/*

 * Copyright (C) 2007, 2008 Apple 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.

 * 3.  Neither the name of Apple Computer, Inc. ("Apple") 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 APPLE 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 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;

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 */

#include "config.h"

#include "DatabaseThread.h"

#if ENABLE(DATABASE)

#include "AutodrainedPool.h"

#include "Database.h"

#include "DatabaseTask.h"

#include "Logging.h"

#include "SQLTransactionClient.h"

#include "SQLTransactionCoordinator.h"

namespace WebCore {

DatabaseThread::DatabaseThread()

    : m_threadID(0)

    , m_transactionClient(new SQLTransactionClient())

    , m_transactionCoordinator(new SQLTransactionCoordinator())

{

    m_selfRef = this;

}

DatabaseThread::~DatabaseThread()

{

    // FIXME: Any cleanup required here?  Since the thread deletes itself after running its detached course, I don't think so.  Lets be sure.

}

bool DatabaseThread::start()

{

    MutexLocker lock(m_threadCreationMutex);

    if (m_threadID)

        return true;

    m_threadID = createThread(DatabaseThread::databaseThreadStart, this, "WebCore: Database");

    return m_threadID;

}

void DatabaseThread::requestTermination()

{

    LOG(StorageAPI, "DatabaseThread %p was asked to terminate\n", this);

    m_queue.kill();

}

bool DatabaseThread::terminationRequested() const

{

    return m_queue.killed();

}

void* DatabaseThread::databaseThreadStart(void* vDatabaseThread)

{

    DatabaseThread* dbThread = static_cast<DatabaseThread*>(vDatabaseThread);

    return dbThread->databaseThread();

}

void* DatabaseThread::databaseThread()

{

    {

        // Wait for DatabaseThread::start() to complete.

        MutexLocker lock(m_threadCreationMutex);

        LOG(StorageAPI, "Started DatabaseThread %p", this);

    }

    AutodrainedPool pool;

    while (true) {

        RefPtr<DatabaseTask> task;

        if (!m_queue.waitForMessage(task))

            break;

        task->performTask();

        pool.cycle();

    }

    // Clean up the list of all pending transactions on this database thread

    m_transactionCoordinator->shutdown();

    LOG(StorageAPI, "About to detach thread %i and clear the ref to DatabaseThread %p, which currently has %i ref(s)", m_threadID, this, refCount());

    // Close the databases that we ran transactions on. This ensures that if any transactions are still open, they are rolled back and we don't leave the database in an

    // inconsistent or locked state.

    if (m_openDatabaseSet.size() > 0) {

        // As the call to close will modify the original set, we must take a copy to iterate over.

        DatabaseSet openSetCopy;

        openSetCopy.swap(m_openDatabaseSet);

        DatabaseSet::iterator end = openSetCopy.end();

        for (DatabaseSet::iterator it = openSetCopy.begin(); it != end; ++it)

           (*it)->close();

    }

    // Detach the thread so its resources are no longer of any concern to anyone else

    detachThread(m_threadID);

    // Clear the self refptr, possibly resulting in deletion

    m_selfRef = 0;

    return 0;

}

void DatabaseThread::recordDatabaseOpen(Database* database)

{

    ASSERT(currentThread() == m_threadID);

    ASSERT(database);

    ASSERT(!m_openDatabaseSet.contains(database));

    m_openDatabaseSet.add(database);

}

void DatabaseThread::recordDatabaseClosed(Database* database)

{

    ASSERT(currentThread() == m_threadID);

    ASSERT(database);

    ASSERT(m_queue.killed() || m_openDatabaseSet.contains(database));

    m_openDatabaseSet.remove(database);

}

void DatabaseThread::scheduleTask(PassRefPtr<DatabaseTask> task)

{

    m_queue.append(task);

}

void DatabaseThread::scheduleImmediateTask(PassRefPtr<DatabaseTask> task)

{

    m_queue.prepend(task);

}

class SameDatabasePredicate {

public:

    SameDatabasePredicate(const Database* database) : m_database(database) { }

    bool operator()(RefPtr<DatabaseTask>& task) const { return task->database() == m_database; }

private:

    const Database* m_database;

};

void DatabaseThread::unscheduleDatabaseTasks(Database* database)

{

    // Note that the thread loop is running, so some tasks for the database

    // may still be executed. This is unavoidable.

    SameDatabasePredicate predicate(database);

    m_queue.removeIf(predicate);

}

} // namespace WebCore

#endif