infutil.h
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上传日期:2013-02-24
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- /* infutil.h -- types and macros common to blocks and codes
- * Copyright (C) 1995-1998 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
- #include "zconf.h"
- #include "inftrees.h"
- #include "infcodes.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 */
- B_DONE, /* finished last block, done */
- B_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_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 */
- inflate_huft *hufts; /* single malloc for tree space */
- 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 zlib_fs_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=zlib_fs_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 zlib_fs_inflate_mask[17];
- /* copy as much as possible from the sliding window to the output area */
- extern int zlib_fs_inflate_flush OF((
- inflate_blocks_statef *,
- z_streamp ,
- int));
- /* inflate private state */
- typedef enum {
- METHOD, /* waiting for method byte */
- FLAG, /* waiting for flag byte */
- DICT4, /* four dictionary check bytes to go */
- DICT3, /* three dictionary check bytes to go */
- DICT2, /* two dictionary check bytes to go */
- DICT1, /* one dictionary check byte to go */
- DICT0, /* waiting for inflateSetDictionary */
- BLOCKS, /* decompressing blocks */
- CHECK4, /* four check bytes to go */
- CHECK3, /* three check bytes to go */
- CHECK2, /* two check bytes to go */
- CHECK1, /* one check byte to go */
- I_DONE, /* finished check, done */
- I_BAD} /* got an error--stay here */
- inflate_mode;
- struct internal_state {
- /* mode */
- inflate_mode mode; /* current inflate mode */
- /* mode dependent information */
- union {
- uInt method; /* if FLAGS, method byte */
- struct {
- uLong was; /* computed check value */
- uLong need; /* stream check value */
- } check; /* if CHECK, check values to compare */
- uInt marker; /* if BAD, inflateSync's marker bytes count */
- } sub; /* submode */
- /* mode independent information */
- int nowrap; /* flag for no wrapper */
- uInt wbits; /* log2(window size) (8..15, defaults to 15) */
- inflate_blocks_statef
- *blocks; /* current inflate_blocks state */
- };
- /* inflate codes private state */
- typedef enum { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
- START, /* x: set up for LEN */
- LEN, /* i: get length/literal/eob next */
- LENEXT, /* i: getting length extra (have base) */
- DIST, /* i: get distance next */
- DISTEXT, /* i: getting distance extra */
- COPY, /* o: copying bytes in window, waiting for space */
- LIT, /* o: got literal, waiting for output space */
- WASH, /* o: got eob, possibly still output waiting */
- END, /* x: got eob and all data flushed */
- BADCODE} /* x: got error */
- inflate_codes_mode;
- struct inflate_codes_state {
- /* mode */
- inflate_codes_mode mode; /* current inflate_codes mode */
- /* mode dependent information */
- uInt len;
- union {
- struct {
- inflate_huft *tree; /* pointer into tree */
- uInt need; /* bits needed */
- } code; /* if LEN or DIST, where in tree */
- uInt lit; /* if LIT, literal */
- struct {
- uInt get; /* bits to get for extra */
- uInt dist; /* distance back to copy from */
- } copy; /* if EXT or COPY, where and how much */
- } sub; /* submode */
- /* mode independent information */
- Byte lbits; /* ltree bits decoded per branch */
- Byte dbits; /* dtree bits decoder per branch */
- inflate_huft *ltree; /* literal/length/eob tree */
- inflate_huft *dtree; /* distance tree */
- };
- /* memory allocation for inflation */
- struct inflate_workspace {
- inflate_codes_statef working_state;
- struct inflate_blocks_state working_blocks_state;
- struct internal_state internal_state;
- unsigned int tree_work_area_1[19];
- unsigned int tree_work_area_2[288];
- unsigned working_blens[258 + 0x1f + 0x1f];
- inflate_huft working_hufts[MANY];
- unsigned char working_window[1 << MAX_WBITS];
- };
- #define WS(z) ((struct inflate_workspace *)(z->workspace))
- #endif