1 files changed, 119 insertions, 0 deletions
diff --git a/Source/WebCore/css/CSSPrimitiveValueCache.cpp b/Source/WebCore/css/CSSPrimitiveValueCache.cpp
new file mode 100644
index 0000000..5c7a4c0
--- /dev/null
+++ b/Source/WebCore/css/CSSPrimitiveValueCache.cpp
@@ -0,0 +1,119 @@
+/*
+ * Copyright (C) 2011 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
+ * THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "CSSPrimitiveValueCache.h"
+
+namespace WebCore {
+
+CSSPrimitiveValueCache::CSSPrimitiveValueCache()
+    : m_colorTransparent(CSSPrimitiveValue::createColor(Color::transparent))
+    , m_colorWhite(CSSPrimitiveValue::createColor(Color::white))
+    , m_colorBlack(CSSPrimitiveValue::createColor(Color::black))
+    , m_pixelZero(CSSPrimitiveValue::create(0, CSSPrimitiveValue::CSS_PX))
+    , m_percentZero(CSSPrimitiveValue::create(0, CSSPrimitiveValue::CSS_PERCENTAGE))
+    , m_numberZero(CSSPrimitiveValue::create(0, CSSPrimitiveValue::CSS_NUMBER))
+{
+}
+
+CSSPrimitiveValueCache::~CSSPrimitiveValueCache()
+{
+}
+
+PassRefPtr<CSSPrimitiveValue> CSSPrimitiveValueCache::createIdentifierValue(int ident)
+{
+    if (ident <= 0 || ident >= numCSSValueKeywords)
+        return CSSPrimitiveValue::createIdentifier(ident);
+
+    RefPtr<CSSPrimitiveValue> dummyValue;
+    pair<IdentifierValueCache::iterator, bool> entry = m_identifierValueCache.add(ident, dummyValue);
+    if (entry.second)
+        entry.first->second = CSSPrimitiveValue::createIdentifier(ident);
+    return entry.first->second;
+}
+
+PassRefPtr<CSSPrimitiveValue> CSSPrimitiveValueCache::createColorValue(unsigned rgbValue)
+{
+    // These are the empty and deleted values of the hash table.
+    if (rgbValue == Color::transparent)
+        return m_colorTransparent;
+    if (rgbValue == Color::white)
+        return m_colorWhite;
+    // Just because it is common.
+    if (rgbValue == Color::black)
+        return m_colorBlack;
+    
+    // Just wipe out the cache and start rebuilding if it gets too big.
+    const int maximumColorCacheSize = 512;
+    if (m_colorValueCache.size() > maximumColorCacheSize)
+        m_colorValueCache.clear();
+
+    RefPtr<CSSPrimitiveValue> dummyValue;
+    pair<ColorValueCache::iterator, bool> entry = m_colorValueCache.add(rgbValue, dummyValue);
+    if (entry.second)
+        entry.first->second = CSSPrimitiveValue::createColor(rgbValue);
+    return entry.first->second;
+}
+
+PassRefPtr<CSSPrimitiveValue> CSSPrimitiveValueCache::createValue(double value, CSSPrimitiveValue::UnitTypes type)
+{
+    // Small positive integers repeat often.
+    static const int maximumCacheableValue = 256;
+    if (value < 0 || value > maximumCacheableValue)
+        return CSSPrimitiveValue::create(value, type);
+
+    int intValue = static_cast<int>(value);
+    if (value != intValue)
+        return CSSPrimitiveValue::create(value, type);
+    
+    IntegerValueCache* cache;
+    switch (type) {
+    case CSSPrimitiveValue::CSS_PX:
+        if (intValue == 0)
+            return m_pixelZero;
+        cache = &m_pixelValueCache;
+        break;
+    case CSSPrimitiveValue::CSS_PERCENTAGE:
+        if (intValue == 0)
+            return m_percentZero;
+        cache = &m_percentValueCache;
+        break;
+    case CSSPrimitiveValue::CSS_NUMBER:
+        if (intValue == 0)
+            return m_numberZero;
+        cache = &m_numberValueCache;
+        break;
+    default:
+        return CSSPrimitiveValue::create(value, type);
+    }
+
+    RefPtr<CSSPrimitiveValue> dummyValue;
+    pair<IntegerValueCache::iterator, bool> entry = cache->add(intValue, dummyValue);
+    if (entry.second)
+        entry.first->second = CSSPrimitiveValue::create(value, type);
+    return entry.first->second;
+}
+
+}