sl@0: /* infutil.h -- types and macros common to blocks and codes
sl@0:  * Copyright (C) 1995-1998 Mark Adler
sl@0:  * For conditions of distribution and use, see copyright notice in zlib.h 
sl@0:  */
sl@0: 
sl@0: /* WARNING: this file should *not* be used by applications. It is
sl@0:    part of the implementation of the compression library and is
sl@0:    subject to change. Applications should only use zlib.h.
sl@0:  */
sl@0: 
sl@0: #ifndef _INFUTIL_H
sl@0: #define _INFUTIL_H
sl@0: 
sl@0: typedef enum {
sl@0:       TYPE,     /* get type bits (3, including end bit) */
sl@0:       LENS,     /* get lengths for stored */
sl@0:       STORED,   /* processing stored block */
sl@0:       TABLE,    /* get table lengths */
sl@0:       BTREE,    /* get bit lengths tree for a dynamic block */
sl@0:       DTREE,    /* get length, distance trees for a dynamic block */
sl@0:       CODES,    /* processing fixed or dynamic block */
sl@0:       DRY,      /* output remaining window bytes */
sl@0:       DONE,     /* finished last block, done */
sl@0:       BAD}      /* got a data error--stuck here */
sl@0: inflate_block_mode;
sl@0: 
sl@0: /* inflate blocks semi-private state */
sl@0: struct inflate_blocks_state {
sl@0: 
sl@0:   /* mode */
sl@0:   inflate_block_mode  mode;     /* current inflate_block mode */
sl@0: 
sl@0:   /* mode dependent information */
sl@0:   union {
sl@0:     uInt left;          /* if STORED, bytes left to copy */
sl@0:     struct {
sl@0:       uInt table;               /* table lengths (14 bits) */
sl@0:       uInt index;               /* index into blens (or border) */
sl@0:       uIntf *blens;             /* bit lengths of codes */
sl@0:       uInt bb;                  /* bit length tree depth */
sl@0:       inflate_huft *tb;         /* bit length decoding tree */
sl@0:     } trees;            /* if DTREE, decoding info for trees */
sl@0:     struct {
sl@0:       inflate_codes_statef 
sl@0:          *codes;
sl@0:     } decode;           /* if CODES, current state */
sl@0:   } sub;                /* submode */
sl@0:   uInt last;            /* true if this block is the last block */
sl@0: 
sl@0:   /* mode independent information */
sl@0:   uInt bitk;            /* bits in bit buffer */
sl@0:   uLong bitb;           /* bit buffer */
sl@0:   inflate_huft *hufts;  /* single malloc for tree space */
sl@0:   Bytef *window;        /* sliding window */
sl@0:   Bytef *end;           /* one byte after sliding window */
sl@0:   Bytef *read;          /* window read pointer */
sl@0:   Bytef *write;         /* window write pointer */
sl@0:   check_func checkfn;   /* check function */
sl@0:   uLong check;          /* check on output */
sl@0: 
sl@0: };
sl@0: 
sl@0: 
sl@0: /* defines for inflate input/output */
sl@0: /*   update pointers and return */
sl@0: #define UPDBITS {s->bitb=b;s->bitk=k;}
sl@0: #define UPDIN {z->avail_in=n;z->total_in+=p-z->next_in;z->next_in=p;}
sl@0: #define UPDOUT {s->write=q;}
sl@0: #define UPDATE {UPDBITS UPDIN UPDOUT}
sl@0: #define LEAVE {UPDATE return inflate_flush(s,z,r);}
sl@0: /*   get bytes and bits */
sl@0: #define LOADIN {p=z->next_in;n=z->avail_in;b=s->bitb;k=s->bitk;}
sl@0: #define NEEDBYTE {if(n)r=Z_OK;else LEAVE}
sl@0: #define NEXTBYTE (n--,*p++)
sl@0: #define NEEDBITS(j) {while(k<(j)){NEEDBYTE;b|=((uLong)NEXTBYTE)<<k;k+=8;}}
sl@0: #define DUMPBITS(j) {b>>=(j);k-=(j);}
sl@0: /*   output bytes */
sl@0: #define WAVAIL (uInt)(q<s->read?s->read-q-1:s->end-q)
sl@0: #define LOADOUT {q=s->write;m=(uInt)WAVAIL;}
sl@0: #define WRAP {if(q==s->end&&s->read!=s->window){q=s->window;m=(uInt)WAVAIL;}}
sl@0: #define FLUSH {UPDOUT r=inflate_flush(s,z,r); LOADOUT}
sl@0: #define NEEDOUT {if(m==0){WRAP if(m==0){FLUSH WRAP if(m==0) LEAVE}}r=Z_OK;}
sl@0: #define OUTBYTE(a) {*q++=(Byte)(a);m--;}
sl@0: /*   load local pointers */
sl@0: #define LOAD {LOADIN LOADOUT}
sl@0: 
sl@0: /* masks for lower bits (size given to avoid silly warnings with Visual C++) */
sl@0: extern const uInt inflate_mask[17];
sl@0: 
sl@0: /* copy as much as possible from the sliding window to the output area */
sl@0: extern int inflate_flush OF((
sl@0:     inflate_blocks_statef *,
sl@0:     z_streamp ,
sl@0:     int));
sl@0: 
sl@0: struct internal_state      {int dummy;}; /* for buggy compilers */
sl@0: 
sl@0: #endif