zlib/infutil.h

   1 /* infutil.h -- types and macros common to blocks and codes
   2  * Copyright (C) 1995-1998 Mark Adler
   3  * For conditions of distribution and use, see copyright notice in zlib.h
   4  */
   5
   6 /* WARNING: this file should *not* be used by applications. It is
   7    part of the implementation of the compression library and is
   8    subject to change. Applications should only use zlib.h.
   9  */
  10
  11 #ifndef _INFUTIL_H
  12 #define _INFUTIL_H
  13
  14 typedef enum {
  15       TYPE,     /* get type bits (3, including end bit) */
  16       LENS,     /* get lengths for stored */
  17       STORED,   /* processing stored block */
  18       TABLE,    /* get table lengths */
  19       BTREE,    /* get bit lengths tree for a dynamic block */
  20       DTREE,    /* get length, distance trees for a dynamic block */
  21       CODES,    /* processing fixed or dynamic block */
  22       DRY,      /* output remaining window bytes */
  23       DONE,     /* finished last block, done */
  24       BAD}      /* got a data error--stuck here */
  25 inflate_block_mode;
  26
  27 /* inflate blocks semi-private state */
  28 struct inflate_blocks_state {
  29
  30   /* mode */
  31   inflate_block_mode  mode;     /* current inflate_block mode */
  32
  33   /* mode dependent information */
  34   union {
  35     uInt left;          /* if STORED, bytes left to copy */
  36     struct {
  37       uInt table;               /* table lengths (14 bits) */
  38       uInt index;               /* index into blens (or border) */
  39       uIntf *blens;             /* bit lengths of codes */
  40       uInt bb;                  /* bit length tree depth */
  41       inflate_huft *tb;         /* bit length decoding tree */
  42     } trees;            /* if DTREE, decoding info for trees */
  43     struct {
  44       inflate_codes_statef
  45          *codes;
  46     } decode;           /* if CODES, current state */
  47   } sub;                /* submode */
  48   uInt last;            /* true if this block is the last block */
  49
  50   /* mode independent information */
  51   uInt bitk;            /* bits in bit buffer */
  52   uLong bitb;           /* bit buffer */
  53   inflate_huft *hufts;  /* single malloc for tree space */
  54   Bytef *window;        /* sliding window */
  55   Bytef *end;           /* one byte after sliding window */
  56   Bytef *read;          /* window read pointer */
  57   Bytef *write;         /* window write pointer */
  58   check_func checkfn;   /* check function */
  59   uLong check;          /* check on output */
  60
  61 };
  62
  63
  64 /* defines for inflate input/output */
  65 /*   update pointers and return */
  66 #define UPDBITS {s->bitb=b;s->bitk=k;}
  67 #define UPDIN {z->avail_in=n;z->total_in+=p-z->next_in;z->next_in=p;}
  68 #define UPDOUT {s->write=q;}
  69 #define UPDATE {UPDBITS UPDIN UPDOUT}
  70 #define LEAVE {UPDATE return inflate_flush(s,z,r);}
  71 /*   get bytes and bits */
  72 #define LOADIN {p=z->next_in;n=z->avail_in;b=s->bitb;k=s->bitk;}
  73 #define NEEDBYTE {if(n)r=Z_OK;else LEAVE}
  74 #define NEXTBYTE (n--,*p++)
  75 #define NEEDBITS(j) {while(k<(j)){NEEDBYTE;b|=((uLong)NEXTBYTE)<<k;k+=8;}}
  76 #define DUMPBITS(j) {b>>=(j);k-=(j);}
  77 /*   output bytes */
  78 #define WAVAIL (uInt)(q<s->read?s->read-q-1:s->end-q)
  79 #define LOADOUT {q=s->write;m=(uInt)WAVAIL;}
  80 #define WRAP {if(q==s->end&&s->read!=s->window){q=s->window;m=(uInt)WAVAIL;}}
  81 #define FLUSH {UPDOUT r=inflate_flush(s,z,r); LOADOUT}
  82 #define NEEDOUT {if(m==0){WRAP if(m==0){FLUSH WRAP if(m==0) LEAVE}}r=Z_OK;}
  83 #define OUTBYTE(a) {*q++=(Byte)(a);m--;}
  84 /*   load local pointers */
  85 #define LOAD {LOADIN LOADOUT}
  86
  87 /* masks for lower bits (size given to avoid silly warnings with Visual C++) */
  88 extern uInt inflate_mask[17];
  89
  90 /* copy as much as possible from the sliding window to the output area */
  91 extern int inflate_flush OF((
  92     inflate_blocks_statef *,
  93     z_streamp ,
  94     int));
  95
  96 struct internal_state      {int dummy;}; /* for buggy compilers */
  97
  98 #endif