Source/bindings/v8/V8PerContextData.cpp

/*
 * Copyright (C) 2012 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:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * 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.
 *     * Neither the name of Google Inc. nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 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 THE COPYRIGHT
 * OWNER OR 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 "bindings/v8/V8PerContextData.h"

#include "bindings/v8/V8Binding.h"
#include "bindings/v8/V8ObjectConstructor.h"
#include "wtf/StringExtras.h"

#include <stdlib.h>

namespace WebCore {

template<typename Map>
static void disposeMapWithUnsafePersistentValues(Map* map)
{
    typename Map::iterator it = map->begin();
    for (; it != map->end(); ++it)
        it->value.dispose();
    map->clear();
}

void V8PerContextData::dispose()
{
    v8::HandleScope handleScope(m_isolate);
    V8PerContextDataHolder::from(v8::Local<v8::Context>::New(m_isolate, m_context))->setPerContextData(0);

    disposeMapWithUnsafePersistentValues(&m_wrapperBoilerplates);
    disposeMapWithUnsafePersistentValues(&m_constructorMap);
    m_customElementBindings.clear();

    m_context.Reset();
}

#define V8_STORE_PRIMORDIAL(name, Name) \
{ \
    ASSERT(m_##name##Prototype.isEmpty()); \
    v8::Handle<v8::String> symbol = v8::String::NewFromUtf8(m_isolate, #Name, v8::String::kInternalizedString); \
    if (symbol.IsEmpty()) \
        return false; \
    v8::Handle<v8::Object> object = v8::Handle<v8::Object>::Cast(v8::Local<v8::Context>::New(m_isolate, m_context)->Global()->Get(symbol)); \
    if (object.IsEmpty()) \
        return false; \
    v8::Handle<v8::Value> prototypeValue = object->Get(prototypeString); \
    if (prototypeValue.IsEmpty()) \
        return false; \
    m_##name##Prototype.set(m_isolate, prototypeValue);  \
}

bool V8PerContextData::init()
{
    v8::Handle<v8::Context> context = v8::Local<v8::Context>::New(m_isolate, m_context);
    V8PerContextDataHolder::from(context)->setPerContextData(this);

    v8::Handle<v8::String> prototypeString = v8AtomicString(m_isolate, "prototype");
    if (prototypeString.IsEmpty())
        return false;

    V8_STORE_PRIMORDIAL(error, Error);

    return true;
}

#undef V8_STORE_PRIMORDIAL

v8::Local<v8::Object> V8PerContextData::createWrapperFromCacheSlowCase(const WrapperTypeInfo* type)
{
    ASSERT(!m_errorPrototype.isEmpty());

    v8::Context::Scope scope(v8::Local<v8::Context>::New(m_isolate, m_context));
    v8::Local<v8::Function> function = constructorForType(type);
    v8::Local<v8::Object> instanceTemplate = V8ObjectConstructor::newInstance(function);
    if (!instanceTemplate.IsEmpty()) {
        m_wrapperBoilerplates.set(type, UnsafePersistent<v8::Object>(m_isolate, instanceTemplate));
        return instanceTemplate->Clone();
    }
    return v8::Local<v8::Object>();
}

v8::Local<v8::Function> V8PerContextData::constructorForTypeSlowCase(const WrapperTypeInfo* type)
{
    ASSERT(!m_errorPrototype.isEmpty());

    v8::Context::Scope scope(v8::Local<v8::Context>::New(m_isolate, m_context));
    v8::Handle<v8::FunctionTemplate> functionTemplate = type->domTemplate(m_isolate, worldType(m_isolate));
    // Getting the function might fail if we're running out of stack or memory.
    v8::TryCatch tryCatch;
    v8::Local<v8::Function> function = functionTemplate->GetFunction();
    if (function.IsEmpty())
        return v8::Local<v8::Function>();

    if (type->parentClass) {
        v8::Local<v8::Object> prototypeTemplate = constructorForType(type->parentClass);
        if (prototypeTemplate.IsEmpty())
            return v8::Local<v8::Function>();
        function->SetPrototype(prototypeTemplate);
    }

    v8::Local<v8::Value> prototypeValue = function->Get(v8AtomicString(m_isolate, "prototype"));
    if (!prototypeValue.IsEmpty() && prototypeValue->IsObject()) {
        v8::Local<v8::Object> prototypeObject = v8::Local<v8::Object>::Cast(prototypeValue);
        if (prototypeObject->InternalFieldCount() == v8PrototypeInternalFieldcount
            && type->wrapperTypePrototype == WrapperTypeObjectPrototype)
            prototypeObject->SetAlignedPointerInInternalField(v8PrototypeTypeIndex, const_cast<WrapperTypeInfo*>(type));
        type->installPerContextEnabledMethods(prototypeObject, m_isolate);
        if (type->wrapperTypePrototype == WrapperTypeErrorPrototype)
            prototypeObject->SetPrototype(m_errorPrototype.newLocal(m_isolate));
    }

    m_constructorMap.set(type, UnsafePersistent<v8::Function>(m_isolate, function));

    return function;
}

v8::Local<v8::Object> V8PerContextData::prototypeForType(const WrapperTypeInfo* type)
{
    v8::Local<v8::Object> constructor = constructorForType(type);
    if (constructor.IsEmpty())
        return v8::Local<v8::Object>();
    return constructor->Get(v8String(m_isolate, "prototype")).As<v8::Object>();
}

void V8PerContextData::addCustomElementBinding(CustomElementDefinition* definition, PassOwnPtr<CustomElementBinding> binding)
{
    ASSERT(!m_customElementBindings->contains(definition));
    m_customElementBindings->add(definition, binding);
}

void V8PerContextData::clearCustomElementBinding(CustomElementDefinition* definition)
{
    CustomElementBindingMap::iterator it = m_customElementBindings->find(definition);
    ASSERT_WITH_SECURITY_IMPLICATION(it != m_customElementBindings->end());
    m_customElementBindings->remove(it);
}

CustomElementBinding* V8PerContextData::customElementBinding(CustomElementDefinition* definition)
{
    CustomElementBindingMap::const_iterator it = m_customElementBindings->find(definition);
    ASSERT_WITH_SECURITY_IMPLICATION(it != m_customElementBindings->end());
    return it->value.get();
}


static v8::Handle<v8::Value> createDebugData(const char* worldName, int debugId, v8::Isolate* isolate)
{
    char buffer[32];
    unsigned wanted;
    if (debugId == -1)
        wanted = snprintf(buffer, sizeof(buffer), "%s", worldName);
    else
        wanted = snprintf(buffer, sizeof(buffer), "%s,%d", worldName, debugId);

    if (wanted < sizeof(buffer))
        return v8AtomicString(isolate, buffer);

    return v8::Undefined(isolate);
}

static v8::Handle<v8::Value> debugData(v8::Handle<v8::Context> context)
{
    v8::Context::Scope contextScope(context);
    return context->GetEmbedderData(v8ContextDebugIdIndex);
}

static void setDebugData(v8::Handle<v8::Context> context, v8::Handle<v8::Value> value)
{
    v8::Context::Scope contextScope(context);
    context->SetEmbedderData(v8ContextDebugIdIndex, value);
}

bool V8PerContextDebugData::setContextDebugData(v8::Handle<v8::Context> context, const char* worldName, int debugId)
{
    if (!debugData(context)->IsUndefined())
        return false;
    v8::HandleScope scope(context->GetIsolate());
    v8::Handle<v8::Value> debugData = createDebugData(worldName, debugId, context->GetIsolate());
    setDebugData(context, debugData);
    return true;
}

int V8PerContextDebugData::contextDebugId(v8::Handle<v8::Context> context)
{
    v8::HandleScope scope(context->GetIsolate());
    v8::Handle<v8::Value> data = debugData(context);

    if (!data->IsString())
        return -1;
    v8::String::Utf8Value utf8(data);
    char* comma = strnstr(*utf8, ",", utf8.length());
    if (!comma)
        return -1;
    return atoi(comma + 1);
}

} // namespace WebCore