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contrib/zlib/deflate.c
Property | Old Value | New Value |
---|---|---|
svn:keywords | FreeBSD=%H \ No newline at end of property | null |
/* 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" | |||||
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 = -2; | |||||
_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->last_flush != -2) { | |||||
/* Flush the last buffer: */ | |||||
int err = deflate(strm, Z_BLOCK); | |||||
if (err == Z_STREAM_ERROR) | |||||
return err; | |||||
if (strm->avail_in || (s->strstart - s->block_start) + s->lookahead) | |||||
return Z_BUF_ERROR; | |||||
} | |||||
if (s->level != level) { | |||||
if (s->level == 0 && s->matches != 0) { | |||||
if (s->matches == 1) | |||||
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; | |||||
} |