nsresult
nsAttrAndChildArray::InsertChildAt(nsIContent* aChild, PRUint32 aPos)
{
NS_ASSERTION(aChild, "nullchild");
NS_ASSERTION(aPos <= ChildCount(), "out-of-bounds");
PRUint32 offset = AttrSlotsSize();
PRUint32 childCount = ChildCount();
NS_ENSURE_TRUE(childCount < ATTRCHILD_ARRAY_MAX_CHILD_COUNT,
NS_ERROR_FAILURE);
// First try to fit new child in existing childlist
if (mImpl && offset + childCount < mImpl->mBufferSize) {
void** pos = mImpl->mBuffer + offset + aPos;
if (childCount != aPos) {
memmove(pos + 1, pos, (childCount - aPos) * sizeof(nsIContent*));
}
SetChildAtPos(pos, aChild, aPos, childCount);
SetChildCount(childCount + 1);
return NS_OK;
}
// Try to fit new child in existing buffer by compressing attrslots
if (offset && !mImpl->mBuffer[offset - ATTRSIZE]) {
// Compress away all empty slots while we're at it. This might not be the
// optimal thing to do.
PRUint32 attrCount = NonMappedAttrCount();
void** newStart = mImpl->mBuffer + attrCount * ATTRSIZE;
void** oldStart = mImpl->mBuffer + offset;
memmove(newStart, oldStart, aPos * sizeof(nsIContent*));
memmove(&newStart[aPos + 1], &oldStart[aPos],
(childCount - aPos) * sizeof(nsIContent*));
SetChildAtPos(newStart + aPos, aChild, aPos, childCount);
SetAttrSlotAndChildCount(attrCount, childCount + 1);
return NS_OK;
}
// We can't fit in current buffer, Realloc time!
if (!GrowBy(1)) {
return NS_ERROR_OUT_OF_MEMORY;
}
void** pos = mImpl->mBuffer + offset + aPos;
if (childCount != aPos) {
memmove(pos + 1, pos, (childCount - aPos) * sizeof(nsIContent*));
}
SetChildAtPos(pos, aChild, aPos, childCount);
SetChildCount(childCount + 1);
return NS_OK;
}
void
nsAttrAndChildArray::RemoveChildAt(PRUint32 aPos)
{
NS_ASSERTION(aPos < ChildCount(), "out-of-bounds");
PRUint32 childCount = ChildCount();
void** pos = mImpl->mBuffer + AttrSlotsSize() + aPos;
nsIContent* child = static_cast<nsIContent*>(*pos);
if (child->mPreviousSibling) {
child->mPreviousSibling->mNextSibling = child->mNextSibling;
}
if (child->mNextSibling) {
child->mNextSibling->mPreviousSibling = child->mPreviousSibling;
}
child->mPreviousSibling = child->mNextSibling = nsnull;
NS_RELEASE(child);
memmove(pos, pos + 1, (childCount - aPos - 1) * sizeof(nsIContent*));
SetChildCount(childCount - 1);
}
already_AddRefed<nsIContent>
nsAttrAndChildArray::TakeChildAt(uint32_t aPos)
{
NS_ASSERTION(aPos < ChildCount(), "out-of-bounds");
uint32_t childCount = ChildCount();
void** pos = mImpl->mBuffer + AttrSlotsSize() + aPos;
nsIContent* child = static_cast<nsIContent*>(*pos);
if (child->mPreviousSibling) {
child->mPreviousSibling->mNextSibling = child->mNextSibling;
}
if (child->mNextSibling) {
child->mNextSibling->mPreviousSibling = child->mPreviousSibling;
}
child->mPreviousSibling = child->mNextSibling = nullptr;
memmove(pos, pos + 1, (childCount - aPos - 1) * sizeof(nsIContent*));
SetChildCount(childCount - 1);
return dont_AddRef(child);
}
PRInt32
nsAttrAndChildArray::IndexOfChild(nsINode* aPossibleChild) const
{
if (!mImpl) {
return -1;
}
void** children = mImpl->mBuffer + AttrSlotsSize();
// Use signed here since we compare count to cursor which has to be signed
PRInt32 i, count = ChildCount();
if (count >= CACHE_CHILD_LIMIT) {
PRInt32 cursor = GetIndexFromCache(this);
// Need to compare to count here since we may have removed children since
// the index was added to the cache.
// We're also relying on that GetIndexFromCache returns -1 if no cached
// index was found.
if (cursor >= count) {
cursor = -1;
}
// Seek outward from the last found index. |inc| will change sign every
// run through the loop. |sign| just exists to make sure the absolute
// value of |inc| increases each time through.
PRInt32 inc = 1, sign = 1;
while (cursor >= 0 && cursor < count) {
if (children[cursor] == aPossibleChild) {
AddIndexToCache(this, cursor);
return cursor;
}
cursor += inc;
inc = -inc - sign;
sign = -sign;
}
// We ran into one 'edge'. Add inc to cursor once more to get back to
// the 'side' where we still need to search, then step in the |sign|
// direction.
cursor += inc;
if (sign > 0) {
for (; cursor < count; ++cursor) {
if (children[cursor] == aPossibleChild) {
AddIndexToCache(this, cursor);
return static_cast<PRInt32>(cursor);
}
}
}
else {
for (; cursor >= 0; --cursor) {
if (children[cursor] == aPossibleChild) {
AddIndexToCache(this, cursor);
return static_cast<PRInt32>(cursor);
}
}
}
// The child wasn't even in the remaining children
return -1;
}
for (i = 0; i < count; ++i) {
if (children[i] == aPossibleChild) {
return static_cast<PRInt32>(i);
}
}
return -1;
}
