/*
 * Copyright (C) 1995-1998 Mark Adler
 * For conditions of distribution and use, see copyright notice in zlib.h 
 */

/**
 * \file infutil.h
 * Types and macros common to blocks and codes.
 */

/* 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 */
/*@-redef@*/ /* FIX: inflate .c has duplicates */
      DONE,	/*!< finished last block, done */
      BAD	/*!< got a data error--stuck here */
/*@=redef@*/
} 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 */
/*@only@*/
  inflate_huft *hufts;  /*!< single malloc for tree space */
/*@owned@*/
  Bytef *window;        /*!< sliding window */
/*@dependent@*/
  Bytef *end;           /*!< one byte after sliding window */
/*@dependent@*/
  Bytef *read;          /*!< window read pointer */
/*@dependent@*/
  Bytef *write;         /*!< window write pointer */
/*@null@*/
  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++)
#ifdef __i386__
#define NEXTSHORT (n-=2, p+=2, (uLong)((unsigned short *)p)[-1])
#else
#define NEXTSHORT (n-=2, p+=2, (uLong)p[-2] | ((uLong)p[-1] << 8))
#endif
#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++) */
/*@unchecked@*/
extern uInt inflate_mask[17];

/* copy as much as possible from the sliding window to the output area */
int inflate_flush OF((
    inflate_blocks_statef *s,
    z_streamp z,
    int r))
#if defined(__i386__)
      __attribute__((regparm(3)))
#endif
	/*@modifies s, z @*/;

#endif