1/******************************************************************************
2* Declarations, global to other of the GIF-HASH.C module.		      *
3*									      *
4*					Written by Gershon Elber,  Jun 1989   *
5*******************************************************************************
6* History:								      *
7* 14 Jun 89 - Version 1.0 by Gershon Elber.				      *
8******************************************************************************/
9
10#ifndef _GIF_HASH_H_
11#define _GIF_HASH_H_
12
13#ifdef HAVE_CONFIG_H
14#include <config.h>
15#endif
16
17/* Find a thirty-two bit int type */
18#ifdef HAVE_STDINT_H
19#include <stdint.h>
20#endif
21#ifdef HAVE_INTTYPES_H
22#include <inttypes.h>
23#endif
24#ifdef HAVE_SYS_TYPES_H
25#include <sys/types.h>
26#endif
27#ifdef HAVE_UNISTD_H
28#include <unistd.h>
29#endif
30
31#ifdef HAVE_BASETSD_H
32#include <basetsd.h>
33#endif
34
35#define HT_SIZE			8192	   /* 12bits = 4096 or twice as big! */
36#define HT_KEY_MASK		0x1FFF			      /* 13bits keys */
37#define HT_KEY_NUM_BITS		13			      /* 13bits keys */
38#define HT_MAX_KEY		8191	/* 13bits - 1, maximal code possible */
39#define HT_MAX_CODE		4095	/* Biggest code possible in 12 bits. */
40
41/* The 32 bits of the long are divided into two parts for the key & code:   */
42/* 1. The code is 12 bits as our compression algorithm is limited to 12bits */
43/* 2. The key is 12 bits Prefix code + 8 bit new char or 20 bits.	    */
44/* The key is the upper 20 bits.  The code is the lower 12. */
45#define HT_GET_KEY(l)	(l >> 12)
46#define HT_GET_CODE(l)	(l & 0x0FFF)
47#define HT_PUT_KEY(l)	(l << 12)
48#define HT_PUT_CODE(l)	(l & 0x0FFF)
49
50typedef struct GifHashTableType {
51    UINT32 HTable[HT_SIZE];
52} GifHashTableType;
53
54GifHashTableType *_InitHashTable(void);
55void _ClearHashTable(GifHashTableType *HashTable);
56void _InsertHashTable(GifHashTableType *HashTable, UINT32 Key, int Code);
57int _ExistsHashTable(GifHashTableType *HashTable, UINT32 Key);
58
59#endif /* _GIF_HASH_H_ */
60