gecko-dev/xpcom/glue/nsClassHashtable.h

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** 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 C++ hashtable templates.
*
* The Initial Developer of the Original Code is
* Benjamin Smedberg.
* Portions created by the Initial Developer are Copyright (C) 2002
* 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 ***** */
#ifndef nsClassHashtable_h__
#define nsClassHashtable_h__
#include "nsBaseHashtable.h"
#include "nsHashKeys.h"
#include "nsAutoPtr.h"
/**
* templated hashtable class maps keys to C++ object pointers.
* See nsBaseHashtable for complete declaration.
* @param KeyClass a wrapper-class for the hashtable key, see nsHashKeys.h
* for a complete specification.
* @param Class the class-type being wrapped
* @see nsInterfaceHashtable, nsClassHashtable
*/
template<class KeyClass,class T>
class nsClassHashtable :
public nsBaseHashtable< KeyClass, nsAutoPtr<T>, T* >
{
public:
typedef typename KeyClass::KeyType KeyType;
typedef T* UserDataType;
typedef nsBaseHashtable< KeyClass, nsAutoPtr<T>, T* > base_type;
/**
* @copydoc nsBaseHashtable::Get
* @param pData if the key doesn't exist, pData will be set to nsnull.
*/
bool Get(KeyType aKey, UserDataType* pData) const;
/**
* @copydoc nsBaseHashtable::Get
* @returns NULL if the key is not present.
*/
UserDataType Get(KeyType aKey) const;
/**
* Remove the entry for the given key from the hashtable and return it in
* aOut. If the key is not in the hashtable, aOut's pointer is set to NULL.
*
* Normally, an entry is deleted when it's removed from an nsClassHashtable,
* but this function transfers ownership of the entry back to the caller
* through aOut -- the entry will be deleted when aOut goes out of scope.
*
* @param aKey the key to get and remove from the hashtable
*/
void RemoveAndForget(KeyType aKey, nsAutoPtr<T> &aOut);
};
/**
* Thread-safe version of nsClassHashtable
* @param KeyClass a wrapper-class for the hashtable key, see nsHashKeys.h
* for a complete specification.
* @param Class the class-type being wrapped
* @see nsInterfaceHashtable, nsClassHashtable
*/
template<class KeyClass,class T>
class nsClassHashtableMT :
public nsBaseHashtableMT< KeyClass, nsAutoPtr<T>, T* >
{
public:
typedef typename KeyClass::KeyType KeyType;
typedef T* UserDataType;
typedef nsBaseHashtableMT< KeyClass, nsAutoPtr<T>, T* > base_type;
/**
* @copydoc nsBaseHashtable::Get
* @param pData if the key doesn't exist, pData will be set to nsnull.
*/
bool Get(KeyType aKey, UserDataType* pData) const;
};
//
// nsClassHashtable definitions
//
template<class KeyClass,class T>
bool
nsClassHashtable<KeyClass,T>::Get(KeyType aKey, T** retVal) const
{
typename base_type::EntryType* ent = this->GetEntry(aKey);
if (ent)
{
if (retVal)
*retVal = ent->mData;
return true;
}
if (retVal)
*retVal = nsnull;
return false;
}
template<class KeyClass,class T>
T*
nsClassHashtable<KeyClass,T>::Get(KeyType aKey) const
{
typename base_type::EntryType* ent = this->GetEntry(aKey);
if (!ent)
return NULL;
return ent->mData;
}
template<class KeyClass,class T>
void
nsClassHashtable<KeyClass,T>::RemoveAndForget(KeyType aKey, nsAutoPtr<T> &aOut)
{
aOut = nsnull;
nsAutoPtr<T> ptr;
typename base_type::EntryType *ent = this->GetEntry(aKey);
if (!ent)
return;
// Transfer ownership from ent->mData into aOut.
aOut = ent->mData;
this->Remove(aKey);
}
//
// nsClassHashtableMT definitions
//
template<class KeyClass,class T>
bool
nsClassHashtableMT<KeyClass,T>::Get(KeyType aKey, T** retVal) const
{
PR_Lock(this->mLock);
typename base_type::EntryType* ent = this->GetEntry(aKey);
if (ent)
{
if (retVal)
*retVal = ent->mData;
PR_Unlock(this->mLock);
return true;
}
if (retVal)
*retVal = nsnull;
PR_Unlock(this->mLock);
return false;
}
#endif // nsClassHashtable_h__