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1#ifndef DEFUTIL_H2#define DEFUTIL_H3 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 2915/* number of length codes, not counting the special END_BLOCK code */16 17#define LITERALS 25618/* 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 3024/* number of distance codes */25 26#define BL_CODES 1927/* 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 1533/* All codes must not exceed MAX_BITS bits */34 35#define INIT_STATE 4236#define BUSY_STATE 11337#define FINISH_STATE 66638/* 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.freq54#define Code fc.code55#define Dad dl.dad56#define Len dl.len57 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 to70 * 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 wSize94 * bytes. With this organization, matches are limited to a distance of95 * wSize-MAX_MATCH bytes, but this ensures that IO is always96 * performed with a length multiple of the block size. Also, it limits97 * 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 buffer103 * 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 this108 * 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 input121 * step. It must be such that after MIN_MATCH steps, the oldest122 * byte no longer takes part in the hash key, that is:123 * hash_shift * MIN_MATCH >= hash_bits124 */125 126 long block_start;127 /* Window position at the beginning of the current output block. Gets128 * 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 this140 * 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 this145 * length. A higher limit improves compression ratio but degrades the146 * speed.147 */148 149 uInt max_lazy_match;150 /* Attempt to find a better match only when the current match is strictly151 * smaller than this value. This mechanism is used only for compression152 * levels >= 4.153 */154# define max_insert_length max_lazy_match155 /* Insert new strings in the hash table only if the match length is not156 * 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 frequency190 */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 for196 * limiting lit_bufsize to 64K:197 * - frequencies can be kept in 16 bit counters198 * - if compression is not successful for the first block, all input199 * data is still in the window so we can still emit a stored block even200 * when input comes from standard input. (This can also be done for201 * all blocks if lit_bufsize is not greater than 32K.)202 * - if compression is not successful for a file smaller than 64K, we can203 * 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 fast206 * adaptation to changes in the input data statistics. (Take for207 * example a binary file with poorly compressible code followed by208 * a highly compressible string table.) Smaller buffer sizes give209 * fast adaptation but have of course the overhead of transmitting210 * trees more frequently.211 * - I can't count above 4212 */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 have218 * the same number of elements. To use different lengths, an extra flag219 * 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_ZLIB229 ulg bits_sent; /* bit length of the compressed data */230#endif231 232 ush bi_buf;233 /* Output buffer. bits are inserted starting at the bottom (least234 * significant bits).235 */236 int bi_valid;237 /* Number of valid bits in bi_buf. All bits above the last valid bit238 * are always zero.239 */240 241} deflate_state;242 243#ifdef CONFIG_ZLIB_DFLTCC244#define zlib_deflate_window_memsize(windowBits) \245 (2 * (1 << (windowBits)) * sizeof(Byte) + PAGE_SIZE)246#else247#define zlib_deflate_window_memsize(windowBits) \248 (2 * (1 << (windowBits)) * sizeof(Byte))249#endif250#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, match270 * 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 faster295 * method would use a table)296 * IN assertion: 1 <= len <= 15297 */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 boundary329 */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_ZLIB340 s->bits_sent = (s->bits_sent+7) & ~7;341#endif342}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 on353 * 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_ZLIB361static 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 and374 * (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 length408)409{410 send_bits(s, value, length);411}412 413/* =========================================================================414 * Flush as much pending output as possible. All deflate() output goes415 * through this function so some applications may wish to modify it416 * 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 strm421)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