lib/zlib_deflate/defutil.h

   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. */
  42 typedef 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
  58 typedef struct static_tree_desc_s  static_tree_desc;
  59
  60 typedef 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
  66 typedef ush Pos;
  67 typedef 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
  73 typedef 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 */
 274 void zlib_tr_init         (deflate_state *s);
 275 int  zlib_tr_tally        (deflate_state *s, unsigned dist, unsigned lc);
 276 ulg  zlib_tr_flush_block  (deflate_state *s, char *buf, ulg stored_len,
 277                            int eof);
 278 void zlib_tr_align        (deflate_state *s);
 279 void zlib_tr_stored_block (deflate_state *s, char *buf, ulg stored_len,
 280                            int eof);
 281 void 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  */
 298 static 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  */
 314 static 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  */
 330 static 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
 344 typedef 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
 361 static void send_bits      (deflate_state *s, int value, int length);
 362
 363 static 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
 404 static 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  */
 419 static 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 */