/*
 * 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:
 *
 *     * 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
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 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "config.h"
#include "DOMDataStore.h"

#include "DOMWrapperMap.h"
#include "V8Binding.h"
#include "WebCoreMemoryInstrumentation.h"
#include <wtf/MainThread.h>

namespace WebCore {

DOMDataStore::DOMDataStore(Type type)
    : m_type(type)
{
    V8PerIsolateData::current()->registerDOMDataStore(this);
}

DOMDataStore::~DOMDataStore()
{
    ASSERT(m_type != MainWorld); // We never actually destruct the main world's DOMDataStore.
    V8PerIsolateData::current()->unregisterDOMDataStore(this);
    m_wrapperMap.clear();
}

DOMDataStore* DOMDataStore::mainWorldStore()
{
    DEFINE_STATIC_LOCAL(DOMDataStore, mainWorldDOMDataStore, (MainWorld));
    ASSERT(isMainThread());
    return &mainWorldDOMDataStore;
}

DOMDataStore* DOMDataStore::current(v8::Isolate* isolate)
{
    V8PerIsolateData* data = isolate ? V8PerIsolateData::from(isolate) : V8PerIsolateData::current();
    if (UNLIKELY(!!data->domDataStore()))
        return data->domDataStore();

    if (DOMWrapperWorld::isolatedWorldsExist()) {
        DOMWrapperWorld* isolatedWorld = DOMWrapperWorld::isolated(v8::Context::GetEntered());
        if (UNLIKELY(!!isolatedWorld))
            return isolatedWorld->isolatedWorldDOMDataStore();
    }

    return mainWorldStore();
}

void DOMDataStore::reportMemoryUsage(MemoryObjectInfo* memoryObjectInfo) const
{
    MemoryClassInfo info(memoryObjectInfo, this, WebCoreMemoryTypes::Binding);
    info.addMember(m_wrapperMap);
}

void DOMDataStore::weakCallback(v8::Persistent<v8::Value> value, void* context)
{
    ScriptWrappable* key = static_cast<ScriptWrappable*>(context);
    ASSERT(value->IsObject());
    v8::Persistent<v8::Object> wrapper = v8::Persistent<v8::Object>::Cast(value);
    ASSERT(key->wrapper() == wrapper);
    // Note: |object| might not be equal to |key|, e.g., if ScriptWrappable isn't a left-most base class.
    void* object = toNative(wrapper);
    WrapperTypeInfo* info = toWrapperTypeInfo(wrapper);
    ASSERT(info->derefObjectFunction);

    key->clearWrapper();
    value.Dispose();
    value.Clear();
    // FIXME: I noticed that 50%~ of minor GC cycle times can be consumed
    // inside key->deref(), which causes Node destructions. We should
    // make Node destructions incremental.
    info->derefObject(object);
}

} // namespace WebCore
