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Diffstat (limited to 'hash.h')
| -rw-r--r-- | hash.h | 154 |
1 files changed, 154 insertions, 0 deletions
@@ -0,0 +1,154 @@ +/* $NetBSD: hash.h,v 1.10 2009/01/24 10:59:09 dsl Exp $ */ + +/* + * Copyright (c) 1988, 1989, 1990 The Regents of the University of California. + * + * This code is derived from software contributed to Berkeley by + * Adam de Boor. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * from: @(#)hash.h 8.1 (Berkeley) 6/6/93 + */ + +/* + * Copyright (c) 1988, 1989 by Adam de Boor + * Copyright (c) 1989 by Berkeley Softworks + * All rights reserved. + * + * This code is derived from software contributed to Berkeley by + * Adam de Boor. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 4. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * from: @(#)hash.h 8.1 (Berkeley) 6/6/93 + */ + +/* hash.h -- + * + * This file contains definitions used by the hash module, + * which maintains hash tables. + */ + +#ifndef _HASH +#define _HASH + +/* + * The following defines one entry in the hash table. + */ + +typedef struct Hash_Entry { + struct Hash_Entry *next; /* Used to link together all the + * entries associated with the same + * bucket. */ + union { + void *clientPtr; /* Arbitrary pointer */ + time_t clientTime; /* Arbitrary Time */ + } clientInfo; + unsigned namehash; /* hash value of key */ + char name[1]; /* key string */ +} Hash_Entry; + +typedef struct Hash_Table { + struct Hash_Entry **bucketPtr;/* Pointers to Hash_Entry, one + * for each bucket in the table. */ + int size; /* Actual size of array. */ + int numEntries; /* Number of entries in the table. */ + int mask; /* Used to select bits for hashing. */ +} Hash_Table; + +/* + * The following structure is used by the searching routines + * to record where we are in the search. + */ + +typedef struct Hash_Search { + Hash_Table *tablePtr; /* Table being searched. */ + int nextIndex; /* Next bucket to check (after current). */ + Hash_Entry *hashEntryPtr; /* Next entry to check in current bucket. */ +} Hash_Search; + +/* + * Macros. + */ + +/* + * void * Hash_GetValue(h) + * Hash_Entry *h; + */ + +#define Hash_GetValue(h) ((h)->clientInfo.clientPtr) +#define Hash_GetTimeValue(h) ((h)->clientInfo.clientTime) + +/* + * Hash_SetValue(h, val); + * Hash_Entry *h; + * char *val; + */ + +#define Hash_SetValue(h, val) ((h)->clientInfo.clientPtr = (val)) +#define Hash_SetTimeValue(h, val) ((h)->clientInfo.clientTime = (val)) + +/* + * Hash_Size(n) returns the number of words in an object of n bytes + */ + +#define Hash_Size(n) (((n) + sizeof (int) - 1) / sizeof (int)) + +void Hash_InitTable(Hash_Table *, int); +void Hash_DeleteTable(Hash_Table *); +Hash_Entry *Hash_FindEntry(Hash_Table *, const char *); +Hash_Entry *Hash_CreateEntry(Hash_Table *, const char *, Boolean *); +void Hash_DeleteEntry(Hash_Table *, Hash_Entry *); +Hash_Entry *Hash_EnumFirst(Hash_Table *, Hash_Search *); +Hash_Entry *Hash_EnumNext(Hash_Search *); + +#endif /* _HASH */ |