Bug 1219352 - Rearrange fields in FrameMetrics. r=botond

This patch: - Maintains a consistent ordering between the lists of fields in the FrameMetrics constructor, operator==, IPC read/write functions, and the actual order of fields in FrameMetrics. As part of this, missing default initializers are added to the FrameMetrics constructor, and fields omitted from the operator== are explicitly noted. - Moves all the boolean values to the end of the set of field (for better packing). - Moves the scroll id and parent scroll id to the front of the list, so that the operator== can fail faster in the common case.
2016-01-06 20:50:01 -05:00
parent aecbdcdf85
commit 735c324052
2 changed files with 101 additions and 91 deletions
--- a/gfx/ipc/GfxMessageUtils.h
+++ b/gfx/ipc/GfxMessageUtils.h
@@ -684,39 +684,39 @@ struct ParamTraits<mozilla::layers::FrameMetrics>

  static void Write(Message* aMsg, const paramType& aParam)
  {
-    WriteParam(aMsg, aParam.mScrollableRect);
-    WriteParam(aMsg, aParam.mViewport);
-    WriteParam(aMsg, aParam.mScrollOffset);
-    WriteParam(aMsg, aParam.mDisplayPort);
-    WriteParam(aMsg, aParam.mDisplayPortMargins);
-    WriteParam(aMsg, aParam.mUseDisplayPortMargins);
-    WriteParam(aMsg, aParam.mCriticalDisplayPort);
-    WriteParam(aMsg, aParam.mCompositionBounds);
-    WriteParam(aMsg, aParam.mRootCompositionSize);
    WriteParam(aMsg, aParam.mScrollId);
    WriteParam(aMsg, aParam.mScrollParentId);
    WriteParam(aMsg, aParam.mPresShellResolution);
+    WriteParam(aMsg, aParam.mCompositionBounds);
+    WriteParam(aMsg, aParam.mDisplayPort);
+    WriteParam(aMsg, aParam.mCriticalDisplayPort);
+    WriteParam(aMsg, aParam.mScrollableRect);
    WriteParam(aMsg, aParam.mCumulativeResolution);
-    WriteParam(aMsg, aParam.mZoom);
    WriteParam(aMsg, aParam.mDevPixelsPerCSSPixel);
+    WriteParam(aMsg, aParam.mScrollOffset);
+    WriteParam(aMsg, aParam.mZoom);
+    WriteParam(aMsg, aParam.mScrollGeneration);
+    WriteParam(aMsg, aParam.mSmoothScrollOffset);
+    WriteParam(aMsg, aParam.mRootCompositionSize);
+    WriteParam(aMsg, aParam.mDisplayPortMargins);
    WriteParam(aMsg, aParam.mPresShellId);
+    WriteParam(aMsg, aParam.mViewport);
+    WriteParam(aMsg, aParam.mExtraResolution);
+    WriteParam(aMsg, aParam.mBackgroundColor);
+    WriteParam(aMsg, aParam.GetContentDescription());
+    WriteParam(aMsg, aParam.mLineScrollAmount);
+    WriteParam(aMsg, aParam.mPageScrollAmount);
+    WriteParam(aMsg, aParam.mClipRect);
+    WriteParam(aMsg, aParam.mMaskLayerIndex);
    WriteParam(aMsg, aParam.mIsRootContent);
    WriteParam(aMsg, aParam.mHasScrollgrab);
    WriteParam(aMsg, aParam.mUpdateScrollOffset);
-    WriteParam(aMsg, aParam.mScrollGeneration);
-    WriteParam(aMsg, aParam.mExtraResolution);
-    WriteParam(aMsg, aParam.mBackgroundColor);
    WriteParam(aMsg, aParam.mDoSmoothScroll);
-    WriteParam(aMsg, aParam.mSmoothScrollOffset);
-    WriteParam(aMsg, aParam.GetLineScrollAmount());
-    WriteParam(aMsg, aParam.GetPageScrollAmount());
-    WriteParam(aMsg, aParam.AllowVerticalScrollWithWheel());
-    WriteParam(aMsg, aParam.mClipRect);
-    WriteParam(aMsg, aParam.mMaskLayerIndex);
+    WriteParam(aMsg, aParam.mUseDisplayPortMargins);
+    WriteParam(aMsg, aParam.mAllowVerticalScrollWithWheel);
    WriteParam(aMsg, aParam.mIsLayersIdRoot);
    WriteParam(aMsg, aParam.mUsesContainerScrolling);
    WriteParam(aMsg, aParam.mIsScrollInfoLayer);
-    WriteParam(aMsg, aParam.GetContentDescription());
  }

  static bool ReadContentDescription(const Message* aMsg, void** aIter, paramType* aResult)
@@ -731,39 +731,39 @@ struct ParamTraits<mozilla::layers::FrameMetrics>

  static bool Read(const Message* aMsg, void** aIter, paramType* aResult)
  {
-    return (ReadParam(aMsg, aIter, &aResult->mScrollableRect) &&
-            ReadParam(aMsg, aIter, &aResult->mViewport) &&
-            ReadParam(aMsg, aIter, &aResult->mScrollOffset) &&
-            ReadParam(aMsg, aIter, &aResult->mDisplayPort) &&
-            ReadParam(aMsg, aIter, &aResult->mDisplayPortMargins) &&
-            ReadParam(aMsg, aIter, &aResult->mUseDisplayPortMargins) &&
-            ReadParam(aMsg, aIter, &aResult->mCriticalDisplayPort) &&
-            ReadParam(aMsg, aIter, &aResult->mCompositionBounds) &&
-            ReadParam(aMsg, aIter, &aResult->mRootCompositionSize) &&
-            ReadParam(aMsg, aIter, &aResult->mScrollId) &&
+    return (ReadParam(aMsg, aIter, &aResult->mScrollId) &&
            ReadParam(aMsg, aIter, &aResult->mScrollParentId) &&
            ReadParam(aMsg, aIter, &aResult->mPresShellResolution) &&
+            ReadParam(aMsg, aIter, &aResult->mCompositionBounds) &&
+            ReadParam(aMsg, aIter, &aResult->mDisplayPort) &&
+            ReadParam(aMsg, aIter, &aResult->mCriticalDisplayPort) &&
+            ReadParam(aMsg, aIter, &aResult->mScrollableRect) &&
            ReadParam(aMsg, aIter, &aResult->mCumulativeResolution) &&
-            ReadParam(aMsg, aIter, &aResult->mZoom) &&
            ReadParam(aMsg, aIter, &aResult->mDevPixelsPerCSSPixel) &&
+            ReadParam(aMsg, aIter, &aResult->mScrollOffset) &&
+            ReadParam(aMsg, aIter, &aResult->mZoom) &&
+            ReadParam(aMsg, aIter, &aResult->mScrollGeneration) &&
+            ReadParam(aMsg, aIter, &aResult->mSmoothScrollOffset) &&
+            ReadParam(aMsg, aIter, &aResult->mRootCompositionSize) &&
+            ReadParam(aMsg, aIter, &aResult->mDisplayPortMargins) &&
            ReadParam(aMsg, aIter, &aResult->mPresShellId) &&
+            ReadParam(aMsg, aIter, &aResult->mViewport) &&
+            ReadParam(aMsg, aIter, &aResult->mExtraResolution) &&
+            ReadParam(aMsg, aIter, &aResult->mBackgroundColor) &&
+            ReadContentDescription(aMsg, aIter, aResult) &&
+            ReadParam(aMsg, aIter, &aResult->mLineScrollAmount) &&
+            ReadParam(aMsg, aIter, &aResult->mPageScrollAmount) &&
+            ReadParam(aMsg, aIter, &aResult->mClipRect) &&
+            ReadParam(aMsg, aIter, &aResult->mMaskLayerIndex) &&
            ReadParam(aMsg, aIter, &aResult->mIsRootContent) &&
            ReadParam(aMsg, aIter, &aResult->mHasScrollgrab) &&
            ReadParam(aMsg, aIter, &aResult->mUpdateScrollOffset) &&
-            ReadParam(aMsg, aIter, &aResult->mScrollGeneration) &&
-            ReadParam(aMsg, aIter, &aResult->mExtraResolution) &&
-            ReadParam(aMsg, aIter, &aResult->mBackgroundColor) &&
            ReadParam(aMsg, aIter, &aResult->mDoSmoothScroll) &&
-            ReadParam(aMsg, aIter, &aResult->mSmoothScrollOffset) &&
-            ReadParam(aMsg, aIter, &aResult->mLineScrollAmount) &&
-            ReadParam(aMsg, aIter, &aResult->mPageScrollAmount) &&
+            ReadParam(aMsg, aIter, &aResult->mUseDisplayPortMargins) &&
            ReadParam(aMsg, aIter, &aResult->mAllowVerticalScrollWithWheel) &&
-            ReadParam(aMsg, aIter, &aResult->mClipRect) &&
-            ReadParam(aMsg, aIter, &aResult->mMaskLayerIndex) &&
            ReadParam(aMsg, aIter, &aResult->mIsLayersIdRoot) &&
            ReadParam(aMsg, aIter, &aResult->mUsesContainerScrolling) &&
-            ReadParam(aMsg, aIter, &aResult->mIsScrollInfoLayer) &&
-            ReadContentDescription(aMsg, aIter, aResult));
+            ReadParam(aMsg, aIter, &aResult->mIsScrollInfoLayer));
  }
 };

--- a/gfx/layers/FrameMetrics.h
+++ b/gfx/layers/FrameMetrics.h
@@ -39,32 +39,35 @@ public:
  static const FrameMetrics sNullMetrics;   // We often need an empty metrics

  FrameMetrics()
-    : mPresShellResolution(1)
+    : mScrollId(NULL_SCROLL_ID)
+    , mScrollParentId(NULL_SCROLL_ID)
+    , mPresShellResolution(1)
    , mCompositionBounds(0, 0, 0, 0)
    , mDisplayPort(0, 0, 0, 0)
    , mCriticalDisplayPort(0, 0, 0, 0)
    , mScrollableRect(0, 0, 0, 0)
    , mCumulativeResolution()
    , mDevPixelsPerCSSPixel(1)
-    , mIsRootContent(false)
-    , mHasScrollgrab(false)
-    , mScrollId(NULL_SCROLL_ID)
-    , mScrollParentId(NULL_SCROLL_ID)
    , mScrollOffset(0, 0)
    , mZoom()
-    , mUpdateScrollOffset(false)
    , mScrollGeneration(0)
-    , mDoSmoothScroll(false)
    , mSmoothScrollOffset(0, 0)
    , mRootCompositionSize(0, 0)
    , mDisplayPortMargins(0, 0, 0, 0)
-    , mUseDisplayPortMargins(false)
    , mPresShellId(-1)
    , mViewport(0, 0, 0, 0)
    , mExtraResolution()
    , mBackgroundColor()
+    , mContentDescription()
    , mLineScrollAmount(0, 0)
    , mPageScrollAmount(0, 0)
+    , mClipRect()
+    , mMaskLayerIndex()
+    , mIsRootContent(false)
+    , mHasScrollgrab(false)
+    , mUpdateScrollOffset(false)
+    , mDoSmoothScroll(false)
+    , mUseDisplayPortMargins(false)
    , mAllowVerticalScrollWithWheel(false)
    , mIsLayersIdRoot(false)
    , mUsesContainerScrolling(false)
@@ -76,38 +79,42 @@ public:

  bool operator==(const FrameMetrics& aOther) const
  {
-    return mCompositionBounds.IsEqualEdges(aOther.mCompositionBounds) &&
-           mRootCompositionSize == aOther.mRootCompositionSize &&
-           mDisplayPort.IsEqualEdges(aOther.mDisplayPort) &&
-           mDisplayPortMargins == aOther.mDisplayPortMargins &&
-           mUseDisplayPortMargins == aOther.mUseDisplayPortMargins &&
-           mCriticalDisplayPort.IsEqualEdges(aOther.mCriticalDisplayPort) &&
-           mViewport.IsEqualEdges(aOther.mViewport) &&
-           mScrollableRect.IsEqualEdges(aOther.mScrollableRect) &&
+    // Put mScrollId at the top since it's the most likely one to fail.
+    return mScrollId == aOther.mScrollId &&
+           mScrollParentId == aOther.mScrollParentId &&
           mPresShellResolution == aOther.mPresShellResolution &&
+           mCompositionBounds.IsEqualEdges(aOther.mCompositionBounds) &&
+           mDisplayPort.IsEqualEdges(aOther.mDisplayPort) &&
+           mCriticalDisplayPort.IsEqualEdges(aOther.mCriticalDisplayPort) &&
+           mScrollableRect.IsEqualEdges(aOther.mScrollableRect) &&
           mCumulativeResolution == aOther.mCumulativeResolution &&
           mDevPixelsPerCSSPixel == aOther.mDevPixelsPerCSSPixel &&
-           mPresShellId == aOther.mPresShellId &&
-           mIsRootContent == aOther.mIsRootContent &&
-           mScrollId == aOther.mScrollId &&
-           mScrollParentId == aOther.mScrollParentId &&
           mScrollOffset == aOther.mScrollOffset &&
-           mSmoothScrollOffset == aOther.mSmoothScrollOffset &&
-           mHasScrollgrab == aOther.mHasScrollgrab &&
-           mUpdateScrollOffset == aOther.mUpdateScrollOffset &&
+           // don't compare mZoom
           mScrollGeneration == aOther.mScrollGeneration &&
+           mSmoothScrollOffset == aOther.mSmoothScrollOffset &&
+           mRootCompositionSize == aOther.mRootCompositionSize &&
+           mDisplayPortMargins == aOther.mDisplayPortMargins &&
+           mPresShellId == aOther.mPresShellId &&
+           mViewport.IsEqualEdges(aOther.mViewport) &&
           mExtraResolution == aOther.mExtraResolution &&
           mBackgroundColor == aOther.mBackgroundColor &&
-           mDoSmoothScroll == aOther.mDoSmoothScroll &&
+           // don't compare mContentDescription
           mLineScrollAmount == aOther.mLineScrollAmount &&
           mPageScrollAmount == aOther.mPageScrollAmount &&
-           mAllowVerticalScrollWithWheel == aOther.mAllowVerticalScrollWithWheel &&
           mClipRect == aOther.mClipRect &&
           mMaskLayerIndex == aOther.mMaskLayerIndex &&
+           mIsRootContent == aOther.mIsRootContent &&
+           mHasScrollgrab == aOther.mHasScrollgrab &&
+           mUpdateScrollOffset == aOther.mUpdateScrollOffset &&
+           mDoSmoothScroll == aOther.mDoSmoothScroll &&
+           mUseDisplayPortMargins == aOther.mUseDisplayPortMargins &&
+           mAllowVerticalScrollWithWheel == aOther.mAllowVerticalScrollWithWheel &&
           mIsLayersIdRoot == aOther.mIsLayersIdRoot &&
           mUsesContainerScrolling == aOther.mUsesContainerScrolling &&
           mIsScrollInfoLayer == aOther.mIsScrollInfoLayer;
  }
+
  bool operator!=(const FrameMetrics& aOther) const
  {
    return !operator==(aOther);
@@ -555,6 +562,11 @@ public:
  }

 private:
+  // A unique ID assigned to each scrollable frame.
+  ViewID mScrollId;
+
+  // The ViewID of the scrollable frame to which overscroll should be handed off.
+  ViewID mScrollParentId;

  // The pres-shell resolution that has been induced on the document containing
  // this scroll frame as a result of zooming this scroll frame (whether via
@@ -634,18 +646,6 @@ private:
  // resolution.
  CSSToLayoutDeviceScale mDevPixelsPerCSSPixel;

-  // Whether or not this is the root scroll frame for the root content document.
-  bool mIsRootContent;
-
-  // Whether or not this frame is for an element marked 'scrollgrab'.
-  bool mHasScrollgrab;
-
-  // A unique ID assigned to each scrollable frame.
-  ViewID mScrollId;
-
-  // The ViewID of the scrollable frame to which overscroll should be handed off.
-  ViewID mScrollParentId;
-
  // The position of the top-left of the CSS viewport, relative to the document
  // (or the document relative to the viewport, if that helps understand it).
  //
@@ -669,15 +669,11 @@ private:
  // diverge. This information is initialized in Gecko but updated in the APZC.
  CSSToParentLayerScale2D mZoom;

-  // Whether mScrollOffset was updated by something other than the APZ code, and
-  // if the APZC receiving this metrics should update its local copy.
-  bool mUpdateScrollOffset;
  // The scroll generation counter used to acknowledge the scroll offset update.
  uint32_t mScrollGeneration;

-  // When mDoSmoothScroll, the scroll offset should be animated to
-  // smoothly transition to mScrollOffset rather than be updated instantly.
-  bool mDoSmoothScroll;
+  // If mDoSmoothScroll is true, the scroll offset will be animated smoothly
+  // to this value.
  CSSPoint mSmoothScrollOffset;

  // The size of the root scrollable's composition bounds, but in local CSS pixels.
@@ -687,10 +683,6 @@ private:
  // is drawn of the scrollable element.
  ScreenMargin mDisplayPortMargins;

-  // If this is true then we use the display port margins on this metrics,
-  // otherwise use the display port rect.
-  bool mUseDisplayPortMargins;
-
  uint32_t mPresShellId;

  // The CSS viewport, which is the dimensions we're using to constrain the
@@ -722,9 +714,6 @@ private:
  // The value of GetPageScrollAmount(), for scroll frames.
  LayoutDeviceIntSize mPageScrollAmount;

-  // Whether or not the frame can be vertically scrolled with a mouse wheel.
-  bool mAllowVerticalScrollWithWheel;
-
  // The clip rect to use when compositing a layer with this FrameMetrics.
  Maybe<ParentLayerIntRect> mClipRect;

@@ -733,6 +722,27 @@ private:
  // the Layer.
  Maybe<size_t> mMaskLayerIndex;

+  // Whether or not this is the root scroll frame for the root content document.
+  bool mIsRootContent;
+
+  // Whether or not this frame is for an element marked 'scrollgrab'.
+  bool mHasScrollgrab;
+
+  // Whether mScrollOffset was updated by something other than the APZ code, and
+  // if the APZC receiving this metrics should update its local copy.
+  bool mUpdateScrollOffset;
+
+  // When mDoSmoothScroll, the scroll offset should be animated to
+  // smoothly transition to mScrollOffset rather than be updated instantly.
+  bool mDoSmoothScroll;
+
+  // If this is true then we use the display port margins on this metrics,
+  // otherwise use the display port rect.
+  bool mUseDisplayPortMargins;
+
+  // Whether or not the frame can be vertically scrolled with a mouse wheel.
+  bool mAllowVerticalScrollWithWheel;
+
  // Whether these framemetrics are for the root scroll frame (root element if
  // we don't have a root scroll frame) for its layers id.
  bool mIsLayersIdRoot;