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 */ bi_reverse(unsigned code,int len)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 */ bi_flush(deflate_state * s)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 */ bi_windup(deflate_state * s)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 send_bits(deflate_state * s,int value,int length)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 zlib_tr_send_bits(deflate_state * s,int value,int length)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 */ flush_pending(z_streamp strm)419 static inline void flush_pending( 420 z_streamp strm 421 ) 422 { 423 unsigned len; 424 deflate_state *s = (deflate_state *) strm->state; 425 426 bi_flush(s); 427 len = s->pending; 428 if (len > strm->avail_out) len = strm->avail_out; 429 if (len == 0) return; 430 431 if (strm->next_out != NULL) { 432 memcpy(strm->next_out, s->pending_out, len); 433 strm->next_out += len; 434 } 435 s->pending_out += len; 436 strm->total_out += len; 437 strm->avail_out -= len; 438 s->pending -= len; 439 if (s->pending == 0) { 440 s->pending_out = s->pending_buf; 441 } 442 } 443 #endif /* DEFUTIL_H */ 444