linux/lib/zlib_deflate/defutil.h
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   1#ifndef DEFUTIL_H
   2#define DEFUTIL_H
   3
   4#include <linux/zutil.h>
   5
   6#define Assert(err, str) 
   7#define Trace(dummy) 
   8#define Tracev(dummy) 
   9#define Tracecv(err, dummy) 
  10#define Tracevv(dummy) 
  11
  12
  13
  14#define LENGTH_CODES 29
  15/* number of length codes, not counting the special END_BLOCK code */
  16
  17#define LITERALS  256
  18/* number of literal bytes 0..255 */
  19
  20#define L_CODES (LITERALS+1+LENGTH_CODES)
  21/* number of Literal or Length codes, including the END_BLOCK code */
  22
  23#define D_CODES   30
  24/* number of distance codes */
  25
  26#define BL_CODES  19
  27/* number of codes used to transfer the bit lengths */
  28
  29#define HEAP_SIZE (2*L_CODES+1)
  30/* maximum heap size */
  31
  32#define MAX_BITS 15
  33/* All codes must not exceed MAX_BITS bits */
  34
  35#define INIT_STATE    42
  36#define BUSY_STATE   113
  37#define FINISH_STATE 666
  38/* Stream status */
  39
  40
  41/* Data structure describing a single value and its code string. */
  42typedef struct ct_data_s {
  43    union {
  44        ush  freq;       /* frequency count */
  45        ush  code;       /* bit string */
  46    } fc;
  47    union {
  48        ush  dad;        /* father node in Huffman tree */
  49        ush  len;        /* length of bit string */
  50    } dl;
  51} ct_data;
  52
  53#define Freq fc.freq
  54#define Code fc.code
  55#define Dad  dl.dad
  56#define Len  dl.len
  57
  58typedef struct static_tree_desc_s  static_tree_desc;
  59
  60typedef struct tree_desc_s {
  61    ct_data *dyn_tree;           /* the dynamic tree */
  62    int     max_code;            /* largest code with non zero frequency */
  63    static_tree_desc *stat_desc; /* the corresponding static tree */
  64} tree_desc;
  65
  66typedef ush Pos;
  67typedef unsigned IPos;
  68
  69/* A Pos is an index in the character window. We use short instead of int to
  70 * save space in the various tables. IPos is used only for parameter passing.
  71 */
  72
  73typedef struct deflate_state {
  74    z_streamp strm;      /* pointer back to this zlib stream */
  75    int   status;        /* as the name implies */
  76    Byte *pending_buf;   /* output still pending */
  77    ulg   pending_buf_size; /* size of pending_buf */
  78    Byte *pending_out;   /* next pending byte to output to the stream */
  79    int   pending;       /* nb of bytes in the pending buffer */
  80    int   noheader;      /* suppress zlib header and adler32 */
  81    Byte  data_type;     /* UNKNOWN, BINARY or ASCII */
  82    Byte  method;        /* STORED (for zip only) or DEFLATED */
  83    int   last_flush;    /* value of flush param for previous deflate call */
  84
  85                /* used by deflate.c: */
  86
  87    uInt  w_size;        /* LZ77 window size (32K by default) */
  88    uInt  w_bits;        /* log2(w_size)  (8..16) */
  89    uInt  w_mask;        /* w_size - 1 */
  90
  91    Byte *window;
  92    /* Sliding window. Input bytes are read into the second half of the window,
  93     * and move to the first half later to keep a dictionary of at least wSize
  94     * bytes. With this organization, matches are limited to a distance of
  95     * wSize-MAX_MATCH bytes, but this ensures that IO is always
  96     * performed with a length multiple of the block size. Also, it limits
  97     * the window size to 64K, which is quite useful on MSDOS.
  98     * To do: use the user input buffer as sliding window.
  99     */
 100
 101    ulg window_size;
 102    /* Actual size of window: 2*wSize, except when the user input buffer
 103     * is directly used as sliding window.
 104     */
 105
 106    Pos *prev;
 107    /* Link to older string with same hash index. To limit the size of this
 108     * array to 64K, this link is maintained only for the last 32K strings.
 109     * An index in this array is thus a window index modulo 32K.
 110     */
 111
 112    Pos *head; /* Heads of the hash chains or NIL. */
 113
 114    uInt  ins_h;          /* hash index of string to be inserted */
 115    uInt  hash_size;      /* number of elements in hash table */
 116    uInt  hash_bits;      /* log2(hash_size) */
 117    uInt  hash_mask;      /* hash_size-1 */
 118
 119    uInt  hash_shift;
 120    /* Number of bits by which ins_h must be shifted at each input
 121     * step. It must be such that after MIN_MATCH steps, the oldest
 122     * byte no longer takes part in the hash key, that is:
 123     *   hash_shift * MIN_MATCH >= hash_bits
 124     */
 125
 126    long block_start;
 127    /* Window position at the beginning of the current output block. Gets
 128     * negative when the window is moved backwards.
 129     */
 130
 131    uInt match_length;           /* length of best match */
 132    IPos prev_match;             /* previous match */
 133    int match_available;         /* set if previous match exists */
 134    uInt strstart;               /* start of string to insert */
 135    uInt match_start;            /* start of matching string */
 136    uInt lookahead;              /* number of valid bytes ahead in window */
 137
 138    uInt prev_length;
 139    /* Length of the best match at previous step. Matches not greater than this
 140     * are discarded. This is used in the lazy match evaluation.
 141     */
 142
 143    uInt max_chain_length;
 144    /* To speed up deflation, hash chains are never searched beyond this
 145     * length.  A higher limit improves compression ratio but degrades the
 146     * speed.
 147     */
 148
 149    uInt max_lazy_match;
 150    /* Attempt to find a better match only when the current match is strictly
 151     * smaller than this value. This mechanism is used only for compression
 152     * levels >= 4.
 153     */
 154#   define max_insert_length  max_lazy_match
 155    /* Insert new strings in the hash table only if the match length is not
 156     * greater than this length. This saves time but degrades compression.
 157     * max_insert_length is used only for compression levels <= 3.
 158     */
 159
 160    int level;    /* compression level (1..9) */
 161    int strategy; /* favor or force Huffman coding*/
 162
 163    uInt good_match;
 164    /* Use a faster search when the previous match is longer than this */
 165
 166    int nice_match; /* Stop searching when current match exceeds this */
 167
 168                /* used by trees.c: */
 169    /* Didn't use ct_data typedef below to suppress compiler warning */
 170    struct ct_data_s dyn_ltree[HEAP_SIZE];   /* literal and length tree */
 171    struct ct_data_s dyn_dtree[2*D_CODES+1]; /* distance tree */
 172    struct ct_data_s bl_tree[2*BL_CODES+1];  /* Huffman tree for bit lengths */
 173
 174    struct tree_desc_s l_desc;               /* desc. for literal tree */
 175    struct tree_desc_s d_desc;               /* desc. for distance tree */
 176    struct tree_desc_s bl_desc;              /* desc. for bit length tree */
 177
 178    ush bl_count[MAX_BITS+1];
 179    /* number of codes at each bit length for an optimal tree */
 180
 181    int heap[2*L_CODES+1];      /* heap used to build the Huffman trees */
 182    int heap_len;               /* number of elements in the heap */
 183    int heap_max;               /* element of largest frequency */
 184    /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
 185     * The same heap array is used to build all trees.
 186     */
 187
 188    uch depth[2*L_CODES+1];
 189    /* Depth of each subtree used as tie breaker for trees of equal frequency
 190     */
 191
 192    uch *l_buf;          /* buffer for literals or lengths */
 193
 194    uInt  lit_bufsize;
 195    /* Size of match buffer for literals/lengths.  There are 4 reasons for
 196     * limiting lit_bufsize to 64K:
 197     *   - frequencies can be kept in 16 bit counters
 198     *   - if compression is not successful for the first block, all input
 199     *     data is still in the window so we can still emit a stored block even
 200     *     when input comes from standard input.  (This can also be done for
 201     *     all blocks if lit_bufsize is not greater than 32K.)
 202     *   - if compression is not successful for a file smaller than 64K, we can
 203     *     even emit a stored file instead of a stored block (saving 5 bytes).
 204     *     This is applicable only for zip (not gzip or zlib).
 205     *   - creating new Huffman trees less frequently may not provide fast
 206     *     adaptation to changes in the input data statistics. (Take for
 207     *     example a binary file with poorly compressible code followed by
 208     *     a highly compressible string table.) Smaller buffer sizes give
 209     *     fast adaptation but have of course the overhead of transmitting
 210     *     trees more frequently.
 211     *   - I can't count above 4
 212     */
 213
 214    uInt last_lit;      /* running index in l_buf */
 215
 216    ush *d_buf;
 217    /* Buffer for distances. To simplify the code, d_buf and l_buf have
 218     * the same number of elements. To use different lengths, an extra flag
 219     * array would be necessary.
 220     */
 221
 222    ulg opt_len;        /* bit length of current block with optimal trees */
 223    ulg static_len;     /* bit length of current block with static trees */
 224    ulg compressed_len; /* total bit length of compressed file */
 225    uInt matches;       /* number of string matches in current block */
 226    int last_eob_len;   /* bit length of EOB code for last block */
 227
 228#ifdef DEBUG_ZLIB
 229    ulg bits_sent;      /* bit length of the compressed data */
 230#endif
 231
 232    ush bi_buf;
 233    /* Output buffer. bits are inserted starting at the bottom (least
 234     * significant bits).
 235     */
 236    int bi_valid;
 237    /* Number of valid bits in bi_buf.  All bits above the last valid bit
 238     * are always zero.
 239     */
 240
 241} deflate_state;
 242
 243#ifdef CONFIG_ZLIB_DFLTCC
 244#define zlib_deflate_window_memsize(windowBits) \
 245        (2 * (1 << (windowBits)) * sizeof(Byte) + PAGE_SIZE)
 246#else
 247#define zlib_deflate_window_memsize(windowBits) \
 248        (2 * (1 << (windowBits)) * sizeof(Byte))
 249#endif
 250#define zlib_deflate_prev_memsize(windowBits) \
 251        ((1 << (windowBits)) * sizeof(Pos))
 252#define zlib_deflate_head_memsize(memLevel) \
 253        ((1 << ((memLevel)+7)) * sizeof(Pos))
 254#define zlib_deflate_overlay_memsize(memLevel) \
 255        ((1 << ((memLevel)+6)) * (sizeof(ush)+2))
 256
 257/* Output a byte on the stream.
 258 * IN assertion: there is enough room in pending_buf.
 259 */
 260#define put_byte(s, c) {s->pending_buf[s->pending++] = (c);}
 261
 262
 263#define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
 264/* Minimum amount of lookahead, except at the end of the input file.
 265 * See deflate.c for comments about the MIN_MATCH+1.
 266 */
 267
 268#define MAX_DIST(s)  ((s)->w_size-MIN_LOOKAHEAD)
 269/* In order to simplify the code, particularly on 16 bit machines, match
 270 * distances are limited to MAX_DIST instead of WSIZE.
 271 */
 272
 273        /* in trees.c */
 274void zlib_tr_init         (deflate_state *s);
 275int  zlib_tr_tally        (deflate_state *s, unsigned dist, unsigned lc);
 276ulg  zlib_tr_flush_block  (deflate_state *s, char *buf, ulg stored_len,
 277                           int eof);
 278void zlib_tr_align        (deflate_state *s);
 279void zlib_tr_stored_block (deflate_state *s, char *buf, ulg stored_len,
 280                           int eof);
 281void zlib_tr_stored_type_only (deflate_state *);
 282
 283
 284/* ===========================================================================
 285 * Output a short LSB first on the stream.
 286 * IN assertion: there is enough room in pendingBuf.
 287 */
 288#define put_short(s, w) { \
 289    put_byte(s, (uch)((w) & 0xff)); \
 290    put_byte(s, (uch)((ush)(w) >> 8)); \
 291}
 292
 293/* ===========================================================================
 294 * Reverse the first len bits of a code, using straightforward code (a faster
 295 * method would use a table)
 296 * IN assertion: 1 <= len <= 15
 297 */
 298static inline unsigned  bi_reverse(
 299    unsigned code, /* the value to invert */
 300    int len        /* its bit length */
 301)
 302{
 303    register unsigned res = 0;
 304    do {
 305        res |= code & 1;
 306        code >>= 1, res <<= 1;
 307    } while (--len > 0);
 308    return res >> 1;
 309}
 310
 311/* ===========================================================================
 312 * Flush the bit buffer, keeping at most 7 bits in it.
 313 */
 314static inline void bi_flush(deflate_state *s)
 315{
 316    if (s->bi_valid == 16) {
 317        put_short(s, s->bi_buf);
 318        s->bi_buf = 0;
 319        s->bi_valid = 0;
 320    } else if (s->bi_valid >= 8) {
 321        put_byte(s, (Byte)s->bi_buf);
 322        s->bi_buf >>= 8;
 323        s->bi_valid -= 8;
 324    }
 325}
 326
 327/* ===========================================================================
 328 * Flush the bit buffer and align the output on a byte boundary
 329 */
 330static inline void bi_windup(deflate_state *s)
 331{
 332    if (s->bi_valid > 8) {
 333        put_short(s, s->bi_buf);
 334    } else if (s->bi_valid > 0) {
 335        put_byte(s, (Byte)s->bi_buf);
 336    }
 337    s->bi_buf = 0;
 338    s->bi_valid = 0;
 339#ifdef DEBUG_ZLIB
 340    s->bits_sent = (s->bits_sent+7) & ~7;
 341#endif
 342}
 343
 344typedef enum {
 345    need_more,      /* block not completed, need more input or more output */
 346    block_done,     /* block flush performed */
 347    finish_started, /* finish started, need only more output at next deflate */
 348    finish_done     /* finish done, accept no more input or output */
 349} block_state;
 350
 351#define Buf_size (8 * 2*sizeof(char))
 352/* Number of bits used within bi_buf. (bi_buf might be implemented on
 353 * more than 16 bits on some systems.)
 354 */
 355
 356/* ===========================================================================
 357 * Send a value on a given number of bits.
 358 * IN assertion: length <= 16 and value fits in length bits.
 359 */
 360#ifdef DEBUG_ZLIB
 361static void send_bits      (deflate_state *s, int value, int length);
 362
 363static void send_bits(
 364    deflate_state *s,
 365    int value,  /* value to send */
 366    int length  /* number of bits */
 367)
 368{
 369    Tracevv((stderr," l %2d v %4x ", length, value));
 370    Assert(length > 0 && length <= 15, "invalid length");
 371    s->bits_sent += (ulg)length;
 372
 373    /* If not enough room in bi_buf, use (valid) bits from bi_buf and
 374     * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid))
 375     * unused bits in value.
 376     */
 377    if (s->bi_valid > (int)Buf_size - length) {
 378        s->bi_buf |= (value << s->bi_valid);
 379        put_short(s, s->bi_buf);
 380        s->bi_buf = (ush)value >> (Buf_size - s->bi_valid);
 381        s->bi_valid += length - Buf_size;
 382    } else {
 383        s->bi_buf |= value << s->bi_valid;
 384        s->bi_valid += length;
 385    }
 386}
 387#else /* !DEBUG_ZLIB */
 388
 389#define send_bits(s, value, length) \
 390{ int len = length;\
 391  if (s->bi_valid > (int)Buf_size - len) {\
 392    int val = value;\
 393    s->bi_buf |= (val << s->bi_valid);\
 394    put_short(s, s->bi_buf);\
 395    s->bi_buf = (ush)val >> (Buf_size - s->bi_valid);\
 396    s->bi_valid += len - Buf_size;\
 397  } else {\
 398    s->bi_buf |= (value) << s->bi_valid;\
 399    s->bi_valid += len;\
 400  }\
 401}
 402#endif /* DEBUG_ZLIB */
 403
 404static inline void zlib_tr_send_bits(
 405    deflate_state *s,
 406    int value,
 407    int length
 408)
 409{
 410    send_bits(s, value, length);
 411}
 412
 413/* =========================================================================
 414 * Flush as much pending output as possible. All deflate() output goes
 415 * through this function so some applications may wish to modify it
 416 * to avoid allocating a large strm->next_out buffer and copying into it.
 417 * (See also read_buf()).
 418 */
 419static inline void flush_pending(
 420        z_streamp strm
 421)
 422{
 423    deflate_state *s = (deflate_state *) strm->state;
 424    unsigned len = s->pending;
 425
 426    if (len > strm->avail_out) len = strm->avail_out;
 427    if (len == 0) return;
 428
 429    if (strm->next_out != NULL) {
 430        memcpy(strm->next_out, s->pending_out, len);
 431        strm->next_out += len;
 432    }
 433    s->pending_out += len;
 434    strm->total_out += len;
 435    strm->avail_out  -= len;
 436    s->pending -= len;
 437    if (s->pending == 0) {
 438        s->pending_out = s->pending_buf;
 439    }
 440}
 441#endif /* DEFUTIL_H */
 442