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Diffstat (limited to 'lib/zlib_deflate/defutil.h')
-rw-r--r-- | lib/zlib_deflate/defutil.h | 334 |
1 files changed, 334 insertions, 0 deletions
diff --git a/lib/zlib_deflate/defutil.h b/lib/zlib_deflate/defutil.h new file mode 100644 index 000000000000..d9feaf638608 --- /dev/null +++ b/lib/zlib_deflate/defutil.h | |||
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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 supress 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[2 * (1 << MAX_WBITS)]; | ||
245 | Pos prev_memory[1 << MAX_WBITS]; | ||
246 | Pos head_memory[1 << (MAX_MEM_LEVEL + 7)]; | ||
247 | char overlay_memory[(1 << (MAX_MEM_LEVEL + 6)) * (sizeof(ush)+2)]; | ||
248 | } deflate_workspace; | ||
249 | |||
250 | /* Output a byte on the stream. | ||
251 | * IN assertion: there is enough room in pending_buf. | ||
252 | */ | ||
253 | #define put_byte(s, c) {s->pending_buf[s->pending++] = (c);} | ||
254 | |||
255 | |||
256 | #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1) | ||
257 | /* Minimum amount of lookahead, except at the end of the input file. | ||
258 | * See deflate.c for comments about the MIN_MATCH+1. | ||
259 | */ | ||
260 | |||
261 | #define MAX_DIST(s) ((s)->w_size-MIN_LOOKAHEAD) | ||
262 | /* In order to simplify the code, particularly on 16 bit machines, match | ||
263 | * distances are limited to MAX_DIST instead of WSIZE. | ||
264 | */ | ||
265 | |||
266 | /* in trees.c */ | ||
267 | void zlib_tr_init (deflate_state *s); | ||
268 | int zlib_tr_tally (deflate_state *s, unsigned dist, unsigned lc); | ||
269 | ulg zlib_tr_flush_block (deflate_state *s, char *buf, ulg stored_len, | ||
270 | int eof); | ||
271 | void zlib_tr_align (deflate_state *s); | ||
272 | void zlib_tr_stored_block (deflate_state *s, char *buf, ulg stored_len, | ||
273 | int eof); | ||
274 | void zlib_tr_stored_type_only (deflate_state *); | ||
275 | |||
276 | |||
277 | /* =========================================================================== | ||
278 | * Output a short LSB first on the stream. | ||
279 | * IN assertion: there is enough room in pendingBuf. | ||
280 | */ | ||
281 | #define put_short(s, w) { \ | ||
282 | put_byte(s, (uch)((w) & 0xff)); \ | ||
283 | put_byte(s, (uch)((ush)(w) >> 8)); \ | ||
284 | } | ||
285 | |||
286 | /* =========================================================================== | ||
287 | * Reverse the first len bits of a code, using straightforward code (a faster | ||
288 | * method would use a table) | ||
289 | * IN assertion: 1 <= len <= 15 | ||
290 | */ | ||
291 | static inline unsigned bi_reverse(unsigned code, /* the value to invert */ | ||
292 | int len) /* its bit length */ | ||
293 | { | ||
294 | register unsigned res = 0; | ||
295 | do { | ||
296 | res |= code & 1; | ||
297 | code >>= 1, res <<= 1; | ||
298 | } while (--len > 0); | ||
299 | return res >> 1; | ||
300 | } | ||
301 | |||
302 | /* =========================================================================== | ||
303 | * Flush the bit buffer, keeping at most 7 bits in it. | ||
304 | */ | ||
305 | static inline void bi_flush(deflate_state *s) | ||
306 | { | ||
307 | if (s->bi_valid == 16) { | ||
308 | put_short(s, s->bi_buf); | ||
309 | s->bi_buf = 0; | ||
310 | s->bi_valid = 0; | ||
311 | } else if (s->bi_valid >= 8) { | ||
312 | put_byte(s, (Byte)s->bi_buf); | ||
313 | s->bi_buf >>= 8; | ||
314 | s->bi_valid -= 8; | ||
315 | } | ||
316 | } | ||
317 | |||
318 | /* =========================================================================== | ||
319 | * Flush the bit buffer and align the output on a byte boundary | ||
320 | */ | ||
321 | static inline void bi_windup(deflate_state *s) | ||
322 | { | ||
323 | if (s->bi_valid > 8) { | ||
324 | put_short(s, s->bi_buf); | ||
325 | } else if (s->bi_valid > 0) { | ||
326 | put_byte(s, (Byte)s->bi_buf); | ||
327 | } | ||
328 | s->bi_buf = 0; | ||
329 | s->bi_valid = 0; | ||
330 | #ifdef DEBUG_ZLIB | ||
331 | s->bits_sent = (s->bits_sent+7) & ~7; | ||
332 | #endif | ||
333 | } | ||
334 | |||