Line data Source code
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 0 : static inline void bi_flush(deflate_state *s)
315 : {
316 0 : if (s->bi_valid == 16) {
317 0 : put_short(s, s->bi_buf);
318 0 : s->bi_buf = 0;
319 0 : s->bi_valid = 0;
320 0 : } else if (s->bi_valid >= 8) {
321 0 : put_byte(s, (Byte)s->bi_buf);
322 0 : s->bi_buf >>= 8;
323 0 : s->bi_valid -= 8;
324 : }
325 0 : }
326 :
327 : /* ===========================================================================
328 : * Flush the bit buffer and align the output on a byte boundary
329 : */
330 0 : static inline void bi_windup(deflate_state *s)
331 : {
332 0 : if (s->bi_valid > 8) {
333 0 : put_short(s, s->bi_buf);
334 0 : } else if (s->bi_valid > 0) {
335 0 : put_byte(s, (Byte)s->bi_buf);
336 : }
337 0 : s->bi_buf = 0;
338 0 : s->bi_valid = 0;
339 : #ifdef DEBUG_ZLIB
340 : s->bits_sent = (s->bits_sent+7) & ~7;
341 : #endif
342 0 : }
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 0 : static inline void flush_pending(
420 : z_streamp strm
421 : )
422 : {
423 0 : deflate_state *s = (deflate_state *) strm->state;
424 0 : unsigned len = s->pending;
425 :
426 0 : if (len > strm->avail_out) len = strm->avail_out;
427 0 : if (len == 0) return;
428 :
429 0 : if (strm->next_out != NULL) {
430 0 : memcpy(strm->next_out, s->pending_out, len);
431 0 : strm->next_out += len;
432 : }
433 0 : s->pending_out += len;
434 0 : strm->total_out += len;
435 0 : strm->avail_out -= len;
436 0 : s->pending -= len;
437 0 : if (s->pending == 0) {
438 0 : s->pending_out = s->pending_buf;
439 : }
440 : }
441 : #endif /* DEFUTIL_H */
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