infutil.h
上传用户:lyxiangda
上传日期:2007-01-12
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文件大小:4k
- /* infutil.h -- types and macros common to blocks and codes
- * Copyright (C) 1995-1996 Mark Adler
- * For conditions of distribution and use, see copyright notice in zlib.h
- */
- /* WARNING: this file should *not* be used by applications. It is
- part of the implementation of the compression library and is
- subject to change. Applications should only use zlib.h.
- */
- #ifndef _INFUTIL_H
- #define _INFUTIL_H
- typedef enum {
- TYPE, /* get type bits (3, including end bit) */
- LENS, /* get lengths for stored */
- STORED, /* processing stored block */
- TABLE, /* get table lengths */
- BTREE, /* get bit lengths tree for a dynamic block */
- DTREE, /* get length, distance trees for a dynamic block */
- CODES, /* processing fixed or dynamic block */
- DRY, /* output remaining window bytes */
- DONE, /* finished last block, done */
- BAD} /* got a data error--stuck here */
- inflate_block_mode;
- /* inflate blocks semi-private state */
- struct inflate_blocks_state {
- /* mode */
- inflate_block_mode mode; /* current inflate_block mode */
- /* mode dependent information */
- union {
- uInt left; /* if STORED, bytes left to copy */
- struct {
- uInt table; /* table lengths (14 bits) */
- uInt index; /* index into blens (or border) */
- uIntf *blens; /* bit lengths of codes */
- uInt bb; /* bit length tree depth */
- inflate_huft *tb; /* bit length decoding tree */
- } trees; /* if DTREE, decoding info for trees */
- struct {
- inflate_huft *tl;
- inflate_huft *td; /* trees to free */
- inflate_codes_statef
- *codes;
- } decode; /* if CODES, current state */
- } sub; /* submode */
- uInt last; /* true if this block is the last block */
- /* mode independent information */
- uInt bitk; /* bits in bit buffer */
- uLong bitb; /* bit buffer */
- Bytef *window; /* sliding window */
- Bytef *end; /* one byte after sliding window */
- Bytef *read; /* window read pointer */
- Bytef *write; /* window write pointer */
- check_func checkfn; /* check function */
- uLong check; /* check on output */
- };
- /* defines for inflate input/output */
- /* update pointers and return */
- #define UPDBITS {s->bitb=b;s->bitk=k;}
- #define UPDIN {z->avail_in=n;z->total_in+=p-z->next_in;z->next_in=p;}
- #define UPDOUT {s->write=q;}
- #define UPDATE {UPDBITS UPDIN UPDOUT}
- #define LEAVE {UPDATE return inflate_flush(s,z,r);}
- /* get bytes and bits */
- #define LOADIN {p=z->next_in;n=z->avail_in;b=s->bitb;k=s->bitk;}
- #define NEEDBYTE {if(n)r=Z_OK;else LEAVE}
- #define NEXTBYTE (n--,*p++)
- #define NEEDBITS(j) {while(k<(j)){NEEDBYTE;b|=((uLong)NEXTBYTE)<<k;k+=8;}}
- #define DUMPBITS(j) {b>>=(j);k-=(j);}
- /* output bytes */
- #define WAVAIL (uInt)(q<s->read?s->read-q-1:s->end-q)
- #define LOADOUT {q=s->write;m=(uInt)WAVAIL;}
- #define WRAP {if(q==s->end&&s->read!=s->window){q=s->window;m=(uInt)WAVAIL;}}
- #define FLUSH {UPDOUT r=inflate_flush(s,z,r); LOADOUT}
- #define NEEDOUT {if(m==0){WRAP if(m==0){FLUSH WRAP if(m==0) LEAVE}}r=Z_OK;}
- #define OUTBYTE(a) {*q++=(Byte)(a);m--;}
- /* load local pointers */
- #define LOAD {LOADIN LOADOUT}
- /* masks for lower bits (size given to avoid silly warnings with Visual C++) */
- extern uInt inflate_mask[17];
- /* copy as much as possible from the sliding window to the output area */
- extern int inflate_flush OF((
- inflate_blocks_statef *,
- z_streamp ,
- int));
- struct internal_state {int dummy;}; /* for buggy compilers */
- #endif