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   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 */
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  */
bi_reverse(unsigned code,int len)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  */
bi_flush(deflate_state * s)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  */
bi_windup(deflate_state * s)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 
send_bits(deflate_state * s,int value,int length)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 
zlib_tr_send_bits(deflate_state * s,int value,int length)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  */
flush_pending(z_streamp strm)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