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aa5b395b MZ |
1 | #ifndef DEFUTIL_H |
2 | #define DEFUTIL_H | |
1da177e4 | 3 | |
aa5b395b | 4 | #include <linux/zutil.h> |
1da177e4 LT |
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: */ | |
643d1f7f | 169 | /* Didn't use ct_data typedef below to suppress compiler warning */ |
1da177e4 LT |
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 | ||
aa5b395b MZ |
243 | #ifdef CONFIG_ZLIB_DFLTCC |
244 | #define zlib_deflate_window_memsize(windowBits) \ | |
245 | (2 * (1 << (windowBits)) * sizeof(Byte) + PAGE_SIZE) | |
246 | #else | |
565d76cb JK |
247 | #define zlib_deflate_window_memsize(windowBits) \ |
248 | (2 * (1 << (windowBits)) * sizeof(Byte)) | |
aa5b395b | 249 | #endif |
565d76cb JK |
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 | ||
1da177e4 LT |
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 | ||
aa5b395b MZ |
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 | ||
1da177e4 LT |
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 | ||
aa5b395b MZ |
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 | { | |
1c0a0af5 | 423 | unsigned len; |
aa5b395b | 424 | deflate_state *s = (deflate_state *) strm->state; |
aa5b395b | 425 | |
1c0a0af5 MZ |
426 | bi_flush(s); |
427 | len = s->pending; | |
aa5b395b MZ |
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 */ |