gecko/xpcom/glue/nsCOMArray.cpp
Ehsan Akhgari 80e08706f6 Bug 570657 - Make the order of releasing objects and removing them in nsCOMArray's consistent; r=shaver
--HG--
extra : rebase_source : 16f05bbfbd31bc01e0545af111dc4e4adbac8e33
2010-06-09 14:13:16 -04:00

181 lines
5.3 KiB
C++

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* ***** 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 a COM aware array class.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corp.
* Portions created by the Initial Developer are Copyright (C) 2002
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Alec Flett <alecf@netscape.com>
*
* 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 ***** */
#include "nsCOMArray.h"
#include "nsCOMPtr.h"
static PRBool ReleaseObjects(void* aElement, void*);
// implementations of non-trivial methods in nsCOMArray_base
// copy constructor - we can't just memcpy here, because
// we have to make sure we own our own array buffer, and that each
// object gets another AddRef()
nsCOMArray_base::nsCOMArray_base(const nsCOMArray_base& aOther)
{
// make sure we do only one allocation
mArray.SizeTo(aOther.Count());
AppendObjects(aOther);
}
nsCOMArray_base::~nsCOMArray_base()
{
Clear();
}
PRInt32
nsCOMArray_base::IndexOfObject(nsISupports* aObject) const {
nsCOMPtr<nsISupports> supports = do_QueryInterface(aObject);
NS_ENSURE_TRUE(supports, -1);
PRInt32 i, count;
PRInt32 retval = -1;
count = mArray.Count();
for (i = 0; i < count; ++i) {
nsCOMPtr<nsISupports> arrayItem =
do_QueryInterface(reinterpret_cast<nsISupports*>(mArray.ElementAt(i)));
if (arrayItem == supports) {
retval = i;
break;
}
}
return retval;
}
PRBool
nsCOMArray_base::InsertObjectAt(nsISupports* aObject, PRInt32 aIndex) {
PRBool result = mArray.InsertElementAt(aObject, aIndex);
if (result)
NS_IF_ADDREF(aObject);
return result;
}
PRBool
nsCOMArray_base::InsertObjectsAt(const nsCOMArray_base& aObjects, PRInt32 aIndex) {
PRBool result = mArray.InsertElementsAt(aObjects.mArray, aIndex);
if (result) {
// need to addref all these
PRInt32 count = aObjects.Count();
for (PRInt32 i = 0; i < count; ++i) {
NS_IF_ADDREF(aObjects.ObjectAt(i));
}
}
return result;
}
PRBool
nsCOMArray_base::ReplaceObjectAt(nsISupports* aObject, PRInt32 aIndex)
{
// its ok if oldObject is null here
nsISupports *oldObject =
reinterpret_cast<nsISupports*>(mArray.SafeElementAt(aIndex));
PRBool result = mArray.ReplaceElementAt(aObject, aIndex);
// ReplaceElementAt could fail, such as if the array grows
// so only release the existing object if the replacement succeeded
if (result) {
// Make sure to addref first, in case aObject == oldObject
NS_IF_ADDREF(aObject);
NS_IF_RELEASE(oldObject);
}
return result;
}
PRBool
nsCOMArray_base::RemoveObject(nsISupports *aObject)
{
PRBool result = mArray.RemoveElement(aObject);
if (result)
NS_IF_RELEASE(aObject);
return result;
}
PRBool
nsCOMArray_base::RemoveObjectAt(PRInt32 aIndex)
{
if (PRUint32(aIndex) < PRUint32(Count())) {
nsISupports* element = ObjectAt(aIndex);
PRBool result = mArray.RemoveElementAt(aIndex);
NS_IF_RELEASE(element);
return result;
}
return PR_FALSE;
}
// useful for destructors
PRBool
ReleaseObjects(void* aElement, void*)
{
nsISupports* element = static_cast<nsISupports*>(aElement);
NS_IF_RELEASE(element);
return PR_TRUE;
}
void
nsCOMArray_base::Clear()
{
nsAutoVoidArray objects;
objects = mArray;
mArray.Clear();
objects.EnumerateForwards(ReleaseObjects, nsnull);
}
PRBool
nsCOMArray_base::SetCount(PRInt32 aNewCount)
{
NS_ASSERTION(aNewCount >= 0,"SetCount(negative index)");
if (aNewCount < 0)
return PR_FALSE;
PRInt32 count = Count(), i;
nsAutoVoidArray objects;
if (count > aNewCount) {
objects.SetCount(count - aNewCount);
for (i = aNewCount; i < count; ++i) {
objects.ReplaceElementAt(ObjectAt(i), i - aNewCount);
}
}
PRBool result = mArray.SetCount(aNewCount);
objects.EnumerateForwards(ReleaseObjects, nsnull);
return result;
}