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inftrees.h
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1 /* inftrees.h -- header to use inftrees.c
2  * Copyright (C) 1995-2005, 2010 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 
12 
13 /* Structure for decoding tables. Each entry provides either the
14  information needed to do the operation requested by the code that
15  indexed that table entry, or it provides a pointer to another
16  table that indexes more bits of the code. op indicates whether
17  the entry is a pointer to another table, a literal, a length or
18  distance, an end-of-block, or an invalid code. For a table
19  pointer, the low four bits of op is the number of index bits of
20  that table. For a length or distance, the low four bits of op
21  is the number of extra bits to get after the code. bits is
22  the number of bits in this code or part of the code to drop off
23  of the bit buffer. val is the actual byte to output in the case
24  of a literal, the base length or distance, or the offset from
25  the current table to the next table. Each entry is four bytes. */
26 typedef struct {
27  unsigned char op; /* operation, extra bits, table bits */
28  unsigned char bits; /* bits in this part of the code */
29  unsigned short val; /* offset in table or code value */
30 } code;
31 
32 /* op values as set by inflate_table():
33  00000000 - literal
34  0000tttt - table link, tttt != 0 is the number of table index bits
35  0001eeee - length or distance, eeee is the number of extra bits
36  01100000 - end of block
37  01000000 - invalid code
38  */
39 
40 /* Maximum size of the dynamic table. The maximum number of code structures is
41  1444, which is the sum of 852 for literal/length codes and 592 for distance
42  codes. These values were found by exhaustive searches using the program
43  examples/enough.c found in the zlib distribtution. The arguments to that
44  program are the number of symbols, the initial root table size, and the
45  maximum bit length of a code. "enough 286 9 15" for literal/length codes
46  returns returns 852, and "enough 30 6 15" for distance codes returns 592.
47  The initial root table size (9 or 6) is found in the fifth argument of the
48  inflate_table() calls in inflate.c and infback.c. If the root table size is
49  changed, then these maximum sizes would be need to be recalculated and
50  updated. */
51 #define ENOUGH_LENS 852
52 #define ENOUGH_DISTS 592
53 #define ENOUGH (ENOUGH_LENS+ENOUGH_DISTS)
54 
55 /* Type of code to build for inflate_table() */
56 typedef enum {
60 } codetype;
61 
62 int ZLIB_INTERNAL inflate_table OF((codetype type, unsigned short FAR *lens,
63  unsigned codes, code FAR * FAR *table,
64  unsigned FAR *bits, unsigned short FAR *work));
65 
unsigned short val
Definition: inftrees.h:29
Definition: inftrees.h:59
int ZLIB_INTERNAL inflate_table OF((codetype type, unsigned short FAR *lens, unsigned codes, code FAR *FAR *table, unsigned FAR *bits, unsigned short FAR *work))
#define ZLIB_INTERNAL
Definition: compress_.c:8
unsigned char op
Definition: inftrees.h:27
int ZLIB_INTERNAL inflate_table(codetype type, unsigned short FAR *lens, unsigned codes, code FAR *FAR *table, unsigned FAR *bits, unsigned short FAR *work)
Definition: inftrees.c:39
Definition: inftrees.h:57
#define ABC_NAMESPACE_HEADER_START
NAMESPACES ///.
Definition: abc_global.h:105
unsigned char bits
Definition: inftrees.h:28
#define ABC_NAMESPACE_HEADER_END
Definition: abc_global.h:106
codetype
Definition: inftrees.h:56
Definition: inftrees.h:26
Definition: inftrees.h:58
#define FAR
Definition: zconf.h:329
static char * bits(int n)
Definition: abcSaucy.c:201