gecko-dev/ef/gc/hash/openhash.c
1999-11-02 06:38:29 +00:00

133 lines
3.7 KiB
C

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; -*-
*
* The contents of this file are subject to the Netscape Public
* License Version 1.1 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.mozilla.org/NPL/
*
* Software distributed under the License is distributed on an "AS
* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
* implied. See the License for the specific language governing
* rights and limitations under the License.
*
* The Original Code is mozilla.org code.
*
* The Initial Developer of the Original Code is Netscape
* Communications Corporation. Portions created by Netscape are
* Copyright (C) 1998 Netscape Communications Corporation. All
* Rights Reserved.
*
* Contributor(s):
*/
#include "openhash.h"
#include "prlog.h"
PR_IMPLEMENT(PRStatus)
PL_OpenhashInit(PLOpenhash* self, PRUint32 initialSize,
PLOpenhashHashFun hash, PLOpenhashEqualFun equal,
PLOpenhashDestroyFun del, void* context)
{
self->header.size = initialSize;
self->header.hash = hash;
self->header.equal = equal;
self->header.destroy = del;
self->header.context = context;
memset(self->element, 0, sizeof(PLOpenhashElement) * initialSize);
return PR_SUCCESS;
}
PR_IMPLEMENT(void)
PL_OpenhashCleanup(PLOpenhash* self)
{
PL_OpenhashEmpty(self);
}
PR_IMPLEMENT(PLOpenhash*)
PL_NewOpenhash(PRUint32 initialSize,
PLOpenhashHashFun hash, PLOpenhashEqualFun equal,
PLOpenhashDestroyFun del, void* context)
{
PRStatus status;
PLOpenhash* self = malloc(sizeof(PLOpenhashHeader)
+ initialSize * sizeof(PLOpenhashElement));
if (self == NULL) return NULL;
status = PL_OpenhashInit(self, initialSize, hash, equal, del, context);
if (status != PR_SUCCESS) {
PL_OpenhashDestroy(self);
return NULL;
}
return self;
}
PR_IMPLEMENT(void)
PL_OpenhashDestroy(PLOpenhash* self)
{
PL_OpenhashCleanup(self);
free((void*)self);
}
#define PR_GOLDEN_RATIO 616161
#define PR_HASH1(key, size) (((key) * PR_GOLDEN_RATIO) & ((size) - 1))
#define PR_HASH2(key, size) (((key) * 97) + 1)
PR_IMPLEMENT(void*)
PL_OpenhashLookup(PLOpenhash* self, PRUword key)
{
PRUword htSize = self->header.size;
PRUword hash1 = PR_HASH1(++key, htSize);
PRUword hash2 = PR_HASH2(key, htSize);
PRUword i = hash1;
PLOpenhashElement* elements = self->element;
while (elements[i].key != 0) {
if (elements[i].key == key)
return elements[i].value;
else {
i = (i + hash2) % htSize;
PR_ASSERT(i != hash1);
}
}
return NULL;
}
PR_IMPLEMENT(void)
PL_OpenhashAdd(PLOpenhash* self, PRUword key, void* value)
{
PRUword htSize = self->header.size;
PRUword hash1 = PR_HASH1(++key, htSize);
PRUword hash2 = PR_HASH2(key, htSize);
PRUword i = hash1;
PLOpenhashElement* elements = self->element;
while (elements[i].key != 0) {
i = (i + hash2) % htSize;
PR_ASSERT(i != hash1);
}
elements[i].key = key;
elements[i].value = value;
}
PR_IMPLEMENT(PRStatus)
PL_OpenhashRemove(PLOpenhash* self, PRUword key)
{
PR_ASSERT(0);
return PR_FAILURE;
}
PR_IMPLEMENT(void)
PL_OpenhashEmpty(PLOpenhash* self)
{
PRUword i;
PLOpenhashElement* element = self->element;
for (i = 0; i < self->header.size; i++) {
if (element->key != 0) {
self->header.destroy(self->header.context, element);
element->key = 0;
}
element++;
}
}
/******************************************************************************/