RetroZilla/security/nss/lib/base/hash.c

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2015-10-21 05:03:22 +02:00
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla 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/MPL/
*
* 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 the Netscape security libraries.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1994-2000
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#ifdef DEBUG
static const char CVS_ID[] = "@(#) $RCSfile: hash.c,v $ $Revision: 1.11 $ $Date: 2008/02/03 01:59:48 $";
#endif /* DEBUG */
/*
* hash.c
*
* This is merely a couple wrappers around NSPR's PLHashTable, using
* the identity hash and arena-aware allocators.
* This is a copy of ckfw/hash.c, with modifications to use NSS types
* (not Cryptoki types). Would like for this to be a single implementation,
* but doesn't seem like it will work.
*/
#ifndef BASE_H
#include "base.h"
#endif /* BASE_H */
#include "prbit.h"
/*
* nssHash
*
* nssHash_Create
* nssHash_Destroy
* nssHash_Add
* nssHash_Remove
* nssHash_Count
* nssHash_Exists
* nssHash_Lookup
* nssHash_Iterate
*/
struct nssHashStr {
NSSArena *arena;
PRBool i_alloced_arena;
PRLock *mutex;
/*
* The invariant that mutex protects is:
* The count accurately reflects the hashtable state.
*/
PLHashTable *plHashTable;
PRUint32 count;
};
static PLHashNumber
nss_identity_hash
(
const void *key
)
{
PRUint32 i = (PRUint32)key;
PR_ASSERT(sizeof(PLHashNumber) == sizeof(PRUint32));
return (PLHashNumber)i;
}
static PLHashNumber
nss_item_hash
(
const void *key
)
{
unsigned int i;
PLHashNumber h;
NSSItem *it = (NSSItem *)key;
h = 0;
for (i=0; i<it->size; i++)
h = PR_ROTATE_LEFT32(h, 4) ^ ((unsigned char *)it->data)[i];
return h;
}
static int
nss_compare_items(const void *v1, const void *v2)
{
PRStatus ignore;
return (int)nssItem_Equal((NSSItem *)v1, (NSSItem *)v2, &ignore);
}
/*
* nssHash_create
*
*/
NSS_IMPLEMENT nssHash *
nssHash_Create
(
NSSArena *arenaOpt,
PRUint32 numBuckets,
PLHashFunction keyHash,
PLHashComparator keyCompare,
PLHashComparator valueCompare
)
{
nssHash *rv;
NSSArena *arena;
PRBool i_alloced;
#ifdef NSSDEBUG
if( arenaOpt && PR_SUCCESS != nssArena_verifyPointer(arenaOpt) ) {
nss_SetError(NSS_ERROR_INVALID_POINTER);
return (nssHash *)NULL;
}
#endif /* NSSDEBUG */
if (arenaOpt) {
arena = arenaOpt;
i_alloced = PR_FALSE;
} else {
arena = nssArena_Create();
i_alloced = PR_TRUE;
}
rv = nss_ZNEW(arena, nssHash);
if( (nssHash *)NULL == rv ) {
goto loser;
}
rv->mutex = PZ_NewLock(nssILockOther);
if( (PZLock *)NULL == rv->mutex ) {
goto loser;
}
rv->plHashTable = PL_NewHashTable(numBuckets,
keyHash, keyCompare, valueCompare,
&nssArenaHashAllocOps, arena);
if( (PLHashTable *)NULL == rv->plHashTable ) {
(void)PZ_DestroyLock(rv->mutex);
goto loser;
}
rv->count = 0;
rv->arena = arena;
rv->i_alloced_arena = i_alloced;
return rv;
loser:
(void)nss_ZFreeIf(rv);
return (nssHash *)NULL;
}
/*
* nssHash_CreatePointer
*
*/
NSS_IMPLEMENT nssHash *
nssHash_CreatePointer
(
NSSArena *arenaOpt,
PRUint32 numBuckets
)
{
return nssHash_Create(arenaOpt, numBuckets,
nss_identity_hash, PL_CompareValues, PL_CompareValues);
}
/*
* nssHash_CreateString
*
*/
NSS_IMPLEMENT nssHash *
nssHash_CreateString
(
NSSArena *arenaOpt,
PRUint32 numBuckets
)
{
return nssHash_Create(arenaOpt, numBuckets,
PL_HashString, PL_CompareStrings, PL_CompareStrings);
}
/*
* nssHash_CreateItem
*
*/
NSS_IMPLEMENT nssHash *
nssHash_CreateItem
(
NSSArena *arenaOpt,
PRUint32 numBuckets
)
{
return nssHash_Create(arenaOpt, numBuckets,
nss_item_hash, nss_compare_items, PL_CompareValues);
}
/*
* nssHash_Destroy
*
*/
NSS_IMPLEMENT void
nssHash_Destroy
(
nssHash *hash
)
{
(void)PZ_DestroyLock(hash->mutex);
PL_HashTableDestroy(hash->plHashTable);
if (hash->i_alloced_arena) {
nssArena_Destroy(hash->arena);
} else {
nss_ZFreeIf(hash);
}
}
/*
* nssHash_Add
*
*/
NSS_IMPLEMENT PRStatus
nssHash_Add
(
nssHash *hash,
const void *key,
const void *value
)
{
PRStatus error = PR_FAILURE;
PLHashEntry *he;
PZ_Lock(hash->mutex);
he = PL_HashTableAdd(hash->plHashTable, key, (void *)value);
if( (PLHashEntry *)NULL == he ) {
nss_SetError(NSS_ERROR_NO_MEMORY);
} else if (he->value != value) {
nss_SetError(NSS_ERROR_HASH_COLLISION);
} else {
hash->count++;
error = PR_SUCCESS;
}
(void)PZ_Unlock(hash->mutex);
return error;
}
/*
* nssHash_Remove
*
*/
NSS_IMPLEMENT void
nssHash_Remove
(
nssHash *hash,
const void *it
)
{
PRBool found;
PZ_Lock(hash->mutex);
found = PL_HashTableRemove(hash->plHashTable, it);
if( found ) {
hash->count--;
}
(void)PZ_Unlock(hash->mutex);
return;
}
/*
* nssHash_Count
*
*/
NSS_IMPLEMENT PRUint32
nssHash_Count
(
nssHash *hash
)
{
PRUint32 count;
PZ_Lock(hash->mutex);
count = hash->count;
(void)PZ_Unlock(hash->mutex);
return count;
}
/*
* nssHash_Exists
*
*/
NSS_IMPLEMENT PRBool
nssHash_Exists
(
nssHash *hash,
const void *it
)
{
void *value;
PZ_Lock(hash->mutex);
value = PL_HashTableLookup(hash->plHashTable, it);
(void)PZ_Unlock(hash->mutex);
if( (void *)NULL == value ) {
return PR_FALSE;
} else {
return PR_TRUE;
}
}
/*
* nssHash_Lookup
*
*/
NSS_IMPLEMENT void *
nssHash_Lookup
(
nssHash *hash,
const void *it
)
{
void *rv;
PZ_Lock(hash->mutex);
rv = PL_HashTableLookup(hash->plHashTable, it);
(void)PZ_Unlock(hash->mutex);
return rv;
}
struct arg_str {
nssHashIterator fcn;
void *closure;
};
static PRIntn
nss_hash_enumerator
(
PLHashEntry *he,
PRIntn index,
void *arg
)
{
struct arg_str *as = (struct arg_str *)arg;
as->fcn(he->key, he->value, as->closure);
return HT_ENUMERATE_NEXT;
}
/*
* nssHash_Iterate
*
* NOTE that the iteration function will be called with the hashtable locked.
*/
NSS_IMPLEMENT void
nssHash_Iterate
(
nssHash *hash,
nssHashIterator fcn,
void *closure
)
{
struct arg_str as;
as.fcn = fcn;
as.closure = closure;
PZ_Lock(hash->mutex);
PL_HashTableEnumerateEntries(hash->plHashTable, nss_hash_enumerator, &as);
(void)PZ_Unlock(hash->mutex);
return;
}