1 /* infutil.h -- types and macros common to blocks and codes
2 * Copyright (C) 1995-1998 Mark Adler
3 * For conditions of distribution and use, see copyright notice in zlib.h
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.
15 TYPE, /* get type bits (3, including end bit) */
16 LENS, /* get lengths for stored */
17 STORED, /* processing stored block */
18 TABLE, /* get table lengths */
19 BTREE, /* get bit lengths tree for a dynamic block */
20 DTREE, /* get length, distance trees for a dynamic block */
21 CODES, /* processing fixed or dynamic block */
22 DRY, /* output remaining window bytes */
23 DONE, /* finished last block, done */
24 BAD} /* got a data error--stuck here */
27 /* inflate blocks semi-private state */
28 struct inflate_blocks_state {
31 inflate_block_mode mode; /* current inflate_block mode */
33 /* mode dependent information */
35 uInt left; /* if STORED, bytes left to copy */
37 uInt table; /* table lengths (14 bits) */
38 uInt index; /* index into blens (or border) */
39 uIntf *blens; /* bit lengths of codes */
40 uInt bb; /* bit length tree depth */
41 inflate_huft *tb; /* bit length decoding tree */
42 } trees; /* if DTREE, decoding info for trees */
46 } decode; /* if CODES, current state */
48 uInt last; /* true if this block is the last block */
50 /* mode independent information */
51 uInt bitk; /* bits in bit buffer */
52 uLong bitb; /* bit buffer */
53 inflate_huft *hufts; /* single malloc for tree space */
54 Bytef *window; /* sliding window */
55 Bytef *end; /* one byte after sliding window */
56 Bytef *read; /* window read pointer */
57 Bytef *write; /* window write pointer */
58 check_func checkfn; /* check function */
59 uLong check; /* check on output */
64 /* defines for inflate input/output */
65 /* update pointers and return */
66 #define UPDBITS {s->bitb=b;s->bitk=k;}
67 #define UPDIN {z->avail_in=n;z->total_in+=p-z->next_in;z->next_in=p;}
68 #define UPDOUT {s->write=q;}
69 #define UPDATE {UPDBITS UPDIN UPDOUT}
70 #define LEAVE {UPDATE return inflate_flush(s,z,r);}
71 /* get bytes and bits */
72 #define LOADIN {p=z->next_in;n=z->avail_in;b=s->bitb;k=s->bitk;}
73 #define NEEDBYTE {if(n)r=Z_OK;else LEAVE}
74 #define NEXTBYTE (n--,*p++)
75 #define NEEDBITS(j) {while(k<(j)){NEEDBYTE;b|=((uLong)NEXTBYTE)<<k;k+=8;}}
76 #define DUMPBITS(j) {b>>=(j);k-=(j);}
78 #define WAVAIL (uInt)(q<s->read?s->read-q-1:s->end-q)
79 #define LOADOUT {q=s->write;m=(uInt)WAVAIL;}
80 #define WRAP {if(q==s->end&&s->read!=s->window){q=s->window;m=(uInt)WAVAIL;}}
81 #define FLUSH {UPDOUT r=inflate_flush(s,z,r); LOADOUT}
82 #define NEEDOUT {if(m==0){WRAP if(m==0){FLUSH WRAP if(m==0) LEAVE}}r=Z_OK;}
83 #define OUTBYTE(a) {*q++=(Byte)(a);m--;}
84 /* load local pointers */
85 #define LOAD {LOADIN LOADOUT}
87 /* masks for lower bits (size given to avoid silly warnings with Visual C++) */
88 extern const uInt inflate_mask[17];
90 /* copy as much as possible from the sliding window to the output area */
91 extern int inflate_flush OF((
92 inflate_blocks_statef *,
96 struct internal_state {int dummy;}; /* for buggy compilers */