gecko-dev/xpcom/glue/nsCOMArray.cpp

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4.4 KiB
C++

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "nsCOMArray.h"
#include "nsCOMPtr.h"
static bool 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();
}
int32_t
nsCOMArray_base::IndexOfObject(nsISupports* aObject) const {
nsCOMPtr<nsISupports> supports = do_QueryInterface(aObject);
NS_ENSURE_TRUE(supports, -1);
int32_t i, count;
int32_t 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;
}
bool
nsCOMArray_base::InsertObjectAt(nsISupports* aObject, int32_t aIndex) {
bool result = mArray.InsertElementAt(aObject, aIndex);
if (result)
NS_IF_ADDREF(aObject);
return result;
}
bool
nsCOMArray_base::InsertObjectsAt(const nsCOMArray_base& aObjects, int32_t aIndex) {
bool result = mArray.InsertElementsAt(aObjects.mArray, aIndex);
if (result) {
// need to addref all these
int32_t count = aObjects.Count();
for (int32_t i = 0; i < count; ++i) {
NS_IF_ADDREF(aObjects.ObjectAt(i));
}
}
return result;
}
bool
nsCOMArray_base::ReplaceObjectAt(nsISupports* aObject, int32_t aIndex)
{
// its ok if oldObject is null here
nsISupports *oldObject =
reinterpret_cast<nsISupports*>(mArray.SafeElementAt(aIndex));
bool 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;
}
bool
nsCOMArray_base::RemoveObject(nsISupports *aObject)
{
bool result = mArray.RemoveElement(aObject);
if (result)
NS_IF_RELEASE(aObject);
return result;
}
bool
nsCOMArray_base::RemoveObjectAt(int32_t aIndex)
{
if (uint32_t(aIndex) < uint32_t(Count())) {
nsISupports* element = ObjectAt(aIndex);
bool result = mArray.RemoveElementAt(aIndex);
NS_IF_RELEASE(element);
return result;
}
return false;
}
bool
nsCOMArray_base::RemoveObjectsAt(int32_t aIndex, int32_t aCount)
{
if (uint32_t(aIndex) + uint32_t(aCount) <= uint32_t(Count())) {
nsVoidArray elementsToDestroy(aCount);
for (int32_t i = 0; i < aCount; ++i) {
elementsToDestroy.InsertElementAt(mArray.FastElementAt(aIndex + i), i);
}
bool result = mArray.RemoveElementsAt(aIndex, aCount);
for (int32_t i = 0; i < aCount; ++i) {
nsISupports* element = static_cast<nsISupports*> (elementsToDestroy.FastElementAt(i));
NS_IF_RELEASE(element);
}
return result;
}
return false;
}
// useful for destructors
bool
ReleaseObjects(void* aElement, void*)
{
nsISupports* element = static_cast<nsISupports*>(aElement);
NS_IF_RELEASE(element);
return true;
}
void
nsCOMArray_base::Clear()
{
nsAutoVoidArray objects;
objects = mArray;
mArray.Clear();
objects.EnumerateForwards(ReleaseObjects, nullptr);
}
bool
nsCOMArray_base::SetCount(int32_t aNewCount)
{
NS_ASSERTION(aNewCount >= 0,"SetCount(negative index)");
if (aNewCount < 0)
return false;
int32_t count = Count(), i;
nsAutoVoidArray objects;
if (count > aNewCount) {
objects.SetCount(count - aNewCount);
for (i = aNewCount; i < count; ++i) {
objects.ReplaceElementAt(ObjectAt(i), i - aNewCount);
}
}
bool result = mArray.SetCount(aNewCount);
objects.EnumerateForwards(ReleaseObjects, nullptr);
return result;
}