1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/libs/zlib/deflate.h	Thu Sep 08 06:28:38 2011 +0300
     1.3 @@ -0,0 +1,331 @@
     1.4 +/* deflate.h -- internal compression state
     1.5 + * Copyright (C) 1995-2004 Jean-loup Gailly
     1.6 + * For conditions of distribution and use, see copyright notice in zlib.h
     1.7 + */
     1.8 +
     1.9 +/* WARNING: this file should *not* be used by applications. It is
    1.10 +   part of the implementation of the compression library and is
    1.11 +   subject to change. Applications should only use zlib.h.
    1.12 + */
    1.13 +
    1.14 +/* @(#) $Id$ */
    1.15 +
    1.16 +#ifndef DEFLATE_H
    1.17 +#define DEFLATE_H
    1.18 +
    1.19 +#include "zutil.h"
    1.20 +
    1.21 +/* define NO_GZIP when compiling if you want to disable gzip header and
    1.22 +   trailer creation by deflate().  NO_GZIP would be used to avoid linking in
    1.23 +   the crc code when it is not needed.  For shared libraries, gzip encoding
    1.24 +   should be left enabled. */
    1.25 +#ifndef NO_GZIP
    1.26 +#  define GZIP
    1.27 +#endif
    1.28 +
    1.29 +/* ===========================================================================
    1.30 + * Internal compression state.
    1.31 + */
    1.32 +
    1.33 +#define LENGTH_CODES 29
    1.34 +/* number of length codes, not counting the special END_BLOCK code */
    1.35 +
    1.36 +#define LITERALS  256
    1.37 +/* number of literal bytes 0..255 */
    1.38 +
    1.39 +#define L_CODES (LITERALS+1+LENGTH_CODES)
    1.40 +/* number of Literal or Length codes, including the END_BLOCK code */
    1.41 +
    1.42 +#define D_CODES   30
    1.43 +/* number of distance codes */
    1.44 +
    1.45 +#define BL_CODES  19
    1.46 +/* number of codes used to transfer the bit lengths */
    1.47 +
    1.48 +#define HEAP_SIZE (2*L_CODES+1)
    1.49 +/* maximum heap size */
    1.50 +
    1.51 +#define MAX_BITS 15
    1.52 +/* All codes must not exceed MAX_BITS bits */
    1.53 +
    1.54 +#define INIT_STATE    42
    1.55 +#define EXTRA_STATE   69
    1.56 +#define NAME_STATE    73
    1.57 +#define COMMENT_STATE 91
    1.58 +#define HCRC_STATE   103
    1.59 +#define BUSY_STATE   113
    1.60 +#define FINISH_STATE 666
    1.61 +/* Stream status */
    1.62 +
    1.63 +
    1.64 +/* Data structure describing a single value and its code string. */
    1.65 +typedef struct ct_data_s {
    1.66 +    union {
    1.67 +        ush  freq;       /* frequency count */
    1.68 +        ush  code;       /* bit string */
    1.69 +    } fc;
    1.70 +    union {
    1.71 +        ush  dad;        /* father node in Huffman tree */
    1.72 +        ush  len;        /* length of bit string */
    1.73 +    } dl;
    1.74 +} FAR ct_data;
    1.75 +
    1.76 +#define Freq fc.freq
    1.77 +#define Code fc.code
    1.78 +#define Dad  dl.dad
    1.79 +#define Len  dl.len
    1.80 +
    1.81 +typedef struct static_tree_desc_s  static_tree_desc;
    1.82 +
    1.83 +typedef struct tree_desc_s {
    1.84 +    ct_data *dyn_tree;           /* the dynamic tree */
    1.85 +    int     max_code;            /* largest code with non zero frequency */
    1.86 +    static_tree_desc *stat_desc; /* the corresponding static tree */
    1.87 +} FAR tree_desc;
    1.88 +
    1.89 +typedef ush Pos;
    1.90 +typedef Pos FAR Posf;
    1.91 +typedef unsigned IPos;
    1.92 +
    1.93 +/* A Pos is an index in the character window. We use short instead of int to
    1.94 + * save space in the various tables. IPos is used only for parameter passing.
    1.95 + */
    1.96 +
    1.97 +typedef struct internal_state {
    1.98 +    z_streamp strm;      /* pointer back to this zlib stream */
    1.99 +    int   status;        /* as the name implies */
   1.100 +    Bytef *pending_buf;  /* output still pending */
   1.101 +    ulg   pending_buf_size; /* size of pending_buf */
   1.102 +    Bytef *pending_out;  /* next pending byte to output to the stream */
   1.103 +    uInt   pending;      /* nb of bytes in the pending buffer */
   1.104 +    int   wrap;          /* bit 0 true for zlib, bit 1 true for gzip */
   1.105 +    gz_headerp  gzhead;  /* gzip header information to write */
   1.106 +    uInt   gzindex;      /* where in extra, name, or comment */
   1.107 +    Byte  method;        /* STORED (for zip only) or DEFLATED */
   1.108 +    int   last_flush;    /* value of flush param for previous deflate call */
   1.109 +
   1.110 +                /* used by deflate.c: */
   1.111 +
   1.112 +    uInt  w_size;        /* LZ77 window size (32K by default) */
   1.113 +    uInt  w_bits;        /* log2(w_size)  (8..16) */
   1.114 +    uInt  w_mask;        /* w_size - 1 */
   1.115 +
   1.116 +    Bytef *window;
   1.117 +    /* Sliding window. Input bytes are read into the second half of the window,
   1.118 +     * and move to the first half later to keep a dictionary of at least wSize
   1.119 +     * bytes. With this organization, matches are limited to a distance of
   1.120 +     * wSize-MAX_MATCH bytes, but this ensures that IO is always
   1.121 +     * performed with a length multiple of the block size. Also, it limits
   1.122 +     * the window size to 64K, which is quite useful on MSDOS.
   1.123 +     * To do: use the user input buffer as sliding window.
   1.124 +     */
   1.125 +
   1.126 +    ulg window_size;
   1.127 +    /* Actual size of window: 2*wSize, except when the user input buffer
   1.128 +     * is directly used as sliding window.
   1.129 +     */
   1.130 +
   1.131 +    Posf *prev;
   1.132 +    /* Link to older string with same hash index. To limit the size of this
   1.133 +     * array to 64K, this link is maintained only for the last 32K strings.
   1.134 +     * An index in this array is thus a window index modulo 32K.
   1.135 +     */
   1.136 +
   1.137 +    Posf *head; /* Heads of the hash chains or NIL. */
   1.138 +
   1.139 +    uInt  ins_h;          /* hash index of string to be inserted */
   1.140 +    uInt  hash_size;      /* number of elements in hash table */
   1.141 +    uInt  hash_bits;      /* log2(hash_size) */
   1.142 +    uInt  hash_mask;      /* hash_size-1 */
   1.143 +
   1.144 +    uInt  hash_shift;
   1.145 +    /* Number of bits by which ins_h must be shifted at each input
   1.146 +     * step. It must be such that after MIN_MATCH steps, the oldest
   1.147 +     * byte no longer takes part in the hash key, that is:
   1.148 +     *   hash_shift * MIN_MATCH >= hash_bits
   1.149 +     */
   1.150 +
   1.151 +    long block_start;
   1.152 +    /* Window position at the beginning of the current output block. Gets
   1.153 +     * negative when the window is moved backwards.
   1.154 +     */
   1.155 +
   1.156 +    uInt match_length;           /* length of best match */
   1.157 +    IPos prev_match;             /* previous match */
   1.158 +    int match_available;         /* set if previous match exists */
   1.159 +    uInt strstart;               /* start of string to insert */
   1.160 +    uInt match_start;            /* start of matching string */
   1.161 +    uInt lookahead;              /* number of valid bytes ahead in window */
   1.162 +
   1.163 +    uInt prev_length;
   1.164 +    /* Length of the best match at previous step. Matches not greater than this
   1.165 +     * are discarded. This is used in the lazy match evaluation.
   1.166 +     */
   1.167 +
   1.168 +    uInt max_chain_length;
   1.169 +    /* To speed up deflation, hash chains are never searched beyond this
   1.170 +     * length.  A higher limit improves compression ratio but degrades the
   1.171 +     * speed.
   1.172 +     */
   1.173 +
   1.174 +    uInt max_lazy_match;
   1.175 +    /* Attempt to find a better match only when the current match is strictly
   1.176 +     * smaller than this value. This mechanism is used only for compression
   1.177 +     * levels >= 4.
   1.178 +     */
   1.179 +#   define max_insert_length  max_lazy_match
   1.180 +    /* Insert new strings in the hash table only if the match length is not
   1.181 +     * greater than this length. This saves time but degrades compression.
   1.182 +     * max_insert_length is used only for compression levels <= 3.
   1.183 +     */
   1.184 +
   1.185 +    int level;    /* compression level (1..9) */
   1.186 +    int strategy; /* favor or force Huffman coding*/
   1.187 +
   1.188 +    uInt good_match;
   1.189 +    /* Use a faster search when the previous match is longer than this */
   1.190 +
   1.191 +    int nice_match; /* Stop searching when current match exceeds this */
   1.192 +
   1.193 +                /* used by trees.c: */
   1.194 +    /* Didn't use ct_data typedef below to supress compiler warning */
   1.195 +    struct ct_data_s dyn_ltree[HEAP_SIZE];   /* literal and length tree */
   1.196 +    struct ct_data_s dyn_dtree[2*D_CODES+1]; /* distance tree */
   1.197 +    struct ct_data_s bl_tree[2*BL_CODES+1];  /* Huffman tree for bit lengths */
   1.198 +
   1.199 +    struct tree_desc_s l_desc;               /* desc. for literal tree */
   1.200 +    struct tree_desc_s d_desc;               /* desc. for distance tree */
   1.201 +    struct tree_desc_s bl_desc;              /* desc. for bit length tree */
   1.202 +
   1.203 +    ush bl_count[MAX_BITS+1];
   1.204 +    /* number of codes at each bit length for an optimal tree */
   1.205 +
   1.206 +    int heap[2*L_CODES+1];      /* heap used to build the Huffman trees */
   1.207 +    int heap_len;               /* number of elements in the heap */
   1.208 +    int heap_max;               /* element of largest frequency */
   1.209 +    /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
   1.210 +     * The same heap array is used to build all trees.
   1.211 +     */
   1.212 +
   1.213 +    uch depth[2*L_CODES+1];
   1.214 +    /* Depth of each subtree used as tie breaker for trees of equal frequency
   1.215 +     */
   1.216 +
   1.217 +    uchf *l_buf;          /* buffer for literals or lengths */
   1.218 +
   1.219 +    uInt  lit_bufsize;
   1.220 +    /* Size of match buffer for literals/lengths.  There are 4 reasons for
   1.221 +     * limiting lit_bufsize to 64K:
   1.222 +     *   - frequencies can be kept in 16 bit counters
   1.223 +     *   - if compression is not successful for the first block, all input
   1.224 +     *     data is still in the window so we can still emit a stored block even
   1.225 +     *     when input comes from standard input.  (This can also be done for
   1.226 +     *     all blocks if lit_bufsize is not greater than 32K.)
   1.227 +     *   - if compression is not successful for a file smaller than 64K, we can
   1.228 +     *     even emit a stored file instead of a stored block (saving 5 bytes).
   1.229 +     *     This is applicable only for zip (not gzip or zlib).
   1.230 +     *   - creating new Huffman trees less frequently may not provide fast
   1.231 +     *     adaptation to changes in the input data statistics. (Take for
   1.232 +     *     example a binary file with poorly compressible code followed by
   1.233 +     *     a highly compressible string table.) Smaller buffer sizes give
   1.234 +     *     fast adaptation but have of course the overhead of transmitting
   1.235 +     *     trees more frequently.
   1.236 +     *   - I can't count above 4
   1.237 +     */
   1.238 +
   1.239 +    uInt last_lit;      /* running index in l_buf */
   1.240 +
   1.241 +    ushf *d_buf;
   1.242 +    /* Buffer for distances. To simplify the code, d_buf and l_buf have
   1.243 +     * the same number of elements. To use different lengths, an extra flag
   1.244 +     * array would be necessary.
   1.245 +     */
   1.246 +
   1.247 +    ulg opt_len;        /* bit length of current block with optimal trees */
   1.248 +    ulg static_len;     /* bit length of current block with static trees */
   1.249 +    uInt matches;       /* number of string matches in current block */
   1.250 +    int last_eob_len;   /* bit length of EOB code for last block */
   1.251 +
   1.252 +#ifdef DEBUG
   1.253 +    ulg compressed_len; /* total bit length of compressed file mod 2^32 */
   1.254 +    ulg bits_sent;      /* bit length of compressed data sent mod 2^32 */
   1.255 +#endif
   1.256 +
   1.257 +    ush bi_buf;
   1.258 +    /* Output buffer. bits are inserted starting at the bottom (least
   1.259 +     * significant bits).
   1.260 +     */
   1.261 +    int bi_valid;
   1.262 +    /* Number of valid bits in bi_buf.  All bits above the last valid bit
   1.263 +     * are always zero.
   1.264 +     */
   1.265 +
   1.266 +} FAR deflate_state;
   1.267 +
   1.268 +/* Output a byte on the stream.
   1.269 + * IN assertion: there is enough room in pending_buf.
   1.270 + */
   1.271 +#define put_byte(s, c) {s->pending_buf[s->pending++] = (c);}
   1.272 +
   1.273 +
   1.274 +#define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
   1.275 +/* Minimum amount of lookahead, except at the end of the input file.
   1.276 + * See deflate.c for comments about the MIN_MATCH+1.
   1.277 + */
   1.278 +
   1.279 +#define MAX_DIST(s)  ((s)->w_size-MIN_LOOKAHEAD)
   1.280 +/* In order to simplify the code, particularly on 16 bit machines, match
   1.281 + * distances are limited to MAX_DIST instead of WSIZE.
   1.282 + */
   1.283 +
   1.284 +        /* in trees.c */
   1.285 +void _tr_init         OF((deflate_state *s));
   1.286 +int  _tr_tally        OF((deflate_state *s, unsigned dist, unsigned lc));
   1.287 +void _tr_flush_block  OF((deflate_state *s, charf *buf, ulg stored_len,
   1.288 +                          int eof));
   1.289 +void _tr_align        OF((deflate_state *s));
   1.290 +void _tr_stored_block OF((deflate_state *s, charf *buf, ulg stored_len,
   1.291 +                          int eof));
   1.292 +
   1.293 +#define d_code(dist) \
   1.294 +   ((dist) < 256 ? _dist_code[dist] : _dist_code[256+((dist)>>7)])
   1.295 +/* Mapping from a distance to a distance code. dist is the distance - 1 and
   1.296 + * must not have side effects. _dist_code[256] and _dist_code[257] are never
   1.297 + * used.
   1.298 + */
   1.299 +
   1.300 +#ifndef DEBUG
   1.301 +/* Inline versions of _tr_tally for speed: */
   1.302 +
   1.303 +#if defined(GEN_TREES_H) || !defined(STDC)
   1.304 +  extern uch _length_code[];
   1.305 +  extern uch _dist_code[];
   1.306 +#else
   1.307 +  extern const uch _length_code[];
   1.308 +  extern const uch _dist_code[];
   1.309 +#endif
   1.310 +
   1.311 +# define _tr_tally_lit(s, c, flush) \
   1.312 +  { uch cc = (c); \
   1.313 +    s->d_buf[s->last_lit] = 0; \
   1.314 +    s->l_buf[s->last_lit++] = cc; \
   1.315 +    s->dyn_ltree[cc].Freq++; \
   1.316 +    flush = (s->last_lit == s->lit_bufsize-1); \
   1.317 +   }
   1.318 +# define _tr_tally_dist(s, distance, length, flush) \
   1.319 +  { uch len = (length); \
   1.320 +    ush dist = (distance); \
   1.321 +    s->d_buf[s->last_lit] = dist; \
   1.322 +    s->l_buf[s->last_lit++] = len; \
   1.323 +    dist--; \
   1.324 +    s->dyn_ltree[_length_code[len]+LITERALS+1].Freq++; \
   1.325 +    s->dyn_dtree[d_code(dist)].Freq++; \
   1.326 +    flush = (s->last_lit == s->lit_bufsize-1); \
   1.327 +  }
   1.328 +#else
   1.329 +# define _tr_tally_lit(s, c, flush) flush = _tr_tally(s, 0, c)
   1.330 +# define _tr_tally_dist(s, distance, length, flush) \
   1.331 +              flush = _tr_tally(s, distance, length)
   1.332 +#endif
   1.333 +
   1.334 +#endif /* DEFLATE_H */