[poc] curve-filter

third_party/WebKit/Source/platform/graphics/ColorSpaceFilterCache.cpp

Index: third_party/WebKit/Source/platform/graphics/ColorSpaceFilterCache.cpp
diff --git a/third_party/WebKit/Source/platform/graphics/ColorSpaceFilterCache.cpp b/third_party/WebKit/Source/platform/graphics/ColorSpaceFilterCache.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..ff85c4fdcd58c5a231463ec591427a650d2a51e2
--- /dev/null
+++ b/third_party/WebKit/Source/platform/graphics/ColorSpaceFilterCache.cpp
@@ -0,0 +1,121 @@
+// 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.
+
+#include "platform/graphics/ColorSpaceFilterCache.h"
+
+#include "platform/graphics/ColorSpaceProfile.h"
+#include "third_party/skia/include/core/SkColorFilter.h"
+#include "wtf/HashMap.h"
+#include "wtf/MainThread.h"
+#include "wtf/text/StringHash.h"
+#include "wtf/text/WTFString.h"
+
+namespace blink {
+
+#if USE(QCMSLIB)
+
+class ColorTransformCache {
+public:
+    void set(ColorSpaceProfile* source, ColorSpaceProfile* target, SkColorFilter* transform)
+    {
+        set(transformCacheKey(source, target), transform);
+    }
+
+    PassRefPtr<SkColorFilter> find(ColorSpaceProfile* source, ColorSpaceProfile* target) const
+    {
+        return find(transformCacheKey(source, target));
+    }
+
+    void prune(ColorSpaceProfile* target)
+    {
+        const size_t cachePruneMinimum = 3; // FIXME: provide a larger prune limit?
+
+        if (!target || m_colorTransforms.size() < cachePruneMinimum)
+            return;
+
+        prune(transformTargetDescription(target));
+    }
+
+private:
+    static String transformCacheKey(ColorSpaceProfile* source, ColorSpaceProfile* target)
+    {
+        return qcms_profile_get_description(source->profile()) + transformTargetDescription(target);
+    }
+
+    static String transformTargetDescription(ColorSpaceProfile* target)
+    {
+        return String(" -> ") + qcms_profile_get_description(target->profile());
+    }
+
+    void set(const String& key, SkColorFilter* transform)
+    {
+        m_colorTransforms.set(key, transform);
+    }
+
+    PassRefPtr<SkColorFilter> find(const String& key) const
+    {
+        HashMap<String, RefPtr<SkColorFilter>>::const_iterator it = m_colorTransforms.find(key);
+        return it != m_colorTransforms.end() ? it->value : nullptr;
+    }
+
+    void prune(const String& target)
+    {
+        Vector<String> removeKeys;
+
+        for (const auto& key : m_colorTransforms.keys()) {
+            SkColorFilter* transform = m_colorTransforms.get(key);
+            fprintf(stderr, " transform cache %s\n", String(key).latin1().data());
+            if (transform->unique() || key.endsWith(target))
+                removeKeys.append(key);
+        }
+
+        for (unsigned i = 0; i < removeKeys.size(); ++i)
+            fprintf(stderr, " prune %s\n", removeKeys[i].latin1().data());
+
+        m_colorTransforms.removeAll(removeKeys);
+    }
+
+    HashMap<String, RefPtr<SkColorFilter>> m_colorTransforms;
+};
+
+static ColorTransformCache& colorTransformCache()
+{
+    DEFINE_STATIC_LOCAL(ColorTransformCache, cache, ());
+    RELEASE_ASSERT(isMainThread());
+    return cache;
+}
+
+PassRefPtr<SkColorFilter> findColorTransform(ColorSpaceProfile* source, ColorSpaceProfile* target)
+{
+    return colorTransformCache().find(source, target);
+}
+
+void cacheColorTransform(ColorSpaceProfile* source, ColorSpaceProfile* target, SkColorFilter* filter)
+{
+    colorTransformCache().set(source, target, filter);
+}
+
+void pruneColorTransform(ColorSpaceProfile* target)
+{
+    colorTransformCache().prune(target);
+}
+
+#else
+
+PassRefPtr<SkColorFilter> findColorTransform(ColorSpaceProfile*, ColorSpaceProfile*)
+{
+    return nullptr;
+}
+
+void cacheColorTransform(ColorSpaceProfile*, ColorSpaceProfile*, SkColorFilter*)
+{
+}
+
+void pruneColorTransform(ColorSpaceProfile*)
+{
+}
+
+#endif // USE(QCMSLIB)
+
+} // namespace blink