5128eecc9f 2011-02-23        kinaba: /* deflate.c -- compress data using the deflation algorithm
5128eecc9f 2011-02-23        kinaba:  * Copyright (C) 1995-1998 Jean-loup Gailly.
5128eecc9f 2011-02-23        kinaba:  * For conditions of distribution and use, see copyright notice in zlib.h
5128eecc9f 2011-02-23        kinaba:  */
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: /*
5128eecc9f 2011-02-23        kinaba:  *  ALGORITHM
5128eecc9f 2011-02-23        kinaba:  *
5128eecc9f 2011-02-23        kinaba:  *      The "deflation" process depends on being able to identify portions
5128eecc9f 2011-02-23        kinaba:  *      of the input text which are identical to earlier input (within a
5128eecc9f 2011-02-23        kinaba:  *      sliding window trailing behind the input currently being processed).
5128eecc9f 2011-02-23        kinaba:  *
5128eecc9f 2011-02-23        kinaba:  *      The most straightforward technique turns out to be the fastest for
5128eecc9f 2011-02-23        kinaba:  *      most input files: try all possible matches and select the longest.
5128eecc9f 2011-02-23        kinaba:  *      The key feature of this algorithm is that insertions into the string
5128eecc9f 2011-02-23        kinaba:  *      dictionary are very simple and thus fast, and deletions are avoided
5128eecc9f 2011-02-23        kinaba:  *      completely. Insertions are performed at each input character, whereas
5128eecc9f 2011-02-23        kinaba:  *      string matches are performed only when the previous match ends. So it
5128eecc9f 2011-02-23        kinaba:  *      is preferable to spend more time in matches to allow very fast string
5128eecc9f 2011-02-23        kinaba:  *      insertions and avoid deletions. The matching algorithm for small
5128eecc9f 2011-02-23        kinaba:  *      strings is inspired from that of Rabin & Karp. A brute force approach
5128eecc9f 2011-02-23        kinaba:  *      is used to find longer strings when a small match has been found.
5128eecc9f 2011-02-23        kinaba:  *      A similar algorithm is used in comic (by Jan-Mark Wams) and freeze
5128eecc9f 2011-02-23        kinaba:  *      (by Leonid Broukhis).
5128eecc9f 2011-02-23        kinaba:  *         A previous version of this file used a more sophisticated algorithm
5128eecc9f 2011-02-23        kinaba:  *      (by Fiala and Greene) which is guaranteed to run in linear amortized
5128eecc9f 2011-02-23        kinaba:  *      time, but has a larger average cost, uses more memory and is patented.
5128eecc9f 2011-02-23        kinaba:  *      However the F&G algorithm may be faster for some highly redundant
5128eecc9f 2011-02-23        kinaba:  *      files if the parameter max_chain_length (described below) is too large.
5128eecc9f 2011-02-23        kinaba:  *
5128eecc9f 2011-02-23        kinaba:  *  ACKNOWLEDGEMENTS
5128eecc9f 2011-02-23        kinaba:  *
5128eecc9f 2011-02-23        kinaba:  *      The idea of lazy evaluation of matches is due to Jan-Mark Wams, and
5128eecc9f 2011-02-23        kinaba:  *      I found it in 'freeze' written by Leonid Broukhis.
5128eecc9f 2011-02-23        kinaba:  *      Thanks to many people for bug reports and testing.
5128eecc9f 2011-02-23        kinaba:  *
5128eecc9f 2011-02-23        kinaba:  *  REFERENCES
5128eecc9f 2011-02-23        kinaba:  *
5128eecc9f 2011-02-23        kinaba:  *      Deutsch, L.P.,"DEFLATE Compressed Data Format Specification".
5128eecc9f 2011-02-23        kinaba:  *      Available in ftp://ds.internic.net/rfc/rfc1951.txt
5128eecc9f 2011-02-23        kinaba:  *
5128eecc9f 2011-02-23        kinaba:  *      A description of the Rabin and Karp algorithm is given in the book
5128eecc9f 2011-02-23        kinaba:  *         "Algorithms" by R. Sedgewick, Addison-Wesley, p252.
5128eecc9f 2011-02-23        kinaba:  *
5128eecc9f 2011-02-23        kinaba:  *      Fiala,E.R., and Greene,D.H.
5128eecc9f 2011-02-23        kinaba:  *         Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595
5128eecc9f 2011-02-23        kinaba:  *
5128eecc9f 2011-02-23        kinaba:  */
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: /* @(#) $Id$ */
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: #include "deflate.h"
5128eecc9f 2011-02-23        kinaba: #ifndef KI_GZ_NO_COMPRESSION
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: const char deflate_copyright[] =
5128eecc9f 2011-02-23        kinaba:    " deflate 1.1.3 Copyright 1995-1998 Jean-loup Gailly ";
5128eecc9f 2011-02-23        kinaba: /*
5128eecc9f 2011-02-23        kinaba:   If you use the zlib library in a product, an acknowledgment is welcome
5128eecc9f 2011-02-23        kinaba:   in the documentation of your product. If for some reason you cannot
5128eecc9f 2011-02-23        kinaba:   include such an acknowledgment, I would appreciate that you keep this
5128eecc9f 2011-02-23        kinaba:   copyright string in the executable of your product.
5128eecc9f 2011-02-23        kinaba:  */
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: /* ===========================================================================
5128eecc9f 2011-02-23        kinaba:  *  Function prototypes.
5128eecc9f 2011-02-23        kinaba:  */
5128eecc9f 2011-02-23        kinaba: typedef enum {
5128eecc9f 2011-02-23        kinaba:     need_more,      /* block not completed, need more input or more output */
5128eecc9f 2011-02-23        kinaba:     block_done,     /* block flush performed */
5128eecc9f 2011-02-23        kinaba:     finish_started, /* finish started, need only more output at next deflate */
5128eecc9f 2011-02-23        kinaba:     finish_done     /* finish done, accept no more input or output */
5128eecc9f 2011-02-23        kinaba: } block_state;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: typedef block_state (*compress_func) OF((deflate_state *s, int flush));
5128eecc9f 2011-02-23        kinaba: /* Compression function. Returns the block state after the call. */
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: local void fill_window    OF((deflate_state *s));
5128eecc9f 2011-02-23        kinaba: local block_state deflate_stored OF((deflate_state *s, int flush));
5128eecc9f 2011-02-23        kinaba: local block_state deflate_fast   OF((deflate_state *s, int flush));
5128eecc9f 2011-02-23        kinaba: local block_state deflate_slow   OF((deflate_state *s, int flush));
5128eecc9f 2011-02-23        kinaba: local void lm_init        OF((deflate_state *s));
5128eecc9f 2011-02-23        kinaba: local void putShortMSB    OF((deflate_state *s, uInt b));
5128eecc9f 2011-02-23        kinaba: local void flush_pending  OF((z_streamp strm));
5128eecc9f 2011-02-23        kinaba: local int read_buf        OF((z_streamp strm, Bytef *buf, unsigned size));
5128eecc9f 2011-02-23        kinaba: #ifdef ASMV
5128eecc9f 2011-02-23        kinaba:       void match_init OF((void)); /* asm code initialization */
5128eecc9f 2011-02-23        kinaba:       uInt longest_match  OF((deflate_state *s, IPos cur_match));
5128eecc9f 2011-02-23        kinaba: #else
5128eecc9f 2011-02-23        kinaba: local uInt longest_match  OF((deflate_state *s, IPos cur_match));
5128eecc9f 2011-02-23        kinaba: #endif
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: #ifdef DEBUG
5128eecc9f 2011-02-23        kinaba: local  void check_match OF((deflate_state *s, IPos start, IPos match,
5128eecc9f 2011-02-23        kinaba:                             int length));
5128eecc9f 2011-02-23        kinaba: #endif
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: /* ===========================================================================
5128eecc9f 2011-02-23        kinaba:  * Local data
5128eecc9f 2011-02-23        kinaba:  */
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: #define NIL 0
5128eecc9f 2011-02-23        kinaba: /* Tail of hash chains */
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: #ifndef TOO_FAR
5128eecc9f 2011-02-23        kinaba: #  define TOO_FAR 4096
5128eecc9f 2011-02-23        kinaba: #endif
5128eecc9f 2011-02-23        kinaba: /* Matches of length 3 are discarded if their distance exceeds TOO_FAR */
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
5128eecc9f 2011-02-23        kinaba: /* Minimum amount of lookahead, except at the end of the input file.
5128eecc9f 2011-02-23        kinaba:  * See deflate.c for comments about the MIN_MATCH+1.
5128eecc9f 2011-02-23        kinaba:  */
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: /* Values for max_lazy_match, good_match and max_chain_length, depending on
5128eecc9f 2011-02-23        kinaba:  * the desired pack level (0..9). The values given below have been tuned to
5128eecc9f 2011-02-23        kinaba:  * exclude worst case performance for pathological files. Better values may be
5128eecc9f 2011-02-23        kinaba:  * found for specific files.
5128eecc9f 2011-02-23        kinaba:  */
5128eecc9f 2011-02-23        kinaba: typedef struct config_s {
5128eecc9f 2011-02-23        kinaba:    ush good_length; /* reduce lazy search above this match length */
5128eecc9f 2011-02-23        kinaba:    ush max_lazy;    /* do not perform lazy search above this match length */
5128eecc9f 2011-02-23        kinaba:    ush nice_length; /* quit search above this match length */
5128eecc9f 2011-02-23        kinaba:    ush max_chain;
5128eecc9f 2011-02-23        kinaba:    compress_func func;
5128eecc9f 2011-02-23        kinaba: } config;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: local const config configuration_table[10] = {
5128eecc9f 2011-02-23        kinaba: /*      good lazy nice chain */
5128eecc9f 2011-02-23        kinaba: /* 0 */ {0,    0,  0,    0, deflate_stored},  /* store only */
5128eecc9f 2011-02-23        kinaba: /* 1 */ {4,    4,  8,    4, deflate_fast}, /* maximum speed, no lazy matches */
5128eecc9f 2011-02-23        kinaba: /* 2 */ {4,    5, 16,    8, deflate_fast},
5128eecc9f 2011-02-23        kinaba: /* 3 */ {4,    6, 32,   32, deflate_fast},
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: /* 4 */ {4,    4, 16,   16, deflate_slow},  /* lazy matches */
5128eecc9f 2011-02-23        kinaba: /* 5 */ {8,   16, 32,   32, deflate_slow},
5128eecc9f 2011-02-23        kinaba: /* 6 */ {8,   16, 128, 128, deflate_slow},
5128eecc9f 2011-02-23        kinaba: /* 7 */ {8,   32, 128, 256, deflate_slow},
5128eecc9f 2011-02-23        kinaba: /* 8 */ {32, 128, 258, 1024, deflate_slow},
5128eecc9f 2011-02-23        kinaba: /* 9 */ {32, 258, 258, 4096, deflate_slow}}; /* maximum compression */
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: /* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4
5128eecc9f 2011-02-23        kinaba:  * For deflate_fast() (levels <= 3) good is ignored and lazy has a different
5128eecc9f 2011-02-23        kinaba:  * meaning.
5128eecc9f 2011-02-23        kinaba:  */
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: #define EQUAL 0
5128eecc9f 2011-02-23        kinaba: /* result of memcmp for equal strings */
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: struct static_tree_desc_s {int dummy;}; /* for buggy compilers */
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: /* ===========================================================================
5128eecc9f 2011-02-23        kinaba:  * Update a hash value with the given input byte
5128eecc9f 2011-02-23        kinaba:  * IN  assertion: all calls to to UPDATE_HASH are made with consecutive
5128eecc9f 2011-02-23        kinaba:  *    input characters, so that a running hash key can be computed from the
5128eecc9f 2011-02-23        kinaba:  *    previous key instead of complete recalculation each time.
5128eecc9f 2011-02-23        kinaba:  */
5128eecc9f 2011-02-23        kinaba: #define UPDATE_HASH(s,h,c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask)
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: /* ===========================================================================
5128eecc9f 2011-02-23        kinaba:  * Insert string str in the dictionary and set match_head to the previous head
5128eecc9f 2011-02-23        kinaba:  * of the hash chain (the most recent string with same hash key). Return
5128eecc9f 2011-02-23        kinaba:  * the previous length of the hash chain.
5128eecc9f 2011-02-23        kinaba:  * If this file is compiled with -DFASTEST, the compression level is forced
5128eecc9f 2011-02-23        kinaba:  * to 1, and no hash chains are maintained.
5128eecc9f 2011-02-23        kinaba:  * IN  assertion: all calls to to INSERT_STRING are made with consecutive
5128eecc9f 2011-02-23        kinaba:  *    input characters and the first MIN_MATCH bytes of str are valid
5128eecc9f 2011-02-23        kinaba:  *    (except for the last MIN_MATCH-1 bytes of the input file).
5128eecc9f 2011-02-23        kinaba:  */
5128eecc9f 2011-02-23        kinaba: #ifdef FASTEST
5128eecc9f 2011-02-23        kinaba: #define INSERT_STRING(s, str, match_head) \
5128eecc9f 2011-02-23        kinaba:    (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
5128eecc9f 2011-02-23        kinaba:     match_head = s->head[s->ins_h], \
5128eecc9f 2011-02-23        kinaba:     s->head[s->ins_h] = (Pos)(str))
5128eecc9f 2011-02-23        kinaba: #else
5128eecc9f 2011-02-23        kinaba: #define INSERT_STRING(s, str, match_head) \
5128eecc9f 2011-02-23        kinaba:    (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
5128eecc9f 2011-02-23        kinaba:     s->prev[(str) & s->w_mask] = match_head = s->head[s->ins_h], \
5128eecc9f 2011-02-23        kinaba:     s->head[s->ins_h] = (Pos)(str))
5128eecc9f 2011-02-23        kinaba: #endif
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: /* ===========================================================================
5128eecc9f 2011-02-23        kinaba:  * Initialize the hash table (avoiding 64K overflow for 16 bit systems).
5128eecc9f 2011-02-23        kinaba:  * prev[] will be initialized on the fly.
5128eecc9f 2011-02-23        kinaba:  */
5128eecc9f 2011-02-23        kinaba: #define CLEAR_HASH(s) \
5128eecc9f 2011-02-23        kinaba:     s->head[s->hash_size-1] = NIL; \
5128eecc9f 2011-02-23        kinaba:     zmemzero((Bytef *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head));
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: /* ========================================================================= */
5128eecc9f 2011-02-23        kinaba: int ZEXPORT deflateInit_(strm, level, version, stream_size)
5128eecc9f 2011-02-23        kinaba:     z_streamp strm;
5128eecc9f 2011-02-23        kinaba:     int level;
5128eecc9f 2011-02-23        kinaba:     const char *version;
5128eecc9f 2011-02-23        kinaba:     int stream_size;
5128eecc9f 2011-02-23        kinaba: {
5128eecc9f 2011-02-23        kinaba:     return deflateInit2_(strm, level, Z_DEFLATED, MAX_WBITS, DEF_MEM_LEVEL,
5128eecc9f 2011-02-23        kinaba: 			 Z_DEFAULT_STRATEGY, version, stream_size);
5128eecc9f 2011-02-23        kinaba:     /* To do: ignore strm->next_in if we use it as window */
5128eecc9f 2011-02-23        kinaba: }
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: /* ========================================================================= */
5128eecc9f 2011-02-23        kinaba: int ZEXPORT deflateInit2_(strm, level, method, windowBits, memLevel, strategy,
5128eecc9f 2011-02-23        kinaba: 		  version, stream_size)
5128eecc9f 2011-02-23        kinaba:     z_streamp strm;
5128eecc9f 2011-02-23        kinaba:     int  level;
5128eecc9f 2011-02-23        kinaba:     int  method;
5128eecc9f 2011-02-23        kinaba:     int  windowBits;
5128eecc9f 2011-02-23        kinaba:     int  memLevel;
5128eecc9f 2011-02-23        kinaba:     int  strategy;
5128eecc9f 2011-02-23        kinaba:     const char *version;
5128eecc9f 2011-02-23        kinaba:     int stream_size;
5128eecc9f 2011-02-23        kinaba: {
5128eecc9f 2011-02-23        kinaba:     deflate_state *s;
5128eecc9f 2011-02-23        kinaba:     int noheader = 0;
5128eecc9f 2011-02-23        kinaba:     static const char* my_version = ZLIB_VERSION;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     ushf *overlay;
5128eecc9f 2011-02-23        kinaba:     /* We overlay pending_buf and d_buf+l_buf. This works since the average
5128eecc9f 2011-02-23        kinaba:      * output size for (length,distance) codes is <= 24 bits.
5128eecc9f 2011-02-23        kinaba:      */
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     if (version == Z_NULL || version[0] != my_version[0] ||
5128eecc9f 2011-02-23        kinaba:         stream_size != sizeof(z_stream)) {
5128eecc9f 2011-02-23        kinaba: 	return Z_VERSION_ERROR;
5128eecc9f 2011-02-23        kinaba:     }
5128eecc9f 2011-02-23        kinaba:     if (strm == Z_NULL) return Z_STREAM_ERROR;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     strm->msg = Z_NULL;
5128eecc9f 2011-02-23        kinaba:     if (strm->zalloc == Z_NULL) {
5128eecc9f 2011-02-23        kinaba: 	strm->zalloc = zcalloc;
5128eecc9f 2011-02-23        kinaba: 	strm->opaque = (voidpf)0;
5128eecc9f 2011-02-23        kinaba:     }
5128eecc9f 2011-02-23        kinaba:     if (strm->zfree == Z_NULL) strm->zfree = zcfree;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     if (level == Z_DEFAULT_COMPRESSION) level = 6;
5128eecc9f 2011-02-23        kinaba: #ifdef FASTEST
5128eecc9f 2011-02-23        kinaba:     level = 1;
5128eecc9f 2011-02-23        kinaba: #endif
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     if (windowBits < 0) { /* undocumented feature: suppress zlib header */
5128eecc9f 2011-02-23        kinaba:         noheader = 1;
5128eecc9f 2011-02-23        kinaba:         windowBits = -windowBits;
5128eecc9f 2011-02-23        kinaba:     }
5128eecc9f 2011-02-23        kinaba:     if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != Z_DEFLATED ||
5128eecc9f 2011-02-23        kinaba:         windowBits < 8 || windowBits > 15 || level < 0 || level > 9 ||
5128eecc9f 2011-02-23        kinaba: 	strategy < 0 || strategy > Z_HUFFMAN_ONLY) {
5128eecc9f 2011-02-23        kinaba:         return Z_STREAM_ERROR;
5128eecc9f 2011-02-23        kinaba:     }
5128eecc9f 2011-02-23        kinaba:     s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state));
5128eecc9f 2011-02-23        kinaba:     if (s == Z_NULL) return Z_MEM_ERROR;
5128eecc9f 2011-02-23        kinaba:     strm->state = (struct internal_state FAR *)s;
5128eecc9f 2011-02-23        kinaba:     s->strm = strm;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     s->noheader = noheader;
5128eecc9f 2011-02-23        kinaba:     s->w_bits = windowBits;
5128eecc9f 2011-02-23        kinaba:     s->w_size = 1 << s->w_bits;
5128eecc9f 2011-02-23        kinaba:     s->w_mask = s->w_size - 1;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     s->hash_bits = memLevel + 7;
5128eecc9f 2011-02-23        kinaba:     s->hash_size = 1 << s->hash_bits;
5128eecc9f 2011-02-23        kinaba:     s->hash_mask = s->hash_size - 1;
5128eecc9f 2011-02-23        kinaba:     s->hash_shift =  ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH);
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte));
5128eecc9f 2011-02-23        kinaba:     s->prev   = (Posf *)  ZALLOC(strm, s->w_size, sizeof(Pos));
5128eecc9f 2011-02-23        kinaba:     s->head   = (Posf *)  ZALLOC(strm, s->hash_size, sizeof(Pos));
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     overlay = (ushf *) ZALLOC(strm, s->lit_bufsize, sizeof(ush)+2);
5128eecc9f 2011-02-23        kinaba:     s->pending_buf = (uchf *) overlay;
5128eecc9f 2011-02-23        kinaba:     s->pending_buf_size = (ulg)s->lit_bufsize * (sizeof(ush)+2L);
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL ||
5128eecc9f 2011-02-23        kinaba:         s->pending_buf == Z_NULL) {
5128eecc9f 2011-02-23        kinaba:         strm->msg = (char*)ERR_MSG(Z_MEM_ERROR);
5128eecc9f 2011-02-23        kinaba:         deflateEnd (strm);
5128eecc9f 2011-02-23        kinaba:         return Z_MEM_ERROR;
5128eecc9f 2011-02-23        kinaba:     }
5128eecc9f 2011-02-23        kinaba:     s->d_buf = overlay + s->lit_bufsize/sizeof(ush);
5128eecc9f 2011-02-23        kinaba:     s->l_buf = s->pending_buf + (1+sizeof(ush))*s->lit_bufsize;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     s->level = level;
5128eecc9f 2011-02-23        kinaba:     s->strategy = strategy;
5128eecc9f 2011-02-23        kinaba:     s->method = (Byte)method;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     return deflateReset(strm);
5128eecc9f 2011-02-23        kinaba: }
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: /* ========================================================================= */
5128eecc9f 2011-02-23        kinaba: int ZEXPORT deflateSetDictionary (strm, dictionary, dictLength)
5128eecc9f 2011-02-23        kinaba:     z_streamp strm;
5128eecc9f 2011-02-23        kinaba:     const Bytef *dictionary;
5128eecc9f 2011-02-23        kinaba:     uInt  dictLength;
5128eecc9f 2011-02-23        kinaba: {
5128eecc9f 2011-02-23        kinaba:     deflate_state *s;
5128eecc9f 2011-02-23        kinaba:     uInt length = dictLength;
5128eecc9f 2011-02-23        kinaba:     uInt n;
5128eecc9f 2011-02-23        kinaba:     IPos hash_head = 0;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     if (strm == Z_NULL || strm->state == Z_NULL || dictionary == Z_NULL ||
5128eecc9f 2011-02-23        kinaba:         strm->state->status != INIT_STATE) return Z_STREAM_ERROR;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     s = strm->state;
5128eecc9f 2011-02-23        kinaba:     strm->adler = adler32(strm->adler, dictionary, dictLength);
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     if (length < MIN_MATCH) return Z_OK;
5128eecc9f 2011-02-23        kinaba:     if (length > MAX_DIST(s)) {
5128eecc9f 2011-02-23        kinaba: 	length = MAX_DIST(s);
5128eecc9f 2011-02-23        kinaba: #ifndef USE_DICT_HEAD
5128eecc9f 2011-02-23        kinaba: 	dictionary += dictLength - length; /* use the tail of the dictionary */
5128eecc9f 2011-02-23        kinaba: #endif
5128eecc9f 2011-02-23        kinaba:     }
5128eecc9f 2011-02-23        kinaba:     zmemcpy(s->window, dictionary, length);
5128eecc9f 2011-02-23        kinaba:     s->strstart = length;
5128eecc9f 2011-02-23        kinaba:     s->block_start = (long)length;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     /* Insert all strings in the hash table (except for the last two bytes).
5128eecc9f 2011-02-23        kinaba:      * s->lookahead stays null, so s->ins_h will be recomputed at the next
5128eecc9f 2011-02-23        kinaba:      * call of fill_window.
5128eecc9f 2011-02-23        kinaba:      */
5128eecc9f 2011-02-23        kinaba:     s->ins_h = s->window[0];
5128eecc9f 2011-02-23        kinaba:     UPDATE_HASH(s, s->ins_h, s->window[1]);
5128eecc9f 2011-02-23        kinaba:     for (n = 0; n <= length - MIN_MATCH; n++) {
5128eecc9f 2011-02-23        kinaba: 	INSERT_STRING(s, n, hash_head);
5128eecc9f 2011-02-23        kinaba:     }
5128eecc9f 2011-02-23        kinaba:     if (hash_head) hash_head = 0;  /* to make compiler happy */
5128eecc9f 2011-02-23        kinaba:     return Z_OK;
5128eecc9f 2011-02-23        kinaba: }
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: /* ========================================================================= */
5128eecc9f 2011-02-23        kinaba: int ZEXPORT deflateReset (strm)
5128eecc9f 2011-02-23        kinaba:     z_streamp strm;
5128eecc9f 2011-02-23        kinaba: {
5128eecc9f 2011-02-23        kinaba:     deflate_state *s;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     if (strm == Z_NULL || strm->state == Z_NULL ||
5128eecc9f 2011-02-23        kinaba:         strm->zalloc == Z_NULL || strm->zfree == Z_NULL) return Z_STREAM_ERROR;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     strm->total_in = strm->total_out = 0;
5128eecc9f 2011-02-23        kinaba:     strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */
5128eecc9f 2011-02-23        kinaba:     strm->data_type = Z_UNKNOWN;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     s = (deflate_state *)strm->state;
5128eecc9f 2011-02-23        kinaba:     s->pending = 0;
5128eecc9f 2011-02-23        kinaba:     s->pending_out = s->pending_buf;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     if (s->noheader < 0) {
5128eecc9f 2011-02-23        kinaba:         s->noheader = 0; /* was set to -1 by deflate(..., Z_FINISH); */
5128eecc9f 2011-02-23        kinaba:     }
5128eecc9f 2011-02-23        kinaba:     s->status = s->noheader ? BUSY_STATE : INIT_STATE;
5128eecc9f 2011-02-23        kinaba:     strm->adler = 1;
5128eecc9f 2011-02-23        kinaba:     s->last_flush = Z_NO_FLUSH;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     _tr_init(s);
5128eecc9f 2011-02-23        kinaba:     lm_init(s);
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     return Z_OK;
5128eecc9f 2011-02-23        kinaba: }
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: /* ========================================================================= */
5128eecc9f 2011-02-23        kinaba: int ZEXPORT deflateParams(strm, level, strategy)
5128eecc9f 2011-02-23        kinaba:     z_streamp strm;
5128eecc9f 2011-02-23        kinaba:     int level;
5128eecc9f 2011-02-23        kinaba:     int strategy;
5128eecc9f 2011-02-23        kinaba: {
5128eecc9f 2011-02-23        kinaba:     deflate_state *s;
5128eecc9f 2011-02-23        kinaba:     compress_func func;
5128eecc9f 2011-02-23        kinaba:     int err = Z_OK;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
5128eecc9f 2011-02-23        kinaba:     s = strm->state;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     if (level == Z_DEFAULT_COMPRESSION) {
5128eecc9f 2011-02-23        kinaba: 	level = 6;
5128eecc9f 2011-02-23        kinaba:     }
5128eecc9f 2011-02-23        kinaba:     if (level < 0 || level > 9 || strategy < 0 || strategy > Z_HUFFMAN_ONLY) {
5128eecc9f 2011-02-23        kinaba: 	return Z_STREAM_ERROR;
5128eecc9f 2011-02-23        kinaba:     }
5128eecc9f 2011-02-23        kinaba:     func = configuration_table[s->level].func;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     if (func != configuration_table[level].func && strm->total_in != 0) {
5128eecc9f 2011-02-23        kinaba: 	/* Flush the last buffer: */
5128eecc9f 2011-02-23        kinaba: 	err = deflate(strm, Z_PARTIAL_FLUSH);
5128eecc9f 2011-02-23        kinaba:     }
5128eecc9f 2011-02-23        kinaba:     if (s->level != level) {
5128eecc9f 2011-02-23        kinaba: 	s->level = level;
5128eecc9f 2011-02-23        kinaba: 	s->max_lazy_match   = configuration_table[level].max_lazy;
5128eecc9f 2011-02-23        kinaba: 	s->good_match       = configuration_table[level].good_length;
5128eecc9f 2011-02-23        kinaba: 	s->nice_match       = configuration_table[level].nice_length;
5128eecc9f 2011-02-23        kinaba: 	s->max_chain_length = configuration_table[level].max_chain;
5128eecc9f 2011-02-23        kinaba:     }
5128eecc9f 2011-02-23        kinaba:     s->strategy = strategy;
5128eecc9f 2011-02-23        kinaba:     return err;
5128eecc9f 2011-02-23        kinaba: }
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: /* =========================================================================
5128eecc9f 2011-02-23        kinaba:  * Put a short in the pending buffer. The 16-bit value is put in MSB order.
5128eecc9f 2011-02-23        kinaba:  * IN assertion: the stream state is correct and there is enough room in
5128eecc9f 2011-02-23        kinaba:  * pending_buf.
5128eecc9f 2011-02-23        kinaba:  */
5128eecc9f 2011-02-23        kinaba: local void putShortMSB (s, b)
5128eecc9f 2011-02-23        kinaba:     deflate_state *s;
5128eecc9f 2011-02-23        kinaba:     uInt b;
5128eecc9f 2011-02-23        kinaba: {
5128eecc9f 2011-02-23        kinaba:     put_byte(s, (Byte)(b >> 8));
5128eecc9f 2011-02-23        kinaba:     put_byte(s, (Byte)(b & 0xff));
5128eecc9f 2011-02-23        kinaba: }
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: /* =========================================================================
5128eecc9f 2011-02-23        kinaba:  * Flush as much pending output as possible. All deflate() output goes
5128eecc9f 2011-02-23        kinaba:  * through this function so some applications may wish to modify it
5128eecc9f 2011-02-23        kinaba:  * to avoid allocating a large strm->next_out buffer and copying into it.
5128eecc9f 2011-02-23        kinaba:  * (See also read_buf()).
5128eecc9f 2011-02-23        kinaba:  */
5128eecc9f 2011-02-23        kinaba: local void flush_pending(strm)
5128eecc9f 2011-02-23        kinaba:     z_streamp strm;
5128eecc9f 2011-02-23        kinaba: {
5128eecc9f 2011-02-23        kinaba:     unsigned len = strm->state->pending;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     if (len > strm->avail_out) len = strm->avail_out;
5128eecc9f 2011-02-23        kinaba:     if (len == 0) return;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     zmemcpy(strm->next_out, strm->state->pending_out, len);
5128eecc9f 2011-02-23        kinaba:     strm->next_out  += len;
5128eecc9f 2011-02-23        kinaba:     strm->state->pending_out  += len;
5128eecc9f 2011-02-23        kinaba:     strm->total_out += len;
5128eecc9f 2011-02-23        kinaba:     strm->avail_out  -= len;
5128eecc9f 2011-02-23        kinaba:     strm->state->pending -= len;
5128eecc9f 2011-02-23        kinaba:     if (strm->state->pending == 0) {
5128eecc9f 2011-02-23        kinaba:         strm->state->pending_out = strm->state->pending_buf;
5128eecc9f 2011-02-23        kinaba:     }
5128eecc9f 2011-02-23        kinaba: }
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: /* ========================================================================= */
5128eecc9f 2011-02-23        kinaba: int ZEXPORT deflate (strm, flush)
5128eecc9f 2011-02-23        kinaba:     z_streamp strm;
5128eecc9f 2011-02-23        kinaba:     int flush;
5128eecc9f 2011-02-23        kinaba: {
5128eecc9f 2011-02-23        kinaba:     int old_flush; /* value of flush param for previous deflate call */
5128eecc9f 2011-02-23        kinaba:     deflate_state *s;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     if (strm == Z_NULL || strm->state == Z_NULL ||
5128eecc9f 2011-02-23        kinaba: 	flush > Z_FINISH || flush < 0) {
5128eecc9f 2011-02-23        kinaba:         return Z_STREAM_ERROR;
5128eecc9f 2011-02-23        kinaba:     }
5128eecc9f 2011-02-23        kinaba:     s = strm->state;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     if (strm->next_out == Z_NULL ||
5128eecc9f 2011-02-23        kinaba:         (strm->next_in == Z_NULL && strm->avail_in != 0) ||
5128eecc9f 2011-02-23        kinaba: 	(s->status == FINISH_STATE && flush != Z_FINISH)) {
5128eecc9f 2011-02-23        kinaba:         ERR_RETURN(strm, Z_STREAM_ERROR);
5128eecc9f 2011-02-23        kinaba:     }
5128eecc9f 2011-02-23        kinaba:     if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR);
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     s->strm = strm; /* just in case */
5128eecc9f 2011-02-23        kinaba:     old_flush = s->last_flush;
5128eecc9f 2011-02-23        kinaba:     s->last_flush = flush;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     /* Write the zlib header */
5128eecc9f 2011-02-23        kinaba:     if (s->status == INIT_STATE) {
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:         uInt header = (Z_DEFLATED + ((s->w_bits-8)<<4)) << 8;
5128eecc9f 2011-02-23        kinaba:         uInt level_flags = (s->level-1) >> 1;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:         if (level_flags > 3) level_flags = 3;
5128eecc9f 2011-02-23        kinaba:         header |= (level_flags << 6);
5128eecc9f 2011-02-23        kinaba: 	if (s->strstart != 0) header |= PRESET_DICT;
5128eecc9f 2011-02-23        kinaba:         header += 31 - (header % 31);
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:         s->status = BUSY_STATE;
5128eecc9f 2011-02-23        kinaba:         putShortMSB(s, header);
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: 	/* Save the adler32 of the preset dictionary: */
5128eecc9f 2011-02-23        kinaba: 	if (s->strstart != 0) {
5128eecc9f 2011-02-23        kinaba: 	    putShortMSB(s, (uInt)(strm->adler >> 16));
5128eecc9f 2011-02-23        kinaba: 	    putShortMSB(s, (uInt)(strm->adler & 0xffff));
5128eecc9f 2011-02-23        kinaba: 	}
5128eecc9f 2011-02-23        kinaba: 	strm->adler = 1L;
5128eecc9f 2011-02-23        kinaba:     }
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     /* Flush as much pending output as possible */
5128eecc9f 2011-02-23        kinaba:     if (s->pending != 0) {
5128eecc9f 2011-02-23        kinaba:         flush_pending(strm);
5128eecc9f 2011-02-23        kinaba:         if (strm->avail_out == 0) {
5128eecc9f 2011-02-23        kinaba: 	    /* Since avail_out is 0, deflate will be called again with
5128eecc9f 2011-02-23        kinaba: 	     * more output space, but possibly with both pending and
5128eecc9f 2011-02-23        kinaba: 	     * avail_in equal to zero. There won't be anything to do,
5128eecc9f 2011-02-23        kinaba: 	     * but this is not an error situation so make sure we
5128eecc9f 2011-02-23        kinaba: 	     * return OK instead of BUF_ERROR at next call of deflate:
5128eecc9f 2011-02-23        kinaba:              */
5128eecc9f 2011-02-23        kinaba: 	    s->last_flush = -1;
5128eecc9f 2011-02-23        kinaba: 	    return Z_OK;
5128eecc9f 2011-02-23        kinaba: 	}
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     /* Make sure there is something to do and avoid duplicate consecutive
5128eecc9f 2011-02-23        kinaba:      * flushes. For repeated and useless calls with Z_FINISH, we keep
5128eecc9f 2011-02-23        kinaba:      * returning Z_STREAM_END instead of Z_BUFF_ERROR.
5128eecc9f 2011-02-23        kinaba:      */
5128eecc9f 2011-02-23        kinaba:     } else if (strm->avail_in == 0 && flush <= old_flush &&
5128eecc9f 2011-02-23        kinaba: 	       flush != Z_FINISH) {
5128eecc9f 2011-02-23        kinaba:         ERR_RETURN(strm, Z_BUF_ERROR);
5128eecc9f 2011-02-23        kinaba:     }
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     /* User must not provide more input after the first FINISH: */
5128eecc9f 2011-02-23        kinaba:     if (s->status == FINISH_STATE && strm->avail_in != 0) {
5128eecc9f 2011-02-23        kinaba:         ERR_RETURN(strm, Z_BUF_ERROR);
5128eecc9f 2011-02-23        kinaba:     }
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     /* Start a new block or continue the current one.
5128eecc9f 2011-02-23        kinaba:      */
5128eecc9f 2011-02-23        kinaba:     if (strm->avail_in != 0 || s->lookahead != 0 ||
5128eecc9f 2011-02-23        kinaba:         (flush != Z_NO_FLUSH && s->status != FINISH_STATE)) {
5128eecc9f 2011-02-23        kinaba:         block_state bstate;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: 	bstate = (*(configuration_table[s->level].func))(s, flush);
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:         if (bstate == finish_started || bstate == finish_done) {
5128eecc9f 2011-02-23        kinaba:             s->status = FINISH_STATE;
5128eecc9f 2011-02-23        kinaba:         }
5128eecc9f 2011-02-23        kinaba:         if (bstate == need_more || bstate == finish_started) {
5128eecc9f 2011-02-23        kinaba: 	    if (strm->avail_out == 0) {
5128eecc9f 2011-02-23        kinaba: 	        s->last_flush = -1; /* avoid BUF_ERROR next call, see above */
5128eecc9f 2011-02-23        kinaba: 	    }
5128eecc9f 2011-02-23        kinaba: 	    return Z_OK;
5128eecc9f 2011-02-23        kinaba: 	    /* If flush != Z_NO_FLUSH && avail_out == 0, the next call
5128eecc9f 2011-02-23        kinaba: 	     * of deflate should use the same flush parameter to make sure
5128eecc9f 2011-02-23        kinaba: 	     * that the flush is complete. So we don't have to output an
5128eecc9f 2011-02-23        kinaba: 	     * empty block here, this will be done at next call. This also
5128eecc9f 2011-02-23        kinaba: 	     * ensures that for a very small output buffer, we emit at most
5128eecc9f 2011-02-23        kinaba: 	     * one empty block.
5128eecc9f 2011-02-23        kinaba: 	     */
5128eecc9f 2011-02-23        kinaba: 	}
5128eecc9f 2011-02-23        kinaba:         if (bstate == block_done) {
5128eecc9f 2011-02-23        kinaba:             if (flush == Z_PARTIAL_FLUSH) {
5128eecc9f 2011-02-23        kinaba:                 _tr_align(s);
5128eecc9f 2011-02-23        kinaba:             } else { /* FULL_FLUSH or SYNC_FLUSH */
5128eecc9f 2011-02-23        kinaba:                 _tr_stored_block(s, (char*)0, 0L, 0);
5128eecc9f 2011-02-23        kinaba:                 /* For a full flush, this empty block will be recognized
5128eecc9f 2011-02-23        kinaba:                  * as a special marker by inflate_sync().
5128eecc9f 2011-02-23        kinaba:                  */
5128eecc9f 2011-02-23        kinaba:                 if (flush == Z_FULL_FLUSH) {
5128eecc9f 2011-02-23        kinaba:                     CLEAR_HASH(s);             /* forget history */
5128eecc9f 2011-02-23        kinaba:                 }
5128eecc9f 2011-02-23        kinaba:             }
5128eecc9f 2011-02-23        kinaba:             flush_pending(strm);
5128eecc9f 2011-02-23        kinaba: 	    if (strm->avail_out == 0) {
5128eecc9f 2011-02-23        kinaba: 	      s->last_flush = -1; /* avoid BUF_ERROR at next call, see above */
5128eecc9f 2011-02-23        kinaba: 	      return Z_OK;
5128eecc9f 2011-02-23        kinaba: 	    }
5128eecc9f 2011-02-23        kinaba:         }
5128eecc9f 2011-02-23        kinaba:     }
5128eecc9f 2011-02-23        kinaba:     Assert(strm->avail_out > 0, "bug2");
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     if (flush != Z_FINISH) return Z_OK;
5128eecc9f 2011-02-23        kinaba:     if (s->noheader) return Z_STREAM_END;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     /* Write the zlib trailer (adler32) */
5128eecc9f 2011-02-23        kinaba:     putShortMSB(s, (uInt)(strm->adler >> 16));
5128eecc9f 2011-02-23        kinaba:     putShortMSB(s, (uInt)(strm->adler & 0xffff));
5128eecc9f 2011-02-23        kinaba:     flush_pending(strm);
5128eecc9f 2011-02-23        kinaba:     /* If avail_out is zero, the application will call deflate again
5128eecc9f 2011-02-23        kinaba:      * to flush the rest.
5128eecc9f 2011-02-23        kinaba:      */
5128eecc9f 2011-02-23        kinaba:     s->noheader = -1; /* write the trailer only once! */
5128eecc9f 2011-02-23        kinaba:     return s->pending != 0 ? Z_OK : Z_STREAM_END;
5128eecc9f 2011-02-23        kinaba: }
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: /* ========================================================================= */
5128eecc9f 2011-02-23        kinaba: int ZEXPORT deflateEnd (strm)
5128eecc9f 2011-02-23        kinaba:     z_streamp strm;
5128eecc9f 2011-02-23        kinaba: {
5128eecc9f 2011-02-23        kinaba:     int status;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     status = strm->state->status;
5128eecc9f 2011-02-23        kinaba:     if (status != INIT_STATE && status != BUSY_STATE &&
5128eecc9f 2011-02-23        kinaba: 	status != FINISH_STATE) {
5128eecc9f 2011-02-23        kinaba:       return Z_STREAM_ERROR;
5128eecc9f 2011-02-23        kinaba:     }
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     /* Deallocate in reverse order of allocations: */
5128eecc9f 2011-02-23        kinaba:     TRY_FREE(strm, strm->state->pending_buf);
5128eecc9f 2011-02-23        kinaba:     TRY_FREE(strm, strm->state->head);
5128eecc9f 2011-02-23        kinaba:     TRY_FREE(strm, strm->state->prev);
5128eecc9f 2011-02-23        kinaba:     TRY_FREE(strm, strm->state->window);
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     ZFREE(strm, strm->state);
5128eecc9f 2011-02-23        kinaba:     strm->state = Z_NULL;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK;
5128eecc9f 2011-02-23        kinaba: }
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: /* =========================================================================
5128eecc9f 2011-02-23        kinaba:  * Copy the source state to the destination state.
5128eecc9f 2011-02-23        kinaba:  * To simplify the source, this is not supported for 16-bit MSDOS (which
5128eecc9f 2011-02-23        kinaba:  * doesn't have enough memory anyway to duplicate compression states).
5128eecc9f 2011-02-23        kinaba:  */
5128eecc9f 2011-02-23        kinaba: int ZEXPORT deflateCopy (dest, source)
5128eecc9f 2011-02-23        kinaba:     z_streamp dest;
5128eecc9f 2011-02-23        kinaba:     z_streamp source;
5128eecc9f 2011-02-23        kinaba: {
5128eecc9f 2011-02-23        kinaba: #ifdef MAXSEG_64K
5128eecc9f 2011-02-23        kinaba:     return Z_STREAM_ERROR;
5128eecc9f 2011-02-23        kinaba: #else
5128eecc9f 2011-02-23        kinaba:     deflate_state *ds;
5128eecc9f 2011-02-23        kinaba:     deflate_state *ss;
5128eecc9f 2011-02-23        kinaba:     ushf *overlay;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     if (source == Z_NULL || dest == Z_NULL || source->state == Z_NULL) {
5128eecc9f 2011-02-23        kinaba:         return Z_STREAM_ERROR;
5128eecc9f 2011-02-23        kinaba:     }
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     ss = source->state;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     *dest = *source;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     ds = (deflate_state *) ZALLOC(dest, 1, sizeof(deflate_state));
5128eecc9f 2011-02-23        kinaba:     if (ds == Z_NULL) return Z_MEM_ERROR;
5128eecc9f 2011-02-23        kinaba:     dest->state = (struct internal_state FAR *) ds;
5128eecc9f 2011-02-23        kinaba:     *ds = *ss;
5128eecc9f 2011-02-23        kinaba:     ds->strm = dest;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     ds->window = (Bytef *) ZALLOC(dest, ds->w_size, 2*sizeof(Byte));
5128eecc9f 2011-02-23        kinaba:     ds->prev   = (Posf *)  ZALLOC(dest, ds->w_size, sizeof(Pos));
5128eecc9f 2011-02-23        kinaba:     ds->head   = (Posf *)  ZALLOC(dest, ds->hash_size, sizeof(Pos));
5128eecc9f 2011-02-23        kinaba:     overlay = (ushf *) ZALLOC(dest, ds->lit_bufsize, sizeof(ush)+2);
5128eecc9f 2011-02-23        kinaba:     ds->pending_buf = (uchf *) overlay;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     if (ds->window == Z_NULL || ds->prev == Z_NULL || ds->head == Z_NULL ||
5128eecc9f 2011-02-23        kinaba:         ds->pending_buf == Z_NULL) {
5128eecc9f 2011-02-23        kinaba:         deflateEnd (dest);
5128eecc9f 2011-02-23        kinaba:         return Z_MEM_ERROR;
5128eecc9f 2011-02-23        kinaba:     }
5128eecc9f 2011-02-23        kinaba:     /* following zmemcpy do not work for 16-bit MSDOS */
5128eecc9f 2011-02-23        kinaba:     zmemcpy(ds->window, ss->window, ds->w_size * 2 * sizeof(Byte));
5128eecc9f 2011-02-23        kinaba:     zmemcpy(ds->prev, ss->prev, ds->w_size * sizeof(Pos));
5128eecc9f 2011-02-23        kinaba:     zmemcpy(ds->head, ss->head, ds->hash_size * sizeof(Pos));
5128eecc9f 2011-02-23        kinaba:     zmemcpy(ds->pending_buf, ss->pending_buf, (uInt)ds->pending_buf_size);
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     ds->pending_out = ds->pending_buf + (ss->pending_out - ss->pending_buf);
5128eecc9f 2011-02-23        kinaba:     ds->d_buf = overlay + ds->lit_bufsize/sizeof(ush);
5128eecc9f 2011-02-23        kinaba:     ds->l_buf = ds->pending_buf + (1+sizeof(ush))*ds->lit_bufsize;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     ds->l_desc.dyn_tree = ds->dyn_ltree;
5128eecc9f 2011-02-23        kinaba:     ds->d_desc.dyn_tree = ds->dyn_dtree;
5128eecc9f 2011-02-23        kinaba:     ds->bl_desc.dyn_tree = ds->bl_tree;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     return Z_OK;
5128eecc9f 2011-02-23        kinaba: #endif
5128eecc9f 2011-02-23        kinaba: }
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: /* ===========================================================================
5128eecc9f 2011-02-23        kinaba:  * Read a new buffer from the current input stream, update the adler32
5128eecc9f 2011-02-23        kinaba:  * and total number of bytes read.  All deflate() input goes through
5128eecc9f 2011-02-23        kinaba:  * this function so some applications may wish to modify it to avoid
5128eecc9f 2011-02-23        kinaba:  * allocating a large strm->next_in buffer and copying from it.
5128eecc9f 2011-02-23        kinaba:  * (See also flush_pending()).
5128eecc9f 2011-02-23        kinaba:  */
5128eecc9f 2011-02-23        kinaba: local int read_buf(strm, buf, size)
5128eecc9f 2011-02-23        kinaba:     z_streamp strm;
5128eecc9f 2011-02-23        kinaba:     Bytef *buf;
5128eecc9f 2011-02-23        kinaba:     unsigned size;
5128eecc9f 2011-02-23        kinaba: {
5128eecc9f 2011-02-23        kinaba:     unsigned len = strm->avail_in;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     if (len > size) len = size;
5128eecc9f 2011-02-23        kinaba:     if (len == 0) return 0;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     strm->avail_in  -= len;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     if (!strm->state->noheader) {
5128eecc9f 2011-02-23        kinaba:         strm->adler = adler32(strm->adler, strm->next_in, len);
5128eecc9f 2011-02-23        kinaba:     }
5128eecc9f 2011-02-23        kinaba:     zmemcpy(buf, strm->next_in, len);
5128eecc9f 2011-02-23        kinaba:     strm->next_in  += len;
5128eecc9f 2011-02-23        kinaba:     strm->total_in += len;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     return (int)len;
5128eecc9f 2011-02-23        kinaba: }
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: /* ===========================================================================
5128eecc9f 2011-02-23        kinaba:  * Initialize the "longest match" routines for a new zlib stream
5128eecc9f 2011-02-23        kinaba:  */
5128eecc9f 2011-02-23        kinaba: local void lm_init (s)
5128eecc9f 2011-02-23        kinaba:     deflate_state *s;
5128eecc9f 2011-02-23        kinaba: {
5128eecc9f 2011-02-23        kinaba:     s->window_size = (ulg)2L*s->w_size;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     CLEAR_HASH(s);
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     /* Set the default configuration parameters:
5128eecc9f 2011-02-23        kinaba:      */
5128eecc9f 2011-02-23        kinaba:     s->max_lazy_match   = configuration_table[s->level].max_lazy;
5128eecc9f 2011-02-23        kinaba:     s->good_match       = configuration_table[s->level].good_length;
5128eecc9f 2011-02-23        kinaba:     s->nice_match       = configuration_table[s->level].nice_length;
5128eecc9f 2011-02-23        kinaba:     s->max_chain_length = configuration_table[s->level].max_chain;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     s->strstart = 0;
5128eecc9f 2011-02-23        kinaba:     s->block_start = 0L;
5128eecc9f 2011-02-23        kinaba:     s->lookahead = 0;
5128eecc9f 2011-02-23        kinaba:     s->match_length = s->prev_length = MIN_MATCH-1;
5128eecc9f 2011-02-23        kinaba:     s->match_available = 0;
5128eecc9f 2011-02-23        kinaba:     s->ins_h = 0;
5128eecc9f 2011-02-23        kinaba: #ifdef ASMV
5128eecc9f 2011-02-23        kinaba:     match_init(); /* initialize the asm code */
5128eecc9f 2011-02-23        kinaba: #endif
5128eecc9f 2011-02-23        kinaba: }
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: /* ===========================================================================
5128eecc9f 2011-02-23        kinaba:  * Set match_start to the longest match starting at the given string and
5128eecc9f 2011-02-23        kinaba:  * return its length. Matches shorter or equal to prev_length are discarded,
5128eecc9f 2011-02-23        kinaba:  * in which case the result is equal to prev_length and match_start is
5128eecc9f 2011-02-23        kinaba:  * garbage.
5128eecc9f 2011-02-23        kinaba:  * IN assertions: cur_match is the head of the hash chain for the current
5128eecc9f 2011-02-23        kinaba:  *   string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
5128eecc9f 2011-02-23        kinaba:  * OUT assertion: the match length is not greater than s->lookahead.
5128eecc9f 2011-02-23        kinaba:  */
5128eecc9f 2011-02-23        kinaba: #ifndef ASMV
5128eecc9f 2011-02-23        kinaba: /* For 80x86 and 680x0, an optimized version will be provided in match.asm or
5128eecc9f 2011-02-23        kinaba:  * match.S. The code will be functionally equivalent.
5128eecc9f 2011-02-23        kinaba:  */
5128eecc9f 2011-02-23        kinaba: #ifndef FASTEST
5128eecc9f 2011-02-23        kinaba: local uInt longest_match(s, cur_match)
5128eecc9f 2011-02-23        kinaba:     deflate_state *s;
5128eecc9f 2011-02-23        kinaba:     IPos cur_match;                             /* current match */
5128eecc9f 2011-02-23        kinaba: {
5128eecc9f 2011-02-23        kinaba:     unsigned chain_length = s->max_chain_length;/* max hash chain length */
5128eecc9f 2011-02-23        kinaba:     register Bytef *scan = s->window + s->strstart; /* current string */
5128eecc9f 2011-02-23        kinaba:     register Bytef *match;                       /* matched string */
5128eecc9f 2011-02-23        kinaba:     register int len;                           /* length of current match */
5128eecc9f 2011-02-23        kinaba:     int best_len = s->prev_length;              /* best match length so far */
5128eecc9f 2011-02-23        kinaba:     int nice_match = s->nice_match;             /* stop if match long enough */
5128eecc9f 2011-02-23        kinaba:     IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
5128eecc9f 2011-02-23        kinaba:         s->strstart - (IPos)MAX_DIST(s) : NIL;
5128eecc9f 2011-02-23        kinaba:     /* Stop when cur_match becomes <= limit. To simplify the code,
5128eecc9f 2011-02-23        kinaba:      * we prevent matches with the string of window index 0.
5128eecc9f 2011-02-23        kinaba:      */
5128eecc9f 2011-02-23        kinaba:     Posf *prev = s->prev;
5128eecc9f 2011-02-23        kinaba:     uInt wmask = s->w_mask;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: #ifdef UNALIGNED_OK
5128eecc9f 2011-02-23        kinaba:     /* Compare two bytes at a time. Note: this is not always beneficial.
5128eecc9f 2011-02-23        kinaba:      * Try with and without -DUNALIGNED_OK to check.
5128eecc9f 2011-02-23        kinaba:      */
5128eecc9f 2011-02-23        kinaba:     register Bytef *strend = s->window + s->strstart + MAX_MATCH - 1;
5128eecc9f 2011-02-23        kinaba:     register ush scan_start = *(ushf*)scan;
5128eecc9f 2011-02-23        kinaba:     register ush scan_end   = *(ushf*)(scan+best_len-1);
5128eecc9f 2011-02-23        kinaba: #else
5128eecc9f 2011-02-23        kinaba:     register Bytef *strend = s->window + s->strstart + MAX_MATCH;
5128eecc9f 2011-02-23        kinaba:     register Byte scan_end1  = scan[best_len-1];
5128eecc9f 2011-02-23        kinaba:     register Byte scan_end   = scan[best_len];
5128eecc9f 2011-02-23        kinaba: #endif
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
5128eecc9f 2011-02-23        kinaba:      * It is easy to get rid of this optimization if necessary.
5128eecc9f 2011-02-23        kinaba:      */
5128eecc9f 2011-02-23        kinaba:     Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     /* Do not waste too much time if we already have a good match: */
5128eecc9f 2011-02-23        kinaba:     if (s->prev_length >= s->good_match) {
5128eecc9f 2011-02-23        kinaba:         chain_length >>= 2;
5128eecc9f 2011-02-23        kinaba:     }
5128eecc9f 2011-02-23        kinaba:     /* Do not look for matches beyond the end of the input. This is necessary
5128eecc9f 2011-02-23        kinaba:      * to make deflate deterministic.
5128eecc9f 2011-02-23        kinaba:      */
5128eecc9f 2011-02-23        kinaba:     if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     do {
5128eecc9f 2011-02-23        kinaba:         Assert(cur_match < s->strstart, "no future");
5128eecc9f 2011-02-23        kinaba:         match = s->window + cur_match;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:         /* Skip to next match if the match length cannot increase
5128eecc9f 2011-02-23        kinaba:          * or if the match length is less than 2:
5128eecc9f 2011-02-23        kinaba:          */
5128eecc9f 2011-02-23        kinaba: #if (defined(UNALIGNED_OK) && MAX_MATCH == 258)
5128eecc9f 2011-02-23        kinaba:         /* This code assumes sizeof(unsigned short) == 2. Do not use
5128eecc9f 2011-02-23        kinaba:          * UNALIGNED_OK if your compiler uses a different size.
5128eecc9f 2011-02-23        kinaba:          */
5128eecc9f 2011-02-23        kinaba:         if (*(ushf*)(match+best_len-1) != scan_end ||
5128eecc9f 2011-02-23        kinaba:             *(ushf*)match != scan_start) continue;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:         /* It is not necessary to compare scan[2] and match[2] since they are
5128eecc9f 2011-02-23        kinaba:          * always equal when the other bytes match, given that the hash keys
5128eecc9f 2011-02-23        kinaba:          * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at
5128eecc9f 2011-02-23        kinaba:          * strstart+3, +5, ... up to strstart+257. We check for insufficient
5128eecc9f 2011-02-23        kinaba:          * lookahead only every 4th comparison; the 128th check will be made
5128eecc9f 2011-02-23        kinaba:          * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is
5128eecc9f 2011-02-23        kinaba:          * necessary to put more guard bytes at the end of the window, or
5128eecc9f 2011-02-23        kinaba:          * to check more often for insufficient lookahead.
5128eecc9f 2011-02-23        kinaba:          */
5128eecc9f 2011-02-23        kinaba:         Assert(scan[2] == match[2], "scan[2]?");
5128eecc9f 2011-02-23        kinaba:         scan++, match++;
5128eecc9f 2011-02-23        kinaba:         do {
5128eecc9f 2011-02-23        kinaba:         } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
5128eecc9f 2011-02-23        kinaba:                  *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
5128eecc9f 2011-02-23        kinaba:                  *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
5128eecc9f 2011-02-23        kinaba:                  *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
5128eecc9f 2011-02-23        kinaba:                  scan < strend);
5128eecc9f 2011-02-23        kinaba:         /* The funny "do {}" generates better code on most compilers */
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:         /* Here, scan <= window+strstart+257 */
5128eecc9f 2011-02-23        kinaba:         Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
5128eecc9f 2011-02-23        kinaba:         if (*scan == *match) scan++;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:         len = (MAX_MATCH - 1) - (int)(strend-scan);
5128eecc9f 2011-02-23        kinaba:         scan = strend - (MAX_MATCH-1);
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: #else /* UNALIGNED_OK */
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:         if (match[best_len]   != scan_end  ||
5128eecc9f 2011-02-23        kinaba:             match[best_len-1] != scan_end1 ||
5128eecc9f 2011-02-23        kinaba:             *match            != *scan     ||
5128eecc9f 2011-02-23        kinaba:             *++match          != scan[1])      continue;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:         /* The check at best_len-1 can be removed because it will be made
5128eecc9f 2011-02-23        kinaba:          * again later. (This heuristic is not always a win.)
5128eecc9f 2011-02-23        kinaba:          * It is not necessary to compare scan[2] and match[2] since they
5128eecc9f 2011-02-23        kinaba:          * are always equal when the other bytes match, given that
5128eecc9f 2011-02-23        kinaba:          * the hash keys are equal and that HASH_BITS >= 8.
5128eecc9f 2011-02-23        kinaba:          */
5128eecc9f 2011-02-23        kinaba:         scan += 2, match++;
5128eecc9f 2011-02-23        kinaba:         Assert(*scan == *match, "match[2]?");
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:         /* We check for insufficient lookahead only every 8th comparison;
5128eecc9f 2011-02-23        kinaba:          * the 256th check will be made at strstart+258.
5128eecc9f 2011-02-23        kinaba:          */
5128eecc9f 2011-02-23        kinaba:         do {
5128eecc9f 2011-02-23        kinaba:         } while (*++scan == *++match && *++scan == *++match &&
5128eecc9f 2011-02-23        kinaba:                  *++scan == *++match && *++scan == *++match &&
5128eecc9f 2011-02-23        kinaba:                  *++scan == *++match && *++scan == *++match &&
5128eecc9f 2011-02-23        kinaba:                  *++scan == *++match && *++scan == *++match &&
5128eecc9f 2011-02-23        kinaba:                  scan < strend);
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:         Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:         len = MAX_MATCH - (int)(strend - scan);
5128eecc9f 2011-02-23        kinaba:         scan = strend - MAX_MATCH;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: #endif /* UNALIGNED_OK */
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:         if (len > best_len) {
5128eecc9f 2011-02-23        kinaba:             s->match_start = cur_match;
5128eecc9f 2011-02-23        kinaba:             best_len = len;
5128eecc9f 2011-02-23        kinaba:             if (len >= nice_match) break;
5128eecc9f 2011-02-23        kinaba: #ifdef UNALIGNED_OK
5128eecc9f 2011-02-23        kinaba:             scan_end = *(ushf*)(scan+best_len-1);
5128eecc9f 2011-02-23        kinaba: #else
5128eecc9f 2011-02-23        kinaba:             scan_end1  = scan[best_len-1];
5128eecc9f 2011-02-23        kinaba:             scan_end   = scan[best_len];
5128eecc9f 2011-02-23        kinaba: #endif
5128eecc9f 2011-02-23        kinaba:         }
5128eecc9f 2011-02-23        kinaba:     } while ((cur_match = prev[cur_match & wmask]) > limit
5128eecc9f 2011-02-23        kinaba:              && --chain_length != 0);
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     if ((uInt)best_len <= s->lookahead) return (uInt)best_len;
5128eecc9f 2011-02-23        kinaba:     return s->lookahead;
5128eecc9f 2011-02-23        kinaba: }
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: #else /* FASTEST */
5128eecc9f 2011-02-23        kinaba: /* ---------------------------------------------------------------------------
5128eecc9f 2011-02-23        kinaba:  * Optimized version for level == 1 only
5128eecc9f 2011-02-23        kinaba:  */
5128eecc9f 2011-02-23        kinaba: local uInt longest_match(s, cur_match)
5128eecc9f 2011-02-23        kinaba:     deflate_state *s;
5128eecc9f 2011-02-23        kinaba:     IPos cur_match;                             /* current match */
5128eecc9f 2011-02-23        kinaba: {
5128eecc9f 2011-02-23        kinaba:     register Bytef *scan = s->window + s->strstart; /* current string */
5128eecc9f 2011-02-23        kinaba:     register Bytef *match;                       /* matched string */
5128eecc9f 2011-02-23        kinaba:     register int len;                           /* length of current match */
5128eecc9f 2011-02-23        kinaba:     register Bytef *strend = s->window + s->strstart + MAX_MATCH;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
5128eecc9f 2011-02-23        kinaba:      * It is easy to get rid of this optimization if necessary.
5128eecc9f 2011-02-23        kinaba:      */
5128eecc9f 2011-02-23        kinaba:     Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     Assert(cur_match < s->strstart, "no future");
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     match = s->window + cur_match;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     /* Return failure if the match length is less than 2:
5128eecc9f 2011-02-23        kinaba:      */
5128eecc9f 2011-02-23        kinaba:     if (match[0] != scan[0] || match[1] != scan[1]) return MIN_MATCH-1;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     /* The check at best_len-1 can be removed because it will be made
5128eecc9f 2011-02-23        kinaba:      * again later. (This heuristic is not always a win.)
5128eecc9f 2011-02-23        kinaba:      * It is not necessary to compare scan[2] and match[2] since they
5128eecc9f 2011-02-23        kinaba:      * are always equal when the other bytes match, given that
5128eecc9f 2011-02-23        kinaba:      * the hash keys are equal and that HASH_BITS >= 8.
5128eecc9f 2011-02-23        kinaba:      */
5128eecc9f 2011-02-23        kinaba:     scan += 2, match += 2;
5128eecc9f 2011-02-23        kinaba:     Assert(*scan == *match, "match[2]?");
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     /* We check for insufficient lookahead only every 8th comparison;
5128eecc9f 2011-02-23        kinaba:      * the 256th check will be made at strstart+258.
5128eecc9f 2011-02-23        kinaba:      */
5128eecc9f 2011-02-23        kinaba:     do {
5128eecc9f 2011-02-23        kinaba:     } while (*++scan == *++match && *++scan == *++match &&
5128eecc9f 2011-02-23        kinaba: 	     *++scan == *++match && *++scan == *++match &&
5128eecc9f 2011-02-23        kinaba: 	     *++scan == *++match && *++scan == *++match &&
5128eecc9f 2011-02-23        kinaba: 	     *++scan == *++match && *++scan == *++match &&
5128eecc9f 2011-02-23        kinaba: 	     scan < strend);
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     len = MAX_MATCH - (int)(strend - scan);
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     if (len < MIN_MATCH) return MIN_MATCH - 1;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     s->match_start = cur_match;
5128eecc9f 2011-02-23        kinaba:     return len <= s->lookahead ? len : s->lookahead;
5128eecc9f 2011-02-23        kinaba: }
5128eecc9f 2011-02-23        kinaba: #endif /* FASTEST */
5128eecc9f 2011-02-23        kinaba: #endif /* ASMV */
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: #ifdef DEBUG
5128eecc9f 2011-02-23        kinaba: /* ===========================================================================
5128eecc9f 2011-02-23        kinaba:  * Check that the match at match_start is indeed a match.
5128eecc9f 2011-02-23        kinaba:  */
5128eecc9f 2011-02-23        kinaba: local void check_match(s, start, match, length)
5128eecc9f 2011-02-23        kinaba:     deflate_state *s;
5128eecc9f 2011-02-23        kinaba:     IPos start, match;
5128eecc9f 2011-02-23        kinaba:     int length;
5128eecc9f 2011-02-23        kinaba: {
5128eecc9f 2011-02-23        kinaba:     /* check that the match is indeed a match */
5128eecc9f 2011-02-23        kinaba:     if (zmemcmp(s->window + match,
5128eecc9f 2011-02-23        kinaba:                 s->window + start, length) != EQUAL) {
5128eecc9f 2011-02-23        kinaba:         fprintf(stderr, " start %u, match %u, length %d\n",
5128eecc9f 2011-02-23        kinaba: 		start, match, length);
5128eecc9f 2011-02-23        kinaba:         do {
5128eecc9f 2011-02-23        kinaba: 	    fprintf(stderr, "%c%c", s->window[match++], s->window[start++]);
5128eecc9f 2011-02-23        kinaba: 	} while (--length != 0);
5128eecc9f 2011-02-23        kinaba:         z_error("invalid match");
5128eecc9f 2011-02-23        kinaba:     }
5128eecc9f 2011-02-23        kinaba:     if (z_verbose > 1) {
5128eecc9f 2011-02-23        kinaba:         fprintf(stderr,"\\[%d,%d]", start-match, length);
5128eecc9f 2011-02-23        kinaba:         do { putc(s->window[start++], stderr); } while (--length != 0);
5128eecc9f 2011-02-23        kinaba:     }
5128eecc9f 2011-02-23        kinaba: }
5128eecc9f 2011-02-23        kinaba: #else
5128eecc9f 2011-02-23        kinaba: #  define check_match(s, start, match, length)
5128eecc9f 2011-02-23        kinaba: #endif
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: /* ===========================================================================
5128eecc9f 2011-02-23        kinaba:  * Fill the window when the lookahead becomes insufficient.
5128eecc9f 2011-02-23        kinaba:  * Updates strstart and lookahead.
5128eecc9f 2011-02-23        kinaba:  *
5128eecc9f 2011-02-23        kinaba:  * IN assertion: lookahead < MIN_LOOKAHEAD
5128eecc9f 2011-02-23        kinaba:  * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD
5128eecc9f 2011-02-23        kinaba:  *    At least one byte has been read, or avail_in == 0; reads are
5128eecc9f 2011-02-23        kinaba:  *    performed for at least two bytes (required for the zip translate_eol
5128eecc9f 2011-02-23        kinaba:  *    option -- not supported here).
5128eecc9f 2011-02-23        kinaba:  */
5128eecc9f 2011-02-23        kinaba: local void fill_window(s)
5128eecc9f 2011-02-23        kinaba:     deflate_state *s;
5128eecc9f 2011-02-23        kinaba: {
5128eecc9f 2011-02-23        kinaba:     register unsigned n, m;
5128eecc9f 2011-02-23        kinaba:     register Posf *p;
5128eecc9f 2011-02-23        kinaba:     unsigned more;    /* Amount of free space at the end of the window. */
5128eecc9f 2011-02-23        kinaba:     uInt wsize = s->w_size;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     do {
5128eecc9f 2011-02-23        kinaba:         more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart);
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:         /* Deal with !@#$% 64K limit: */
5128eecc9f 2011-02-23        kinaba:         if (more == 0 && s->strstart == 0 && s->lookahead == 0) {
5128eecc9f 2011-02-23        kinaba:             more = wsize;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:         } else if (more == (unsigned)(-1)) {
5128eecc9f 2011-02-23        kinaba:             /* Very unlikely, but possible on 16 bit machine if strstart == 0
5128eecc9f 2011-02-23        kinaba:              * and lookahead == 1 (input done one byte at time)
5128eecc9f 2011-02-23        kinaba:              */
5128eecc9f 2011-02-23        kinaba:             more--;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:         /* If the window is almost full and there is insufficient lookahead,
5128eecc9f 2011-02-23        kinaba:          * move the upper half to the lower one to make room in the upper half.
5128eecc9f 2011-02-23        kinaba:          */
5128eecc9f 2011-02-23        kinaba:         } else if (s->strstart >= wsize+MAX_DIST(s)) {
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:             zmemcpy(s->window, s->window+wsize, (unsigned)wsize);
5128eecc9f 2011-02-23        kinaba:             s->match_start -= wsize;
5128eecc9f 2011-02-23        kinaba:             s->strstart    -= wsize; /* we now have strstart >= MAX_DIST */
5128eecc9f 2011-02-23        kinaba:             s->block_start -= (long) wsize;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:             /* Slide the hash table (could be avoided with 32 bit values
5128eecc9f 2011-02-23        kinaba:                at the expense of memory usage). We slide even when level == 0
5128eecc9f 2011-02-23        kinaba:                to keep the hash table consistent if we switch back to level > 0
5128eecc9f 2011-02-23        kinaba:                later. (Using level 0 permanently is not an optimal usage of
5128eecc9f 2011-02-23        kinaba:                zlib, so we don't care about this pathological case.)
5128eecc9f 2011-02-23        kinaba:              */
5128eecc9f 2011-02-23        kinaba: 	    n = s->hash_size;
5128eecc9f 2011-02-23        kinaba: 	    p = &s->head[n];
5128eecc9f 2011-02-23        kinaba: 	    do {
5128eecc9f 2011-02-23        kinaba: 		m = *--p;
5128eecc9f 2011-02-23        kinaba: 		*p = (Pos)(m >= wsize ? m-wsize : NIL);
5128eecc9f 2011-02-23        kinaba: 	    } while (--n);
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: 	    n = wsize;
5128eecc9f 2011-02-23        kinaba: #ifndef FASTEST
5128eecc9f 2011-02-23        kinaba: 	    p = &s->prev[n];
5128eecc9f 2011-02-23        kinaba: 	    do {
5128eecc9f 2011-02-23        kinaba: 		m = *--p;
5128eecc9f 2011-02-23        kinaba: 		*p = (Pos)(m >= wsize ? m-wsize : NIL);
5128eecc9f 2011-02-23        kinaba: 		/* If n is not on any hash chain, prev[n] is garbage but
5128eecc9f 2011-02-23        kinaba: 		 * its value will never be used.
5128eecc9f 2011-02-23        kinaba: 		 */
5128eecc9f 2011-02-23        kinaba: 	    } while (--n);
5128eecc9f 2011-02-23        kinaba: #endif
5128eecc9f 2011-02-23        kinaba:             more += wsize;
5128eecc9f 2011-02-23        kinaba:         }
5128eecc9f 2011-02-23        kinaba:         if (s->strm->avail_in == 0) return;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:         /* If there was no sliding:
5128eecc9f 2011-02-23        kinaba:          *    strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
5128eecc9f 2011-02-23        kinaba:          *    more == window_size - lookahead - strstart
5128eecc9f 2011-02-23        kinaba:          * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
5128eecc9f 2011-02-23        kinaba:          * => more >= window_size - 2*WSIZE + 2
5128eecc9f 2011-02-23        kinaba:          * In the BIG_MEM or MMAP case (not yet supported),
5128eecc9f 2011-02-23        kinaba:          *   window_size == input_size + MIN_LOOKAHEAD  &&
5128eecc9f 2011-02-23        kinaba:          *   strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD.
5128eecc9f 2011-02-23        kinaba:          * Otherwise, window_size == 2*WSIZE so more >= 2.
5128eecc9f 2011-02-23        kinaba:          * If there was sliding, more >= WSIZE. So in all cases, more >= 2.
5128eecc9f 2011-02-23        kinaba:          */
5128eecc9f 2011-02-23        kinaba:         Assert(more >= 2, "more < 2");
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:         n = read_buf(s->strm, s->window + s->strstart + s->lookahead, more);
5128eecc9f 2011-02-23        kinaba:         s->lookahead += n;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:         /* Initialize the hash value now that we have some input: */
5128eecc9f 2011-02-23        kinaba:         if (s->lookahead >= MIN_MATCH) {
5128eecc9f 2011-02-23        kinaba:             s->ins_h = s->window[s->strstart];
5128eecc9f 2011-02-23        kinaba:             UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
5128eecc9f 2011-02-23        kinaba: #if MIN_MATCH != 3
5128eecc9f 2011-02-23        kinaba:             Call UPDATE_HASH() MIN_MATCH-3 more times
5128eecc9f 2011-02-23        kinaba: #endif
5128eecc9f 2011-02-23        kinaba:         }
5128eecc9f 2011-02-23        kinaba:         /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage,
5128eecc9f 2011-02-23        kinaba:          * but this is not important since only literal bytes will be emitted.
5128eecc9f 2011-02-23        kinaba:          */
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0);
5128eecc9f 2011-02-23        kinaba: }
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: /* ===========================================================================
5128eecc9f 2011-02-23        kinaba:  * Flush the current block, with given end-of-file flag.
5128eecc9f 2011-02-23        kinaba:  * IN assertion: strstart is set to the end of the current match.
5128eecc9f 2011-02-23        kinaba:  */
5128eecc9f 2011-02-23        kinaba: #define FLUSH_BLOCK_ONLY(s, eof) { \
5128eecc9f 2011-02-23        kinaba:    _tr_flush_block(s, (s->block_start >= 0L ? \
5128eecc9f 2011-02-23        kinaba:                    (charf *)&s->window[(unsigned)s->block_start] : \
5128eecc9f 2011-02-23        kinaba:                    (charf *)Z_NULL), \
5128eecc9f 2011-02-23        kinaba: 		(ulg)((long)s->strstart - s->block_start), \
5128eecc9f 2011-02-23        kinaba: 		(eof)); \
5128eecc9f 2011-02-23        kinaba:    s->block_start = s->strstart; \
5128eecc9f 2011-02-23        kinaba:    flush_pending(s->strm); \
5128eecc9f 2011-02-23        kinaba:    Tracev((stderr,"[FLUSH]")); \
5128eecc9f 2011-02-23        kinaba: }
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: /* Same but force premature exit if necessary. */
5128eecc9f 2011-02-23        kinaba: #define FLUSH_BLOCK(s, eof) { \
5128eecc9f 2011-02-23        kinaba:    FLUSH_BLOCK_ONLY(s, eof); \
5128eecc9f 2011-02-23        kinaba:    if (s->strm->avail_out == 0) return (eof) ? finish_started : need_more; \
5128eecc9f 2011-02-23        kinaba: }
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: /* ===========================================================================
5128eecc9f 2011-02-23        kinaba:  * Copy without compression as much as possible from the input stream, return
5128eecc9f 2011-02-23        kinaba:  * the current block state.
5128eecc9f 2011-02-23        kinaba:  * This function does not insert new strings in the dictionary since
5128eecc9f 2011-02-23        kinaba:  * uncompressible data is probably not useful. This function is used
5128eecc9f 2011-02-23        kinaba:  * only for the level=0 compression option.
5128eecc9f 2011-02-23        kinaba:  * NOTE: this function should be optimized to avoid extra copying from
5128eecc9f 2011-02-23        kinaba:  * window to pending_buf.
5128eecc9f 2011-02-23        kinaba:  */
5128eecc9f 2011-02-23        kinaba: local block_state deflate_stored(s, flush)
5128eecc9f 2011-02-23        kinaba:     deflate_state *s;
5128eecc9f 2011-02-23        kinaba:     int flush;
5128eecc9f 2011-02-23        kinaba: {
5128eecc9f 2011-02-23        kinaba:     /* Stored blocks are limited to 0xffff bytes, pending_buf is limited
5128eecc9f 2011-02-23        kinaba:      * to pending_buf_size, and each stored block has a 5 byte header:
5128eecc9f 2011-02-23        kinaba:      */
5128eecc9f 2011-02-23        kinaba:     ulg max_block_size = 0xffff;
5128eecc9f 2011-02-23        kinaba:     ulg max_start;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     if (max_block_size > s->pending_buf_size - 5) {
5128eecc9f 2011-02-23        kinaba:         max_block_size = s->pending_buf_size - 5;
5128eecc9f 2011-02-23        kinaba:     }
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     /* Copy as much as possible from input to output: */
5128eecc9f 2011-02-23        kinaba:     for (;;) {
5128eecc9f 2011-02-23        kinaba:         /* Fill the window as much as possible: */
5128eecc9f 2011-02-23        kinaba:         if (s->lookahead <= 1) {
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:             Assert(s->strstart < s->w_size+MAX_DIST(s) ||
5128eecc9f 2011-02-23        kinaba: 		   s->block_start >= (long)s->w_size, "slide too late");
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:             fill_window(s);
5128eecc9f 2011-02-23        kinaba:             if (s->lookahead == 0 && flush == Z_NO_FLUSH) return need_more;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:             if (s->lookahead == 0) break; /* flush the current block */
5128eecc9f 2011-02-23        kinaba:         }
5128eecc9f 2011-02-23        kinaba: 	Assert(s->block_start >= 0L, "block gone");
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: 	s->strstart += s->lookahead;
5128eecc9f 2011-02-23        kinaba: 	s->lookahead = 0;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: 	/* Emit a stored block if pending_buf will be full: */
5128eecc9f 2011-02-23        kinaba:  	max_start = s->block_start + max_block_size;
5128eecc9f 2011-02-23        kinaba:         if (s->strstart == 0 || (ulg)s->strstart >= max_start) {
5128eecc9f 2011-02-23        kinaba: 	    /* strstart == 0 is possible when wraparound on 16-bit machine */
5128eecc9f 2011-02-23        kinaba: 	    s->lookahead = (uInt)(s->strstart - max_start);
5128eecc9f 2011-02-23        kinaba: 	    s->strstart = (uInt)max_start;
5128eecc9f 2011-02-23        kinaba:             FLUSH_BLOCK(s, 0);
5128eecc9f 2011-02-23        kinaba: 	}
5128eecc9f 2011-02-23        kinaba: 	/* Flush if we may have to slide, otherwise block_start may become
5128eecc9f 2011-02-23        kinaba:          * negative and the data will be gone:
5128eecc9f 2011-02-23        kinaba:          */
5128eecc9f 2011-02-23        kinaba:         if (s->strstart - (uInt)s->block_start >= MAX_DIST(s)) {
5128eecc9f 2011-02-23        kinaba:             FLUSH_BLOCK(s, 0);
5128eecc9f 2011-02-23        kinaba: 	}
5128eecc9f 2011-02-23        kinaba:     }
5128eecc9f 2011-02-23        kinaba:     FLUSH_BLOCK(s, flush == Z_FINISH);
5128eecc9f 2011-02-23        kinaba:     return flush == Z_FINISH ? finish_done : block_done;
5128eecc9f 2011-02-23        kinaba: }
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: /* ===========================================================================
5128eecc9f 2011-02-23        kinaba:  * Compress as much as possible from the input stream, return the current
5128eecc9f 2011-02-23        kinaba:  * block state.
5128eecc9f 2011-02-23        kinaba:  * This function does not perform lazy evaluation of matches and inserts
5128eecc9f 2011-02-23        kinaba:  * new strings in the dictionary only for unmatched strings or for short
5128eecc9f 2011-02-23        kinaba:  * matches. It is used only for the fast compression options.
5128eecc9f 2011-02-23        kinaba:  */
5128eecc9f 2011-02-23        kinaba: local block_state deflate_fast(s, flush)
5128eecc9f 2011-02-23        kinaba:     deflate_state *s;
5128eecc9f 2011-02-23        kinaba:     int flush;
5128eecc9f 2011-02-23        kinaba: {
5128eecc9f 2011-02-23        kinaba:     IPos hash_head = NIL; /* head of the hash chain */
5128eecc9f 2011-02-23        kinaba:     int bflush;           /* set if current block must be flushed */
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     for (;;) {
5128eecc9f 2011-02-23        kinaba:         /* Make sure that we always have enough lookahead, except
5128eecc9f 2011-02-23        kinaba:          * at the end of the input file. We need MAX_MATCH bytes
5128eecc9f 2011-02-23        kinaba:          * for the next match, plus MIN_MATCH bytes to insert the
5128eecc9f 2011-02-23        kinaba:          * string following the next match.
5128eecc9f 2011-02-23        kinaba:          */
5128eecc9f 2011-02-23        kinaba:         if (s->lookahead < MIN_LOOKAHEAD) {
5128eecc9f 2011-02-23        kinaba:             fill_window(s);
5128eecc9f 2011-02-23        kinaba:             if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
5128eecc9f 2011-02-23        kinaba: 	        return need_more;
5128eecc9f 2011-02-23        kinaba: 	    }
5128eecc9f 2011-02-23        kinaba:             if (s->lookahead == 0) break; /* flush the current block */
5128eecc9f 2011-02-23        kinaba:         }
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:         /* Insert the string window[strstart .. strstart+2] in the
5128eecc9f 2011-02-23        kinaba:          * dictionary, and set hash_head to the head of the hash chain:
5128eecc9f 2011-02-23        kinaba:          */
5128eecc9f 2011-02-23        kinaba:         if (s->lookahead >= MIN_MATCH) {
5128eecc9f 2011-02-23        kinaba:             INSERT_STRING(s, s->strstart, hash_head);
5128eecc9f 2011-02-23        kinaba:         }
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:         /* Find the longest match, discarding those <= prev_length.
5128eecc9f 2011-02-23        kinaba:          * At this point we have always match_length < MIN_MATCH
5128eecc9f 2011-02-23        kinaba:          */
5128eecc9f 2011-02-23        kinaba:         if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) {
5128eecc9f 2011-02-23        kinaba:             /* To simplify the code, we prevent matches with the string
5128eecc9f 2011-02-23        kinaba:              * of window index 0 (in particular we have to avoid a match
5128eecc9f 2011-02-23        kinaba:              * of the string with itself at the start of the input file).
5128eecc9f 2011-02-23        kinaba:              */
5128eecc9f 2011-02-23        kinaba:             if (s->strategy != Z_HUFFMAN_ONLY) {
5128eecc9f 2011-02-23        kinaba:                 s->match_length = longest_match (s, hash_head);
5128eecc9f 2011-02-23        kinaba:             }
5128eecc9f 2011-02-23        kinaba:             /* longest_match() sets match_start */
5128eecc9f 2011-02-23        kinaba:         }
5128eecc9f 2011-02-23        kinaba:         if (s->match_length >= MIN_MATCH) {
5128eecc9f 2011-02-23        kinaba:             check_match(s, s->strstart, s->match_start, s->match_length);
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:             _tr_tally_dist(s, s->strstart - s->match_start,
5128eecc9f 2011-02-23        kinaba:                            s->match_length - MIN_MATCH, bflush);
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:             s->lookahead -= s->match_length;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:             /* Insert new strings in the hash table only if the match length
5128eecc9f 2011-02-23        kinaba:              * is not too large. This saves time but degrades compression.
5128eecc9f 2011-02-23        kinaba:              */
5128eecc9f 2011-02-23        kinaba: #ifndef FASTEST
5128eecc9f 2011-02-23        kinaba:             if (s->match_length <= s->max_insert_length &&
5128eecc9f 2011-02-23        kinaba:                 s->lookahead >= MIN_MATCH) {
5128eecc9f 2011-02-23        kinaba:                 s->match_length--; /* string at strstart already in hash table */
5128eecc9f 2011-02-23        kinaba:                 do {
5128eecc9f 2011-02-23        kinaba:                     s->strstart++;
5128eecc9f 2011-02-23        kinaba:                     INSERT_STRING(s, s->strstart, hash_head);
5128eecc9f 2011-02-23        kinaba:                     /* strstart never exceeds WSIZE-MAX_MATCH, so there are
5128eecc9f 2011-02-23        kinaba:                      * always MIN_MATCH bytes ahead.
5128eecc9f 2011-02-23        kinaba:                      */
5128eecc9f 2011-02-23        kinaba:                 } while (--s->match_length != 0);
5128eecc9f 2011-02-23        kinaba:                 s->strstart++;
5128eecc9f 2011-02-23        kinaba:             } else
5128eecc9f 2011-02-23        kinaba: #endif
5128eecc9f 2011-02-23        kinaba: 	    {
5128eecc9f 2011-02-23        kinaba:                 s->strstart += s->match_length;
5128eecc9f 2011-02-23        kinaba:                 s->match_length = 0;
5128eecc9f 2011-02-23        kinaba:                 s->ins_h = s->window[s->strstart];
5128eecc9f 2011-02-23        kinaba:                 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
5128eecc9f 2011-02-23        kinaba: #if MIN_MATCH != 3
5128eecc9f 2011-02-23        kinaba:                 Call UPDATE_HASH() MIN_MATCH-3 more times
5128eecc9f 2011-02-23        kinaba: #endif
5128eecc9f 2011-02-23        kinaba:                 /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not
5128eecc9f 2011-02-23        kinaba:                  * matter since it will be recomputed at next deflate call.
5128eecc9f 2011-02-23        kinaba:                  */
5128eecc9f 2011-02-23        kinaba:             }
5128eecc9f 2011-02-23        kinaba:         } else {
5128eecc9f 2011-02-23        kinaba:             /* No match, output a literal byte */
5128eecc9f 2011-02-23        kinaba:             Tracevv((stderr,"%c", s->window[s->strstart]));
5128eecc9f 2011-02-23        kinaba:             _tr_tally_lit (s, s->window[s->strstart], bflush);
5128eecc9f 2011-02-23        kinaba:             s->lookahead--;
5128eecc9f 2011-02-23        kinaba:             s->strstart++;
5128eecc9f 2011-02-23        kinaba:         }
5128eecc9f 2011-02-23        kinaba:         if (bflush) FLUSH_BLOCK(s, 0);
5128eecc9f 2011-02-23        kinaba:     }
5128eecc9f 2011-02-23        kinaba:     FLUSH_BLOCK(s, flush == Z_FINISH);
5128eecc9f 2011-02-23        kinaba:     return flush == Z_FINISH ? finish_done : block_done;
5128eecc9f 2011-02-23        kinaba: }
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: /* ===========================================================================
5128eecc9f 2011-02-23        kinaba:  * Same as above, but achieves better compression. We use a lazy
5128eecc9f 2011-02-23        kinaba:  * evaluation for matches: a match is finally adopted only if there is
5128eecc9f 2011-02-23        kinaba:  * no better match at the next window position.
5128eecc9f 2011-02-23        kinaba:  */
5128eecc9f 2011-02-23        kinaba: local block_state deflate_slow(s, flush)
5128eecc9f 2011-02-23        kinaba:     deflate_state *s;
5128eecc9f 2011-02-23        kinaba:     int flush;
5128eecc9f 2011-02-23        kinaba: {
5128eecc9f 2011-02-23        kinaba:     IPos hash_head = NIL;    /* head of hash chain */
5128eecc9f 2011-02-23        kinaba:     int bflush;              /* set if current block must be flushed */
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:     /* Process the input block. */
5128eecc9f 2011-02-23        kinaba:     for (;;) {
5128eecc9f 2011-02-23        kinaba:         /* Make sure that we always have enough lookahead, except
5128eecc9f 2011-02-23        kinaba:          * at the end of the input file. We need MAX_MATCH bytes
5128eecc9f 2011-02-23        kinaba:          * for the next match, plus MIN_MATCH bytes to insert the
5128eecc9f 2011-02-23        kinaba:          * string following the next match.
5128eecc9f 2011-02-23        kinaba:          */
5128eecc9f 2011-02-23        kinaba:         if (s->lookahead < MIN_LOOKAHEAD) {
5128eecc9f 2011-02-23        kinaba:             fill_window(s);
5128eecc9f 2011-02-23        kinaba:             if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
5128eecc9f 2011-02-23        kinaba: 	        return need_more;
5128eecc9f 2011-02-23        kinaba: 	    }
5128eecc9f 2011-02-23        kinaba:             if (s->lookahead == 0) break; /* flush the current block */
5128eecc9f 2011-02-23        kinaba:         }
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:         /* Insert the string window[strstart .. strstart+2] in the
5128eecc9f 2011-02-23        kinaba:          * dictionary, and set hash_head to the head of the hash chain:
5128eecc9f 2011-02-23        kinaba:          */
5128eecc9f 2011-02-23        kinaba:         if (s->lookahead >= MIN_MATCH) {
5128eecc9f 2011-02-23        kinaba:             INSERT_STRING(s, s->strstart, hash_head);
5128eecc9f 2011-02-23        kinaba:         }
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:         /* Find the longest match, discarding those <= prev_length.
5128eecc9f 2011-02-23        kinaba:          */
5128eecc9f 2011-02-23        kinaba:         s->prev_length = s->match_length, s->prev_match = s->match_start;
5128eecc9f 2011-02-23        kinaba:         s->match_length = MIN_MATCH-1;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:         if (hash_head != NIL && s->prev_length < s->max_lazy_match &&
5128eecc9f 2011-02-23        kinaba:             s->strstart - hash_head <= MAX_DIST(s)) {
5128eecc9f 2011-02-23        kinaba:             /* To simplify the code, we prevent matches with the string
5128eecc9f 2011-02-23        kinaba:              * of window index 0 (in particular we have to avoid a match
5128eecc9f 2011-02-23        kinaba:              * of the string with itself at the start of the input file).
5128eecc9f 2011-02-23        kinaba:              */
5128eecc9f 2011-02-23        kinaba:             if (s->strategy != Z_HUFFMAN_ONLY) {
5128eecc9f 2011-02-23        kinaba:                 s->match_length = longest_match (s, hash_head);
5128eecc9f 2011-02-23        kinaba:             }
5128eecc9f 2011-02-23        kinaba:             /* longest_match() sets match_start */
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:             if (s->match_length <= 5 && (s->strategy == Z_FILTERED ||
5128eecc9f 2011-02-23        kinaba:                  (s->match_length == MIN_MATCH &&
5128eecc9f 2011-02-23        kinaba:                   s->strstart - s->match_start > TOO_FAR))) {
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:                 /* If prev_match is also MIN_MATCH, match_start is garbage
5128eecc9f 2011-02-23        kinaba:                  * but we will ignore the current match anyway.
5128eecc9f 2011-02-23        kinaba:                  */
5128eecc9f 2011-02-23        kinaba:                 s->match_length = MIN_MATCH-1;
5128eecc9f 2011-02-23        kinaba:             }
5128eecc9f 2011-02-23        kinaba:         }
5128eecc9f 2011-02-23        kinaba:         /* If there was a match at the previous step and the current
5128eecc9f 2011-02-23        kinaba:          * match is not better, output the previous match:
5128eecc9f 2011-02-23        kinaba:          */
5128eecc9f 2011-02-23        kinaba:         if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) {
5128eecc9f 2011-02-23        kinaba:             uInt max_insert = s->strstart + s->lookahead - MIN_MATCH;
5128eecc9f 2011-02-23        kinaba:             /* Do not insert strings in hash table beyond this. */
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:             check_match(s, s->strstart-1, s->prev_match, s->prev_length);
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:             _tr_tally_dist(s, s->strstart -1 - s->prev_match,
5128eecc9f 2011-02-23        kinaba: 			   s->prev_length - MIN_MATCH, bflush);
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:             /* Insert in hash table all strings up to the end of the match.
5128eecc9f 2011-02-23        kinaba:              * strstart-1 and strstart are already inserted. If there is not
5128eecc9f 2011-02-23        kinaba:              * enough lookahead, the last two strings are not inserted in
5128eecc9f 2011-02-23        kinaba:              * the hash table.
5128eecc9f 2011-02-23        kinaba:              */
5128eecc9f 2011-02-23        kinaba:             s->lookahead -= s->prev_length-1;
5128eecc9f 2011-02-23        kinaba:             s->prev_length -= 2;
5128eecc9f 2011-02-23        kinaba:             do {
5128eecc9f 2011-02-23        kinaba:                 if (++s->strstart <= max_insert) {
5128eecc9f 2011-02-23        kinaba:                     INSERT_STRING(s, s->strstart, hash_head);
5128eecc9f 2011-02-23        kinaba:                 }
5128eecc9f 2011-02-23        kinaba:             } while (--s->prev_length != 0);
5128eecc9f 2011-02-23        kinaba:             s->match_available = 0;
5128eecc9f 2011-02-23        kinaba:             s->match_length = MIN_MATCH-1;
5128eecc9f 2011-02-23        kinaba:             s->strstart++;
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:             if (bflush) FLUSH_BLOCK(s, 0);
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba:         } else if (s->match_available) {
5128eecc9f 2011-02-23        kinaba:             /* If there was no match at the previous position, output a
5128eecc9f 2011-02-23        kinaba:              * single literal. If there was a match but the current match
5128eecc9f 2011-02-23        kinaba:              * is longer, truncate the previous match to a single literal.
5128eecc9f 2011-02-23        kinaba:              */
5128eecc9f 2011-02-23        kinaba:             Tracevv((stderr,"%c", s->window[s->strstart-1]));
5128eecc9f 2011-02-23        kinaba: 	    _tr_tally_lit(s, s->window[s->strstart-1], bflush);
5128eecc9f 2011-02-23        kinaba: 	    if (bflush) {
5128eecc9f 2011-02-23        kinaba:                 FLUSH_BLOCK_ONLY(s, 0);
5128eecc9f 2011-02-23        kinaba:             }
5128eecc9f 2011-02-23        kinaba:             s->strstart++;
5128eecc9f 2011-02-23        kinaba:             s->lookahead--;
5128eecc9f 2011-02-23        kinaba:             if (s->strm->avail_out == 0) return need_more;
5128eecc9f 2011-02-23        kinaba:         } else {
5128eecc9f 2011-02-23        kinaba:             /* There is no previous match to compare with, wait for
5128eecc9f 2011-02-23        kinaba:              * the next step to decide.
5128eecc9f 2011-02-23        kinaba:              */
5128eecc9f 2011-02-23        kinaba:             s->match_available = 1;
5128eecc9f 2011-02-23        kinaba:             s->strstart++;
5128eecc9f 2011-02-23        kinaba:             s->lookahead--;
5128eecc9f 2011-02-23        kinaba:         }
5128eecc9f 2011-02-23        kinaba:     }
5128eecc9f 2011-02-23        kinaba:     Assert (flush != Z_NO_FLUSH, "no flush?");
5128eecc9f 2011-02-23        kinaba:     if (s->match_available) {
5128eecc9f 2011-02-23        kinaba:         Tracevv((stderr,"%c", s->window[s->strstart-1]));
5128eecc9f 2011-02-23        kinaba:         _tr_tally_lit(s, s->window[s->strstart-1], bflush);
5128eecc9f 2011-02-23        kinaba:         s->match_available = 0;
5128eecc9f 2011-02-23        kinaba:     }
5128eecc9f 2011-02-23        kinaba:     FLUSH_BLOCK(s, flush == Z_FINISH);
5128eecc9f 2011-02-23        kinaba:     return flush == Z_FINISH ? finish_done : block_done;
5128eecc9f 2011-02-23        kinaba: }
5128eecc9f 2011-02-23        kinaba: 
5128eecc9f 2011-02-23        kinaba: #endif /* KI_GZ_NO_COMPRESSION */