/* 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

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_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 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 const 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