sky/engine/bindings-dart/core/dart/DartStringCache.h

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#ifndef DartStringCache_h
#define DartStringCache_h

#include "wtf/HashMap.h"
#include "wtf/RefPtr.h"
#include "wtf/text/StringHash.h"
#include "wtf/text/StringImpl.h"

#include <dart_api.h>

namespace blink {

class DartStringCache {
public:
    DartStringCache();

    Dart_WeakPersistentHandle get(StringImpl* stringImpl, bool autoDartScope = true)
    {
        ASSERT(stringImpl);

        if (m_lastStringImpl.get() == stringImpl)
            return m_lastDartString;

        return getSlow(stringImpl, autoDartScope);
    }

    void clearWeakHandles();

    // FIXME: implement clearing on GC.

private:
    Dart_WeakPersistentHandle getSlow(StringImpl*, bool autoDartScope);
    static void handleFinalizer(void*, Dart_WeakPersistentHandle, void* peer);

    typedef HashMap<StringImpl*, Dart_WeakPersistentHandle> StringCache;
    StringCache m_stringCache;
    Dart_WeakPersistentHandle m_lastDartString;
    // Note: RefPtr is a must as we cache by StringImpl* equality, not identity
    // hence lastStringImpl might be not a key of the cache (in sense of identity)
    // and hence it's not refed on addition.
    RefPtr<StringImpl> m_lastStringImpl;
};

}

#endif