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0001 #ifndef DEFUTIL_H 0002 #define DEFUTIL_H 0003 0004 #include <linux/zutil.h> 0005 0006 #define Assert(err, str) 0007 #define Trace(dummy) 0008 #define Tracev(dummy) 0009 #define Tracecv(err, dummy) 0010 #define Tracevv(dummy) 0011 0012 0013 0014 #define LENGTH_CODES 29 0015 /* number of length codes, not counting the special END_BLOCK code */ 0016 0017 #define LITERALS 256 0018 /* number of literal bytes 0..255 */ 0019 0020 #define L_CODES (LITERALS+1+LENGTH_CODES) 0021 /* number of Literal or Length codes, including the END_BLOCK code */ 0022 0023 #define D_CODES 30 0024 /* number of distance codes */ 0025 0026 #define BL_CODES 19 0027 /* number of codes used to transfer the bit lengths */ 0028 0029 #define HEAP_SIZE (2*L_CODES+1) 0030 /* maximum heap size */ 0031 0032 #define MAX_BITS 15 0033 /* All codes must not exceed MAX_BITS bits */ 0034 0035 #define INIT_STATE 42 0036 #define BUSY_STATE 113 0037 #define FINISH_STATE 666 0038 /* Stream status */ 0039 0040 0041 /* Data structure describing a single value and its code string. */ 0042 typedef struct ct_data_s { 0043 union { 0044 ush freq; /* frequency count */ 0045 ush code; /* bit string */ 0046 } fc; 0047 union { 0048 ush dad; /* father node in Huffman tree */ 0049 ush len; /* length of bit string */ 0050 } dl; 0051 } ct_data; 0052 0053 #define Freq fc.freq 0054 #define Code fc.code 0055 #define Dad dl.dad 0056 #define Len dl.len 0057 0058 typedef struct static_tree_desc_s static_tree_desc; 0059 0060 typedef struct tree_desc_s { 0061 ct_data *dyn_tree; /* the dynamic tree */ 0062 int max_code; /* largest code with non zero frequency */ 0063 static_tree_desc *stat_desc; /* the corresponding static tree */ 0064 } tree_desc; 0065 0066 typedef ush Pos; 0067 typedef unsigned IPos; 0068 0069 /* A Pos is an index in the character window. We use short instead of int to 0070 * save space in the various tables. IPos is used only for parameter passing. 0071 */ 0072 0073 typedef struct deflate_state { 0074 z_streamp strm; /* pointer back to this zlib stream */ 0075 int status; /* as the name implies */ 0076 Byte *pending_buf; /* output still pending */ 0077 ulg pending_buf_size; /* size of pending_buf */ 0078 Byte *pending_out; /* next pending byte to output to the stream */ 0079 int pending; /* nb of bytes in the pending buffer */ 0080 int noheader; /* suppress zlib header and adler32 */ 0081 Byte data_type; /* UNKNOWN, BINARY or ASCII */ 0082 Byte method; /* STORED (for zip only) or DEFLATED */ 0083 int last_flush; /* value of flush param for previous deflate call */ 0084 0085 /* used by deflate.c: */ 0086 0087 uInt w_size; /* LZ77 window size (32K by default) */ 0088 uInt w_bits; /* log2(w_size) (8..16) */ 0089 uInt w_mask; /* w_size - 1 */ 0090 0091 Byte *window; 0092 /* Sliding window. Input bytes are read into the second half of the window, 0093 * and move to the first half later to keep a dictionary of at least wSize 0094 * bytes. With this organization, matches are limited to a distance of 0095 * wSize-MAX_MATCH bytes, but this ensures that IO is always 0096 * performed with a length multiple of the block size. Also, it limits 0097 * the window size to 64K, which is quite useful on MSDOS. 0098 * To do: use the user input buffer as sliding window. 0099 */ 0100 0101 ulg window_size; 0102 /* Actual size of window: 2*wSize, except when the user input buffer 0103 * is directly used as sliding window. 0104 */ 0105 0106 Pos *prev; 0107 /* Link to older string with same hash index. To limit the size of this 0108 * array to 64K, this link is maintained only for the last 32K strings. 0109 * An index in this array is thus a window index modulo 32K. 0110 */ 0111 0112 Pos *head; /* Heads of the hash chains or NIL. */ 0113 0114 uInt ins_h; /* hash index of string to be inserted */ 0115 uInt hash_size; /* number of elements in hash table */ 0116 uInt hash_bits; /* log2(hash_size) */ 0117 uInt hash_mask; /* hash_size-1 */ 0118 0119 uInt hash_shift; 0120 /* Number of bits by which ins_h must be shifted at each input 0121 * step. It must be such that after MIN_MATCH steps, the oldest 0122 * byte no longer takes part in the hash key, that is: 0123 * hash_shift * MIN_MATCH >= hash_bits 0124 */ 0125 0126 long block_start; 0127 /* Window position at the beginning of the current output block. Gets 0128 * negative when the window is moved backwards. 0129 */ 0130 0131 uInt match_length; /* length of best match */ 0132 IPos prev_match; /* previous match */ 0133 int match_available; /* set if previous match exists */ 0134 uInt strstart; /* start of string to insert */ 0135 uInt match_start; /* start of matching string */ 0136 uInt lookahead; /* number of valid bytes ahead in window */ 0137 0138 uInt prev_length; 0139 /* Length of the best match at previous step. Matches not greater than this 0140 * are discarded. This is used in the lazy match evaluation. 0141 */ 0142 0143 uInt max_chain_length; 0144 /* To speed up deflation, hash chains are never searched beyond this 0145 * length. A higher limit improves compression ratio but degrades the 0146 * speed. 0147 */ 0148 0149 uInt max_lazy_match; 0150 /* Attempt to find a better match only when the current match is strictly 0151 * smaller than this value. This mechanism is used only for compression 0152 * levels >= 4. 0153 */ 0154 # define max_insert_length max_lazy_match 0155 /* Insert new strings in the hash table only if the match length is not 0156 * greater than this length. This saves time but degrades compression. 0157 * max_insert_length is used only for compression levels <= 3. 0158 */ 0159 0160 int level; /* compression level (1..9) */ 0161 int strategy; /* favor or force Huffman coding*/ 0162 0163 uInt good_match; 0164 /* Use a faster search when the previous match is longer than this */ 0165 0166 int nice_match; /* Stop searching when current match exceeds this */ 0167 0168 /* used by trees.c: */ 0169 /* Didn't use ct_data typedef below to suppress compiler warning */ 0170 struct ct_data_s dyn_ltree[HEAP_SIZE]; /* literal and length tree */ 0171 struct ct_data_s dyn_dtree[2*D_CODES+1]; /* distance tree */ 0172 struct ct_data_s bl_tree[2*BL_CODES+1]; /* Huffman tree for bit lengths */ 0173 0174 struct tree_desc_s l_desc; /* desc. for literal tree */ 0175 struct tree_desc_s d_desc; /* desc. for distance tree */ 0176 struct tree_desc_s bl_desc; /* desc. for bit length tree */ 0177 0178 ush bl_count[MAX_BITS+1]; 0179 /* number of codes at each bit length for an optimal tree */ 0180 0181 int heap[2*L_CODES+1]; /* heap used to build the Huffman trees */ 0182 int heap_len; /* number of elements in the heap */ 0183 int heap_max; /* element of largest frequency */ 0184 /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used. 0185 * The same heap array is used to build all trees. 0186 */ 0187 0188 uch depth[2*L_CODES+1]; 0189 /* Depth of each subtree used as tie breaker for trees of equal frequency 0190 */ 0191 0192 uch *l_buf; /* buffer for literals or lengths */ 0193 0194 uInt lit_bufsize; 0195 /* Size of match buffer for literals/lengths. There are 4 reasons for 0196 * limiting lit_bufsize to 64K: 0197 * - frequencies can be kept in 16 bit counters 0198 * - if compression is not successful for the first block, all input 0199 * data is still in the window so we can still emit a stored block even 0200 * when input comes from standard input. (This can also be done for 0201 * all blocks if lit_bufsize is not greater than 32K.) 0202 * - if compression is not successful for a file smaller than 64K, we can 0203 * even emit a stored file instead of a stored block (saving 5 bytes). 0204 * This is applicable only for zip (not gzip or zlib). 0205 * - creating new Huffman trees less frequently may not provide fast 0206 * adaptation to changes in the input data statistics. (Take for 0207 * example a binary file with poorly compressible code followed by 0208 * a highly compressible string table.) Smaller buffer sizes give 0209 * fast adaptation but have of course the overhead of transmitting 0210 * trees more frequently. 0211 * - I can't count above 4 0212 */ 0213 0214 uInt last_lit; /* running index in l_buf */ 0215 0216 ush *d_buf; 0217 /* Buffer for distances. To simplify the code, d_buf and l_buf have 0218 * the same number of elements. To use different lengths, an extra flag 0219 * array would be necessary. 0220 */ 0221 0222 ulg opt_len; /* bit length of current block with optimal trees */ 0223 ulg static_len; /* bit length of current block with static trees */ 0224 ulg compressed_len; /* total bit length of compressed file */ 0225 uInt matches; /* number of string matches in current block */ 0226 int last_eob_len; /* bit length of EOB code for last block */ 0227 0228 #ifdef DEBUG_ZLIB 0229 ulg bits_sent; /* bit length of the compressed data */ 0230 #endif 0231 0232 ush bi_buf; 0233 /* Output buffer. bits are inserted starting at the bottom (least 0234 * significant bits). 0235 */ 0236 int bi_valid; 0237 /* Number of valid bits in bi_buf. All bits above the last valid bit 0238 * are always zero. 0239 */ 0240 0241 } deflate_state; 0242 0243 #ifdef CONFIG_ZLIB_DFLTCC 0244 #define zlib_deflate_window_memsize(windowBits) \ 0245 (2 * (1 << (windowBits)) * sizeof(Byte) + PAGE_SIZE) 0246 #else 0247 #define zlib_deflate_window_memsize(windowBits) \ 0248 (2 * (1 << (windowBits)) * sizeof(Byte)) 0249 #endif 0250 #define zlib_deflate_prev_memsize(windowBits) \ 0251 ((1 << (windowBits)) * sizeof(Pos)) 0252 #define zlib_deflate_head_memsize(memLevel) \ 0253 ((1 << ((memLevel)+7)) * sizeof(Pos)) 0254 #define zlib_deflate_overlay_memsize(memLevel) \ 0255 ((1 << ((memLevel)+6)) * (sizeof(ush)+2)) 0256 0257 /* Output a byte on the stream. 0258 * IN assertion: there is enough room in pending_buf. 0259 */ 0260 #define put_byte(s, c) {s->pending_buf[s->pending++] = (c);} 0261 0262 0263 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1) 0264 /* Minimum amount of lookahead, except at the end of the input file. 0265 * See deflate.c for comments about the MIN_MATCH+1. 0266 */ 0267 0268 #define MAX_DIST(s) ((s)->w_size-MIN_LOOKAHEAD) 0269 /* In order to simplify the code, particularly on 16 bit machines, match 0270 * distances are limited to MAX_DIST instead of WSIZE. 0271 */ 0272 0273 /* in trees.c */ 0274 void zlib_tr_init (deflate_state *s); 0275 int zlib_tr_tally (deflate_state *s, unsigned dist, unsigned lc); 0276 ulg zlib_tr_flush_block (deflate_state *s, char *buf, ulg stored_len, 0277 int eof); 0278 void zlib_tr_align (deflate_state *s); 0279 void zlib_tr_stored_block (deflate_state *s, char *buf, ulg stored_len, 0280 int eof); 0281 void zlib_tr_stored_type_only (deflate_state *); 0282 0283 0284 /* =========================================================================== 0285 * Output a short LSB first on the stream. 0286 * IN assertion: there is enough room in pendingBuf. 0287 */ 0288 #define put_short(s, w) { \ 0289 put_byte(s, (uch)((w) & 0xff)); \ 0290 put_byte(s, (uch)((ush)(w) >> 8)); \ 0291 } 0292 0293 /* =========================================================================== 0294 * Reverse the first len bits of a code, using straightforward code (a faster 0295 * method would use a table) 0296 * IN assertion: 1 <= len <= 15 0297 */ 0298 static inline unsigned bi_reverse( 0299 unsigned code, /* the value to invert */ 0300 int len /* its bit length */ 0301 ) 0302 { 0303 register unsigned res = 0; 0304 do { 0305 res |= code & 1; 0306 code >>= 1, res <<= 1; 0307 } while (--len > 0); 0308 return res >> 1; 0309 } 0310 0311 /* =========================================================================== 0312 * Flush the bit buffer, keeping at most 7 bits in it. 0313 */ 0314 static inline void bi_flush(deflate_state *s) 0315 { 0316 if (s->bi_valid == 16) { 0317 put_short(s, s->bi_buf); 0318 s->bi_buf = 0; 0319 s->bi_valid = 0; 0320 } else if (s->bi_valid >= 8) { 0321 put_byte(s, (Byte)s->bi_buf); 0322 s->bi_buf >>= 8; 0323 s->bi_valid -= 8; 0324 } 0325 } 0326 0327 /* =========================================================================== 0328 * Flush the bit buffer and align the output on a byte boundary 0329 */ 0330 static inline void bi_windup(deflate_state *s) 0331 { 0332 if (s->bi_valid > 8) { 0333 put_short(s, s->bi_buf); 0334 } else if (s->bi_valid > 0) { 0335 put_byte(s, (Byte)s->bi_buf); 0336 } 0337 s->bi_buf = 0; 0338 s->bi_valid = 0; 0339 #ifdef DEBUG_ZLIB 0340 s->bits_sent = (s->bits_sent+7) & ~7; 0341 #endif 0342 } 0343 0344 typedef enum { 0345 need_more, /* block not completed, need more input or more output */ 0346 block_done, /* block flush performed */ 0347 finish_started, /* finish started, need only more output at next deflate */ 0348 finish_done /* finish done, accept no more input or output */ 0349 } block_state; 0350 0351 #define Buf_size (8 * 2*sizeof(char)) 0352 /* Number of bits used within bi_buf. (bi_buf might be implemented on 0353 * more than 16 bits on some systems.) 0354 */ 0355 0356 /* =========================================================================== 0357 * Send a value on a given number of bits. 0358 * IN assertion: length <= 16 and value fits in length bits. 0359 */ 0360 #ifdef DEBUG_ZLIB 0361 static void send_bits (deflate_state *s, int value, int length); 0362 0363 static void send_bits( 0364 deflate_state *s, 0365 int value, /* value to send */ 0366 int length /* number of bits */ 0367 ) 0368 { 0369 Tracevv((stderr," l %2d v %4x ", length, value)); 0370 Assert(length > 0 && length <= 15, "invalid length"); 0371 s->bits_sent += (ulg)length; 0372 0373 /* If not enough room in bi_buf, use (valid) bits from bi_buf and 0374 * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid)) 0375 * unused bits in value. 0376 */ 0377 if (s->bi_valid > (int)Buf_size - length) { 0378 s->bi_buf |= (value << s->bi_valid); 0379 put_short(s, s->bi_buf); 0380 s->bi_buf = (ush)value >> (Buf_size - s->bi_valid); 0381 s->bi_valid += length - Buf_size; 0382 } else { 0383 s->bi_buf |= value << s->bi_valid; 0384 s->bi_valid += length; 0385 } 0386 } 0387 #else /* !DEBUG_ZLIB */ 0388 0389 #define send_bits(s, value, length) \ 0390 { int len = length;\ 0391 if (s->bi_valid > (int)Buf_size - len) {\ 0392 int val = value;\ 0393 s->bi_buf |= (val << s->bi_valid);\ 0394 put_short(s, s->bi_buf);\ 0395 s->bi_buf = (ush)val >> (Buf_size - s->bi_valid);\ 0396 s->bi_valid += len - Buf_size;\ 0397 } else {\ 0398 s->bi_buf |= (value) << s->bi_valid;\ 0399 s->bi_valid += len;\ 0400 }\ 0401 } 0402 #endif /* DEBUG_ZLIB */ 0403 0404 static inline void zlib_tr_send_bits( 0405 deflate_state *s, 0406 int value, 0407 int length 0408 ) 0409 { 0410 send_bits(s, value, length); 0411 } 0412 0413 /* ========================================================================= 0414 * Flush as much pending output as possible. All deflate() output goes 0415 * through this function so some applications may wish to modify it 0416 * to avoid allocating a large strm->next_out buffer and copying into it. 0417 * (See also read_buf()). 0418 */ 0419 static inline void flush_pending( 0420 z_streamp strm 0421 ) 0422 { 0423 deflate_state *s = (deflate_state *) strm->state; 0424 unsigned len = s->pending; 0425 0426 if (len > strm->avail_out) len = strm->avail_out; 0427 if (len == 0) return; 0428 0429 if (strm->next_out != NULL) { 0430 memcpy(strm->next_out, s->pending_out, len); 0431 strm->next_out += len; 0432 } 0433 s->pending_out += len; 0434 strm->total_out += len; 0435 strm->avail_out -= len; 0436 s->pending -= len; 0437 if (s->pending == 0) { 0438 s->pending_out = s->pending_buf; 0439 } 0440 } 0441 #endif /* DEFUTIL_H */
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