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1408 lines
50 KiB
C
1408 lines
50 KiB
C
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/* deflate.c -- compress data using the deflation algorithm
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* Copyright (C) 1995-2013 Jean-loup Gailly and Mark Adler
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* For conditions of distribution and use, see copyright notice in zlib.h
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*/
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/*
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* ALGORITHM
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*
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* The "deflation" process depends on being able to identify portions
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* of the input text which are identical to earlier input (within a
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* sliding window trailing behind the input currently being processed).
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*
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* The most straightforward technique turns out to be the fastest for
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* most input files: try all possible matches and select the longest.
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* The key feature of this algorithm is that insertions into the string
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* dictionary are very simple and thus fast, and deletions are avoided
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* completely. Insertions are performed at each input character, whereas
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* string matches are performed only when the previous match ends. So it
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* is preferable to spend more time in matches to allow very fast string
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* insertions and avoid deletions. The matching algorithm for small
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* strings is inspired from that of Rabin & Karp. A brute force approach
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* is used to find longer strings when a small match has been found.
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* A similar algorithm is used in comic (by Jan-Mark Wams) and freeze
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* (by Leonid Broukhis).
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* A previous version of this file used a more sophisticated algorithm
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* (by Fiala and Greene) which is guaranteed to run in linear amortized
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* time, but has a larger average cost, uses more memory and is patented.
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* However the F&G algorithm may be faster for some highly redundant
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* files if the parameter max_chain_length (described below) is too large.
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*
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* ACKNOWLEDGEMENTS
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*
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* The idea of lazy evaluation of matches is due to Jan-Mark Wams, and
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* I found it in 'freeze' written by Leonid Broukhis.
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* Thanks to many people for bug reports and testing.
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*
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* REFERENCES
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*
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* Deutsch, L.P.,"DEFLATE Compressed Data Format Specification".
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* Available in http://tools.ietf.org/html/rfc1951
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*
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* A description of the Rabin and Karp algorithm is given in the book
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* "Algorithms" by R. Sedgewick, Addison-Wesley, p252.
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*
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* Fiala,E.R., and Greene,D.H.
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* Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595
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*
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*/
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/* @(#) $Id$ */
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#include "deflate.h"
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#include "deflate_p.h"
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#include "match.h"
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const char deflate_copyright[] = " deflate 1.2.8.f Copyright 1995-2013 Jean-loup Gailly and Mark Adler ";
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/*
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If you use the zlib library in a product, an acknowledgment is welcome
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in the documentation of your product. If for some reason you cannot
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include such an acknowledgment, I would appreciate that you keep this
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copyright string in the executable of your product.
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*/
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/* ===========================================================================
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* Function prototypes.
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*/
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typedef block_state (*compress_func) (deflate_state *s, int flush);
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/* Compression function. Returns the block state after the call. */
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void fill_window (deflate_state *s);
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local block_state deflate_stored (deflate_state *s, int flush);
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block_state deflate_fast (deflate_state *s, int flush);
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block_state deflate_quick (deflate_state *s, int flush);
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#ifdef MEDIUM_STRATEGY
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block_state deflate_medium (deflate_state *s, int flush);
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#endif
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block_state deflate_slow (deflate_state *s, int flush);
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local block_state deflate_rle (deflate_state *s, int flush);
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local block_state deflate_huff (deflate_state *s, int flush);
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local void lm_init (deflate_state *s);
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local void putShortMSB (deflate_state *s, uint16_t b);
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ZLIB_INTERNAL void flush_pending (z_stream *strm);
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ZLIB_INTERNAL int read_buf (z_stream *strm, unsigned char *buf, unsigned size);
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extern void crc_reset(deflate_state *const s);
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extern void crc_finalize(deflate_state *const s);
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extern void copy_with_crc(z_stream *strm, unsigned char *dst, long size);
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/* ===========================================================================
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* Local data
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*/
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#define NIL 0
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/* Tail of hash chains */
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/* Values for max_lazy_match, good_match and max_chain_length, depending on
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* the desired pack level (0..9). The values given below have been tuned to
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* exclude worst case performance for pathological files. Better values may be
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* found for specific files.
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*/
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typedef struct config_s {
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uint16_t good_length; /* reduce lazy search above this match length */
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uint16_t max_lazy; /* do not perform lazy search above this match length */
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uint16_t nice_length; /* quit search above this match length */
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uint16_t max_chain;
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compress_func func;
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} config;
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local const config configuration_table[10] = {
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/* good lazy nice chain */
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/* 0 */ {0, 0, 0, 0, deflate_stored}, /* store only */
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#ifdef X86_QUICK_STRATEGY
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/* 1 */ {4, 4, 8, 4, deflate_quick},
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/* 2 */ {4, 4, 8, 4, deflate_fast}, /* max speed, no lazy matches */
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#else
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/* 1 */ {4, 4, 8, 4, deflate_fast}, /* max speed, no lazy matches */
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/* 2 */ {4, 5, 16, 8, deflate_fast},
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#endif
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/* 3 */ {4, 6, 32, 32, deflate_fast},
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#ifdef MEDIUM_STRATEGY
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/* 4 */ {4, 4, 16, 16, deflate_medium}, /* lazy matches */
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/* 5 */ {8, 16, 32, 32, deflate_medium},
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/* 6 */ {8, 16, 128, 128, deflate_medium},
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#else
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/* 4 */ {4, 4, 16, 16, deflate_slow}, /* lazy matches */
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/* 5 */ {8, 16, 32, 32, deflate_slow},
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/* 6 */ {8, 16, 128, 128, deflate_slow},
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#endif
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/* 7 */ {8, 32, 128, 256, deflate_slow},
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/* 8 */ {32, 128, 258, 1024, deflate_slow},
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/* 9 */ {32, 258, 258, 4096, deflate_slow}}; /* max compression */
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/* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4
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* For deflate_fast() (levels <= 3) good is ignored and lazy has a different
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* meaning.
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*/
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#define EQUAL 0
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/* result of memcmp for equal strings */
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/* rank Z_BLOCK between Z_NO_FLUSH and Z_PARTIAL_FLUSH */
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#define RANK(f) (((f) * 2) - ((f) > 4 ? 9 : 0))
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/* ===========================================================================
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* Initialize the hash table (avoiding 64K overflow for 16 bit systems).
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* prev[] will be initialized on the fly.
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*/
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#define CLEAR_HASH(s) \
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s->head[s->hash_size-1] = NIL; \
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memset((unsigned char *)s->head, 0, (unsigned)(s->hash_size-1)*sizeof(*s->head));
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/* ========================================================================= */
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int ZEXPORT deflateInit_(z_stream *strm, int level, const char *version, int stream_size) {
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return deflateInit2_(strm, level, Z_DEFLATED, MAX_WBITS, DEF_MEM_LEVEL, Z_DEFAULT_STRATEGY, version, stream_size);
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/* Todo: ignore strm->next_in if we use it as window */
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}
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/* ========================================================================= */
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int ZEXPORT deflateInit2_(z_stream *strm, int level, int method, int windowBits,
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int memLevel, int strategy, const char *version, int stream_size) {
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unsigned window_padding = 0;
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deflate_state *s;
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int wrap = 1;
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static const char my_version[] = ZLIB_VERSION;
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uint16_t *overlay;
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/* We overlay pending_buf and d_buf+l_buf. This works since the average
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* output size for (length,distance) codes is <= 24 bits.
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*/
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#if defined(X86_SSE2_FILL_WINDOW) || defined(X86_SSE4_2_CRC_HASH)
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x86_check_features();
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#endif
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if (version == Z_NULL || version[0] != my_version[0] || stream_size != sizeof(z_stream)) {
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return Z_VERSION_ERROR;
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}
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if (strm == Z_NULL)
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return Z_STREAM_ERROR;
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strm->msg = Z_NULL;
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if (strm->zalloc == (alloc_func)0) {
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strm->zalloc = zcalloc;
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strm->opaque = NULL;
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}
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if (strm->zfree == (free_func)0)
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strm->zfree = zcfree;
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if (level == Z_DEFAULT_COMPRESSION)
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level = 6;
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if (windowBits < 0) { /* suppress zlib wrapper */
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wrap = 0;
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windowBits = -windowBits;
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#ifdef GZIP
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} else if (windowBits > 15) {
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wrap = 2; /* write gzip wrapper instead */
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windowBits -= 16;
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#endif
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}
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if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != Z_DEFLATED || windowBits < 8 ||
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windowBits > 15 || level < 0 || level > 9 || strategy < 0 || strategy > Z_FIXED) {
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return Z_STREAM_ERROR;
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}
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if (windowBits == 8)
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windowBits = 9; /* until 256-byte window bug fixed */
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#ifdef X86_QUICK_STRATEGY
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if (level == 1)
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windowBits = 13;
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#endif
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s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state));
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if (s == Z_NULL)
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return Z_MEM_ERROR;
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strm->state = (struct internal_state *)s;
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s->strm = strm;
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s->wrap = wrap;
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s->gzhead = Z_NULL;
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s->w_bits = windowBits;
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s->w_size = 1 << s->w_bits;
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s->w_mask = s->w_size - 1;
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#ifdef X86_SSE4_2_CRC_HASH
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if (x86_cpu_has_sse42)
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s->hash_bits = 15;
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else
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#endif
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s->hash_bits = memLevel + 7;
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s->hash_size = 1 << s->hash_bits;
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s->hash_mask = s->hash_size - 1;
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s->hash_shift = ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH);
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#ifdef X86_PCLMULQDQ_CRC
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window_padding = 8;
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#endif
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s->window = (unsigned char *) ZALLOC(strm, s->w_size + window_padding, 2*sizeof(unsigned char));
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s->prev = (Pos *) ZALLOC(strm, s->w_size, sizeof(Pos));
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s->head = (Pos *) ZALLOC(strm, s->hash_size, sizeof(Pos));
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s->high_water = 0; /* nothing written to s->window yet */
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s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */
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overlay = (uint16_t *) ZALLOC(strm, s->lit_bufsize, sizeof(uint16_t)+2);
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s->pending_buf = (unsigned char *) overlay;
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s->pending_buf_size = (unsigned long)s->lit_bufsize * (sizeof(uint16_t)+2L);
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if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL ||
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s->pending_buf == Z_NULL) {
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s->status = FINISH_STATE;
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strm->msg = ERR_MSG(Z_MEM_ERROR);
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deflateEnd(strm);
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return Z_MEM_ERROR;
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}
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s->d_buf = overlay + s->lit_bufsize/sizeof(uint16_t);
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s->l_buf = s->pending_buf + (1+sizeof(uint16_t))*s->lit_bufsize;
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s->level = level;
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s->strategy = strategy;
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s->method = (unsigned char)method;
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return deflateReset(strm);
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}
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/* ========================================================================= */
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int ZEXPORT deflateSetDictionary(z_stream *strm, const unsigned char *dictionary, unsigned int dictLength) {
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deflate_state *s;
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unsigned int str, n;
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int wrap;
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uint32_t avail;
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const unsigned char *next;
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if (strm == Z_NULL || strm->state == Z_NULL || dictionary == Z_NULL)
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return Z_STREAM_ERROR;
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s = strm->state;
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wrap = s->wrap;
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if (wrap == 2 || (wrap == 1 && s->status != INIT_STATE) || s->lookahead)
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return Z_STREAM_ERROR;
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/* when using zlib wrappers, compute Adler-32 for provided dictionary */
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if (wrap == 1)
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strm->adler = adler32(strm->adler, dictionary, dictLength);
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s->wrap = 0; /* avoid computing Adler-32 in read_buf */
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/* if dictionary would fill window, just replace the history */
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if (dictLength >= s->w_size) {
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if (wrap == 0) { /* already empty otherwise */
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CLEAR_HASH(s);
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s->strstart = 0;
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s->block_start = 0L;
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s->insert = 0;
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}
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dictionary += dictLength - s->w_size; /* use the tail */
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dictLength = s->w_size;
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}
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/* insert dictionary into window and hash */
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avail = strm->avail_in;
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next = strm->next_in;
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strm->avail_in = dictLength;
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strm->next_in = (const unsigned char *)dictionary;
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fill_window(s);
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while (s->lookahead >= MIN_MATCH) {
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str = s->strstart;
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n = s->lookahead - (MIN_MATCH-1);
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bulk_insert_str(s, str, n);
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s->strstart = str + n;
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s->lookahead = MIN_MATCH-1;
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fill_window(s);
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}
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s->strstart += s->lookahead;
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s->block_start = (long)s->strstart;
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s->insert = s->lookahead;
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s->lookahead = 0;
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s->match_length = s->prev_length = MIN_MATCH-1;
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s->match_available = 0;
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strm->next_in = next;
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strm->avail_in = avail;
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s->wrap = wrap;
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return Z_OK;
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}
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/* ========================================================================= */
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int ZEXPORT deflateResetKeep(z_stream *strm) {
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deflate_state *s;
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if (strm == Z_NULL || strm->state == Z_NULL || strm->zalloc == (alloc_func)0 || strm->zfree == (free_func)0) {
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return Z_STREAM_ERROR;
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}
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strm->total_in = strm->total_out = 0;
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strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */
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strm->data_type = Z_UNKNOWN;
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s = (deflate_state *)strm->state;
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s->pending = 0;
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s->pending_out = s->pending_buf;
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if (s->wrap < 0) {
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s->wrap = -s->wrap; /* was made negative by deflate(..., Z_FINISH); */
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}
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s->status = s->wrap ? INIT_STATE : BUSY_STATE;
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#ifdef GZIP
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strm->adler = s->wrap == 2 ? crc32(0L, Z_NULL, 0) : adler32(0L, Z_NULL, 0);
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#else
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strm->adler = adler32(0L, Z_NULL, 0);
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#endif
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s->last_flush = Z_NO_FLUSH;
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_tr_init(s);
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return Z_OK;
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}
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||
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||
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/* ========================================================================= */
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int ZEXPORT deflateReset(z_stream *strm) {
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int ret;
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ret = deflateResetKeep(strm);
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if (ret == Z_OK)
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||
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lm_init(strm->state);
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return ret;
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}
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||
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/* ========================================================================= */
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int ZEXPORT deflateSetHeader(z_stream *strm, gz_headerp head) {
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||
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if (strm == Z_NULL || strm->state == Z_NULL)
|
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return Z_STREAM_ERROR;
|
||
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if (strm->state->wrap != 2)
|
||
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return Z_STREAM_ERROR;
|
||
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strm->state->gzhead = head;
|
||
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return Z_OK;
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}
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/* ========================================================================= */
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||
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int ZEXPORT deflatePending(z_stream *strm, uint32_t *pending, int *bits) {
|
||
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if (strm == Z_NULL || strm->state == Z_NULL)
|
||
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return Z_STREAM_ERROR;
|
||
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if (pending != Z_NULL)
|
||
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*pending = strm->state->pending;
|
||
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if (bits != Z_NULL)
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||
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*bits = strm->state->bi_valid;
|
||
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return Z_OK;
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||
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}
|
||
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||
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/* ========================================================================= */
|
||
|
int ZEXPORT deflatePrime(z_stream *strm, int bits, int value) {
|
||
|
deflate_state *s;
|
||
|
int put;
|
||
|
|
||
|
if (strm == Z_NULL || strm->state == Z_NULL)
|
||
|
return Z_STREAM_ERROR;
|
||
|
s = strm->state;
|
||
|
if ((unsigned char *)(s->d_buf) < s->pending_out + ((Buf_size + 7) >> 3))
|
||
|
return Z_BUF_ERROR;
|
||
|
do {
|
||
|
put = Buf_size - s->bi_valid;
|
||
|
if (put > bits)
|
||
|
put = bits;
|
||
|
s->bi_buf |= (uint16_t)((value & ((1 << put) - 1)) << s->bi_valid);
|
||
|
s->bi_valid += put;
|
||
|
_tr_flush_bits(s);
|
||
|
value >>= put;
|
||
|
bits -= put;
|
||
|
} while (bits);
|
||
|
return Z_OK;
|
||
|
}
|
||
|
|
||
|
/* ========================================================================= */
|
||
|
int ZEXPORT deflateParams(z_stream *strm, int level, int strategy) {
|
||
|
deflate_state *s;
|
||
|
compress_func func;
|
||
|
int err = Z_OK;
|
||
|
|
||
|
if (strm == Z_NULL || strm->state == Z_NULL)
|
||
|
return Z_STREAM_ERROR;
|
||
|
s = strm->state;
|
||
|
|
||
|
if (level == Z_DEFAULT_COMPRESSION)
|
||
|
level = 6;
|
||
|
if (level < 0 || level > 9 || strategy < 0 || strategy > Z_FIXED) {
|
||
|
return Z_STREAM_ERROR;
|
||
|
}
|
||
|
func = configuration_table[s->level].func;
|
||
|
|
||
|
if ((strategy != s->strategy || func != configuration_table[level].func)) {
|
||
|
/* Flush the last buffer: */
|
||
|
err = deflate(strm, Z_BLOCK);
|
||
|
if (err == Z_BUF_ERROR && s->pending == 0)
|
||
|
err = Z_OK;
|
||
|
}
|
||
|
if (s->level != level) {
|
||
|
s->level = level;
|
||
|
s->max_lazy_match = configuration_table[level].max_lazy;
|
||
|
s->good_match = configuration_table[level].good_length;
|
||
|
s->nice_match = configuration_table[level].nice_length;
|
||
|
s->max_chain_length = configuration_table[level].max_chain;
|
||
|
}
|
||
|
s->strategy = strategy;
|
||
|
return err;
|
||
|
}
|
||
|
|
||
|
/* ========================================================================= */
|
||
|
int ZEXPORT deflateTune(z_stream *strm, int good_length, int max_lazy, int nice_length, int max_chain) {
|
||
|
deflate_state *s;
|
||
|
|
||
|
if (strm == Z_NULL || strm->state == Z_NULL)
|
||
|
return Z_STREAM_ERROR;
|
||
|
s = strm->state;
|
||
|
s->good_match = good_length;
|
||
|
s->max_lazy_match = max_lazy;
|
||
|
s->nice_match = nice_length;
|
||
|
s->max_chain_length = max_chain;
|
||
|
return Z_OK;
|
||
|
}
|
||
|
|
||
|
/* =========================================================================
|
||
|
* For the default windowBits of 15 and memLevel of 8, this function returns
|
||
|
* a close to exact, as well as small, upper bound on the compressed size.
|
||
|
* They are coded as constants here for a reason--if the #define's are
|
||
|
* changed, then this function needs to be changed as well. The return
|
||
|
* value for 15 and 8 only works for those exact settings.
|
||
|
*
|
||
|
* For any setting other than those defaults for windowBits and memLevel,
|
||
|
* the value returned is a conservative worst case for the maximum expansion
|
||
|
* resulting from using fixed blocks instead of stored blocks, which deflate
|
||
|
* can emit on compressed data for some combinations of the parameters.
|
||
|
*
|
||
|
* This function could be more sophisticated to provide closer upper bounds for
|
||
|
* every combination of windowBits and memLevel. But even the conservative
|
||
|
* upper bound of about 14% expansion does not seem onerous for output buffer
|
||
|
* allocation.
|
||
|
*/
|
||
|
unsigned long ZEXPORT deflateBound(z_stream *strm, unsigned long sourceLen) {
|
||
|
deflate_state *s;
|
||
|
unsigned long complen, wraplen;
|
||
|
unsigned char *str;
|
||
|
|
||
|
/* conservative upper bound for compressed data */
|
||
|
complen = sourceLen + ((sourceLen + 7) >> 3) + ((sourceLen + 63) >> 6) + 5;
|
||
|
|
||
|
/* if can't get parameters, return conservative bound plus zlib wrapper */
|
||
|
if (strm == Z_NULL || strm->state == Z_NULL)
|
||
|
return complen + 6;
|
||
|
|
||
|
/* compute wrapper length */
|
||
|
s = strm->state;
|
||
|
switch (s->wrap) {
|
||
|
case 0: /* raw deflate */
|
||
|
wraplen = 0;
|
||
|
break;
|
||
|
case 1: /* zlib wrapper */
|
||
|
wraplen = 6 + (s->strstart ? 4 : 0);
|
||
|
break;
|
||
|
case 2: /* gzip wrapper */
|
||
|
wraplen = 18;
|
||
|
if (s->gzhead != Z_NULL) { /* user-supplied gzip header */
|
||
|
if (s->gzhead->extra != Z_NULL) {
|
||
|
wraplen += 2 + s->gzhead->extra_len;
|
||
|
}
|
||
|
str = s->gzhead->name;
|
||
|
if (str != Z_NULL) {
|
||
|
do {
|
||
|
wraplen++;
|
||
|
} while (*str++);
|
||
|
}
|
||
|
str = s->gzhead->comment;
|
||
|
if (str != Z_NULL) {
|
||
|
do {
|
||
|
wraplen++;
|
||
|
} while (*str++);
|
||
|
}
|
||
|
if (s->gzhead->hcrc)
|
||
|
wraplen += 2;
|
||
|
}
|
||
|
break;
|
||
|
default: /* for compiler happiness */
|
||
|
wraplen = 6;
|
||
|
}
|
||
|
|
||
|
/* if not default parameters, return conservative bound */
|
||
|
if (s->w_bits != 15 || s->hash_bits != 8 + 7)
|
||
|
return complen + wraplen;
|
||
|
|
||
|
/* default settings: return tight bound for that case */
|
||
|
return sourceLen + (sourceLen >> 12) + (sourceLen >> 14) + (sourceLen >> 25) + 13 - 6 + wraplen;
|
||
|
}
|
||
|
|
||
|
/* =========================================================================
|
||
|
* Put a short in the pending buffer. The 16-bit value is put in MSB order.
|
||
|
* IN assertion: the stream state is correct and there is enough room in
|
||
|
* pending_buf.
|
||
|
*/
|
||
|
local void putShortMSB(deflate_state *s, uint16_t b) {
|
||
|
put_byte(s, (unsigned char)(b >> 8));
|
||
|
put_byte(s, (unsigned char)(b & 0xff));
|
||
|
}
|
||
|
|
||
|
/* =========================================================================
|
||
|
* Flush as much pending output as possible. All deflate() output goes
|
||
|
* through this function so some applications may wish to modify it
|
||
|
* to avoid allocating a large strm->next_out buffer and copying into it.
|
||
|
* (See also read_buf()).
|
||
|
*/
|
||
|
ZLIB_INTERNAL void flush_pending(z_stream *strm) {
|
||
|
uint32_t len;
|
||
|
deflate_state *s = strm->state;
|
||
|
|
||
|
_tr_flush_bits(s);
|
||
|
len = s->pending;
|
||
|
if (len > strm->avail_out)
|
||
|
len = strm->avail_out;
|
||
|
if (len == 0)
|
||
|
return;
|
||
|
|
||
|
memcpy(strm->next_out, s->pending_out, len);
|
||
|
strm->next_out += len;
|
||
|
s->pending_out += len;
|
||
|
strm->total_out += len;
|
||
|
strm->avail_out -= len;
|
||
|
s->pending -= len;
|
||
|
if (s->pending == 0) {
|
||
|
s->pending_out = s->pending_buf;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* ========================================================================= */
|
||
|
int ZEXPORT deflate(z_stream *strm, int flush) {
|
||
|
int old_flush; /* value of flush param for previous deflate call */
|
||
|
deflate_state *s;
|
||
|
|
||
|
if (strm == Z_NULL || strm->state == Z_NULL || flush > Z_BLOCK || flush < 0) {
|
||
|
return Z_STREAM_ERROR;
|
||
|
}
|
||
|
s = strm->state;
|
||
|
|
||
|
if (strm->next_out == Z_NULL || (strm->avail_in != 0 && strm->next_in == Z_NULL) ||
|
||
|
(s->status == FINISH_STATE && flush != Z_FINISH)) {
|
||
|
ERR_RETURN(strm, Z_STREAM_ERROR);
|
||
|
}
|
||
|
if (strm->avail_out == 0)
|
||
|
ERR_RETURN(strm, Z_BUF_ERROR);
|
||
|
|
||
|
s->strm = strm; /* just in case */
|
||
|
old_flush = s->last_flush;
|
||
|
s->last_flush = flush;
|
||
|
|
||
|
/* Write the header */
|
||
|
if (s->status == INIT_STATE) {
|
||
|
#ifdef GZIP
|
||
|
if (s->wrap == 2) {
|
||
|
crc_reset(s);
|
||
|
put_byte(s, 31);
|
||
|
put_byte(s, 139);
|
||
|
put_byte(s, 8);
|
||
|
if (s->gzhead == Z_NULL) {
|
||
|
put_byte(s, 0);
|
||
|
put_byte(s, 0);
|
||
|
put_byte(s, 0);
|
||
|
put_byte(s, 0);
|
||
|
put_byte(s, 0);
|
||
|
put_byte(s, s->level == 9 ? 2 :
|
||
|
(s->strategy >= Z_HUFFMAN_ONLY || s->level < 2 ?
|
||
|
4 : 0));
|
||
|
put_byte(s, OS_CODE);
|
||
|
s->status = BUSY_STATE;
|
||
|
} else {
|
||
|
put_byte(s, (s->gzhead->text ? 1 : 0) +
|
||
|
(s->gzhead->hcrc ? 2 : 0) +
|
||
|
(s->gzhead->extra == Z_NULL ? 0 : 4) +
|
||
|
(s->gzhead->name == Z_NULL ? 0 : 8) +
|
||
|
(s->gzhead->comment == Z_NULL ? 0 : 16) );
|
||
|
put_byte(s, (unsigned char)(s->gzhead->time & 0xff));
|
||
|
put_byte(s, (unsigned char)((s->gzhead->time >> 8) & 0xff));
|
||
|
put_byte(s, (unsigned char)((s->gzhead->time >> 16) & 0xff));
|
||
|
put_byte(s, (unsigned char)((s->gzhead->time >> 24) & 0xff));
|
||
|
put_byte(s, s->level == 9 ? 2 :
|
||
|
(s->strategy >= Z_HUFFMAN_ONLY || s->level < 2 ?
|
||
|
4 : 0));
|
||
|
put_byte(s, s->gzhead->os & 0xff);
|
||
|
if (s->gzhead->extra != Z_NULL) {
|
||
|
put_byte(s, s->gzhead->extra_len & 0xff);
|
||
|
put_byte(s, (s->gzhead->extra_len >> 8) & 0xff);
|
||
|
}
|
||
|
if (s->gzhead->hcrc)
|
||
|
strm->adler = crc32(strm->adler, s->pending_buf, s->pending);
|
||
|
s->gzindex = 0;
|
||
|
s->status = EXTRA_STATE;
|
||
|
}
|
||
|
} else
|
||
|
#endif
|
||
|
{
|
||
|
unsigned int header = (Z_DEFLATED + ((s->w_bits-8) << 4)) << 8;
|
||
|
unsigned int level_flags;
|
||
|
|
||
|
if (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2)
|
||
|
level_flags = 0;
|
||
|
else if (s->level < 6)
|
||
|
level_flags = 1;
|
||
|
else if (s->level == 6)
|
||
|
level_flags = 2;
|
||
|
else
|
||
|
level_flags = 3;
|
||
|
header |= (level_flags << 6);
|
||
|
if (s->strstart != 0)
|
||
|
header |= PRESET_DICT;
|
||
|
header += 31 - (header % 31);
|
||
|
|
||
|
s->status = BUSY_STATE;
|
||
|
putShortMSB(s, header);
|
||
|
|
||
|
/* Save the adler32 of the preset dictionary: */
|
||
|
if (s->strstart != 0) {
|
||
|
putShortMSB(s, (uint16_t)(strm->adler >> 16));
|
||
|
putShortMSB(s, (uint16_t)strm->adler);
|
||
|
}
|
||
|
strm->adler = adler32(0L, Z_NULL, 0);
|
||
|
}
|
||
|
}
|
||
|
#ifdef GZIP
|
||
|
if (s->status == EXTRA_STATE) {
|
||
|
if (s->gzhead->extra != Z_NULL) {
|
||
|
uint32_t beg = s->pending; /* start of bytes to update crc */
|
||
|
|
||
|
while (s->gzindex < (s->gzhead->extra_len & 0xffff)) {
|
||
|
if (s->pending == s->pending_buf_size) {
|
||
|
if (s->gzhead->hcrc && s->pending > beg)
|
||
|
strm->adler = crc32(strm->adler, s->pending_buf + beg, s->pending - beg);
|
||
|
flush_pending(strm);
|
||
|
beg = s->pending;
|
||
|
if (s->pending == s->pending_buf_size)
|
||
|
break;
|
||
|
}
|
||
|
put_byte(s, s->gzhead->extra[s->gzindex]);
|
||
|
s->gzindex++;
|
||
|
}
|
||
|
if (s->gzhead->hcrc && s->pending > beg)
|
||
|
strm->adler = crc32(strm->adler, s->pending_buf + beg, s->pending - beg);
|
||
|
if (s->gzindex == s->gzhead->extra_len) {
|
||
|
s->gzindex = 0;
|
||
|
s->status = NAME_STATE;
|
||
|
}
|
||
|
} else {
|
||
|
s->status = NAME_STATE;
|
||
|
}
|
||
|
}
|
||
|
if (s->status == NAME_STATE) {
|
||
|
if (s->gzhead->name != Z_NULL) {
|
||
|
uint32_t beg = s->pending; /* start of bytes to update crc */
|
||
|
int val;
|
||
|
|
||
|
do {
|
||
|
if (s->pending == s->pending_buf_size) {
|
||
|
if (s->gzhead->hcrc && s->pending > beg)
|
||
|
strm->adler = crc32(strm->adler, s->pending_buf + beg, s->pending - beg);
|
||
|
flush_pending(strm);
|
||
|
beg = s->pending;
|
||
|
if (s->pending == s->pending_buf_size) {
|
||
|
val = 1;
|
||
|
break;
|
||
|
}
|
||
|
}
|
||
|
val = s->gzhead->name[s->gzindex++];
|
||
|
put_byte(s, val);
|
||
|
} while (val != 0);
|
||
|
if (s->gzhead->hcrc && s->pending > beg)
|
||
|
strm->adler = crc32(strm->adler, s->pending_buf + beg, s->pending - beg);
|
||
|
if (val == 0) {
|
||
|
s->gzindex = 0;
|
||
|
s->status = COMMENT_STATE;
|
||
|
}
|
||
|
} else {
|
||
|
s->status = COMMENT_STATE;
|
||
|
}
|
||
|
}
|
||
|
if (s->status == COMMENT_STATE) {
|
||
|
if (s->gzhead->comment != Z_NULL) {
|
||
|
uint32_t beg = s->pending; /* start of bytes to update crc */
|
||
|
int val;
|
||
|
|
||
|
do {
|
||
|
if (s->pending == s->pending_buf_size) {
|
||
|
if (s->gzhead->hcrc && s->pending > beg)
|
||
|
strm->adler = crc32(strm->adler, s->pending_buf + beg, s->pending - beg);
|
||
|
flush_pending(strm);
|
||
|
beg = s->pending;
|
||
|
if (s->pending == s->pending_buf_size) {
|
||
|
val = 1;
|
||
|
break;
|
||
|
}
|
||
|
}
|
||
|
val = s->gzhead->comment[s->gzindex++];
|
||
|
put_byte(s, val);
|
||
|
} while (val != 0);
|
||
|
if (s->gzhead->hcrc && s->pending > beg)
|
||
|
strm->adler = crc32(strm->adler, s->pending_buf + beg, s->pending - beg);
|
||
|
if (val == 0)
|
||
|
s->status = HCRC_STATE;
|
||
|
} else {
|
||
|
s->status = HCRC_STATE;
|
||
|
}
|
||
|
}
|
||
|
if (s->status == HCRC_STATE) {
|
||
|
if (s->gzhead->hcrc) {
|
||
|
if (s->pending + 2 > s->pending_buf_size)
|
||
|
flush_pending(strm);
|
||
|
if (s->pending + 2 <= s->pending_buf_size) {
|
||
|
put_byte(s, (unsigned char)(strm->adler & 0xff));
|
||
|
put_byte(s, (unsigned char)((strm->adler >> 8) & 0xff));
|
||
|
strm->adler = crc32(0L, Z_NULL, 0);
|
||
|
s->status = BUSY_STATE;
|
||
|
}
|
||
|
} else {
|
||
|
s->status = BUSY_STATE;
|
||
|
}
|
||
|
}
|
||
|
#endif
|
||
|
|
||
|
/* Flush as much pending output as possible */
|
||
|
if (s->pending != 0) {
|
||
|
flush_pending(strm);
|
||
|
if (strm->avail_out == 0) {
|
||
|
/* Since avail_out is 0, deflate will be called again with
|
||
|
* more output space, but possibly with both pending and
|
||
|
* avail_in equal to zero. There won't be anything to do,
|
||
|
* but this is not an error situation so make sure we
|
||
|
* return OK instead of BUF_ERROR at next call of deflate:
|
||
|
*/
|
||
|
s->last_flush = -1;
|
||
|
return Z_OK;
|
||
|
}
|
||
|
|
||
|
/* Make sure there is something to do and avoid duplicate consecutive
|
||
|
* flushes. For repeated and useless calls with Z_FINISH, we keep
|
||
|
* returning Z_STREAM_END instead of Z_BUF_ERROR.
|
||
|
*/
|
||
|
} else if (strm->avail_in == 0 && RANK(flush) <= RANK(old_flush) && flush != Z_FINISH) {
|
||
|
ERR_RETURN(strm, Z_BUF_ERROR);
|
||
|
}
|
||
|
|
||
|
/* User must not provide more input after the first FINISH: */
|
||
|
if (s->status == FINISH_STATE && strm->avail_in != 0) {
|
||
|
ERR_RETURN(strm, Z_BUF_ERROR);
|
||
|
}
|
||
|
|
||
|
/* Start a new block or continue the current one.
|
||
|
*/
|
||
|
if (strm->avail_in != 0 || s->lookahead != 0 || (flush != Z_NO_FLUSH && s->status != FINISH_STATE)) {
|
||
|
block_state bstate;
|
||
|
|
||
|
#ifdef X86_QUICK_STRATEGY
|
||
|
if (s->level == 1 && !x86_cpu_has_sse42)
|
||
|
bstate = s->strategy == Z_HUFFMAN_ONLY ? deflate_huff(s, flush) :
|
||
|
(s->strategy == Z_RLE ? deflate_rle(s, flush) : deflate_fast(s, flush));
|
||
|
else
|
||
|
#endif
|
||
|
bstate = s->strategy == Z_HUFFMAN_ONLY ? deflate_huff(s, flush) :
|
||
|
(s->strategy == Z_RLE ? deflate_rle(s, flush) : (*(configuration_table[s->level].func))(s, flush));
|
||
|
|
||
|
if (bstate == finish_started || bstate == finish_done) {
|
||
|
s->status = FINISH_STATE;
|
||
|
}
|
||
|
if (bstate == need_more || bstate == finish_started) {
|
||
|
if (strm->avail_out == 0) {
|
||
|
s->last_flush = -1; /* avoid BUF_ERROR next call, see above */
|
||
|
}
|
||
|
return Z_OK;
|
||
|
/* If flush != Z_NO_FLUSH && avail_out == 0, the next call
|
||
|
* of deflate should use the same flush parameter to make sure
|
||
|
* that the flush is complete. So we don't have to output an
|
||
|
* empty block here, this will be done at next call. This also
|
||
|
* ensures that for a very small output buffer, we emit at most
|
||
|
* one empty block.
|
||
|
*/
|
||
|
}
|
||
|
if (bstate == block_done) {
|
||
|
if (flush == Z_PARTIAL_FLUSH) {
|
||
|
_tr_align(s);
|
||
|
} else if (flush != Z_BLOCK) { /* FULL_FLUSH or SYNC_FLUSH */
|
||
|
_tr_stored_block(s, (char*)0, 0L, 0);
|
||
|
/* For a full flush, this empty block will be recognized
|
||
|
* as a special marker by inflate_sync().
|
||
|
*/
|
||
|
if (flush == Z_FULL_FLUSH) {
|
||
|
CLEAR_HASH(s); /* forget history */
|
||
|
if (s->lookahead == 0) {
|
||
|
s->strstart = 0;
|
||
|
s->block_start = 0L;
|
||
|
s->insert = 0;
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
flush_pending(strm);
|
||
|
if (strm->avail_out == 0) {
|
||
|
s->last_flush = -1; /* avoid BUF_ERROR at next call, see above */
|
||
|
return Z_OK;
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
Assert(strm->avail_out > 0, "bug2");
|
||
|
|
||
|
if (flush != Z_FINISH)
|
||
|
return Z_OK;
|
||
|
if (s->wrap <= 0)
|
||
|
return Z_STREAM_END;
|
||
|
|
||
|
/* Write the trailer */
|
||
|
#ifdef GZIP
|
||
|
if (s->wrap == 2) {
|
||
|
crc_finalize(s);
|
||
|
put_byte(s, (unsigned char)(strm->adler & 0xff));
|
||
|
put_byte(s, (unsigned char)((strm->adler >> 8) & 0xff));
|
||
|
put_byte(s, (unsigned char)((strm->adler >> 16) & 0xff));
|
||
|
put_byte(s, (unsigned char)((strm->adler >> 24) & 0xff));
|
||
|
put_byte(s, (unsigned char)(strm->total_in & 0xff));
|
||
|
put_byte(s, (unsigned char)((strm->total_in >> 8) & 0xff));
|
||
|
put_byte(s, (unsigned char)((strm->total_in >> 16) & 0xff));
|
||
|
put_byte(s, (unsigned char)((strm->total_in >> 24) & 0xff));
|
||
|
} else
|
||
|
#endif
|
||
|
{
|
||
|
putShortMSB(s, (uint16_t)(strm->adler >> 16));
|
||
|
putShortMSB(s, (uint16_t)strm->adler);
|
||
|
}
|
||
|
flush_pending(strm);
|
||
|
/* If avail_out is zero, the application will call deflate again
|
||
|
* to flush the rest.
|
||
|
*/
|
||
|
if (s->wrap > 0)
|
||
|
s->wrap = -s->wrap; /* write the trailer only once! */
|
||
|
return s->pending != 0 ? Z_OK : Z_STREAM_END;
|
||
|
}
|
||
|
|
||
|
/* ========================================================================= */
|
||
|
int ZEXPORT deflateEnd(z_stream *strm) {
|
||
|
int status;
|
||
|
|
||
|
if (strm == Z_NULL || strm->state == Z_NULL)
|
||
|
return Z_STREAM_ERROR;
|
||
|
|
||
|
status = strm->state->status;
|
||
|
if (status != INIT_STATE &&
|
||
|
status != EXTRA_STATE &&
|
||
|
status != NAME_STATE &&
|
||
|
status != COMMENT_STATE &&
|
||
|
status != HCRC_STATE &&
|
||
|
status != BUSY_STATE &&
|
||
|
status != FINISH_STATE) {
|
||
|
return Z_STREAM_ERROR;
|
||
|
}
|
||
|
|
||
|
/* Deallocate in reverse order of allocations: */
|
||
|
TRY_FREE(strm, strm->state->pending_buf);
|
||
|
TRY_FREE(strm, strm->state->head);
|
||
|
TRY_FREE(strm, strm->state->prev);
|
||
|
TRY_FREE(strm, strm->state->window);
|
||
|
|
||
|
ZFREE(strm, strm->state);
|
||
|
strm->state = Z_NULL;
|
||
|
|
||
|
return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK;
|
||
|
}
|
||
|
|
||
|
/* =========================================================================
|
||
|
* Copy the source state to the destination state.
|
||
|
*/
|
||
|
int ZEXPORT deflateCopy(z_stream *dest, z_stream *source) {
|
||
|
deflate_state *ds;
|
||
|
deflate_state *ss;
|
||
|
uint16_t *overlay;
|
||
|
|
||
|
if (source == Z_NULL || dest == Z_NULL || source->state == Z_NULL) {
|
||
|
return Z_STREAM_ERROR;
|
||
|
}
|
||
|
|
||
|
ss = source->state;
|
||
|
|
||
|
memcpy((void *)dest, (void *)source, sizeof(z_stream));
|
||
|
|
||
|
ds = (deflate_state *) ZALLOC(dest, 1, sizeof(deflate_state));
|
||
|
if (ds == Z_NULL)
|
||
|
return Z_MEM_ERROR;
|
||
|
dest->state = (struct internal_state *) ds;
|
||
|
memcpy((void *)ds, (void *)ss, sizeof(deflate_state));
|
||
|
ds->strm = dest;
|
||
|
|
||
|
ds->window = (unsigned char *) ZALLOC(dest, ds->w_size, 2*sizeof(unsigned char));
|
||
|
ds->prev = (Pos *) ZALLOC(dest, ds->w_size, sizeof(Pos));
|
||
|
ds->head = (Pos *) ZALLOC(dest, ds->hash_size, sizeof(Pos));
|
||
|
overlay = (uint16_t *) ZALLOC(dest, ds->lit_bufsize, sizeof(uint16_t)+2);
|
||
|
ds->pending_buf = (unsigned char *) overlay;
|
||
|
|
||
|
if (ds->window == Z_NULL || ds->prev == Z_NULL || ds->head == Z_NULL || ds->pending_buf == Z_NULL) {
|
||
|
deflateEnd(dest);
|
||
|
return Z_MEM_ERROR;
|
||
|
}
|
||
|
|
||
|
memcpy(ds->window, ss->window, ds->w_size * 2 * sizeof(unsigned char));
|
||
|
memcpy((void *)ds->prev, (void *)ss->prev, ds->w_size * sizeof(Pos));
|
||
|
memcpy((void *)ds->head, (void *)ss->head, ds->hash_size * sizeof(Pos));
|
||
|
memcpy(ds->pending_buf, ss->pending_buf, (unsigned int)ds->pending_buf_size);
|
||
|
|
||
|
ds->pending_out = ds->pending_buf + (ss->pending_out - ss->pending_buf);
|
||
|
ds->d_buf = overlay + ds->lit_bufsize/sizeof(uint16_t);
|
||
|
ds->l_buf = ds->pending_buf + (1+sizeof(uint16_t))*ds->lit_bufsize;
|
||
|
|
||
|
ds->l_desc.dyn_tree = ds->dyn_ltree;
|
||
|
ds->d_desc.dyn_tree = ds->dyn_dtree;
|
||
|
ds->bl_desc.dyn_tree = ds->bl_tree;
|
||
|
|
||
|
return Z_OK;
|
||
|
}
|
||
|
|
||
|
/* ===========================================================================
|
||
|
* Read a new buffer from the current input stream, update the adler32
|
||
|
* and total number of bytes read. All deflate() input goes through
|
||
|
* this function so some applications may wish to modify it to avoid
|
||
|
* allocating a large strm->next_in buffer and copying from it.
|
||
|
* (See also flush_pending()).
|
||
|
*/
|
||
|
ZLIB_INTERNAL int read_buf(z_stream *strm, unsigned char *buf, unsigned size) {
|
||
|
uint32_t len = strm->avail_in;
|
||
|
|
||
|
if (len > size)
|
||
|
len = size;
|
||
|
if (len == 0)
|
||
|
return 0;
|
||
|
|
||
|
strm->avail_in -= len;
|
||
|
|
||
|
#ifdef GZIP
|
||
|
if (strm->state->wrap == 2)
|
||
|
copy_with_crc(strm, buf, len);
|
||
|
else
|
||
|
#endif
|
||
|
{
|
||
|
memcpy(buf, strm->next_in, len);
|
||
|
if (strm->state->wrap == 1)
|
||
|
strm->adler = adler32(strm->adler, buf, len);
|
||
|
}
|
||
|
strm->next_in += len;
|
||
|
strm->total_in += len;
|
||
|
|
||
|
return (int)len;
|
||
|
}
|
||
|
|
||
|
/* ===========================================================================
|
||
|
* Initialize the "longest match" routines for a new zlib stream
|
||
|
*/
|
||
|
local void lm_init(deflate_state *s) {
|
||
|
s->window_size = (unsigned long)2L*s->w_size;
|
||
|
|
||
|
CLEAR_HASH(s);
|
||
|
|
||
|
/* Set the default configuration parameters:
|
||
|
*/
|
||
|
s->max_lazy_match = configuration_table[s->level].max_lazy;
|
||
|
s->good_match = configuration_table[s->level].good_length;
|
||
|
s->nice_match = configuration_table[s->level].nice_length;
|
||
|
s->max_chain_length = configuration_table[s->level].max_chain;
|
||
|
|
||
|
s->strstart = 0;
|
||
|
s->block_start = 0L;
|
||
|
s->lookahead = 0;
|
||
|
s->insert = 0;
|
||
|
s->match_length = s->prev_length = MIN_MATCH-1;
|
||
|
s->match_available = 0;
|
||
|
s->ins_h = 0;
|
||
|
}
|
||
|
|
||
|
#ifdef DEBUG
|
||
|
/* ===========================================================================
|
||
|
* Check that the match at match_start is indeed a match.
|
||
|
*/
|
||
|
void check_match(deflate_state *s, IPos start, IPos match, int length) {
|
||
|
/* check that the match is indeed a match */
|
||
|
if (memcmp(s->window + match, s->window + start, length) != EQUAL) {
|
||
|
fprintf(stderr, " start %u, match %u, length %d\n", start, match, length);
|
||
|
do {
|
||
|
fprintf(stderr, "%c%c", s->window[match++], s->window[start++]);
|
||
|
} while (--length != 0);
|
||
|
z_error("invalid match");
|
||
|
}
|
||
|
if (z_verbose > 1) {
|
||
|
fprintf(stderr, "\\[%u,%d]", start-match, length);
|
||
|
do {
|
||
|
putc(s->window[start++], stderr);
|
||
|
} while (--length != 0);
|
||
|
}
|
||
|
}
|
||
|
#else
|
||
|
# define check_match(s, start, match, length)
|
||
|
#endif /* DEBUG */
|
||
|
|
||
|
/* ===========================================================================
|
||
|
* Fill the window when the lookahead becomes insufficient.
|
||
|
* Updates strstart and lookahead.
|
||
|
*
|
||
|
* IN assertion: lookahead < MIN_LOOKAHEAD
|
||
|
* OUT assertions: strstart <= window_size-MIN_LOOKAHEAD
|
||
|
* At least one byte has been read, or avail_in == 0; reads are
|
||
|
* performed for at least two bytes (required for the zip translate_eol
|
||
|
* option -- not supported here).
|
||
|
*/
|
||
|
#ifdef X86_SSE2_FILL_WINDOW
|
||
|
extern void fill_window_sse(deflate_state *s);
|
||
|
#endif
|
||
|
void fill_window_c(deflate_state *s);
|
||
|
|
||
|
void fill_window(deflate_state *s) {
|
||
|
#ifdef X86_SSE2_FILL_WINDOW
|
||
|
# ifndef X86_NOCHECK_SSE2
|
||
|
if (x86_cpu_has_sse2) {
|
||
|
# endif
|
||
|
fill_window_sse(s);
|
||
|
# ifndef X86_NOCHECK_SSE2
|
||
|
} else {
|
||
|
fill_window_c(s);
|
||
|
}
|
||
|
# endif
|
||
|
|
||
|
#else
|
||
|
fill_window_c(s);
|
||
|
#endif
|
||
|
}
|
||
|
|
||
|
void fill_window_c(deflate_state *s) {
|
||
|
register unsigned n;
|
||
|
register Pos *p;
|
||
|
unsigned more; /* Amount of free space at the end of the window. */
|
||
|
unsigned int wsize = s->w_size;
|
||
|
|
||
|
Assert(s->lookahead < MIN_LOOKAHEAD, "already enough lookahead");
|
||
|
|
||
|
do {
|
||
|
more = (unsigned)(s->window_size -(unsigned long)s->lookahead -(unsigned long)s->strstart);
|
||
|
|
||
|
/* If the window is almost full and there is insufficient lookahead,
|
||
|
* move the upper half to the lower one to make room in the upper half.
|
||
|
*/
|
||
|
if (s->strstart >= wsize+MAX_DIST(s)) {
|
||
|
memcpy(s->window, s->window+wsize, (unsigned)wsize);
|
||
|
s->match_start -= wsize;
|
||
|
s->strstart -= wsize; /* we now have strstart >= MAX_DIST */
|
||
|
s->block_start -= (long) wsize;
|
||
|
|
||
|
/* Slide the hash table (could be avoided with 32 bit values
|
||
|
at the expense of memory usage). We slide even when level == 0
|
||
|
to keep the hash table consistent if we switch back to level > 0
|
||
|
later. (Using level 0 permanently is not an optimal usage of
|
||
|
zlib, so we don't care about this pathological case.)
|
||
|
*/
|
||
|
n = s->hash_size;
|
||
|
p = &s->head[n];
|
||
|
#ifdef NOT_TWEAK_COMPILER
|
||
|
do {
|
||
|
unsigned m;
|
||
|
m = *--p;
|
||
|
*p = (Pos)(m >= wsize ? m-wsize : NIL);
|
||
|
} while (--n);
|
||
|
#else
|
||
|
/* As of I make this change, gcc (4.8.*) isn't able to vectorize
|
||
|
* this hot loop using saturated-subtraction on x86-64 architecture.
|
||
|
* To avoid this defect, we can change the loop such that
|
||
|
* o. the pointer advance forward, and
|
||
|
* o. demote the variable 'm' to be local to the loop, and
|
||
|
* choose type "Pos" (instead of 'unsigned int') for the
|
||
|
* variable to avoid unncessary zero-extension.
|
||
|
*/
|
||
|
{
|
||
|
unsigned int i;
|
||
|
Pos *q = p - n;
|
||
|
for (i = 0; i < n; i++) {
|
||
|
Pos m = *q;
|
||
|
Pos t = wsize;
|
||
|
*q++ = (Pos)(m >= t ? m-t: NIL);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
#endif /* NOT_TWEAK_COMPILER */
|
||
|
n = wsize;
|
||
|
p = &s->prev[n];
|
||
|
#ifdef NOT_TWEAK_COMPILER
|
||
|
do {
|
||
|
unsigned m;
|
||
|
m = *--p;
|
||
|
*p = (Pos)(m >= wsize ? m-wsize : NIL);
|
||
|
/* If n is not on any hash chain, prev[n] is garbage but
|
||
|
* its value will never be used.
|
||
|
*/
|
||
|
} while (--n);
|
||
|
#else
|
||
|
{
|
||
|
unsigned int i;
|
||
|
Pos *q = p - n;
|
||
|
for (i = 0; i < n; i++) {
|
||
|
Pos m = *q;
|
||
|
Pos t = wsize;
|
||
|
*q++ = (Pos)(m >= t ? m-t: NIL);
|
||
|
}
|
||
|
}
|
||
|
#endif /* NOT_TWEAK_COMPILER */
|
||
|
more += wsize;
|
||
|
}
|
||
|
if (s->strm->avail_in == 0)
|
||
|
break;
|
||
|
|
||
|
/* If there was no sliding:
|
||
|
* strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
|
||
|
* more == window_size - lookahead - strstart
|
||
|
* => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
|
||
|
* => more >= window_size - 2*WSIZE + 2
|
||
|
* In the BIG_MEM or MMAP case (not yet supported),
|
||
|
* window_size == input_size + MIN_LOOKAHEAD &&
|
||
|
* strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD.
|
||
|
* Otherwise, window_size == 2*WSIZE so more >= 2.
|
||
|
* If there was sliding, more >= WSIZE. So in all cases, more >= 2.
|
||
|
*/
|
||
|
Assert(more >= 2, "more < 2");
|
||
|
|
||
|
n = read_buf(s->strm, s->window + s->strstart + s->lookahead, more);
|
||
|
s->lookahead += n;
|
||
|
|
||
|
/* Initialize the hash value now that we have some input: */
|
||
|
if (s->lookahead + s->insert >= MIN_MATCH) {
|
||
|
unsigned int str = s->strstart - s->insert;
|
||
|
s->ins_h = s->window[str];
|
||
|
if (str >= 1)
|
||
|
UPDATE_HASH(s, s->ins_h, str + 1 - (MIN_MATCH-1));
|
||
|
#if MIN_MATCH != 3
|
||
|
Call UPDATE_HASH() MIN_MATCH-3 more times
|
||
|
#endif
|
||
|
while (s->insert) {
|
||
|
UPDATE_HASH(s, s->ins_h, str);
|
||
|
s->prev[str & s->w_mask] = s->head[s->ins_h];
|
||
|
s->head[s->ins_h] = (Pos)str;
|
||
|
str++;
|
||
|
s->insert--;
|
||
|
if (s->lookahead + s->insert < MIN_MATCH)
|
||
|
break;
|
||
|
}
|
||
|
}
|
||
|
/* If the whole input has less than MIN_MATCH bytes, ins_h is garbage,
|
||
|
* but this is not important since only literal bytes will be emitted.
|
||
|
*/
|
||
|
} while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0);
|
||
|
|
||
|
/* If the WIN_INIT bytes after the end of the current data have never been
|
||
|
* written, then zero those bytes in order to avoid memory check reports of
|
||
|
* the use of uninitialized (or uninitialised as Julian writes) bytes by
|
||
|
* the longest match routines. Update the high water mark for the next
|
||
|
* time through here. WIN_INIT is set to MAX_MATCH since the longest match
|
||
|
* routines allow scanning to strstart + MAX_MATCH, ignoring lookahead.
|
||
|
*/
|
||
|
if (s->high_water < s->window_size) {
|
||
|
unsigned long curr = s->strstart + (unsigned long)(s->lookahead);
|
||
|
unsigned long init;
|
||
|
|
||
|
if (s->high_water < curr) {
|
||
|
/* Previous high water mark below current data -- zero WIN_INIT
|
||
|
* bytes or up to end of window, whichever is less.
|
||
|
*/
|
||
|
init = s->window_size - curr;
|
||
|
if (init > WIN_INIT)
|
||
|
init = WIN_INIT;
|
||
|
memset(s->window + curr, 0, (unsigned)init);
|
||
|
s->high_water = curr + init;
|
||
|
} else if (s->high_water < (unsigned long)curr + WIN_INIT) {
|
||
|
/* High water mark at or above current data, but below current data
|
||
|
* plus WIN_INIT -- zero out to current data plus WIN_INIT, or up
|
||
|
* to end of window, whichever is less.
|
||
|
*/
|
||
|
init = (unsigned long)curr + WIN_INIT - s->high_water;
|
||
|
if (init > s->window_size - s->high_water)
|
||
|
init = s->window_size - s->high_water;
|
||
|
memset(s->window + s->high_water, 0, (unsigned)init);
|
||
|
s->high_water += init;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
Assert((unsigned long)s->strstart <= s->window_size - MIN_LOOKAHEAD,
|
||
|
"not enough room for search");
|
||
|
}
|
||
|
|
||
|
/* ===========================================================================
|
||
|
* Copy without compression as much as possible from the input stream, return
|
||
|
* the current block state.
|
||
|
* This function does not insert new strings in the dictionary since
|
||
|
* uncompressible data is probably not useful. This function is used
|
||
|
* only for the level=0 compression option.
|
||
|
* NOTE: this function should be optimized to avoid extra copying from
|
||
|
* window to pending_buf.
|
||
|
*/
|
||
|
local block_state deflate_stored(deflate_state *s, int flush) {
|
||
|
/* Stored blocks are limited to 0xffff bytes, pending_buf is limited
|
||
|
* to pending_buf_size, and each stored block has a 5 byte header:
|
||
|
*/
|
||
|
unsigned long max_block_size = 0xffff;
|
||
|
unsigned long max_start;
|
||
|
|
||
|
if (max_block_size > s->pending_buf_size - 5) {
|
||
|
max_block_size = (uint32_t)(s->pending_buf_size - 5);
|
||
|
}
|
||
|
|
||
|
/* Copy as much as possible from input to output: */
|
||
|
for (;;) {
|
||
|
/* Fill the window as much as possible: */
|
||
|
if (s->lookahead <= 1) {
|
||
|
Assert(s->strstart < s->w_size+MAX_DIST(s) || s->block_start >= (long)s->w_size, "slide too late");
|
||
|
|
||
|
fill_window(s);
|
||
|
if (s->lookahead == 0 && flush == Z_NO_FLUSH)
|
||
|
return need_more;
|
||
|
|
||
|
if (s->lookahead == 0)
|
||
|
break; /* flush the current block */
|
||
|
}
|
||
|
Assert(s->block_start >= 0L, "block gone");
|
||
|
|
||
|
s->strstart += s->lookahead;
|
||
|
s->lookahead = 0;
|
||
|
|
||
|
/* Emit a stored block if pending_buf will be full: */
|
||
|
max_start = s->block_start + max_block_size;
|
||
|
if (s->strstart == 0 || (unsigned long)s->strstart >= max_start) {
|
||
|
/* strstart == 0 is possible when wraparound on 16-bit machine */
|
||
|
s->lookahead = (unsigned int)(s->strstart - max_start);
|
||
|
s->strstart = (unsigned int)max_start;
|
||
|
FLUSH_BLOCK(s, 0);
|
||
|
}
|
||
|
/* Flush if we may have to slide, otherwise block_start may become
|
||
|
* negative and the data will be gone:
|
||
|
*/
|
||
|
if (s->strstart - (unsigned int)s->block_start >= MAX_DIST(s)) {
|
||
|
FLUSH_BLOCK(s, 0);
|
||
|
}
|
||
|
}
|
||
|
s->insert = 0;
|
||
|
if (flush == Z_FINISH) {
|
||
|
FLUSH_BLOCK(s, 1);
|
||
|
return finish_done;
|
||
|
}
|
||
|
if ((long)s->strstart > s->block_start)
|
||
|
FLUSH_BLOCK(s, 0);
|
||
|
return block_done;
|
||
|
}
|
||
|
|
||
|
|
||
|
/* ===========================================================================
|
||
|
* For Z_RLE, simply look for runs of bytes, generate matches only of distance
|
||
|
* one. Do not maintain a hash table. (It will be regenerated if this run of
|
||
|
* deflate switches away from Z_RLE.)
|
||
|
*/
|
||
|
local block_state deflate_rle(deflate_state *s, int flush) {
|
||
|
int bflush; /* set if current block must be flushed */
|
||
|
unsigned int prev; /* byte at distance one to match */
|
||
|
unsigned char *scan, *strend; /* scan goes up to strend for length of run */
|
||
|
|
||
|
for (;;) {
|
||
|
/* Make sure that we always have enough lookahead, except
|
||
|
* at the end of the input file. We need MAX_MATCH bytes
|
||
|
* for the longest run, plus one for the unrolled loop.
|
||
|
*/
|
||
|
if (s->lookahead <= MAX_MATCH) {
|
||
|
fill_window(s);
|
||
|
if (s->lookahead <= MAX_MATCH && flush == Z_NO_FLUSH) {
|
||
|
return need_more;
|
||
|
}
|
||
|
if (s->lookahead == 0)
|
||
|
break; /* flush the current block */
|
||
|
}
|
||
|
|
||
|
/* See how many times the previous byte repeats */
|
||
|
s->match_length = 0;
|
||
|
if (s->lookahead >= MIN_MATCH && s->strstart > 0) {
|
||
|
scan = s->window + s->strstart - 1;
|
||
|
prev = *scan;
|
||
|
if (prev == *++scan && prev == *++scan && prev == *++scan) {
|
||
|
strend = s->window + s->strstart + MAX_MATCH;
|
||
|
do {
|
||
|
} while (prev == *++scan && prev == *++scan &&
|
||
|
prev == *++scan && prev == *++scan &&
|
||
|
prev == *++scan && prev == *++scan &&
|
||
|
prev == *++scan && prev == *++scan &&
|
||
|
scan < strend);
|
||
|
s->match_length = MAX_MATCH - (int)(strend - scan);
|
||
|
if (s->match_length > s->lookahead)
|
||
|
s->match_length = s->lookahead;
|
||
|
}
|
||
|
Assert(scan <= s->window+(unsigned int)(s->window_size-1), "wild scan");
|
||
|
}
|
||
|
|
||
|
/* Emit match if have run of MIN_MATCH or longer, else emit literal */
|
||
|
if (s->match_length >= MIN_MATCH) {
|
||
|
check_match(s, s->strstart, s->strstart - 1, s->match_length);
|
||
|
|
||
|
_tr_tally_dist(s, 1, s->match_length - MIN_MATCH, bflush);
|
||
|
|
||
|
s->lookahead -= s->match_length;
|
||
|
s->strstart += s->match_length;
|
||
|
s->match_length = 0;
|
||
|
} else {
|
||
|
/* No match, output a literal byte */
|
||
|
Tracevv((stderr, "%c", s->window[s->strstart]));
|
||
|
_tr_tally_lit(s, s->window[s->strstart], bflush);
|
||
|
s->lookahead--;
|
||
|
s->strstart++;
|
||
|
}
|
||
|
if (bflush)
|
||
|
FLUSH_BLOCK(s, 0);
|
||
|
}
|
||
|
s->insert = 0;
|
||
|
if (flush == Z_FINISH) {
|
||
|
FLUSH_BLOCK(s, 1);
|
||
|
return finish_done;
|
||
|
}
|
||
|
if (s->last_lit)
|
||
|
FLUSH_BLOCK(s, 0);
|
||
|
return block_done;
|
||
|
}
|
||
|
|
||
|
/* ===========================================================================
|
||
|
* For Z_HUFFMAN_ONLY, do not look for matches. Do not maintain a hash table.
|
||
|
* (It will be regenerated if this run of deflate switches away from Huffman.)
|
||
|
*/
|
||
|
local block_state deflate_huff(deflate_state *s, int flush) {
|
||
|
int bflush; /* set if current block must be flushed */
|
||
|
|
||
|
for (;;) {
|
||
|
/* Make sure that we have a literal to write. */
|
||
|
if (s->lookahead == 0) {
|
||
|
fill_window(s);
|
||
|
if (s->lookahead == 0) {
|
||
|
if (flush == Z_NO_FLUSH)
|
||
|
return need_more;
|
||
|
break; /* flush the current block */
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* Output a literal byte */
|
||
|
s->match_length = 0;
|
||
|
Tracevv((stderr, "%c", s->window[s->strstart]));
|
||
|
_tr_tally_lit(s, s->window[s->strstart], bflush);
|
||
|
s->lookahead--;
|
||
|
s->strstart++;
|
||
|
if (bflush)
|
||
|
FLUSH_BLOCK(s, 0);
|
||
|
}
|
||
|
s->insert = 0;
|
||
|
if (flush == Z_FINISH) {
|
||
|
FLUSH_BLOCK(s, 1);
|
||
|
return finish_done;
|
||
|
}
|
||
|
if (s->last_lit)
|
||
|
FLUSH_BLOCK(s, 0);
|
||
|
return block_done;
|
||
|
}
|