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 ; /* 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 | 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 | |
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 | { |
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 | |