Bug 551660. Create FramePropertyTable. r=mats,sr=dbaron

layout/base/FramePropertyTable.cpp

@@ -0,0 +1,260 @@
+/* -*- Mode: C++; tab-width: 20; 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 Corporation code.
+ *
+ * The Initial Developer of the Original Code is Mozilla Foundation.
+ * Portions created by the Initial Developer are Copyright (C) 2010
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *   Robert O'Callahan <robert@ocallahan.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 ***** */
+
+#include "FramePropertyTable.h"
+#include "prlog.h"
+
+namespace mozilla {
+
+void
+FramePropertyTable::Set(nsIFrame* aFrame, const FramePropertyDescriptor* aProperty,
+                        void* aValue)
+{
+  NS_ASSERTION(aFrame, "Null frame?");
+  NS_ASSERTION(aProperty, "Null property?");
+
+  if (mLastFrame != aFrame || !mLastEntry) {
+    mLastFrame = aFrame;
+    mLastEntry = mEntries.PutEntry(aFrame);
+  }
+  Entry* entry = mLastEntry;
+
+  if (!entry->mProp.IsArray()) {
+    if (!entry->mProp.mProperty) {
+      // Empty entry, so we can just store our property in the empty slot
+      entry->mProp.mProperty = aProperty;
+      entry->mProp.mValue = aValue;
+      return;
+    }
+    if (entry->mProp.mProperty == aProperty) {
+      // Just overwrite the current value
+      entry->mProp.DestroyValue();
+      entry->mProp.mValue = aValue;
+      return;
+    }
+
+    // We need to expand the single current entry to an array
+    PropertyValue current = entry->mProp;
+    entry->mProp.mProperty = nsnull;
+    PR_STATIC_ASSERT(sizeof(nsTArray<PropertyValue>) <= sizeof(entry->mProp.mValue));
+    new (&entry->mProp.mValue) nsTArray<PropertyValue>(4);
+    entry->mProp.ToArray()->AppendElement(current);
+  }
+
+  nsTArray<PropertyValue>* array = entry->mProp.ToArray();
+  nsTArray<PropertyValue>::index_type index =
+    array->IndexOf(aProperty, 0, PropertyComparator());
+  if (index != nsTArray<PropertyValue>::NoIndex) {
+    PropertyValue* pv = &array->ElementAt(index);
+    pv->DestroyValue();
+    pv->mValue = aValue;
+    return;
+  }
+
+  array->AppendElement(PropertyValue(aProperty, aValue));
+}
+
+void*
+FramePropertyTable::Get(const nsIFrame* aFrame,
+                        const FramePropertyDescriptor* aProperty,
+                        PRBool* aFoundResult)
+{
+  NS_ASSERTION(aFrame, "Null frame?");
+  NS_ASSERTION(aProperty, "Null property?");
+
+  if (aFoundResult) {
+    *aFoundResult = PR_FALSE;
+  }
+
+  if (mLastFrame != aFrame) {
+    mLastFrame = const_cast<nsIFrame*>(aFrame);
+    mLastEntry = mEntries.GetEntry(mLastFrame);
+  }
+  Entry* entry = mLastEntry;
+  if (!entry)
+    return nsnull;
+
+  if (entry->mProp.mProperty == aProperty) {
+    if (aFoundResult) {
+      *aFoundResult = PR_TRUE;
+    }
+    return entry->mProp.mValue;
+  }
+  if (!entry->mProp.IsArray()) {
+    // There's just one property and it's not the one we want, bail
+    return nsnull;
+  }
+
+  nsTArray<PropertyValue>* array = entry->mProp.ToArray();
+  nsTArray<PropertyValue>::index_type index =
+    array->IndexOf(aProperty, 0, PropertyComparator());
+  if (index == nsTArray<PropertyValue>::NoIndex)
+    return nsnull;
+
+  if (aFoundResult) {
+    *aFoundResult = PR_TRUE;
+  }
+
+  return array->ElementAt(index).mValue;
+}
+
+void*
+FramePropertyTable::Remove(nsIFrame* aFrame, const FramePropertyDescriptor* aProperty,
+                           PRBool* aFoundResult)
+{
+  NS_ASSERTION(aFrame, "Null frame?");
+  NS_ASSERTION(aProperty, "Null property?");
+
+  if (aFoundResult) {
+    *aFoundResult = PR_FALSE;
+  }
+
+  if (mLastFrame != aFrame) {
+    mLastFrame = aFrame;
+    mLastEntry = mEntries.GetEntry(aFrame);
+  }
+  Entry* entry = mLastEntry;
+  if (!entry)
+    return nsnull;
+
+  if (entry->mProp.mProperty == aProperty) {
+    // There's only one entry and it's the one we want
+    void* value = entry->mProp.mValue;
+    mEntries.RawRemoveEntry(entry);
+    mLastEntry = nsnull;
+    if (aFoundResult) {
+      *aFoundResult = PR_TRUE;
+    }
+    return value;
+  }
+  if (!entry->mProp.IsArray()) {
+    // There's just one property and it's not the one we want, bail
+    return nsnull;
+  }
+
+  nsTArray<PropertyValue>* array = entry->mProp.ToArray();
+  nsTArray<PropertyValue>::index_type index =
+    array->IndexOf(aProperty, 0, PropertyComparator());
+  if (index == nsTArray<PropertyValue>::NoIndex) {
+    // No such property, bail
+    return nsnull;
+  }
+
+  if (aFoundResult) {
+    *aFoundResult = PR_TRUE;
+  }
+
+  void* result = array->ElementAt(index).mValue;
+
+  PRUint32 last = array->Length() - 1;
+  array->ElementAt(index) = array->ElementAt(last);
+  array->RemoveElementAt(last);
+
+  if (last == 1) {
+    PropertyValue pv = array->ElementAt(0);
+    array->nsTArray<PropertyValue>::~nsTArray<PropertyValue>();
+    entry->mProp = pv;
+  }
+  
+  return result;
+}
+
+void
+FramePropertyTable::Delete(nsIFrame* aFrame, const FramePropertyDescriptor* aProperty)
+{
+  NS_ASSERTION(aFrame, "Null frame?");
+  NS_ASSERTION(aProperty, "Null property?");
+
+  PRBool found;
+  void* v = Remove(aFrame, aProperty, &found);
+  if (found && aProperty->mDestructor) {
+    aProperty->mDestructor(v);
+  }
+}
+
+/* static */ void
+FramePropertyTable::DeleteAllForEntry(Entry* aEntry)
+{
+  if (!aEntry->mProp.IsArray()) {
+    aEntry->mProp.DestroyValue();
+    return;
+  }
+
+  nsTArray<PropertyValue>* array = aEntry->mProp.ToArray();
+  for (PRUint32 i = 0; i < array->Length(); ++i) {
+    array->ElementAt(i).DestroyValue();
+  }
+  array->nsTArray<PropertyValue>::~nsTArray<PropertyValue>();
+}
+
+void
+FramePropertyTable::DeleteAllFor(nsIFrame* aFrame)
+{
+  NS_ASSERTION(aFrame, "Null frame?");
+
+  Entry* entry = mEntries.GetEntry(aFrame);
+  if (!entry)
+    return;
+
+  if (mLastFrame == aFrame) {
+    // Flush cache. We assume DeleteAllForEntry will be called before
+    // a frame is destroyed.
+    mLastFrame = nsnull;
+    mLastEntry = nsnull;
+  }
+
+  DeleteAllForEntry(entry);
+  mEntries.RawRemoveEntry(entry);
+}
+
+/* static */ PLDHashOperator
+FramePropertyTable::DeleteEnumerator(Entry* aEntry, void* aArg)
+{
+  DeleteAllForEntry(aEntry);
+  return PL_DHASH_REMOVE;
+}
+
+void
+FramePropertyTable::DeleteAll()
+{
+  mLastFrame = nsnull;
+  mLastEntry = nsnull;
+
+  mEntries.EnumerateEntries(DeleteEnumerator, nsnull);
+}
+
+}