gecko-dev/xpcom/ds/nsHashtable.cpp

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C++

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/*
* The contents of this file are subject to the Netscape Public License
* Version 1.0 (the "NPL"); you may not use this file except in
* compliance with the NPL. You may obtain a copy of the NPL at
* http://www.mozilla.org/NPL/
*
* Software distributed under the NPL is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
* for the specific language governing rights and limitations under the
* NPL.
*
* The Initial Developer of this code under the NPL is Netscape
* Communications Corporation. Portions created by Netscape are
* Copyright (C) 1998 Netscape Communications Corporation. All Rights
* Reserved.
*/
#include "prmem.h"
#include "prlog.h"
#include "nsHashtable.h"
//
// Key operations
//
static PR_CALLBACK PLHashNumber _hashValue(const void *key)
{
return ((const nsHashKey *) key)->HashValue();
}
static PR_CALLBACK PRIntn _hashKeyCompare(const void *key1, const void *key2) {
return ((const nsHashKey *) key1)->Equals((const nsHashKey *) key2);
}
static PR_CALLBACK PRIntn _hashValueCompare(const void *value1,
const void *value2) {
// We're not going to make any assumptions about value equality
return 0;
}
//
// Memory callbacks
//
static PR_CALLBACK void *_hashAllocTable(void *pool, PRSize size) {
return PR_MALLOC(size);
}
static PR_CALLBACK void _hashFreeTable(void *pool, void *item) {
PR_DELETE(item);
}
static PR_CALLBACK PLHashEntry *_hashAllocEntry(void *pool, const void *key) {
return PR_NEW(PLHashEntry);
}
static PR_CALLBACK void _hashFreeEntry(void *pool, PLHashEntry *entry,
PRUintn flag) {
if (flag == HT_FREE_ENTRY) {
delete (nsHashKey *) (entry->key);
PR_DELETE(entry);
}
}
static PLHashAllocOps _hashAllocOps = {
_hashAllocTable, _hashFreeTable,
_hashAllocEntry, _hashFreeEntry
};
//
// Enumerator callback
//
struct _HashEnumerateArgs {
nsHashtableEnumFunc fn;
void* arg;
};
static PR_CALLBACK PRIntn _hashEnumerate(PLHashEntry *he, PRIntn i, void *arg)
{
_HashEnumerateArgs* thunk = (_HashEnumerateArgs*)arg;
return thunk->fn((nsHashKey *) he->key, he->value, thunk->arg)
? HT_ENUMERATE_NEXT
: HT_ENUMERATE_STOP;
}
//
// HashKey
//
nsHashKey::nsHashKey(void)
{
}
nsHashKey::~nsHashKey(void)
{
}
nsHashtable::nsHashtable(PRUint32 aInitSize, PRBool threadSafe)
: mLock(NULL)
{
hashtable = PL_NewHashTable(aInitSize,
_hashValue,
_hashKeyCompare,
_hashValueCompare,
&_hashAllocOps,
NULL);
if (threadSafe == PR_TRUE)
{
mLock = PR_NewLock();
if (mLock == NULL)
{
// Cannot create a lock. If running on a multiprocessing system
// we are sure to die.
PR_ASSERT(mLock != NULL);
}
}
}
nsHashtable::~nsHashtable() {
PL_HashTableDestroy(hashtable);
if (mLock) PR_DestroyLock(mLock);
}
PRBool nsHashtable::Exists(nsHashKey *aKey)
{
PLHashNumber hash = aKey->HashValue();
if (mLock) PR_Lock(mLock);
PLHashEntry **hep = PL_HashTableRawLookup(hashtable, hash, (void *) aKey);
if (mLock) PR_Unlock(mLock);
return *hep != NULL;
}
void *nsHashtable::Put(nsHashKey *aKey, void *aData) {
void *res = NULL;
PLHashNumber hash = aKey->HashValue();
PLHashEntry *he;
if (mLock) PR_Lock(mLock);
PLHashEntry **hep = PL_HashTableRawLookup(hashtable, hash, (void *) aKey);
if ((he = *hep) != NULL) {
res = he->value;
he->value = aData;
} else {
PL_HashTableRawAdd(hashtable, hep, hash,
(void *) aKey->Clone(), aData);
}
if (mLock) PR_Unlock(mLock);
return res;
}
void *nsHashtable::Get(nsHashKey *aKey) {
if (mLock) PR_Lock(mLock);
void *ret = PL_HashTableLookup(hashtable, (void *) aKey);
if (mLock) PR_Unlock(mLock);
return ret;
}
void *nsHashtable::Remove(nsHashKey *aKey) {
PLHashNumber hash = aKey->HashValue();
PLHashEntry *he;
if (mLock) PR_Lock(mLock);
PLHashEntry **hep = PL_HashTableRawLookup(hashtable, hash, (void *) aKey);
void *res = NULL;
if ((he = *hep) != NULL) {
res = he->value;
PL_HashTableRawRemove(hashtable, hep, he);
}
if (mLock) PR_Unlock(mLock);
return res;
}
static PR_CALLBACK PRIntn _hashEnumerateCopy(PLHashEntry *he, PRIntn i, void *arg)
{
nsHashtable *newHashtable = (nsHashtable *)arg;
newHashtable->Put((nsHashKey *) he->key, he->value);
return HT_ENUMERATE_NEXT;
}
nsHashtable * nsHashtable::Clone() {
PRBool threadSafe = PR_FALSE;
if (mLock)
threadSafe = PR_TRUE;
nsHashtable *newHashTable = new nsHashtable(hashtable->nentries, threadSafe);
PL_HashTableEnumerateEntries(hashtable, _hashEnumerateCopy, newHashTable);
return newHashTable;
}
void nsHashtable::Enumerate(nsHashtableEnumFunc aEnumFunc, void* closure) {
_HashEnumerateArgs thunk;
thunk.fn = aEnumFunc;
thunk.arg = closure;
PL_HashTableEnumerateEntries(hashtable, _hashEnumerate, &thunk);
}
static PR_CALLBACK PRIntn _hashEnumerateRemove(PLHashEntry *he, PRIntn i, void *arg)
{
return HT_ENUMERATE_REMOVE;
}
void nsHashtable::Reset() {
PL_HashTableEnumerateEntries(hashtable, _hashEnumerateRemove, NULL);
}
////////////////////////////////////////////////////////////////////////////////
nsCStringKey::nsCStringKey(const char* str)
: mStr(mBuf)
{
PRUint32 len = PL_strlen(str);
if (len >= sizeof(mBuf)) {
mStr = PL_strdup(str);
NS_ASSERTION(mStr, "out of memory");
}
else {
PL_strcpy(mStr, str);
}
}
nsCStringKey::~nsCStringKey(void)
{
if (mStr != mBuf)
PL_strfree(mStr);
}
PRUint32 nsCStringKey::HashValue(void) const
{
return (PRUint32) PL_HashString((const void*) mStr);
}
PRBool nsCStringKey::Equals(const nsHashKey* aKey) const
{
return PL_strcmp( ((nsCStringKey*)aKey)->mStr, mStr ) == 0;
}
nsHashKey* nsCStringKey::Clone() const
{
return new nsCStringKey(mStr);
}
////////////////////////////////////////////////////////////////////////////////