Root/
1 | |
2 | |
3 | |
4 | #define Assert(err, str) |
5 | #define Trace(dummy) |
6 | #define Tracev(dummy) |
7 | #define Tracecv(err, dummy) |
8 | #define Tracevv(dummy) |
9 | |
10 | |
11 | |
12 | #define LENGTH_CODES 29 |
13 | /* number of length codes, not counting the special END_BLOCK code */ |
14 | |
15 | #define LITERALS 256 |
16 | /* number of literal bytes 0..255 */ |
17 | |
18 | #define L_CODES (LITERALS+1+LENGTH_CODES) |
19 | /* number of Literal or Length codes, including the END_BLOCK code */ |
20 | |
21 | #define D_CODES 30 |
22 | /* number of distance codes */ |
23 | |
24 | #define BL_CODES 19 |
25 | /* number of codes used to transfer the bit lengths */ |
26 | |
27 | #define HEAP_SIZE (2*L_CODES+1) |
28 | /* maximum heap size */ |
29 | |
30 | #define MAX_BITS 15 |
31 | /* All codes must not exceed MAX_BITS bits */ |
32 | |
33 | #define INIT_STATE 42 |
34 | #define BUSY_STATE 113 |
35 | #define FINISH_STATE 666 |
36 | /* Stream status */ |
37 | |
38 | |
39 | /* Data structure describing a single value and its code string. */ |
40 | typedef struct ct_data_s { |
41 | union { |
42 | ush freq; /* frequency count */ |
43 | ush code; /* bit string */ |
44 | } fc; |
45 | union { |
46 | ush dad; /* father node in Huffman tree */ |
47 | ush len; /* length of bit string */ |
48 | } dl; |
49 | } ct_data; |
50 | |
51 | #define Freq fc.freq |
52 | #define Code fc.code |
53 | #define Dad dl.dad |
54 | #define Len dl.len |
55 | |
56 | typedef struct static_tree_desc_s static_tree_desc; |
57 | |
58 | typedef struct tree_desc_s { |
59 | ct_data *dyn_tree; /* the dynamic tree */ |
60 | int max_code; /* largest code with non zero frequency */ |
61 | static_tree_desc *stat_desc; /* the corresponding static tree */ |
62 | } tree_desc; |
63 | |
64 | typedef ush Pos; |
65 | typedef unsigned IPos; |
66 | |
67 | /* A Pos is an index in the character window. We use short instead of int to |
68 | * save space in the various tables. IPos is used only for parameter passing. |
69 | */ |
70 | |
71 | typedef struct deflate_state { |
72 | z_streamp strm; /* pointer back to this zlib stream */ |
73 | int status; /* as the name implies */ |
74 | Byte *pending_buf; /* output still pending */ |
75 | ulg pending_buf_size; /* size of pending_buf */ |
76 | Byte *pending_out; /* next pending byte to output to the stream */ |
77 | int pending; /* nb of bytes in the pending buffer */ |
78 | int noheader; /* suppress zlib header and adler32 */ |
79 | Byte data_type; /* UNKNOWN, BINARY or ASCII */ |
80 | Byte method; /* STORED (for zip only) or DEFLATED */ |
81 | int last_flush; /* value of flush param for previous deflate call */ |
82 | |
83 | /* used by deflate.c: */ |
84 | |
85 | uInt w_size; /* LZ77 window size (32K by default) */ |
86 | uInt w_bits; /* log2(w_size) (8..16) */ |
87 | uInt w_mask; /* w_size - 1 */ |
88 | |
89 | Byte *window; |
90 | /* Sliding window. Input bytes are read into the second half of the window, |
91 | * and move to the first half later to keep a dictionary of at least wSize |
92 | * bytes. With this organization, matches are limited to a distance of |
93 | * wSize-MAX_MATCH bytes, but this ensures that IO is always |
94 | * performed with a length multiple of the block size. Also, it limits |
95 | * the window size to 64K, which is quite useful on MSDOS. |
96 | * To do: use the user input buffer as sliding window. |
97 | */ |
98 | |
99 | ulg window_size; |
100 | /* Actual size of window: 2*wSize, except when the user input buffer |
101 | * is directly used as sliding window. |
102 | */ |
103 | |
104 | Pos *prev; |
105 | /* Link to older string with same hash index. To limit the size of this |
106 | * array to 64K, this link is maintained only for the last 32K strings. |
107 | * An index in this array is thus a window index modulo 32K. |
108 | */ |
109 | |
110 | Pos *head; /* Heads of the hash chains or NIL. */ |
111 | |
112 | uInt ins_h; /* hash index of string to be inserted */ |
113 | uInt hash_size; /* number of elements in hash table */ |
114 | uInt hash_bits; /* log2(hash_size) */ |
115 | uInt hash_mask; /* hash_size-1 */ |
116 | |
117 | uInt hash_shift; |
118 | /* Number of bits by which ins_h must be shifted at each input |
119 | * step. It must be such that after MIN_MATCH steps, the oldest |
120 | * byte no longer takes part in the hash key, that is: |
121 | * hash_shift * MIN_MATCH >= hash_bits |
122 | */ |
123 | |
124 | long block_start; |
125 | /* Window position at the beginning of the current output block. Gets |
126 | * negative when the window is moved backwards. |
127 | */ |
128 | |
129 | uInt match_length; /* length of best match */ |
130 | IPos prev_match; /* previous match */ |
131 | int match_available; /* set if previous match exists */ |
132 | uInt strstart; /* start of string to insert */ |
133 | uInt match_start; /* start of matching string */ |
134 | uInt lookahead; /* number of valid bytes ahead in window */ |
135 | |
136 | uInt prev_length; |
137 | /* Length of the best match at previous step. Matches not greater than this |
138 | * are discarded. This is used in the lazy match evaluation. |
139 | */ |
140 | |
141 | uInt max_chain_length; |
142 | /* To speed up deflation, hash chains are never searched beyond this |
143 | * length. A higher limit improves compression ratio but degrades the |
144 | * speed. |
145 | */ |
146 | |
147 | uInt max_lazy_match; |
148 | /* Attempt to find a better match only when the current match is strictly |
149 | * smaller than this value. This mechanism is used only for compression |
150 | * levels >= 4. |
151 | */ |
152 | # define max_insert_length max_lazy_match |
153 | /* Insert new strings in the hash table only if the match length is not |
154 | * greater than this length. This saves time but degrades compression. |
155 | * max_insert_length is used only for compression levels <= 3. |
156 | */ |
157 | |
158 | int level; /* compression level (1..9) */ |
159 | int strategy; /* favor or force Huffman coding*/ |
160 | |
161 | uInt good_match; |
162 | /* Use a faster search when the previous match is longer than this */ |
163 | |
164 | int nice_match; /* Stop searching when current match exceeds this */ |
165 | |
166 | /* used by trees.c: */ |
167 | /* Didn't use ct_data typedef below to suppress compiler warning */ |
168 | struct ct_data_s dyn_ltree[HEAP_SIZE]; /* literal and length tree */ |
169 | struct ct_data_s dyn_dtree[2*D_CODES+1]; /* distance tree */ |
170 | struct ct_data_s bl_tree[2*BL_CODES+1]; /* Huffman tree for bit lengths */ |
171 | |
172 | struct tree_desc_s l_desc; /* desc. for literal tree */ |
173 | struct tree_desc_s d_desc; /* desc. for distance tree */ |
174 | struct tree_desc_s bl_desc; /* desc. for bit length tree */ |
175 | |
176 | ush bl_count[MAX_BITS+1]; |
177 | /* number of codes at each bit length for an optimal tree */ |
178 | |
179 | int heap[2*L_CODES+1]; /* heap used to build the Huffman trees */ |
180 | int heap_len; /* number of elements in the heap */ |
181 | int heap_max; /* element of largest frequency */ |
182 | /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used. |
183 | * The same heap array is used to build all trees. |
184 | */ |
185 | |
186 | uch depth[2*L_CODES+1]; |
187 | /* Depth of each subtree used as tie breaker for trees of equal frequency |
188 | */ |
189 | |
190 | uch *l_buf; /* buffer for literals or lengths */ |
191 | |
192 | uInt lit_bufsize; |
193 | /* Size of match buffer for literals/lengths. There are 4 reasons for |
194 | * limiting lit_bufsize to 64K: |
195 | * - frequencies can be kept in 16 bit counters |
196 | * - if compression is not successful for the first block, all input |
197 | * data is still in the window so we can still emit a stored block even |
198 | * when input comes from standard input. (This can also be done for |
199 | * all blocks if lit_bufsize is not greater than 32K.) |
200 | * - if compression is not successful for a file smaller than 64K, we can |
201 | * even emit a stored file instead of a stored block (saving 5 bytes). |
202 | * This is applicable only for zip (not gzip or zlib). |
203 | * - creating new Huffman trees less frequently may not provide fast |
204 | * adaptation to changes in the input data statistics. (Take for |
205 | * example a binary file with poorly compressible code followed by |
206 | * a highly compressible string table.) Smaller buffer sizes give |
207 | * fast adaptation but have of course the overhead of transmitting |
208 | * trees more frequently. |
209 | * - I can't count above 4 |
210 | */ |
211 | |
212 | uInt last_lit; /* running index in l_buf */ |
213 | |
214 | ush *d_buf; |
215 | /* Buffer for distances. To simplify the code, d_buf and l_buf have |
216 | * the same number of elements. To use different lengths, an extra flag |
217 | * array would be necessary. |
218 | */ |
219 | |
220 | ulg opt_len; /* bit length of current block with optimal trees */ |
221 | ulg static_len; /* bit length of current block with static trees */ |
222 | ulg compressed_len; /* total bit length of compressed file */ |
223 | uInt matches; /* number of string matches in current block */ |
224 | int last_eob_len; /* bit length of EOB code for last block */ |
225 | |
226 | #ifdef DEBUG_ZLIB |
227 | ulg bits_sent; /* bit length of the compressed data */ |
228 | #endif |
229 | |
230 | ush bi_buf; |
231 | /* Output buffer. bits are inserted starting at the bottom (least |
232 | * significant bits). |
233 | */ |
234 | int bi_valid; |
235 | /* Number of valid bits in bi_buf. All bits above the last valid bit |
236 | * are always zero. |
237 | */ |
238 | |
239 | } deflate_state; |
240 | |
241 | typedef struct deflate_workspace { |
242 | /* State memory for the deflator */ |
243 | deflate_state deflate_memory; |
244 | Byte *window_memory; |
245 | Pos *prev_memory; |
246 | Pos *head_memory; |
247 | char *overlay_memory; |
248 | } deflate_workspace; |
249 | |
250 | #define zlib_deflate_window_memsize(windowBits) \ |
251 | (2 * (1 << (windowBits)) * sizeof(Byte)) |
252 | #define zlib_deflate_prev_memsize(windowBits) \ |
253 | ((1 << (windowBits)) * sizeof(Pos)) |
254 | #define zlib_deflate_head_memsize(memLevel) \ |
255 | ((1 << ((memLevel)+7)) * sizeof(Pos)) |
256 | #define zlib_deflate_overlay_memsize(memLevel) \ |
257 | ((1 << ((memLevel)+6)) * (sizeof(ush)+2)) |
258 | |
259 | /* Output a byte on the stream. |
260 | * IN assertion: there is enough room in pending_buf. |
261 | */ |
262 | #define put_byte(s, c) {s->pending_buf[s->pending++] = (c);} |
263 | |
264 | |
265 | #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1) |
266 | /* Minimum amount of lookahead, except at the end of the input file. |
267 | * See deflate.c for comments about the MIN_MATCH+1. |
268 | */ |
269 | |
270 | #define MAX_DIST(s) ((s)->w_size-MIN_LOOKAHEAD) |
271 | /* In order to simplify the code, particularly on 16 bit machines, match |
272 | * distances are limited to MAX_DIST instead of WSIZE. |
273 | */ |
274 | |
275 | /* in trees.c */ |
276 | void zlib_tr_init (deflate_state *s); |
277 | int zlib_tr_tally (deflate_state *s, unsigned dist, unsigned lc); |
278 | ulg zlib_tr_flush_block (deflate_state *s, char *buf, ulg stored_len, |
279 | int eof); |
280 | void zlib_tr_align (deflate_state *s); |
281 | void zlib_tr_stored_block (deflate_state *s, char *buf, ulg stored_len, |
282 | int eof); |
283 | void zlib_tr_stored_type_only (deflate_state *); |
284 | |
285 | |
286 | /* =========================================================================== |
287 | * Output a short LSB first on the stream. |
288 | * IN assertion: there is enough room in pendingBuf. |
289 | */ |
290 | #define put_short(s, w) { \ |
291 | put_byte(s, (uch)((w) & 0xff)); \ |
292 | put_byte(s, (uch)((ush)(w) >> 8)); \ |
293 | } |
294 | |
295 | /* =========================================================================== |
296 | * Reverse the first len bits of a code, using straightforward code (a faster |
297 | * method would use a table) |
298 | * IN assertion: 1 <= len <= 15 |
299 | */ |
300 | static inline unsigned bi_reverse(unsigned code, /* the value to invert */ |
301 | int len) /* its bit length */ |
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 |
Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.11
jz-3.12
jz-3.13
jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master
Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9