hash.h revision 256281
1/* $NetBSD: hash.h,v 1.10 2009/01/24 10:59:09 dsl Exp $ */ 2 3/* 4 * Copyright (c) 1988, 1989, 1990 The Regents of the University of California. 5 * 6 * This code is derived from software contributed to Berkeley by 7 * Adam de Boor. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * from: @(#)hash.h 8.1 (Berkeley) 6/6/93 34 */ 35 36/* 37 * Copyright (c) 1988, 1989 by Adam de Boor 38 * Copyright (c) 1989 by Berkeley Softworks 39 * All rights reserved. 40 * 41 * This code is derived from software contributed to Berkeley by 42 * Adam de Boor. 43 * 44 * Redistribution and use in source and binary forms, with or without 45 * modification, are permitted provided that the following conditions 46 * are met: 47 * 1. Redistributions of source code must retain the above copyright 48 * notice, this list of conditions and the following disclaimer. 49 * 2. Redistributions in binary form must reproduce the above copyright 50 * notice, this list of conditions and the following disclaimer in the 51 * documentation and/or other materials provided with the distribution. 52 * 3. All advertising materials mentioning features or use of this software 53 * must display the following acknowledgement: 54 * This product includes software developed by the University of 55 * California, Berkeley and its contributors. 56 * 4. Neither the name of the University nor the names of its contributors 57 * may be used to endorse or promote products derived from this software 58 * without specific prior written permission. 59 * 60 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 61 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 62 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 63 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 64 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 65 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 66 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 67 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 68 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 69 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 70 * SUCH DAMAGE. 71 * 72 * from: @(#)hash.h 8.1 (Berkeley) 6/6/93 73 */ 74 75/* hash.h -- 76 * 77 * This file contains definitions used by the hash module, 78 * which maintains hash tables. 79 */ 80 81#ifndef _HASH 82#define _HASH 83 84/* 85 * The following defines one entry in the hash table. 86 */ 87 88typedef struct Hash_Entry { 89 struct Hash_Entry *next; /* Used to link together all the 90 * entries associated with the same 91 * bucket. */ 92 union { 93 void *clientPtr; /* Arbitrary pointer */ 94 time_t clientTime; /* Arbitrary Time */ 95 } clientInfo; 96 unsigned namehash; /* hash value of key */ 97 char name[1]; /* key string */ 98} Hash_Entry; 99 100typedef struct Hash_Table { 101 struct Hash_Entry **bucketPtr;/* Pointers to Hash_Entry, one 102 * for each bucket in the table. */ 103 int size; /* Actual size of array. */ 104 int numEntries; /* Number of entries in the table. */ 105 int mask; /* Used to select bits for hashing. */ 106} Hash_Table; 107 108/* 109 * The following structure is used by the searching routines 110 * to record where we are in the search. 111 */ 112 113typedef struct Hash_Search { 114 Hash_Table *tablePtr; /* Table being searched. */ 115 int nextIndex; /* Next bucket to check (after current). */ 116 Hash_Entry *hashEntryPtr; /* Next entry to check in current bucket. */ 117} Hash_Search; 118 119/* 120 * Macros. 121 */ 122 123/* 124 * void * Hash_GetValue(h) 125 * Hash_Entry *h; 126 */ 127 128#define Hash_GetValue(h) ((h)->clientInfo.clientPtr) 129#define Hash_GetTimeValue(h) ((h)->clientInfo.clientTime) 130 131/* 132 * Hash_SetValue(h, val); 133 * Hash_Entry *h; 134 * char *val; 135 */ 136 137#define Hash_SetValue(h, val) ((h)->clientInfo.clientPtr = (val)) 138#define Hash_SetTimeValue(h, val) ((h)->clientInfo.clientTime = (val)) 139 140/* 141 * Hash_Size(n) returns the number of words in an object of n bytes 142 */ 143 144#define Hash_Size(n) (((n) + sizeof (int) - 1) / sizeof (int)) 145 146void Hash_InitTable(Hash_Table *, int); 147void Hash_DeleteTable(Hash_Table *); 148Hash_Entry *Hash_FindEntry(Hash_Table *, const char *); 149Hash_Entry *Hash_CreateEntry(Hash_Table *, const char *, Boolean *); 150void Hash_DeleteEntry(Hash_Table *, Hash_Entry *); 151Hash_Entry *Hash_EnumFirst(Hash_Table *, Hash_Search *); 152Hash_Entry *Hash_EnumNext(Hash_Search *); 153 154#endif /* _HASH */ 155