Client Side Speed Index

third_party/WebKit/Source/core/paint/PaintTiming.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef PaintTiming_h
 #define PaintTiming_h
 
 #include "core/dom/Document.h"
 #include "platform/Supplementable.h"
+#include "platform/geometry/IntRect.h"
 #include "platform/heap/Handle.h"
+#include "wtf/HashMap.h"
+#include "wtf/Int32Array.h"
 
 namespace blink {
 
 class LocalFrame;
 
 class PaintTiming final : public NoBaseWillBeGarbageCollectedFinalized<PaintTiming>, public WillBeHeapSupplement<Document> {
     WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(PaintTiming);
 public:
     virtual ~PaintTiming() { }
 
     static PaintTiming& from(Document&);
 
     void markFirstPaint();
     void markFirstTextPaint();
     void markFirstImagePaint();
+    void markPaintInvalidation(const IntRect* visualRect, int paintCount);
 
     // These return monotonically-increasing seconds.
     double firstPaint() const { return m_firstPaint; }
     double firstTextPaint() const { return m_firstTextPaint; }
     double firstImagePaint() const { return m_firstImagePaint; }
 
+    // When a consumer asks for the speed index, stop collecting and analyzing
+    // invalidation rects and give the result using information collected at the
+    // first request time.
+    double speedIndex(double referenceTime) const;
+
+    void setLoadCommitted() { m_loadCommitted = true; }
+
     DECLARE_VIRTUAL_TRACE();
 
 private:
     explicit PaintTiming(Document&);
     LocalFrame* frame() const;
     void notifyPaintTimingChanged();
 
     double m_firstPaint = 0.0;
     double m_firstTextPaint = 0.0;
     double m_firstImagePaint = 0.0;
+    // Speed Index is calculated once when first queried, then cached.
+    mutable double m_speedIndex = 0.0;
+
+    // Members needed to calculate SpeedIndex:
+
+    // Ignore all paint invalidations until the load commits.
+    bool m_loadCommitted = false;
+
+    IntRect m_viewPortRect;
+    int m_lastPaintCount = 0;
+
+    // Forbids duplicate rect invalidations that occur before painting.
+    WTF::HashSet<unsigned> frameRects;
+
+    // Counts rect occurrences.
+    typedef WTF::HashMap<unsigned, int> RectCountMap;
+    RectCountMap m_rectCounts;
+
+    double m_lastPaintInvalidationTime = 0.0;
+
+    // The current area under the curve of "painted area over time."
+    double m_totalLoadedArea = 0.0;
+    // The total amount of painted area.
+    double m_totalContributions = 0.0;
 
     RawPtrWillBeMember<Document> m_document;
 };
 
 }
 
 #endif