1 /* infutil.h -- types and macros common to blocks and codes
2  * Copyright (C) 1995-2002 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 #ifndef NO_INFLATE_MASK
89 local uInt inflate_mask[17];
90 #endif
91 
92 /* copy as much as possible from the sliding window to the output area */
93 local int inflate_flush OF((
94     inflate_blocks_statef *,
95     z_streamp ,
96     int));
97 
98 #endif
99