First commit ~0,10

G/LIB/GIF_HASH.H

@@ -0,0 +1,31 @@
+/******************************************************************************
+* Declarations, global to other of the GIF-HASH.C module.		      *
+*									      *
+*					Written by Gershon Elber,  Jun 1989   *
+*******************************************************************************
+* History:								      *
+* 14 Jun 89 - Version 1.0 by Gershon Elber.				      *
+******************************************************************************/
+
+#define HT_SIZE			8192	   /* 12bits = 4096 or twice as big! */
+#define HT_KEY_MASK		0x1FFF			      /* 13bits keys */
+#define HT_KEY_NUM_BITS		13			      /* 13bits keys */
+#define HT_MAX_KEY		8191	/* 13bits - 1, maximal code possible */
+#define HT_MAX_CODE		4095	/* Biggest code possible in 12 bits. */
+
+/* The 32 bits of the long are divided into two parts for the key & code:   */
+/* 1. The code is 12 bits as our compression algorithm is limited to 12bits */
+/* 2. The key is 12 bits Prefix code + 8 bit new char or 20 bits.	    */
+#define HT_GET_KEY(l)	(l >> 12)
+#define HT_GET_CODE(l)	(l & 0x0FFF)
+#define HT_PUT_KEY(l)	(l << 12)
+#define HT_PUT_CODE(l)	(l & 0x0FFF)
+
+typedef struct GifHashTableType {
+    unsigned long HTable[HT_SIZE];
+} GifHashTableType;
+
+GifHashTableType *_InitHashTable(void);
+void _ClearHashTable(GifHashTableType *HashTable);
+void _InsertHashTable(GifHashTableType *HashTable, unsigned long Key, int Code);
+int _ExistsHashTable(GifHashTableType *HashTable, unsigned long Key);