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/*
* Copyright (c) 1995-2002 Silicon Graphics, Inc. All Rights Reserved.
* Copyright (c) 2013 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published
* by the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
* License for more details.
*/
#include "pmapi.h"
#include "impl.h"
#include <stddef.h>
void
__pmHashInit(__pmHashCtl *hcp)
{
memset(hcp, 0, sizeof(*hcp));
}
__pmHashNode *
__pmHashSearch(unsigned int key, __pmHashCtl *hcp)
{
__pmHashNode *hp;
if (hcp->hsize == 0)
return NULL;
for (hp = hcp->hash[key % hcp->hsize]; hp != NULL; hp = hp->next) {
if (hp->key == key)
return hp;
}
return NULL;
}
int
__pmHashAdd(unsigned int key, void *data, __pmHashCtl *hcp)
{
__pmHashNode *hp;
int k;
hcp->nodes++;
if (hcp->hsize == 0) {
hcp->hsize = 1; /* arbitrary number */
if ((hcp->hash = (__pmHashNode **)calloc(hcp->hsize, sizeof(__pmHashNode *))) == NULL) {
hcp->hsize = 0;
return -oserror();
}
}
else if (hcp->nodes / 4 > hcp->hsize) {
__pmHashNode *tp;
__pmHashNode **old = hcp->hash;
int oldsize = hcp->hsize;
hcp->hsize *= 2;
if (hcp->hsize % 2) hcp->hsize++;
if (hcp->hsize % 3) hcp->hsize += 2;
if (hcp->hsize % 5) hcp->hsize += 2;
if ((hcp->hash = (__pmHashNode **)calloc(hcp->hsize, sizeof(__pmHashNode *))) == NULL) {
hcp->hsize = oldsize;
hcp->hash = old;
return -oserror();
}
/*
* re-link chains
*/
while (oldsize) {
for (hp = old[--oldsize]; hp != NULL; ) {
tp = hp;
hp = hp->next;
k = tp->key % hcp->hsize;
tp->next = hcp->hash[k];
hcp->hash[k] = tp;
}
}
free(old);
}
if ((hp = (__pmHashNode *)malloc(sizeof(__pmHashNode))) == NULL)
return -oserror();
k = key % hcp->hsize;
hp->key = key;
hp->data = data;
hp->next = hcp->hash[k];
hcp->hash[k] = hp;
return 1;
}
int
__pmHashDel(unsigned int key, void *data, __pmHashCtl *hcp)
{
__pmHashNode *hp;
__pmHashNode *lhp = NULL;
if (hcp->hsize == 0)
return 0;
for (hp = hcp->hash[key % hcp->hsize]; hp != NULL; hp = hp->next) {
if (hp->key == key && hp->data == data) {
if (lhp == NULL)
hcp->hash[key % hcp->hsize] = hp->next;
else
lhp->next = hp->next;
free(hp);
return 1;
}
lhp = hp;
}
return 0;
}
void
__pmHashClear(__pmHashCtl *hcp)
{
if (hcp->hsize != 0) {
free(hcp->hash);
hcp->hsize = 0;
}
}
/*
* Iterate over the entire hash table. For each entry, call *cb,
* passing *cdata and the current key/value pair. The function's
* return value decides how to continue or abort iteration. The
* callback function must not modify the hash table.
*/
void
__pmHashWalkCB(__pmHashWalkCallback cb, void *cdata, const __pmHashCtl *hcp)
{
int n;
for (n = 0; n < hcp->hsize; n++) {
__pmHashNode *tp = hcp->hash[n];
__pmHashNode **tpp = & hcp->hash[n];
while (tp != NULL) {
__pmHashWalkState state = (*cb)(tp, cdata);
switch (state) {
case PM_HASH_WALK_DELETE_STOP:
*tpp = tp->next; /* unlink */
free(tp); /* delete */
return; /* & stop */
case PM_HASH_WALK_NEXT:
tpp = &tp->next;
tp = *tpp;
break;
case PM_HASH_WALK_DELETE_NEXT:
*tpp = tp->next; /* unlink */
/* NB: do not change tpp. It will still point at the previous
* node's "next" pointer. Consider consecutive CONTINUE_DELETEs.
*/
free(tp); /* delete */
tp = *tpp; /* == tp->next, except that tp is already freed. */
break; /* & next */
case PM_HASH_WALK_STOP:
default:
return;
}
}
}
}
/*
* Walk a hash table; state flow is START ... NEXT ... NEXT ...
*/
__pmHashNode *
__pmHashWalk(__pmHashCtl *hcp, __pmHashWalkState state)
{
__pmHashNode *node;
if (hcp->hsize == 0)
return NULL;
if (state == PM_HASH_WALK_START) {
hcp->index = 0;
hcp->next = hcp->hash[0];
}
while (hcp->next == NULL) {
hcp->index++;
if (hcp->index >= hcp->hsize)
return NULL;
hcp->next = hcp->hash[hcp->index];
}
node = hcp->next;
hcp->next = node->next;
return node;
}
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