#ifdef GZIP
- else if (strm->state->wrap == 2) {
- strm->adler = crc32(strm->adler, buf, len);
- }
-#endif
- strm->next_in += len;
- strm->total_in += len;
-
- return len;
-}
-
-/* ===========================================================================
- * Initialize the "longest match" routines for a new zlib stream
- */
-local void lm_init (s)
- deflate_state *s;
-{
- s->window_size = (ulg)2L*s->w_size;
-
- CLEAR_HASH(s);
-
- /* Set the default configuration parameters:
- */
- s->max_lazy_match = configuration_table[s->level].max_lazy;
- s->good_match = configuration_table[s->level].good_length;
- s->nice_match = configuration_table[s->level].nice_length;
- s->max_chain_length = configuration_table[s->level].max_chain;
-
- s->strstart = 0;
- s->block_start = 0L;
- s->lookahead = 0;
- s->insert = 0;
- s->match_length = s->prev_length = MIN_MATCH-1;
- s->match_available = 0;
- s->ins_h = 0;
-#ifndef FASTEST
-#ifdef ASMV
- match_init(); /* initialize the asm code */
-#endif
-#endif
-}
-
-#ifndef FASTEST
-/* ===========================================================================
- * Set match_start to the longest match starting at the given string and
- * return its length. Matches shorter or equal to prev_length are discarded,
- * in which case the result is equal to prev_length and match_start is
- * garbage.
- * IN assertions: cur_match is the head of the hash chain for the current
- * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
- * OUT assertion: the match length is not greater than s->lookahead.
- */
-#ifndef ASMV
-/* For 80x86 and 680x0, an optimized version will be provided in match.asm or
- * match.S. The code will be functionally equivalent.
- */
-local uInt longest_match(s, cur_match)
- deflate_state *s;
- IPos cur_match; /* current match */
-{
- unsigned chain_length = s->max_chain_length;/* max hash chain length */
- register Bytef *scan = s->window + s->strstart; /* current string */
- register Bytef *match; /* matched string */
- register int len; /* length of current match */
- int best_len = (int)s->prev_length; /* best match length so far */
- int nice_match = s->nice_match; /* stop if match long enough */
- IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
- s->strstart - (IPos)MAX_DIST(s) : NIL;
- /* Stop when cur_match becomes <= limit. To simplify the code,
- * we prevent matches with the string of window index 0.
- */
- Posf *prev = s->prev;
- uInt wmask = s->w_mask;
-
-#ifdef UNALIGNED_OK
- /* Compare two bytes at a time. Note: this is not always beneficial.
- * Try with and without -DUNALIGNED_OK to check.
- */
- register Bytef *strend = s->window + s->strstart + MAX_MATCH - 1;
- register ush scan_start = *(ushf*)scan;
- register ush scan_end = *(ushf*)(scan+best_len-1);
-#else
- register Bytef *strend = s->window + s->strstart + MAX_MATCH;
- register Byte scan_end1 = scan[best_len-1];
- register Byte scan_end = scan[best_len];
-#endif
-
- /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
- * It is easy to get rid of this optimization if necessary.
- */
- Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
-
- /* Do not waste too much time if we already have a good match: */
- if (s->prev_length >= s->good_match) {
- chain_length >>= 2;
- }
- /* Do not look for matches beyond the end of the input. This is necessary
- * to make deflate deterministic.
- */
- if ((uInt)nice_match > s->lookahead) nice_match = (int)s->lookahead;
-
- Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
-
- do {
- Assert(cur_match < s->strstart, "no future");
- match = s->window + cur_match;
-
- /* Skip to next match if the match length cannot increase
- * or if the match length is less than 2. Note that the checks below
- * for insufficient lookahead only occur occasionally for performance
- * reasons. Therefore uninitialized memory will be accessed, and
- * conditional jumps will be made that depend on those values.
- * However the length of the match is limited to the lookahead, so
- * the output of deflate is not affected by the uninitialized values.
- */
-#if (defined(UNALIGNED_OK) && MAX_MATCH == 258)
- /* This code assumes sizeof(unsigned short) == 2. Do not use
- * UNALIGNED_OK if your compiler uses a different size.
- */
- if (*(ushf*)(match+best_len-1) != scan_end ||
- *(ushf*)match != scan_start) continue;
-
- /* It is not necessary to compare scan[2] and match[2] since they are
- * always equal when the other bytes match, given that the hash keys
- * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at
- * strstart+3, +5, ... up to strstart+257. We check for insufficient
- * lookahead only every 4th comparison; the 128th check will be made
- * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is
- * necessary to put more guard bytes at the end of the window, or
- * to check more often for insufficient lookahead.
- */
- Assert(scan[2] == match[2], "scan[2]?");
- scan++, match++;
- do {
- } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
- *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
- *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
- *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
- scan < strend);
- /* The funny "do {}" generates better code on most compilers */
-
- /* Here, scan <= window+strstart+257 */
- Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
- if (*scan == *match) scan++;
-
- len = (MAX_MATCH - 1) - (int)(strend-scan);
- scan = strend - (MAX_MATCH-1);
-
-#else /* UNALIGNED_OK */
-
- if (match[best_len] != scan_end ||
- match[best_len-1] != scan_end1 ||
- *match != *scan ||
- *++match != scan[1]) continue;
-
- /* The check at best_len-1 can be removed because it will be made
- * again later. (This heuristic is not always a win.)
- * It is not necessary to compare scan[2] and match[2] since they
- * are always equal when the other bytes match, given that
- * the hash keys are equal and that HASH_BITS >= 8.
- */
- scan += 2, match++;
- Assert(*scan == *match, "match[2]?");
-
- /* We check for insufficient lookahead only every 8th comparison;
- * the 256th check will be made at strstart+258.
- */
- do {
- } while (*++scan == *++match && *++scan == *++match &&
- *++scan == *++match && *++scan == *++match &&
- *++scan == *++match && *++scan == *++match &&
- *++scan == *++match && *++scan == *++match &&
- scan < strend);
-
- Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
-
- len = MAX_MATCH - (int)(strend - scan);
- scan = strend - MAX_MATCH;
-
-#endif /* UNALIGNED_OK */
-
- if (len > best_len) {
- s->match_start = cur_match;
- best_len = len;
- if (len >= nice_match) break;
-#ifdef UNALIGNED_OK
- scan_end = *(ushf*)(scan+best_len-1);
-#else
- scan_end1 = scan[best_len-1];
- scan_end = scan[best_len];
-#endif
- }
- } while ((cur_match = prev[cur_match & wmask]) > limit
- && --chain_length != 0);
-
- if ((uInt)best_len <= s->lookahead) return (uInt)best_len;
- return s->lookahead;
-}
-#endif /* ASMV */
-
-#else /* FASTEST */
-
-/* ---------------------------------------------------------------------------
- * Optimized version for FASTEST only
- */
-local uInt longest_match(s, cur_match)
- deflate_state *s;
- IPos cur_match; /* current match */
-{
- register Bytef *scan = s->window + s->strstart; /* current string */
- register Bytef *match; /* matched string */
- register int len; /* length of current match */
- register Bytef *strend = s->window + s->strstart + MAX_MATCH;
-
- /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
- * It is easy to get rid of this optimization if necessary.
- */
- Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
-
- Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
-
- Assert(cur_match < s->strstart, "no future");
-
- match = s->window + cur_match;
-
- /* Return failure if the match length is less than 2:
- */
- if (match[0] != scan[0] || match[1] != scan[1]) return MIN_MATCH-1;
-
- /* The check at best_len-1 can be removed because it will be made
- * again later. (This heuristic is not always a win.)
- * It is not necessary to compare scan[2] and match[2] since they
- * are always equal when the other bytes match, given that
- * the hash keys are equal and that HASH_BITS >= 8.
- */
- scan += 2, match += 2;
- Assert(*scan == *match, "match[2]?");
-
- /* We check for insufficient lookahead only every 8th comparison;
- * the 256th check will be made at strstart+258.
- */
- do {
- } while (*++scan == *++match && *++scan == *++match &&
- *++scan == *++match && *++scan == *++match &&
- *++scan == *++match && *++scan == *++match &&
- *++scan == *++match && *++scan == *++match &&
- scan < strend);
-
- Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
-
- len = MAX_MATCH - (int)(strend - scan);
-
- if (len < MIN_MATCH) return MIN_MATCH - 1;
-
- s->match_start = cur_match;
- return (uInt)len <= s->lookahead ? (uInt)len : s->lookahead;
-}
-
-#endif /* FASTEST */
-
-#ifdef ZLIB_DEBUG
-
-#define EQUAL 0
-/* result of memcmp for equal strings */
-
-/* ===========================================================================
- * Check that the match at match_start is indeed a match.
- */
-local void check_match(s, start, match, length)
- deflate_state *s;
- IPos start, match;
- int length;
-{
- /* check that the match is indeed a match */
- if (zmemcmp(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,"\\[%d,%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).
- */
-local void fill_window(s)
- deflate_state *s;
-{
- unsigned n;
- unsigned more; /* Amount of free space at the end of the window. */
- uInt wsize = s->w_size;
-
- Assert(s->lookahead < MIN_LOOKAHEAD, "already enough lookahead");
-
- do {
- more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart);
-
- /* Deal with !@#$% 64K limit: */
- if (sizeof(int) <= 2) {
- if (more == 0 && s->strstart == 0 && s->lookahead == 0) {
- more = wsize;
-
- } else if (more == (unsigned)(-1)) {
- /* Very unlikely, but possible on 16 bit machine if
- * strstart == 0 && lookahead == 1 (input done a byte at time)
- */
- more--;
- }
- }
-
- /* 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)) {
-
- zmemcpy(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;
- 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) {
- uInt str = s->strstart - s->insert;
- s->ins_h = s->window[str];
- UPDATE_HASH(s, s->ins_h, s->window[str + 1]);
-#if MIN_MATCH != 3
- Call UPDATE_HASH() MIN_MATCH-3 more times
-#endif
- while (s->insert) {
- UPDATE_HASH(s, s->ins_h, s->window[str + MIN_MATCH-1]);
-#ifndef FASTEST
- s->prev[str & s->w_mask] = s->head[s->ins_h];
-#endif
- s->head[s->ins_h] = (Pos)str;
- str++;
- s->insert--;
- if (s->lookahead + s->insert < MIN_MATCH)
- break;
- }
- }
- /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage,
- * but this is not important since only literal bytes will be emitted.
- */
-
- } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0);
-
- /* If the WIN_INIT bytes after the end of the current data have never been
- * written, then zero those bytes in order to avoid memory check reports of
- * the use of uninitialized (or uninitialised as Julian writes) bytes by
- * the longest match routines. Update the high water mark for the next
- * time through here. WIN_INIT is set to MAX_MATCH since the longest match
- * routines allow scanning to strstart + MAX_MATCH, ignoring lookahead.
- */
- if (s->high_water < s->window_size) {
- ulg curr = s->strstart + (ulg)(s->lookahead);
- ulg init;
-
- if (s->high_water < curr) {
- /* Previous high water mark below current data -- zero WIN_INIT
- * bytes or up to end of window, whichever is less.
- */
- init = s->window_size - curr;
- if (init > WIN_INIT)
- init = WIN_INIT;
- zmemzero(s->window + curr, (unsigned)init);
- s->high_water = curr + init;
- }
- else if (s->high_water < (ulg)curr + WIN_INIT) {
- /* High water mark at or above current data, but below current data
- * plus WIN_INIT -- zero out to current data plus WIN_INIT, or up
- * to end of window, whichever is less.
- */
- init = (ulg)curr + WIN_INIT - s->high_water;
- if (init > s->window_size - s->high_water)
- init = s->window_size - s->high_water;
- zmemzero(s->window + s->high_water, (unsigned)init);
- s->high_water += init;
- }
- }
-
- Assert((ulg)s->strstart <= s->window_size - MIN_LOOKAHEAD,
- "not enough room for search");
-}
-
-/* ===========================================================================
- * Flush the current block, with given end-of-file flag.
- * IN assertion: strstart is set to the end of the current match.
- */
-#define FLUSH_BLOCK_ONLY(s, last) { \
- _tr_flush_block(s, (s->block_start >= 0L ? \
- (charf *)&s->window[(unsigned)s->block_start] : \
- (charf *)Z_NULL), \
- (ulg)((long)s->strstart - s->block_start), \
- (last)); \
- s->block_start = s->strstart; \
- flush_pending(s->strm); \
- Tracev((stderr,"[FLUSH]")); \
-}
-
-/* Same but force premature exit if necessary. */
-#define FLUSH_BLOCK(s, last) { \
- FLUSH_BLOCK_ONLY(s, last); \
- if (s->strm->avail_out == 0) return (last) ? finish_started : need_more; \
-}
-
-/* Maximum stored block length in deflate format (not including header). */
-#define MAX_STORED 65535
-
-/* Minimum of a and b. */
-#define MIN(a, b) ((a) > (b) ? (b) : (a))
-
-/* ===========================================================================
- * 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.
- */
-local block_state deflate_stored(s, flush)
- 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 > (ulg)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;
- _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;
- zmemcpy(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 */
- zmemcpy(s->window, s->strm->next_in - s->w_size, s->w_size);
- s->strstart = s->w_size;
- }
- else {
- if (s->window_size - s->strstart <= used) {
- /* Slide the window down. */
- s->strstart -= s->w_size;
- zmemcpy(s->window, s->window + s->w_size, s->strstart);
- if (s->matches < 2)
- s->matches++; /* add a pending slide_hash() */
- }
- zmemcpy(s->window + s->strstart, s->strm->next_in - used, used);
- s->strstart += used;
- }
- s->block_start = s->strstart;
- s->insert += MIN(used, s->w_size - s->insert);
- }
- 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 - 1;
- 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;
- zmemcpy(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 (have > s->strm->avail_in)
- have = s->strm->avail_in;
- if (have) {
- read_buf(s->strm, s->window + s->strstart, have);
- s->strstart += have;
- }
- 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;
- _tr_stored_block(s, (charf *)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;
-}
-
-/* ===========================================================================
- * Compress as much as possible from the input stream, return the current
- * block state.
- * This function does not perform lazy evaluation of matches and inserts
- * new strings in the dictionary only for unmatched strings or for short
- * matches. It is used only for the fast compression options.
- */
-local block_state deflate_fast(s, flush)
- deflate_state *s;
- int flush;
-{
- IPos hash_head; /* head of the hash chain */
- int bflush; /* set if current block must be flushed */
-
- for (;;) {
- /* Make sure that we always have enough lookahead, except
- * at the end of the input file. We need MAX_MATCH bytes
- * for the next match, plus MIN_MATCH bytes to insert the
- * string following the next match.
- */
- if (s->lookahead < MIN_LOOKAHEAD) {
- fill_window(s);
- if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
- return need_more;
- }
- if (s->lookahead == 0) break; /* flush the current block */
- }
-
- /* Insert the string window[strstart .. strstart+2] in the
- * dictionary, and set hash_head to the head of the hash chain:
- */
- hash_head = NIL;
- if (s->lookahead >= MIN_MATCH) {
- INSERT_STRING(s, s->strstart, hash_head);
- }
-
- /* Find the longest match, discarding those <= prev_length.
- * At this point we have always match_length < MIN_MATCH
- */
- if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) {
- /* To simplify the code, we prevent matches with the string
- * of window index 0 (in particular we have to avoid a match
- * of the string with itself at the start of the input file).
- */
- s->match_length = longest_match (s, hash_head);
- /* longest_match() sets match_start */
- }
- if (s->match_length >= MIN_MATCH) {
- check_match(s, s->strstart, s->match_start, s->match_length);
-
- _tr_tally_dist(s, s->strstart - s->match_start,
- s->match_length - MIN_MATCH, bflush);
-
- s->lookahead -= s->match_length;
-
- /* Insert new strings in the hash table only if the match length
- * is not too large. This saves time but degrades compression.
- */
-#ifndef FASTEST
- if (s->match_length <= s->max_insert_length &&
- s->lookahead >= MIN_MATCH) {
- s->match_length--; /* string at strstart already in table */
- do {
- s->strstart++;
- INSERT_STRING(s, s->strstart, hash_head);
- /* strstart never exceeds WSIZE-MAX_MATCH, so there are
- * always MIN_MATCH bytes ahead.
- */
- } while (--s->match_length != 0);
- s->strstart++;
- } else
-#endif
- {
- s->strstart += s->match_length;
- s->match_length = 0;
- s->ins_h = s->window[s->strstart];
- UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
-#if MIN_MATCH != 3
- Call UPDATE_HASH() MIN_MATCH-3 more times
-#endif
- /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not
- * matter since it will be recomputed at next deflate call.
- */
- }
- } else {
- /* No match, output a literal byte */
- Tracevv((stderr,"%c", s->window[s->strstart]));
- _tr_tally_lit (s, s->window[s->strstart], bflush);
- s->lookahead--;
- s->strstart++;
- }
- if (bflush) FLUSH_BLOCK(s, 0);
- }
- s->insert = s->strstart < MIN_MATCH-1 ? s->strstart : MIN_MATCH-1;
- if (flush == Z_FINISH) {
- FLUSH_BLOCK(s, 1);
- return finish_done;
- }
- if (s->last_lit)
- FLUSH_BLOCK(s, 0);
- return block_done;
-}
-
-#ifndef FASTEST
-/* ===========================================================================
- * Same as above, but achieves better compression. We use a lazy
- * evaluation for matches: a match is finally adopted only if there is
- * no better match at the next window position.
- */
-local block_state deflate_slow(s, flush)
- deflate_state *s;
- int flush;
-{
- IPos hash_head; /* head of hash chain */
- int bflush; /* set if current block must be flushed */
-
- /* Process the input block. */
- for (;;) {
- /* Make sure that we always have enough lookahead, except
- * at the end of the input file. We need MAX_MATCH bytes
- * for the next match, plus MIN_MATCH bytes to insert the
- * string following the next match.
- */
- if (s->lookahead < MIN_LOOKAHEAD) {
- fill_window(s);
- if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
- return need_more;
- }
- if (s->lookahead == 0) break; /* flush the current block */
- }
-
- /* Insert the string window[strstart .. strstart+2] in the
- * dictionary, and set hash_head to the head of the hash chain:
- */
- hash_head = NIL;
- if (s->lookahead >= MIN_MATCH) {
- INSERT_STRING(s, s->strstart, hash_head);
- }
-
- /* Find the longest match, discarding those <= prev_length.
- */
- s->prev_length = s->match_length, s->prev_match = s->match_start;
- s->match_length = MIN_MATCH-1;
-
- if (hash_head != NIL && s->prev_length < s->max_lazy_match &&
- s->strstart - hash_head <= MAX_DIST(s)) {
- /* To simplify the code, we prevent matches with the string
- * of window index 0 (in particular we have to avoid a match
- * of the string with itself at the start of the input file).
- */
- s->match_length = longest_match (s, hash_head);
- /* longest_match() sets match_start */
-
- if (s->match_length <= 5 && (s->strategy == Z_FILTERED
-#if TOO_FAR <= 32767
- || (s->match_length == MIN_MATCH &&
- s->strstart - s->match_start > TOO_FAR)
-#endif
- )) {
-
- /* If prev_match is also MIN_MATCH, match_start is garbage
- * but we will ignore the current match anyway.
- */
- s->match_length = MIN_MATCH-1;
- }
- }
- /* If there was a match at the previous step and the current
- * match is not better, output the previous match:
- */
- if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) {
- uInt max_insert = s->strstart + s->lookahead - MIN_MATCH;
- /* Do not insert strings in hash table beyond this. */
-
- check_match(s, s->strstart-1, s->prev_match, s->prev_length);
-
- _tr_tally_dist(s, s->strstart -1 - s->prev_match,
- s->prev_length - MIN_MATCH, bflush);
-
- /* Insert in hash table all strings up to the end of the match.
- * strstart-1 and strstart are already inserted. If there is not
- * enough lookahead, the last two strings are not inserted in
- * the hash table.
- */
- s->lookahead -= s->prev_length-1;
- s->prev_length -= 2;
- do {
- if (++s->strstart <= max_insert) {
- INSERT_STRING(s, s->strstart, hash_head);
- }
- } while (--s->prev_length != 0);
- s->match_available = 0;
- s->match_length = MIN_MATCH-1;
- s->strstart++;
-
- if (bflush) FLUSH_BLOCK(s, 0);
-
- } else if (s->match_available) {
- /* If there was no match at the previous position, output a
- * single literal. If there was a match but the current match
- * is longer, truncate the previous match to a single literal.
- */
- Tracevv((stderr,"%c", s->window[s->strstart-1]));
- _tr_tally_lit(s, s->window[s->strstart-1], bflush);
- if (bflush) {
- FLUSH_BLOCK_ONLY(s, 0);
- }
- s->strstart++;
- s->lookahead--;
- if (s->strm->avail_out == 0) return need_more;
- } else {
- /* There is no previous match to compare with, wait for
- * the next step to decide.
- */
- s->match_available = 1;
- s->strstart++;
- s->lookahead--;
- }
- }
- Assert (flush != Z_NO_FLUSH, "no flush?");
- if (s->match_available) {
- Tracevv((stderr,"%c", s->window[s->strstart-1]));
- _tr_tally_lit(s, s->window[s->strstart-1], bflush);
- s->match_available = 0;
- }
- s->insert = s->strstart < MIN_MATCH-1 ? s->strstart : MIN_MATCH-1;
- if (flush == Z_FINISH) {
- FLUSH_BLOCK(s, 1);
- return finish_done;
- }
- if (s->last_lit)
- FLUSH_BLOCK(s, 0);
- return block_done;
-}
-#endif /* FASTEST */
-
-/* ===========================================================================
- * For Z_RLE, simply look for runs of bytes, generate matches only of distance
- * one. Do not maintain a hash table. (It will be regenerated if this run of
- * deflate switches away from Z_RLE.)
- */
-local block_state deflate_rle(s, flush)
- deflate_state *s;
- int flush;
-{
- int bflush; /* set if current block must be flushed */
- uInt prev; /* byte at distance one to match */
- Bytef *scan, *strend; /* scan goes up to strend for length of run */
-
- for (;;) {
- /* Make sure that we always have enough lookahead, except
- * at the end of the input file. We need MAX_MATCH bytes
- * for the longest run, plus one for the unrolled loop.
- */
- if (s->lookahead <= MAX_MATCH) {
- fill_window(s);
- if (s->lookahead <= MAX_MATCH && flush == Z_NO_FLUSH) {
- return need_more;
- }
- if (s->lookahead == 0) break; /* flush the current block */
- }
-
- /* See how many times the previous byte repeats */
- s->match_length = 0;
- if (s->lookahead >= MIN_MATCH && s->strstart > 0) {
- scan = s->window + s->strstart - 1;
- prev = *scan;
- if (prev == *++scan && prev == *++scan && prev == *++scan) {
- strend = s->window + s->strstart + MAX_MATCH;
- do {
- } while (prev == *++scan && prev == *++scan &&
- prev == *++scan && prev == *++scan &&
- prev == *++scan && prev == *++scan &&
- prev == *++scan && prev == *++scan &&
- scan < strend);
- s->match_length = MAX_MATCH - (uInt)(strend - scan);
- if (s->match_length > s->lookahead)
- s->match_length = s->lookahead;
- }
- Assert(scan <= s->window+(uInt)(s->window_size-1), "wild scan");
- }
-
- /* Emit match if have run of MIN_MATCH or longer, else emit literal */
- if (s->match_length >= MIN_MATCH) {
- check_match(s, s->strstart, s->strstart - 1, s->match_length);
-
- _tr_tally_dist(s, 1, s->match_length - MIN_MATCH, bflush);
-
- s->lookahead -= s->match_length;
- s->strstart += s->match_length;
- s->match_length = 0;
- } else {
- /* No match, output a literal byte */
- Tracevv((stderr,"%c", s->window[s->strstart]));
- _tr_tally_lit (s, s->window[s->strstart], bflush);
- s->lookahead--;
- s->strstart++;
- }
- if (bflush) FLUSH_BLOCK(s, 0);
- }
- s->insert = 0;
- if (flush == Z_FINISH) {
- FLUSH_BLOCK(s, 1);
- return finish_done;
- }
- if (s->last_lit)
- FLUSH_BLOCK(s, 0);
- return block_done;
-}
-
-/* ===========================================================================
- * For Z_HUFFMAN_ONLY, do not look for matches. Do not maintain a hash table.
- * (It will be regenerated if this run of deflate switches away from Huffman.)
- */
-local block_state deflate_huff(s, flush)
- deflate_state *s;
- int flush;
-{
- int bflush; /* set if current block must be flushed */
-
- for (;;) {
- /* Make sure that we have a literal to write. */
- if (s->lookahead == 0) {
- fill_window(s);
- if (s->lookahead == 0) {
- if (flush == Z_NO_FLUSH)
- return need_more;
- break; /* flush the current block */
- }
- }
-
- /* Output a literal byte */
- s->match_length = 0;
- Tracevv((stderr,"%c", s->window[s->strstart]));
- _tr_tally_lit (s, s->window[s->strstart], bflush);
- s->lookahead--;
- s->strstart++;
- if (bflush) FLUSH_BLOCK(s, 0);
- }
- s->insert = 0;
- if (flush == Z_FINISH) {
- FLUSH_BLOCK(s, 1);
- return finish_done;
- }
- if (s->last_lit)
- FLUSH_BLOCK(s, 0);
- return block_done;
-}