| /* |
| * 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 V8StringResource_h |
| #define V8StringResource_h |
| |
| #include "bindings/core/v8/ExceptionState.h" |
| #include "wtf/Threading.h" |
| #include "wtf/text/AtomicString.h" |
| #include <v8.h> |
| |
| namespace blink { |
| |
| // WebCoreStringResource is a helper class for v8ExternalString. It is used |
| // to manage the life-cycle of the underlying buffer of the external string. |
| class WebCoreStringResourceBase { |
| public: |
| explicit WebCoreStringResourceBase(const String& string) |
| : m_plainString(string) |
| { |
| #if ENABLE(ASSERT) |
| m_threadId = WTF::currentThread(); |
| #endif |
| ASSERT(!string.isNull()); |
| v8::Isolate::GetCurrent()->AdjustAmountOfExternalAllocatedMemory(memoryConsumption(string)); |
| } |
| |
| explicit WebCoreStringResourceBase(const AtomicString& string) |
| : m_plainString(string.string()) |
| , m_atomicString(string) |
| { |
| #if ENABLE(ASSERT) |
| m_threadId = WTF::currentThread(); |
| #endif |
| ASSERT(!string.isNull()); |
| v8::Isolate::GetCurrent()->AdjustAmountOfExternalAllocatedMemory(memoryConsumption(string)); |
| } |
| |
| virtual ~WebCoreStringResourceBase() |
| { |
| #if ENABLE(ASSERT) |
| ASSERT(m_threadId == WTF::currentThread()); |
| #endif |
| int reducedExternalMemory = -memoryConsumption(m_plainString); |
| if (m_plainString.impl() != m_atomicString.impl() && !m_atomicString.isNull()) |
| reducedExternalMemory -= memoryConsumption(m_atomicString.string()); |
| v8::Isolate::GetCurrent()->AdjustAmountOfExternalAllocatedMemory(reducedExternalMemory); |
| } |
| |
| const String& webcoreString() { return m_plainString; } |
| |
| const AtomicString& atomicString() |
| { |
| #if ENABLE(ASSERT) |
| ASSERT(m_threadId == WTF::currentThread()); |
| #endif |
| if (m_atomicString.isNull()) { |
| m_atomicString = AtomicString(m_plainString); |
| ASSERT(!m_atomicString.isNull()); |
| if (m_plainString.impl() != m_atomicString.impl()) |
| v8::Isolate::GetCurrent()->AdjustAmountOfExternalAllocatedMemory(memoryConsumption(m_atomicString.string())); |
| } |
| return m_atomicString; |
| } |
| |
| protected: |
| // A shallow copy of the string. Keeps the string buffer alive until the V8 engine garbage collects it. |
| String m_plainString; |
| // If this string is atomic or has been made atomic earlier the |
| // atomic string is held here. In the case where the string starts |
| // off non-atomic and becomes atomic later it is necessary to keep |
| // the original string alive because v8 may keep derived pointers |
| // into that string. |
| AtomicString m_atomicString; |
| |
| private: |
| static int memoryConsumption(const String& string) |
| { |
| return string.length() * (string.is8Bit() ? sizeof(LChar) : sizeof(UChar)); |
| } |
| #if ENABLE(ASSERT) |
| WTF::ThreadIdentifier m_threadId; |
| #endif |
| }; |
| |
| class WebCoreStringResource16 final : public WebCoreStringResourceBase, public v8::String::ExternalStringResource { |
| public: |
| explicit WebCoreStringResource16(const String& string) |
| : WebCoreStringResourceBase(string) |
| { |
| ASSERT(!string.is8Bit()); |
| } |
| |
| explicit WebCoreStringResource16(const AtomicString& string) |
| : WebCoreStringResourceBase(string) |
| { |
| ASSERT(!string.is8Bit()); |
| } |
| |
| virtual size_t length() const override { return m_plainString.impl()->length(); } |
| virtual const uint16_t* data() const override |
| { |
| return reinterpret_cast<const uint16_t*>(m_plainString.impl()->characters16()); |
| } |
| }; |
| |
| class WebCoreStringResource8 final : public WebCoreStringResourceBase, public v8::String::ExternalOneByteStringResource { |
| public: |
| explicit WebCoreStringResource8(const String& string) |
| : WebCoreStringResourceBase(string) |
| { |
| ASSERT(string.is8Bit()); |
| } |
| |
| explicit WebCoreStringResource8(const AtomicString& string) |
| : WebCoreStringResourceBase(string) |
| { |
| ASSERT(string.is8Bit()); |
| } |
| |
| virtual size_t length() const override { return m_plainString.impl()->length(); } |
| virtual const char* data() const override |
| { |
| return reinterpret_cast<const char*>(m_plainString.impl()->characters8()); |
| } |
| }; |
| |
| enum ExternalMode { |
| Externalize, |
| DoNotExternalize |
| }; |
| |
| template <typename StringType> |
| StringType v8StringToWebCoreString(v8::Handle<v8::String>, ExternalMode); |
| String int32ToWebCoreString(int value); |
| |
| // V8StringResource is an adapter class that converts V8 values to Strings |
| // or AtomicStrings as appropriate, using multiple typecast operators. |
| enum V8StringResourceMode { |
| DefaultMode, |
| TreatNullAsEmptyString, |
| TreatNullAsNullString, |
| TreatNullAndUndefinedAsNullString |
| }; |
| |
| template <V8StringResourceMode Mode = DefaultMode> |
| class V8StringResource { |
| public: |
| V8StringResource() |
| : m_mode(Externalize) |
| { |
| } |
| |
| V8StringResource(v8::Handle<v8::Value> object) |
| : m_v8Object(object) |
| , m_mode(Externalize) |
| { |
| } |
| |
| void operator=(v8::Handle<v8::Value> object) |
| { |
| m_v8Object = object; |
| } |
| |
| void operator=(const String& string) |
| { |
| setString(string); |
| } |
| |
| void operator=(std::nullptr_t) |
| { |
| setString(String()); |
| } |
| |
| bool prepare() |
| { |
| if (prepareFast()) |
| return true; |
| |
| m_v8Object = m_v8Object->ToString(); |
| // Handle the case where an exception is thrown as part of invoking toString on the object. |
| if (m_v8Object.IsEmpty()) |
| return false; |
| return true; |
| } |
| |
| bool prepare(ExceptionState& exceptionState) |
| { |
| if (prepareFast()) |
| return true; |
| |
| v8::TryCatch block; |
| m_v8Object = m_v8Object->ToString(); |
| // Handle the case where an exception is thrown as part of invoking toString on the object. |
| if (block.HasCaught()) { |
| exceptionState.rethrowV8Exception(block.Exception()); |
| return false; |
| } |
| return true; |
| } |
| |
| operator String() const { return toString<String>(); } |
| operator AtomicString() const { return toString<AtomicString>(); } |
| |
| private: |
| bool prepareFast() |
| { |
| if (m_v8Object.IsEmpty()) |
| return true; |
| |
| if (!isValid()) { |
| setString(fallbackString()); |
| return true; |
| } |
| |
| if (LIKELY(m_v8Object->IsString())) |
| return true; |
| |
| if (LIKELY(m_v8Object->IsInt32())) { |
| setString(int32ToWebCoreString(m_v8Object->Int32Value())); |
| return true; |
| } |
| |
| m_mode = DoNotExternalize; |
| return false; |
| } |
| |
| bool isValid() const; |
| String fallbackString() const; |
| |
| void setString(const String& string) |
| { |
| m_string = string; |
| m_v8Object.Clear(); // To signal that String is ready. |
| } |
| |
| template <class StringType> |
| StringType toString() const |
| { |
| if (LIKELY(!m_v8Object.IsEmpty())) |
| return v8StringToWebCoreString<StringType>(const_cast<v8::Handle<v8::Value>*>(&m_v8Object)->As<v8::String>(), m_mode); |
| |
| return StringType(m_string); |
| } |
| |
| v8::Handle<v8::Value> m_v8Object; |
| ExternalMode m_mode; |
| String m_string; |
| }; |
| |
| template<> inline bool V8StringResource<DefaultMode>::isValid() const |
| { |
| return true; |
| } |
| |
| template<> inline String V8StringResource<DefaultMode>::fallbackString() const |
| { |
| ASSERT_NOT_REACHED(); |
| return String(); |
| } |
| |
| template<> inline bool V8StringResource<TreatNullAsEmptyString>::isValid() const |
| { |
| return !m_v8Object->IsNull(); |
| } |
| |
| template<> inline String V8StringResource<TreatNullAsEmptyString>::fallbackString() const |
| { |
| return emptyString(); |
| } |
| |
| template<> inline bool V8StringResource<TreatNullAsNullString>::isValid() const |
| { |
| return !m_v8Object->IsNull(); |
| } |
| |
| template<> inline String V8StringResource<TreatNullAsNullString>::fallbackString() const |
| { |
| return String(); |
| } |
| |
| template<> inline bool V8StringResource<TreatNullAndUndefinedAsNullString>::isValid() const |
| { |
| return !m_v8Object->IsNull() && !m_v8Object->IsUndefined(); |
| } |
| |
| template<> inline String V8StringResource<TreatNullAndUndefinedAsNullString>::fallbackString() const |
| { |
| return String(); |
| } |
| |
| } // namespace blink |
| |
| #endif // V8StringResource_h |