gecko-dev/xpcom/ds/nsAtomTable.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 mozilla.org code.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the terms of
* either of 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
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#ifndef nsAtomTable_h__
#define nsAtomTable_h__
#include "nsIAtom.h"
#include "nsStringBuffer.h"
/**
* Note that AtomImpl objects are sometimes converted into PermanentAtomImpl
* objects using placement new and just overwriting the vtable pointer.
*/
class AtomImpl : public nsIAtom {
public:
AtomImpl(const nsAString& aString);
// This is currently only used during startup when creating a permanent atom
// from NS_RegisterStaticAtoms
AtomImpl(nsStringBuffer* aData, PRUint32 aLength);
protected:
// This is only intended to be used when a normal atom is turned into a
// permanent one.
AtomImpl() {
// We can't really assert that mString is a valid nsStringBuffer string,
// so do the best we can do and check for some consistencies.
NS_ASSERTION((mLength + 1) * sizeof(PRUnichar) <=
nsStringBuffer::FromData(mString)->StorageSize() &&
mString[mLength] == 0,
"Not initialized atom");
}
// We don't need a virtual destructor here because PermanentAtomImpl
// deletions aren't handled through Release().
~AtomImpl();
public:
NS_DECL_ISUPPORTS
NS_DECL_NSIATOM
enum { REFCNT_PERMANENT_SENTINEL = PR_UINT32_MAX };
virtual bool IsPermanent();
// We can't use the virtual function in the base class destructor.
bool IsPermanentInDestructor() {
return mRefCnt == REFCNT_PERMANENT_SENTINEL;
}
// for |#ifdef NS_BUILD_REFCNT_LOGGING| access to reference count
nsrefcnt GetRefCount() { return mRefCnt; }
};
/**
* A non-refcounted implementation of nsIAtom.
*/
class PermanentAtomImpl : public AtomImpl {
public:
PermanentAtomImpl(const nsAString& aString)
: AtomImpl(aString)
{}
PermanentAtomImpl(nsStringBuffer* aData, PRUint32 aLength)
: AtomImpl(aData, aLength)
{}
PermanentAtomImpl()
{}
~PermanentAtomImpl();
NS_IMETHOD_(nsrefcnt) AddRef();
NS_IMETHOD_(nsrefcnt) Release();
virtual bool IsPermanent();
void* operator new(size_t size, AtomImpl* aAtom) CPP_THROW_NEW;
void* operator new(size_t size) CPP_THROW_NEW
{
return ::operator new(size);
}
};
void NS_PurgeAtomTable();
#endif // nsAtomTable_h__