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. */
42typedef 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
58typedef struct static_tree_desc_s  static_tree_desc;
59
60typedef 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
66typedef ush Pos;
67typedef 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
73typedef 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 */
274void zlib_tr_init         (deflate_state *s);
275int  zlib_tr_tally        (deflate_state *s, unsigned dist, unsigned lc);
276ulg  zlib_tr_flush_block  (deflate_state *s, char *buf, ulg stored_len,
277			   int eof);
278void zlib_tr_align        (deflate_state *s);
279void zlib_tr_stored_block (deflate_state *s, char *buf, ulg stored_len,
280			   int eof);
281void 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 */
298static 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 */
314static 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 */
330static 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
344typedef 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
361static void send_bits      (deflate_state *s, int value, int length);
362
363static 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
404static 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 */
419static 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