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Diffstat (limited to '20120831/hash.c')
| -rw-r--r-- | 20120831/hash.c | 463 |
1 files changed, 0 insertions, 463 deletions
diff --git a/20120831/hash.c b/20120831/hash.c deleted file mode 100644 index a22e2f2..0000000 --- a/20120831/hash.c +++ /dev/null @@ -1,463 +0,0 @@ -/* $NetBSD: hash.c,v 1.19 2009/01/24 10:59:09 dsl Exp $ */ - -/* - * Copyright (c) 1988, 1989, 1990 The Regents of the University of California. - * 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. 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. - */ - -/* - * 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. - */ - -#ifndef MAKE_NATIVE -static char rcsid[] = "$NetBSD: hash.c,v 1.19 2009/01/24 10:59:09 dsl Exp $"; -#else -#include <sys/cdefs.h> -#ifndef lint -#if 0 -static char sccsid[] = "@(#)hash.c 8.1 (Berkeley) 6/6/93"; -#else -__RCSID("$NetBSD: hash.c,v 1.19 2009/01/24 10:59:09 dsl Exp $"); -#endif -#endif /* not lint */ -#endif - -/* hash.c -- - * - * This module contains routines to manipulate a hash table. - * See hash.h for a definition of the structure of the hash - * table. Hash tables grow automatically as the amount of - * information increases. - */ -#include "sprite.h" -#include "make.h" -#include "hash.h" - -/* - * Forward references to local procedures that are used before they're - * defined: - */ - -static void RebuildTable(Hash_Table *); - -/* - * The following defines the ratio of # entries to # buckets - * at which we rebuild the table to make it larger. - */ - -#define rebuildLimit 3 - -/* - *--------------------------------------------------------- - * - * Hash_InitTable -- - * - * This routine just sets up the hash table. - * - * Input: - * t Structure to to hold table. - * numBuckets How many buckets to create for starters. This - * number is rounded up to a power of two. If - * <= 0, a reasonable default is chosen. The - * table will grow in size later as needed. - * - * Results: - * None. - * - * Side Effects: - * Memory is allocated for the initial bucket area. - * - *--------------------------------------------------------- - */ - -void -Hash_InitTable(Hash_Table *t, int numBuckets) -{ - int i; - struct Hash_Entry **hp; - - /* - * Round up the size to a power of two. - */ - if (numBuckets <= 0) - i = 16; - else { - for (i = 2; i < numBuckets; i <<= 1) - continue; - } - t->numEntries = 0; - t->size = i; - t->mask = i - 1; - t->bucketPtr = hp = bmake_malloc(sizeof(*hp) * i); - while (--i >= 0) - *hp++ = NULL; -} - -/* - *--------------------------------------------------------- - * - * Hash_DeleteTable -- - * - * This routine removes everything from a hash table - * and frees up the memory space it occupied (except for - * the space in the Hash_Table structure). - * - * Results: - * None. - * - * Side Effects: - * Lots of memory is freed up. - * - *--------------------------------------------------------- - */ - -void -Hash_DeleteTable(Hash_Table *t) -{ - struct Hash_Entry **hp, *h, *nexth = NULL; - int i; - - for (hp = t->bucketPtr, i = t->size; --i >= 0;) { - for (h = *hp++; h != NULL; h = nexth) { - nexth = h->next; - free(h); - } - } - free(t->bucketPtr); - - /* - * Set up the hash table to cause memory faults on any future access - * attempts until re-initialization. - */ - t->bucketPtr = NULL; -} - -/* - *--------------------------------------------------------- - * - * Hash_FindEntry -- - * - * Searches a hash table for an entry corresponding to key. - * - * Input: - * t Hash table to search. - * key A hash key. - * - * Results: - * The return value is a pointer to the entry for key, - * if key was present in the table. If key was not - * present, NULL is returned. - * - * Side Effects: - * None. - * - *--------------------------------------------------------- - */ - -Hash_Entry * -Hash_FindEntry(Hash_Table *t, const char *key) -{ - Hash_Entry *e; - unsigned h; - const char *p; - - for (h = 0, p = key; *p;) - h = (h << 5) - h + *p++; - p = key; - for (e = t->bucketPtr[h & t->mask]; e != NULL; e = e->next) - if (e->namehash == h && strcmp(e->name, p) == 0) - return (e); - return NULL; -} - -/* - *--------------------------------------------------------- - * - * Hash_CreateEntry -- - * - * Searches a hash table for an entry corresponding to - * key. If no entry is found, then one is created. - * - * Input: - * t Hash table to search. - * key A hash key. - * newPtr Filled in with TRUE if new entry created, - * FALSE otherwise. - * - * Results: - * The return value is a pointer to the entry. If *newPtr - * isn't NULL, then *newPtr is filled in with TRUE if a - * new entry was created, and FALSE if an entry already existed - * with the given key. - * - * Side Effects: - * Memory may be allocated, and the hash buckets may be modified. - *--------------------------------------------------------- - */ - -Hash_Entry * -Hash_CreateEntry(Hash_Table *t, const char *key, Boolean *newPtr) -{ - Hash_Entry *e; - unsigned h; - const char *p; - int keylen; - struct Hash_Entry **hp; - - /* - * Hash the key. As a side effect, save the length (strlen) of the - * key in case we need to create the entry. - */ - for (h = 0, p = key; *p;) - h = (h << 5) - h + *p++; - keylen = p - key; - p = key; - for (e = t->bucketPtr[h & t->mask]; e != NULL; e = e->next) { - if (e->namehash == h && strcmp(e->name, p) == 0) { - if (newPtr != NULL) - *newPtr = FALSE; - return (e); - } - } - - /* - * The desired entry isn't there. Before allocating a new entry, - * expand the table if necessary (and this changes the resulting - * bucket chain). - */ - if (t->numEntries >= rebuildLimit * t->size) - RebuildTable(t); - e = bmake_malloc(sizeof(*e) + keylen); - hp = &t->bucketPtr[h & t->mask]; - e->next = *hp; - *hp = e; - Hash_SetValue(e, NULL); - e->namehash = h; - (void)strcpy(e->name, p); - t->numEntries++; - - if (newPtr != NULL) - *newPtr = TRUE; - return (e); -} - -/* - *--------------------------------------------------------- - * - * Hash_DeleteEntry -- - * - * Delete the given hash table entry and free memory associated with - * it. - * - * Results: - * None. - * - * Side Effects: - * Hash chain that entry lives in is modified and memory is freed. - * - *--------------------------------------------------------- - */ - -void -Hash_DeleteEntry(Hash_Table *t, Hash_Entry *e) -{ - Hash_Entry **hp, *p; - - if (e == NULL) - return; - for (hp = &t->bucketPtr[e->namehash & t->mask]; - (p = *hp) != NULL; hp = &p->next) { - if (p == e) { - *hp = p->next; - free(p); - t->numEntries--; - return; - } - } - (void)write(2, "bad call to Hash_DeleteEntry\n", 29); - abort(); -} - -/* - *--------------------------------------------------------- - * - * Hash_EnumFirst -- - * This procedure sets things up for a complete search - * of all entries recorded in the hash table. - * - * Input: - * t Table to be searched. - * searchPtr Area in which to keep state about search. - * - * Results: - * The return value is the address of the first entry in - * the hash table, or NULL if the table is empty. - * - * Side Effects: - * The information in searchPtr is initialized so that successive - * calls to Hash_Next will return successive HashEntry's - * from the table. - * - *--------------------------------------------------------- - */ - -Hash_Entry * -Hash_EnumFirst(Hash_Table *t, Hash_Search *searchPtr) -{ - searchPtr->tablePtr = t; - searchPtr->nextIndex = 0; - searchPtr->hashEntryPtr = NULL; - return Hash_EnumNext(searchPtr); -} - -/* - *--------------------------------------------------------- - * - * Hash_EnumNext -- - * This procedure returns successive entries in the hash table. - * - * Input: - * searchPtr Area used to keep state about search. - * - * Results: - * The return value is a pointer to the next HashEntry - * in the table, or NULL when the end of the table is - * reached. - * - * Side Effects: - * The information in searchPtr is modified to advance to the - * next entry. - * - *--------------------------------------------------------- - */ - -Hash_Entry * -Hash_EnumNext(Hash_Search *searchPtr) -{ - Hash_Entry *e; - Hash_Table *t = searchPtr->tablePtr; - - /* - * The hashEntryPtr field points to the most recently returned - * entry, or is nil if we are starting up. If not nil, we have - * to start at the next one in the chain. - */ - e = searchPtr->hashEntryPtr; - if (e != NULL) - e = e->next; - /* - * If the chain ran out, or if we are starting up, we need to - * find the next nonempty chain. - */ - while (e == NULL) { - if (searchPtr->nextIndex >= t->size) - return NULL; - e = t->bucketPtr[searchPtr->nextIndex++]; - } - searchPtr->hashEntryPtr = e; - return (e); -} - -/* - *--------------------------------------------------------- - * - * RebuildTable -- - * This local routine makes a new hash table that - * is larger than the old one. - * - * Results: - * None. - * - * Side Effects: - * The entire hash table is moved, so any bucket numbers - * from the old table are invalid. - * - *--------------------------------------------------------- - */ - -static void -RebuildTable(Hash_Table *t) -{ - Hash_Entry *e, *next = NULL, **hp, **xp; - int i, mask; - Hash_Entry **oldhp; - int oldsize; - - oldhp = t->bucketPtr; - oldsize = i = t->size; - i <<= 1; - t->size = i; - t->mask = mask = i - 1; - t->bucketPtr = hp = bmake_malloc(sizeof(*hp) * i); - while (--i >= 0) - *hp++ = NULL; - for (hp = oldhp, i = oldsize; --i >= 0;) { - for (e = *hp++; e != NULL; e = next) { - next = e->next; - xp = &t->bucketPtr[e->namehash & mask]; - e->next = *xp; - *xp = e; - } - } - free(oldhp); -} |
