зеркало из https://github.com/mozilla/pjs.git
155 строки
5.1 KiB
C++
155 строки
5.1 KiB
C++
/* -*- 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 Gecko DOM code.
|
|
*
|
|
* The Initial Developer of the Original Code is
|
|
* Mozilla Corporation.
|
|
* Portions created by the Initial Developer are Copyright (C) 2008
|
|
* the Initial Developer. All Rights Reserved.
|
|
*
|
|
* Contributor(s):
|
|
* Peter Van der Beken <peterv@propagandism.org>
|
|
*
|
|
* 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 nsWrapperCache_h___
|
|
#define nsWrapperCache_h___
|
|
|
|
#include "nsCycleCollectionParticipant.h"
|
|
|
|
struct JSObject;
|
|
class nsContentUtils;
|
|
|
|
typedef PRUptrdiff PtrBits;
|
|
|
|
#define NS_WRAPPERCACHE_IID \
|
|
{ 0x3a51ca81, 0xddab, 0x422c, \
|
|
{ 0x95, 0x3a, 0x13, 0x06, 0x28, 0x0e, 0xee, 0x14 } }
|
|
|
|
/**
|
|
* Class to store the XPCWrappedNative for an object. This can only be used
|
|
* with objects that only have one XPCWrappedNative at a time (usually ensured
|
|
* by setting an explicit parent in the PreCreate hook for the class). This
|
|
* object can be gotten by calling QueryInterface, note that this breaks XPCOM
|
|
* rules a bit (this object doesn't derive from nsISupports).
|
|
*/
|
|
class nsWrapperCache
|
|
{
|
|
friend class nsContentUtils;
|
|
|
|
public:
|
|
NS_DECLARE_STATIC_IID_ACCESSOR(NS_WRAPPERCACHE_IID)
|
|
|
|
nsWrapperCache() : mWrapperPtrBits(0)
|
|
{
|
|
}
|
|
~nsWrapperCache()
|
|
{
|
|
NS_ASSERTION(!PreservingWrapper(),
|
|
"Destroying cache with a preserved wrapper!");
|
|
}
|
|
|
|
/**
|
|
* This getter clears the gray bit before handing out the JSObject which means
|
|
* that the object is guaranteed to be kept alive past the next CC.
|
|
*
|
|
* Implemented in xpcpublic.h because we have to include some JS headers that
|
|
* don't play nicely with the rest of the codebase. Include xpcpublic.h if you
|
|
* need to call this method.
|
|
*/
|
|
inline JSObject* GetWrapper() const;
|
|
|
|
/**
|
|
* This getter does not change the color of the JSObject meaning that the
|
|
* object returned is not guaranteed to be kept alive past the next CC.
|
|
*
|
|
* This should only be called if you are certain that the return value won't
|
|
* be passed into a JS API function and that it won't be stored without being
|
|
* rooted (or otherwise signaling the stored value to the CC).
|
|
*/
|
|
JSObject* GetWrapperPreserveColor() const
|
|
{
|
|
return reinterpret_cast<JSObject*>(mWrapperPtrBits & ~kWrapperBitMask);
|
|
}
|
|
|
|
void SetWrapper(JSObject* aWrapper)
|
|
{
|
|
NS_ASSERTION(!PreservingWrapper(), "Clearing a preserved wrapper!");
|
|
mWrapperPtrBits = reinterpret_cast<PtrBits>(aWrapper) |
|
|
(mWrapperPtrBits & WRAPPER_IS_PROXY);
|
|
}
|
|
|
|
void ClearWrapper()
|
|
{
|
|
NS_ASSERTION(!PreservingWrapper(), "Clearing a preserved wrapper!");
|
|
mWrapperPtrBits = 0;
|
|
}
|
|
|
|
PRBool PreservingWrapper()
|
|
{
|
|
return (mWrapperPtrBits & WRAPPER_BIT_PRESERVED) != 0;
|
|
}
|
|
|
|
void SetIsProxy()
|
|
{
|
|
mWrapperPtrBits |= WRAPPER_IS_PROXY;
|
|
}
|
|
|
|
PRBool IsProxy()
|
|
{
|
|
return (mWrapperPtrBits & WRAPPER_IS_PROXY) != 0;
|
|
}
|
|
|
|
private:
|
|
// Only meant to be called by nsContentUtils.
|
|
void SetPreservingWrapper(PRBool aPreserve)
|
|
{
|
|
if(aPreserve) {
|
|
mWrapperPtrBits |= WRAPPER_BIT_PRESERVED;
|
|
}
|
|
else {
|
|
mWrapperPtrBits &= ~WRAPPER_BIT_PRESERVED;
|
|
}
|
|
}
|
|
|
|
enum { WRAPPER_BIT_PRESERVED = 1 << 0 };
|
|
enum { WRAPPER_IS_PROXY = 1 << 1 };
|
|
enum { kWrapperBitMask = (WRAPPER_BIT_PRESERVED | WRAPPER_IS_PROXY) };
|
|
|
|
PtrBits mWrapperPtrBits;
|
|
};
|
|
|
|
NS_DEFINE_STATIC_IID_ACCESSOR(nsWrapperCache, NS_WRAPPERCACHE_IID)
|
|
|
|
#define NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY \
|
|
if ( aIID.Equals(NS_GET_IID(nsWrapperCache)) ) { \
|
|
*aInstancePtr = static_cast<nsWrapperCache*>(this); \
|
|
return NS_OK; \
|
|
}
|
|
|
|
#endif /* nsWrapperCache_h___ */
|