| /* |
| * Copyright (C) 2009 Google 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. |
| */ |
| |
| #ifndef V8ValueCache_h |
| #define V8ValueCache_h |
| |
| #include "bindings/v8/ScopedPersistent.h" |
| #include "bindings/v8/UnsafePersistent.h" |
| #include <v8.h> |
| #include "wtf/HashMap.h" |
| #include "wtf/RefPtr.h" |
| #include "wtf/text/AtomicString.h" |
| #include "wtf/text/WTFString.h" |
| |
| namespace WebCore { |
| |
| class StringCache { |
| public: |
| StringCache() { } |
| |
| v8::Handle<v8::String> v8ExternalString(StringImpl* stringImpl, v8::Isolate* isolate) |
| { |
| if (m_lastStringImpl.get() == stringImpl && m_lastV8String.isWeak()) |
| return m_lastV8String.newLocal(isolate); |
| return v8ExternalStringSlow(stringImpl, isolate); |
| } |
| |
| template <class T> |
| void setReturnValueFromString(const T& info, StringImpl* stringImpl, v8::Isolate* isolate) |
| { |
| if (m_lastStringImpl.get() == stringImpl && m_lastV8String.isWeak()) |
| info.GetReturnValue().Set(*m_lastV8String.persistent()); |
| else |
| setReturnValueFromStringSlow(info, stringImpl, isolate); |
| } |
| |
| void clearOnGC() |
| { |
| m_lastStringImpl = 0; |
| m_lastV8String.clear(); |
| } |
| |
| void remove(StringImpl*); |
| |
| private: |
| static v8::Local<v8::String> makeExternalString(const String&); |
| static void makeWeakCallback(v8::Isolate*, v8::Persistent<v8::String>*, StringImpl*); |
| |
| v8::Handle<v8::String> v8ExternalStringSlow(StringImpl*, v8::Isolate*); |
| |
| template <class CallbackInfo> |
| void setReturnValueFromStringSlow(const CallbackInfo& info, StringImpl* stringImpl, v8::Isolate* isolate) |
| { |
| if (!stringImpl->length()) { |
| info.GetReturnValue().SetEmptyString(); |
| return; |
| } |
| |
| UnsafePersistent<v8::String> cachedV8String = m_stringCache.get(stringImpl); |
| if (cachedV8String.isWeak()) { |
| m_lastStringImpl = stringImpl; |
| m_lastV8String = cachedV8String; |
| info.GetReturnValue().Set(*cachedV8String.persistent()); |
| return; |
| } |
| |
| v8::Local<v8::String> newString = createStringAndInsertIntoCache(stringImpl, isolate); |
| if (newString.IsEmpty()) |
| info.GetReturnValue().SetEmptyString(); |
| else |
| info.GetReturnValue().Set(newString); |
| } |
| |
| v8::Local<v8::String> createStringAndInsertIntoCache(StringImpl*, v8::Isolate*); |
| |
| HashMap<StringImpl*, UnsafePersistent<v8::String> > m_stringCache; |
| UnsafePersistent<v8::String> m_lastV8String; |
| // 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; |
| }; |
| |
| } // namespace WebCore |
| |
| #endif // V8ValueCache_h |