source: s10k/CommonLibs/zlib-1.2.8/deflate.h @ 1096

Last change on this file since 1096 was 1096, checked in by s10k, 23 months ago

Added zlib, quazip, basicxmlsyntaxhighlighter, conditionalsemaphore and linenumberdisplay libraries. zlib and quazip are pre-compiled, but you can compile them yourself, just delete the dll files (or equivalent binary files to your OS)

File size: 12.5 KB
Line 
1/* deflate.h -- internal compression state
2 * Copyright (C) 1995-2012 Jean-loup Gailly
3 * For conditions of distribution and use, see copyright notice in zlib.h
4 */
5
6/* WARNING: this file should *not* be used by applications. It is
7   part of the implementation of the compression library and is
8   subject to change. Applications should only use zlib.h.
9 */
10
11/* @(#) $Id$ */
12
13#ifndef DEFLATE_H
14#define DEFLATE_H
15
16#include "zutil.h"
17
18/* define NO_GZIP when compiling if you want to disable gzip header and
19   trailer creation by deflate().  NO_GZIP would be used to avoid linking in
20   the crc code when it is not needed.  For shared libraries, gzip encoding
21   should be left enabled. */
22#ifndef NO_GZIP
23#  define GZIP
24#endif
25
26/* ===========================================================================
27 * Internal compression state.
28 */
29
30#define LENGTH_CODES 29
31/* number of length codes, not counting the special END_BLOCK code */
32
33#define LITERALS  256
34/* number of literal bytes 0..255 */
35
36#define L_CODES (LITERALS+1+LENGTH_CODES)
37/* number of Literal or Length codes, including the END_BLOCK code */
38
39#define D_CODES   30
40/* number of distance codes */
41
42#define BL_CODES  19
43/* number of codes used to transfer the bit lengths */
44
45#define HEAP_SIZE (2*L_CODES+1)
46/* maximum heap size */
47
48#define MAX_BITS 15
49/* All codes must not exceed MAX_BITS bits */
50
51#define Buf_size 16
52/* size of bit buffer in bi_buf */
53
54#define INIT_STATE    42
55#define EXTRA_STATE   69
56#define NAME_STATE    73
57#define COMMENT_STATE 91
58#define HCRC_STATE   103
59#define BUSY_STATE   113
60#define FINISH_STATE 666
61/* Stream status */
62
63
64/* Data structure describing a single value and its code string. */
65typedef struct ct_data_s {
66    union {
67        ush  freq;       /* frequency count */
68        ush  code;       /* bit string */
69    } fc;
70    union {
71        ush  dad;        /* father node in Huffman tree */
72        ush  len;        /* length of bit string */
73    } dl;
74} FAR ct_data;
75
76#define Freq fc.freq
77#define Code fc.code
78#define Dad  dl.dad
79#define Len  dl.len
80
81typedef struct static_tree_desc_s  static_tree_desc;
82
83typedef struct tree_desc_s {
84    ct_data *dyn_tree;           /* the dynamic tree */
85    int     max_code;            /* largest code with non zero frequency */
86    static_tree_desc *stat_desc; /* the corresponding static tree */
87} FAR tree_desc;
88
89typedef ush Pos;
90typedef Pos FAR Posf;
91typedef unsigned IPos;
92
93/* A Pos is an index in the character window. We use short instead of int to
94 * save space in the various tables. IPos is used only for parameter passing.
95 */
96
97typedef struct internal_state {
98    z_streamp strm;      /* pointer back to this zlib stream */
99    int   status;        /* as the name implies */
100    Bytef *pending_buf;  /* output still pending */
101    ulg   pending_buf_size; /* size of pending_buf */
102    Bytef *pending_out;  /* next pending byte to output to the stream */
103    uInt   pending;      /* nb of bytes in the pending buffer */
104    int   wrap;          /* bit 0 true for zlib, bit 1 true for gzip */
105    gz_headerp  gzhead;  /* gzip header information to write */
106    uInt   gzindex;      /* where in extra, name, or comment */
107    Byte  method;        /* can only be DEFLATED */
108    int   last_flush;    /* value of flush param for previous deflate call */
109
110                /* used by deflate.c: */
111
112    uInt  w_size;        /* LZ77 window size (32K by default) */
113    uInt  w_bits;        /* log2(w_size)  (8..16) */
114    uInt  w_mask;        /* w_size - 1 */
115
116    Bytef *window;
117    /* Sliding window. Input bytes are read into the second half of the window,
118     * and move to the first half later to keep a dictionary of at least wSize
119     * bytes. With this organization, matches are limited to a distance of
120     * wSize-MAX_MATCH bytes, but this ensures that IO is always
121     * performed with a length multiple of the block size. Also, it limits
122     * the window size to 64K, which is quite useful on MSDOS.
123     * To do: use the user input buffer as sliding window.
124     */
125
126    ulg window_size;
127    /* Actual size of window: 2*wSize, except when the user input buffer
128     * is directly used as sliding window.
129     */
130
131    Posf *prev;
132    /* Link to older string with same hash index. To limit the size of this
133     * array to 64K, this link is maintained only for the last 32K strings.
134     * An index in this array is thus a window index modulo 32K.
135     */
136
137    Posf *head; /* Heads of the hash chains or NIL. */
138
139    uInt  ins_h;          /* hash index of string to be inserted */
140    uInt  hash_size;      /* number of elements in hash table */
141    uInt  hash_bits;      /* log2(hash_size) */
142    uInt  hash_mask;      /* hash_size-1 */
143
144    uInt  hash_shift;
145    /* Number of bits by which ins_h must be shifted at each input
146     * step. It must be such that after MIN_MATCH steps, the oldest
147     * byte no longer takes part in the hash key, that is:
148     *   hash_shift * MIN_MATCH >= hash_bits
149     */
150
151    long block_start;
152    /* Window position at the beginning of the current output block. Gets
153     * negative when the window is moved backwards.
154     */
155
156    uInt match_length;           /* length of best match */
157    IPos prev_match;             /* previous match */
158    int match_available;         /* set if previous match exists */
159    uInt strstart;               /* start of string to insert */
160    uInt match_start;            /* start of matching string */
161    uInt lookahead;              /* number of valid bytes ahead in window */
162
163    uInt prev_length;
164    /* Length of the best match at previous step. Matches not greater than this
165     * are discarded. This is used in the lazy match evaluation.
166     */
167
168    uInt max_chain_length;
169    /* To speed up deflation, hash chains are never searched beyond this
170     * length.  A higher limit improves compression ratio but degrades the
171     * speed.
172     */
173
174    uInt max_lazy_match;
175    /* Attempt to find a better match only when the current match is strictly
176     * smaller than this value. This mechanism is used only for compression
177     * levels >= 4.
178     */
179#   define max_insert_length  max_lazy_match
180    /* Insert new strings in the hash table only if the match length is not
181     * greater than this length. This saves time but degrades compression.
182     * max_insert_length is used only for compression levels <= 3.
183     */
184
185    int level;    /* compression level (1..9) */
186    int strategy; /* favor or force Huffman coding*/
187
188    uInt good_match;
189    /* Use a faster search when the previous match is longer than this */
190
191    int nice_match; /* Stop searching when current match exceeds this */
192
193                /* used by trees.c: */
194    /* Didn't use ct_data typedef below to suppress compiler warning */
195    struct ct_data_s dyn_ltree[HEAP_SIZE];   /* literal and length tree */
196    struct ct_data_s dyn_dtree[2*D_CODES+1]; /* distance tree */
197    struct ct_data_s bl_tree[2*BL_CODES+1];  /* Huffman tree for bit lengths */
198
199    struct tree_desc_s l_desc;               /* desc. for literal tree */
200    struct tree_desc_s d_desc;               /* desc. for distance tree */
201    struct tree_desc_s bl_desc;              /* desc. for bit length tree */
202
203    ush bl_count[MAX_BITS+1];
204    /* number of codes at each bit length for an optimal tree */
205
206    int heap[2*L_CODES+1];      /* heap used to build the Huffman trees */
207    int heap_len;               /* number of elements in the heap */
208    int heap_max;               /* element of largest frequency */
209    /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
210     * The same heap array is used to build all trees.
211     */
212
213    uch depth[2*L_CODES+1];
214    /* Depth of each subtree used as tie breaker for trees of equal frequency
215     */
216
217    uchf *l_buf;          /* buffer for literals or lengths */
218
219    uInt  lit_bufsize;
220    /* Size of match buffer for literals/lengths.  There are 4 reasons for
221     * limiting lit_bufsize to 64K:
222     *   - frequencies can be kept in 16 bit counters
223     *   - if compression is not successful for the first block, all input
224     *     data is still in the window so we can still emit a stored block even
225     *     when input comes from standard input.  (This can also be done for
226     *     all blocks if lit_bufsize is not greater than 32K.)
227     *   - if compression is not successful for a file smaller than 64K, we can
228     *     even emit a stored file instead of a stored block (saving 5 bytes).
229     *     This is applicable only for zip (not gzip or zlib).
230     *   - creating new Huffman trees less frequently may not provide fast
231     *     adaptation to changes in the input data statistics. (Take for
232     *     example a binary file with poorly compressible code followed by
233     *     a highly compressible string table.) Smaller buffer sizes give
234     *     fast adaptation but have of course the overhead of transmitting
235     *     trees more frequently.
236     *   - I can't count above 4
237     */
238
239    uInt last_lit;      /* running index in l_buf */
240
241    ushf *d_buf;
242    /* Buffer for distances. To simplify the code, d_buf and l_buf have
243     * the same number of elements. To use different lengths, an extra flag
244     * array would be necessary.
245     */
246
247    ulg opt_len;        /* bit length of current block with optimal trees */
248    ulg static_len;     /* bit length of current block with static trees */
249    uInt matches;       /* number of string matches in current block */
250    uInt insert;        /* bytes at end of window left to insert */
251
252#ifdef DEBUG
253    ulg compressed_len; /* total bit length of compressed file mod 2^32 */
254    ulg bits_sent;      /* bit length of compressed data sent mod 2^32 */
255#endif
256
257    ush bi_buf;
258    /* Output buffer. bits are inserted starting at the bottom (least
259     * significant bits).
260     */
261    int bi_valid;
262    /* Number of valid bits in bi_buf.  All bits above the last valid bit
263     * are always zero.
264     */
265
266    ulg high_water;
267    /* High water mark offset in window for initialized bytes -- bytes above
268     * this are set to zero in order to avoid memory check warnings when
269     * longest match routines access bytes past the input.  This is then
270     * updated to the new high water mark.
271     */
272
273} FAR deflate_state;
274
275/* Output a byte on the stream.
276 * IN assertion: there is enough room in pending_buf.
277 */
278#define put_byte(s, c) {s->pending_buf[s->pending++] = (c);}
279
280
281#define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
282/* Minimum amount of lookahead, except at the end of the input file.
283 * See deflate.c for comments about the MIN_MATCH+1.
284 */
285
286#define MAX_DIST(s)  ((s)->w_size-MIN_LOOKAHEAD)
287/* In order to simplify the code, particularly on 16 bit machines, match
288 * distances are limited to MAX_DIST instead of WSIZE.
289 */
290
291#define WIN_INIT MAX_MATCH
292/* Number of bytes after end of data in window to initialize in order to avoid
293   memory checker errors from longest match routines */
294
295        /* in trees.c */
296void ZLIB_INTERNAL _tr_init OF((deflate_state *s));
297int ZLIB_INTERNAL _tr_tally OF((deflate_state *s, unsigned dist, unsigned lc));
298void ZLIB_INTERNAL _tr_flush_block OF((deflate_state *s, charf *buf,
299                        ulg stored_len, int last));
300void ZLIB_INTERNAL _tr_flush_bits OF((deflate_state *s));
301void ZLIB_INTERNAL _tr_align OF((deflate_state *s));
302void ZLIB_INTERNAL _tr_stored_block OF((deflate_state *s, charf *buf,
303                        ulg stored_len, int last));
304
305#define d_code(dist) \
306   ((dist) < 256 ? _dist_code[dist] : _dist_code[256+((dist)>>7)])
307/* Mapping from a distance to a distance code. dist is the distance - 1 and
308 * must not have side effects. _dist_code[256] and _dist_code[257] are never
309 * used.
310 */
311
312#ifndef DEBUG
313/* Inline versions of _tr_tally for speed: */
314
315#if defined(GEN_TREES_H) || !defined(STDC)
316  extern uch ZLIB_INTERNAL _length_code[];
317  extern uch ZLIB_INTERNAL _dist_code[];
318#else
319  extern const uch ZLIB_INTERNAL _length_code[];
320  extern const uch ZLIB_INTERNAL _dist_code[];
321#endif
322
323# define _tr_tally_lit(s, c, flush) \
324  { uch cc = (c); \
325    s->d_buf[s->last_lit] = 0; \
326    s->l_buf[s->last_lit++] = cc; \
327    s->dyn_ltree[cc].Freq++; \
328    flush = (s->last_lit == s->lit_bufsize-1); \
329   }
330# define _tr_tally_dist(s, distance, length, flush) \
331  { uch len = (length); \
332    ush dist = (distance); \
333    s->d_buf[s->last_lit] = dist; \
334    s->l_buf[s->last_lit++] = len; \
335    dist--; \
336    s->dyn_ltree[_length_code[len]+LITERALS+1].Freq++; \
337    s->dyn_dtree[d_code(dist)].Freq++; \
338    flush = (s->last_lit == s->lit_bufsize-1); \
339  }
340#else
341# define _tr_tally_lit(s, c, flush) flush = _tr_tally(s, 0, c)
342# define _tr_tally_dist(s, distance, length, flush) \
343              flush = _tr_tally(s, distance, length)
344#endif
345
346#endif /* DEFLATE_H */
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