|
10
|
1 /* infutil.h -- types and macros common to blocks and codes
|
|
|
2 * Copyright (C) 1995 Mark Adler
|
|
|
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 /* inflate blocks semi-private state */
|
|
|
12 struct inflate_blocks_state {
|
|
|
13
|
|
|
14 /* mode */
|
|
|
15 enum {
|
|
|
16 TYPE, /* get type bits (3, including end bit) */
|
|
|
17 LENS, /* get lengths for stored */
|
|
|
18 STORED, /* processing stored block */
|
|
|
19 TABLE, /* get table lengths */
|
|
|
20 BTREE, /* get bit lengths tree for a dynamic block */
|
|
|
21 DTREE, /* get length, distance trees for a dynamic block */
|
|
|
22 CODES, /* processing fixed or dynamic block */
|
|
|
23 DRY, /* output remaining window bytes */
|
|
|
24 DONE, /* finished last block, done */
|
|
|
25 BAD} /* got a data error--stuck here */
|
|
|
26 mode; /* current inflate_block mode */
|
|
|
27
|
|
|
28 /* mode dependent information */
|
|
|
29 union {
|
|
|
30 uInt left; /* if STORED, bytes left to copy */
|
|
|
31 struct {
|
|
|
32 uInt table; /* table lengths (14 bits) */
|
|
|
33 uInt index; /* index into blens (or border) */
|
|
|
34 uIntf *blens; /* bit lengths of codes */
|
|
|
35 uInt bb; /* bit length tree depth */
|
|
|
36 inflate_huft *tb; /* bit length decoding tree */
|
|
|
37 } trees; /* if DTREE, decoding info for trees */
|
|
|
38 struct {
|
|
|
39 inflate_huft *tl, *td; /* trees to free */
|
|
|
40 inflate_codes_statef
|
|
|
41 *codes;
|
|
|
42 } decode; /* if CODES, current state */
|
|
|
43 } sub; /* submode */
|
|
|
44 uInt last; /* true if this block is the last block */
|
|
|
45
|
|
|
46 /* mode independent information */
|
|
|
47 uInt bitk; /* bits in bit buffer */
|
|
|
48 uLong bitb; /* bit buffer */
|
|
|
49 Bytef *window; /* sliding window */
|
|
|
50 Bytef *end; /* one byte after sliding window */
|
|
|
51 Bytef *read; /* window read pointer */
|
|
|
52 Bytef *write; /* window write pointer */
|
|
|
53 check_func checkfn; /* check function */
|
|
|
54 uLong check; /* check on output */
|
|
|
55
|
|
|
56 };
|
|
|
57
|
|
|
58
|
|
|
59 /* defines for inflate input/output */
|
|
|
60 /* update pointers and return */
|
|
|
61 #define UPDBITS {s->bitb=b;s->bitk=k;}
|
|
|
62 #define UPDIN {z->avail_in=n;z->total_in+=p-z->next_in;z->next_in=p;}
|
|
|
63 #define UPDOUT {s->write=q;}
|
|
|
64 #define UPDATE {UPDBITS UPDIN UPDOUT}
|
|
|
65 #define LEAVE {UPDATE return inflate_flush(s,z,r);}
|
|
|
66 /* get bytes and bits */
|
|
|
67 #define LOADIN {p=z->next_in;n=z->avail_in;b=s->bitb;k=s->bitk;}
|
|
|
68 #define NEEDBYTE {if(n)r=Z_OK;else LEAVE}
|
|
|
69 #define NEXTBYTE (n--,*p++)
|
|
|
70 #define NEEDBITS(j) {while(k<(j)){NEEDBYTE;b|=((uLong)NEXTBYTE)<<k;k+=8;}}
|
|
|
71 #define DUMPBITS(j) {b>>=(j);k-=(j);}
|
|
|
72 /* output bytes */
|
|
|
73 #define WAVAIL (q<s->read?s->read-q-1:s->end-q)
|
|
|
74 #define LOADOUT {q=s->write;m=WAVAIL;}
|
|
|
75 #define WRAP {if(q==s->end&&s->read!=s->window){q=s->window;m=WAVAIL;}}
|
|
|
76 #define FLUSH {UPDOUT r=inflate_flush(s,z,r); LOADOUT}
|
|
|
77 #define NEEDOUT {if(m==0){WRAP if(m==0){FLUSH WRAP if(m==0) LEAVE}}r=Z_OK;}
|
|
|
78 #define OUTBYTE(a) {*q++=(Byte)(a);m--;}
|
|
|
79 /* load local pointers */
|
|
|
80 #define LOAD {LOADIN LOADOUT}
|
|
|
81
|
|
|
82 /* masks for lower bits */
|
|
|
83 extern uInt inflate_mask[];
|
|
|
84
|
|
|
85 /* copy as much as possible from the sliding window to the output area */
|
|
|
86 extern int inflate_flush OF((
|
|
|
87 inflate_blocks_statef *,
|
|
|
88 z_stream *,
|
|
|
89 int));
|
|
|
90
|
|
|
91 struct internal_state {int dummy;}; /* for buggy compilers */
|
