1 files changed, 76 insertions, 50 deletions

diff --git a/Source/WebCore/rendering/style/GridTrackSize.h b/Source/WebCore/rendering/style/GridTrackSize.h
index d5fca8948..a7ec78dbe 100644
--- a/Source/WebCore/rendering/style/GridTrackSize.h
+++ b/Source/WebCore/rendering/style/GridTrackSize.h
@@ -1,5 +1,6 @@
 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
+ * Copyright (C) 2013, 2014 Igalia S.L.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
@@ -28,8 +29,7 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#ifndef GridTrackSize_h
-#define GridTrackSize_h
+#pragma once
 
 #include "GridLength.h"
 
@@ -37,81 +37,107 @@ namespace WebCore {
 
 enum GridTrackSizeType {
     LengthTrackSizing,
-    MinMaxTrackSizing
+    MinMaxTrackSizing,
+    FitContentTrackSizing
 };
 
+// This class represents a <track-size> from the spec. Althought there are 3 different types of
+// <track-size> there is always an equivalent minmax() representation that could represent any of
+// them. The only special case is fit-content(argument) which is similar to minmax(auto,
+// max-content) except that the track size is clamped at argument if it is greater than the auto
+// minimum. At the GridTrackSize level we don't need to worry about clamping so we treat that case
+// exactly as auto.
+//
+// We're using a separate attribute to store fit-content argument even though we could directly use
+// m_maxTrackBreadth. The reason why we don't do it is because the maxTrackBreadh() call is a hot
+// spot, so adding a conditional statement there (to distinguish between fit-content and any other
+// case) was causing a severe performance drop.
 class GridTrackSize {
 public:
-    GridTrackSize(LengthType type = Undefined)
-        : m_type(LengthTrackSizing)
-        , m_minTrackBreadth(type)
-        , m_maxTrackBreadth(type)
+    GridTrackSize(const GridLength& length, GridTrackSizeType trackSizeType = LengthTrackSizing)
+        : m_type(trackSizeType)
+        , m_minTrackBreadth(trackSizeType == FitContentTrackSizing ? Length(Auto) : length)
+        , m_maxTrackBreadth(trackSizeType == FitContentTrackSizing ? Length(Auto) : length)
+        , m_fitContentTrackBreadth(trackSizeType == FitContentTrackSizing ? length : GridLength(Length(Fixed)))
     {
+        ASSERT(trackSizeType == LengthTrackSizing || trackSizeType == FitContentTrackSizing);
+        ASSERT(trackSizeType != FitContentTrackSizing || length.isLength());
+        cacheMinMaxTrackBreadthTypes();
     }
 
-    const GridLength& length() const
+    GridTrackSize(const GridLength& minTrackBreadth, const GridLength& maxTrackBreadth)
+        : m_type(MinMaxTrackSizing)
+        , m_minTrackBreadth(minTrackBreadth)
+        , m_maxTrackBreadth(maxTrackBreadth)
+        , m_fitContentTrackBreadth(GridLength(Length(Fixed)))
     {
-        ASSERT(m_type == LengthTrackSizing);
-        ASSERT(m_minTrackBreadth == m_maxTrackBreadth);
-        const GridLength& minTrackBreadth = m_minTrackBreadth;
-        ASSERT(!minTrackBreadth.isLength() || !minTrackBreadth.length().isUndefined());
-        return minTrackBreadth;
+        cacheMinMaxTrackBreadthTypes();
     }
 
-    void setLength(const GridLength& length)
+    const GridLength& fitContentTrackBreadth() const
     {
-        m_type = LengthTrackSizing;
-        m_minTrackBreadth = length;
-        m_maxTrackBreadth = length;
+        ASSERT(m_type == FitContentTrackSizing);
+        return m_fitContentTrackBreadth;
     }
 
-    const GridLength& minTrackBreadth() const
-    {
-        ASSERT(!m_minTrackBreadth.isLength() || !m_minTrackBreadth.length().isUndefined());
-        if (m_minTrackBreadth.isLength() && m_minTrackBreadth.length().isAuto()) {
-            DEFINE_STATIC_LOCAL(GridLength, minContent, (MinContent));
-            return minContent;
-        }
-        return m_minTrackBreadth;
-    }
-
-    const GridLength& maxTrackBreadth() const
-    {
-        ASSERT(!m_maxTrackBreadth.isLength() || !m_maxTrackBreadth.length().isUndefined());
-        if (m_maxTrackBreadth.isLength() && m_maxTrackBreadth.length().isAuto()) {
-            DEFINE_STATIC_LOCAL(GridLength, maxContent, (MaxContent));
-            return maxContent;
-        }
-        return m_maxTrackBreadth;
-    }
-
-    void setMinMax(const GridLength& minTrackBreadth, const GridLength& maxTrackBreadth)
-    {
-        m_type = MinMaxTrackSizing;
-        m_minTrackBreadth = minTrackBreadth;
-        m_maxTrackBreadth = maxTrackBreadth;
-    }
+    const GridLength& minTrackBreadth() const { return m_minTrackBreadth; }
+    const GridLength& maxTrackBreadth() const { return m_maxTrackBreadth; }
 
     GridTrackSizeType type() const { return m_type; }
 
     bool isContentSized() const { return m_minTrackBreadth.isContentSized() || m_maxTrackBreadth.isContentSized(); }
+    bool isFitContent() const { return m_type == FitContentTrackSizing; }
 
     bool operator==(const GridTrackSize& other) const
     {
-        return m_type == other.m_type && m_minTrackBreadth == other.m_minTrackBreadth && m_maxTrackBreadth == other.m_maxTrackBreadth;
+        return m_type == other.m_type && m_minTrackBreadth == other.m_minTrackBreadth && m_maxTrackBreadth == other.m_maxTrackBreadth
+            && m_fitContentTrackBreadth == other.m_fitContentTrackBreadth;
+    }
+
+    void cacheMinMaxTrackBreadthTypes()
+    {
+        m_minTrackBreadthIsAuto = minTrackBreadth().isLength() && minTrackBreadth().length().isAuto();
+        m_minTrackBreadthIsMinContent = minTrackBreadth().isLength() && minTrackBreadth().length().isMinContent();
+        m_minTrackBreadthIsMaxContent = minTrackBreadth().isLength() && minTrackBreadth().length().isMaxContent();
+        m_maxTrackBreadthIsMaxContent = maxTrackBreadth().isLength() && maxTrackBreadth().length().isMaxContent();
+        m_maxTrackBreadthIsMinContent = maxTrackBreadth().isLength() && maxTrackBreadth().length().isMinContent();
+        m_maxTrackBreadthIsAuto = maxTrackBreadth().isLength() && maxTrackBreadth().length().isAuto();
+
+        // These values depend on the above ones so keep them here.
+        m_minTrackBreadthIsIntrinsic = m_minTrackBreadthIsMaxContent || m_minTrackBreadthIsMinContent
+            || m_minTrackBreadthIsAuto || isFitContent();
+        m_maxTrackBreadthIsIntrinsic = m_maxTrackBreadthIsMaxContent || m_maxTrackBreadthIsMinContent
+            || m_maxTrackBreadthIsAuto || isFitContent();
     }
 
-    bool hasMinOrMaxContentMinTrackBreadth() const { return minTrackBreadth().isLength() && (minTrackBreadth().length().isMinContent() || minTrackBreadth().length().isMaxContent()); }
-    bool hasMaxContentMinTrackBreadth() const { return minTrackBreadth().isLength() && minTrackBreadth().length().isMaxContent(); }
-    bool hasMinOrMaxContentMaxTrackBreadth() const { return maxTrackBreadth().isLength() && (maxTrackBreadth().length().isMinContent() || maxTrackBreadth().length().isMaxContent()); }
-    bool hasMaxContentMaxTrackBreadth() const { return maxTrackBreadth().isLength() && maxTrackBreadth().length().isMaxContent(); }
+    bool hasIntrinsicMinTrackBreadth() const { return m_minTrackBreadthIsIntrinsic; }
+    bool hasIntrinsicMaxTrackBreadth() const { return m_maxTrackBreadthIsIntrinsic; }
+    bool hasMinOrMaxContentMinTrackBreadth() const { return m_minTrackBreadthIsMaxContent || m_minTrackBreadthIsMinContent; }
+    bool hasAutoMinTrackBreadth() const { return m_minTrackBreadthIsAuto; }
+    bool hasAutoMaxTrackBreadth() const { return m_maxTrackBreadthIsAuto; }
+    bool hasMaxContentMaxTrackBreadth() const { return m_maxTrackBreadthIsMaxContent; }
+    bool hasMaxContentOrAutoMaxTrackBreadth() const { return m_maxTrackBreadthIsMaxContent || m_maxTrackBreadthIsAuto; }
+    bool hasMinContentMaxTrackBreadth() const { return m_maxTrackBreadthIsMinContent; }
+    bool hasMinOrMaxContentMaxTrackBreadth() const { return m_maxTrackBreadthIsMaxContent || m_maxTrackBreadthIsMinContent; }
+    bool hasMaxContentMinTrackBreadth() const { return m_minTrackBreadthIsMaxContent; }
+    bool hasMinContentMinTrackBreadth() const { return m_minTrackBreadthIsMinContent; }
+    bool hasMaxContentMinTrackBreadthAndMaxContentMaxTrackBreadth() const { return m_minTrackBreadthIsMaxContent && m_maxTrackBreadthIsMaxContent; }
+    bool hasAutoOrMinContentMinTrackBreadthAndIntrinsicMaxTrackBreadth() const { return (m_minTrackBreadthIsMinContent || m_minTrackBreadthIsAuto) && m_maxTrackBreadthIsIntrinsic; }
 
 private:
     GridTrackSizeType m_type;
     GridLength m_minTrackBreadth;
     GridLength m_maxTrackBreadth;
+    GridLength m_fitContentTrackBreadth;
+
+    bool m_minTrackBreadthIsAuto : 1;
+    bool m_maxTrackBreadthIsAuto : 1;
+    bool m_minTrackBreadthIsMaxContent : 1;
+    bool m_minTrackBreadthIsMinContent : 1;
+    bool m_maxTrackBreadthIsMaxContent : 1;
+    bool m_maxTrackBreadthIsMinContent : 1;
+    bool m_minTrackBreadthIsIntrinsic : 1;
+    bool m_maxTrackBreadthIsIntrinsic : 1;
 };
 
 } // namespace WebCore
-
-#endif // GridTrackSize_h