database.cpp

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    m_document->databaseThread()->unscheduleDatabaseTasks(this);

    RefPtr<DatabaseCloseTask> task = DatabaseCloseTask::create(this);

    task->lockForSynchronousScheduling();
    m_document->databaseThread()->scheduleImmediateTask(task);
    task->waitForSynchronousCompletion();
}

void Database::close()
{
    m_sqliteDatabase.close();
}

void Database::stop()
{
    // FIXME: The net effect of the following code is to remove all pending transactions and statements, but allow the current statement
    // to run to completion.  In the future we can use the sqlite3_progress_handler or sqlite3_interrupt interfaces to cancel the current
    // statement in response to close(), as well.
    
    // This method is meant to be used as an analog to cancelling a loader, and is used when a document is shut down as the result of 
    // a page load or closing the page
    m_stopped = true;

    {
        MutexLocker locker(m_transactionInProgressMutex);
        m_transactionQueue.kill();
        m_transactionInProgress = false;
    }
}

unsigned long long Database::databaseSize() const
{
    long long size;
    if (!getFileSize(m_filename, size))
        size = 0;
    return size;
}

unsigned long long Database::maximumSize() const
{
    // The maximum size for this database is the full quota for this origin, minus the current usage within this origin,
    // except for the current usage of this database
    
    OriginQuotaManager& manager(DatabaseTracker::tracker().originQuotaManager());
    Locker<OriginQuotaManager> locker(manager);
    
    return DatabaseTracker::tracker().quotaForOrigin(m_securityOrigin.get()) - manager.diskUsage(m_securityOrigin.get()) + databaseSize();
}

void Database::disableAuthorizer()
{
    ASSERT(m_databaseAuthorizer);
    m_databaseAuthorizer->disable();
}

void Database::enableAuthorizer()
{
    ASSERT(m_databaseAuthorizer);
    m_databaseAuthorizer->enable();
}

static int guidForOriginAndName(const String& origin, const String& name)
{
    String stringID;
    if (origin.endsWith("/"))
        stringID = origin + name;
    else
        stringID = origin + "/" + name;

    // Note: We don't have to use AtomicallyInitializedStatic here because
    // this function is called once in the constructor on the main thread
    // before any other threads that call this function are used.
    DEFINE_STATIC_LOCAL(Mutex, stringIdentifierMutex, ());
    MutexLocker locker(stringIdentifierMutex);
    typedef HashMap<String, int> IDGuidMap;
    DEFINE_STATIC_LOCAL(IDGuidMap, stringIdentifierToGUIDMap, ());
    int guid = stringIdentifierToGUIDMap.get(stringID);
    if (!guid) {
        static int currentNewGUID = 1;
        guid = currentNewGUID++;
        stringIdentifierToGUIDMap.set(stringID, guid);
    }

    return guid;
}

void Database::resetAuthorizer()
{
    if (m_databaseAuthorizer)
        m_databaseAuthorizer->reset();
}

void Database::performPolicyChecks()
{
    // FIXME: Code similar to the following will need to be run to enforce the per-origin size limit the spec mandates.
    // Additionally, we might need a way to pause the database thread while the UA prompts the user for permission to
    // increase the size limit

    /*
    if (m_databaseAuthorizer->lastActionIncreasedSize())
        DatabaseTracker::scheduleFileSizeCheckOnMainThread(this);
    */

    notImplemented();
}

bool Database::performOpenAndVerify(ExceptionCode& e)
{
    if (!m_sqliteDatabase.open(m_filename)) {
        LOG_ERROR("Unable to open database at path %s", m_filename.ascii().data());
        e = INVALID_STATE_ERR;
        return false;
    }

    ASSERT(m_databaseAuthorizer);
    m_sqliteDatabase.setAuthorizer(m_databaseAuthorizer);

    if (!m_sqliteDatabase.tableExists(databaseInfoTableName())) {
        if (!m_sqliteDatabase.executeCommand("CREATE TABLE " + databaseInfoTableName() + " (key TEXT NOT NULL ON CONFLICT FAIL UNIQUE ON CONFLICT REPLACE,value TEXT NOT NULL ON CONFLICT FAIL);")) {
            LOG_ERROR("Unable to create table %s in database %s", databaseInfoTableName().ascii().data(), databaseDebugName().ascii().data());
            e = INVALID_STATE_ERR;
            return false;
        }
    }


    String currentVersion;
    {
        MutexLocker locker(guidMutex());
        currentVersion = guidToVersionMap().get(m_guid);

        if (currentVersion.isNull())
            LOG(StorageAPI, "Current cached version for guid %i is null", m_guid);
        else
            LOG(StorageAPI, "Current cached version for guid %i is %s", m_guid, currentVersion.ascii().data());

        if (currentVersion.isNull()) {
            if (!getVersionFromDatabase(currentVersion)) {
                LOG_ERROR("Failed to get current version from database %s", databaseDebugName().ascii().data());
                e = INVALID_STATE_ERR;
                return false;
            }
            if (currentVersion.length()) {
                LOG(StorageAPI, "Retrieved current version %s from database %s", currentVersion.ascii().data(), databaseDebugName().ascii().data());
            } else {
                LOG(StorageAPI, "Setting version %s in database %s that was just created", m_expectedVersion.ascii().data(), databaseDebugName().ascii().data());
                if (!setVersionInDatabase(m_expectedVersion)) {
                    LOG_ERROR("Failed to set version %s in database %s", m_expectedVersion.ascii().data(), databaseDebugName().ascii().data());
                    e = INVALID_STATE_ERR;
                    return false;
                }

                currentVersion = m_expectedVersion;
            }

            guidToVersionMap().set(m_guid, currentVersion.copy());
        }
    }

    if (currentVersion.isNull()) {
        LOG(StorageAPI, "Database %s does not have its version set", databaseDebugName().ascii().data());
        currentVersion = "";
    }

    // FIXME: For now, the spec says that if the database has no version, it is valid for any "Expected version" string.  That seems silly and I think it should be
    // changed, and here's where we would change it
    if (m_expectedVersion.length()) {
        if (currentVersion.length() && m_expectedVersion != currentVersion) {
            LOG(StorageAPI, "page expects version %s from database %s, which actually has version name %s - openDatabase() call will fail", m_expectedVersion.ascii().data(),
                databaseDebugName().ascii().data(), currentVersion.ascii().data());
            e = INVALID_STATE_ERR;
            return false;
        }
    }

    return true;
}

void Database::changeVersion(const String& oldVersion, const String& newVersion, 
                             PassRefPtr<SQLTransactionCallback> callback, PassRefPtr<SQLTransactionErrorCallback> errorCallback,
                             PassRefPtr<VoidCallback> successCallback)
{
    m_transactionQueue.append(SQLTransaction::create(this, callback, errorCallback, successCallback, ChangeVersionWrapper::create(oldVersion, newVersion)));
    MutexLocker locker(m_transactionInProgressMutex);
    if (!m_transactionInProgress)
        scheduleTransaction();
}

void Database::transaction(PassRefPtr<SQLTransactionCallback> callback, PassRefPtr<SQLTransactionErrorCallback> errorCallback,
                           PassRefPtr<VoidCallback> successCallback)
{
    m_transactionQueue.append(SQLTransaction::create(this, callback, errorCallback, successCallback, 0));
    MutexLocker locker(m_transactionInProgressMutex);
    if (!m_transactionInProgress)
        scheduleTransaction();
}

void Database::scheduleTransaction()
{
    ASSERT(!m_transactionInProgressMutex.tryLock()); // Locked by caller.
    RefPtr<SQLTransaction> transaction;
    if (m_transactionQueue.tryGetMessage(transaction) && m_document->databaseThread()) {
        RefPtr<DatabaseTransactionTask> task = DatabaseTransactionTask::create(transaction);
        LOG(StorageAPI, "Scheduling DatabaseTransactionTask %p for transaction %p\n", task.get(), task->transaction());
        m_transactionInProgress = true;
        m_document->databaseThread()->scheduleTask(task.release());
    } else
        m_transactionInProgress = false;
}

void Database::scheduleTransactionStep(SQLTransaction* transaction)
{
    if (m_document->databaseThread()) {
        RefPtr<DatabaseTransactionTask> task = DatabaseTransactionTask::create(transaction);
        LOG(StorageAPI, "Scheduling DatabaseTransactionTask %p for the transaction step\n", task.get());
        m_document->databaseThread()->scheduleTask(task.release());
    }
}

void Database::scheduleTransactionCallback(SQLTransaction* transaction)
{
    transaction->ref();
    callOnMainThread(deliverPendingCallback, transaction);
}

Vector<String> Database::performGetTableNames()
{
    disableAuthorizer();

    SQLiteStatement statement(m_sqliteDatabase, "SELECT name FROM sqlite_master WHERE type='table';");
    if (statement.prepare() != SQLResultOk) {
        LOG_ERROR("Unable to retrieve list of tables for database %s", databaseDebugName().ascii().data());
        enableAuthorizer();
        return Vector<String>();
    }

    Vector<String> tableNames;
    int result;
    while ((result = statement.step()) == SQLResultRow) {
        String name = statement.getColumnText(0);
        if (name != databaseInfoTableName())
            tableNames.append(name);
    }

    enableAuthorizer();

    if (result != SQLResultDone) {
        LOG_ERROR("Error getting tables for database %s", databaseDebugName().ascii().data());
        return Vector<String>();
    }

    return tableNames;
}

String Database::version() const
{
    if (m_deleted)
        return String();
    MutexLocker locker(guidMutex());
    return guidToVersionMap().get(m_guid).copy();
}

void Database::deliverPendingCallback(void* context)
{
    SQLTransaction* transaction = static_cast<SQLTransaction*>(context);
    transaction->performPendingCallback();
    transaction->deref(); // Was ref'd in scheduleTransactionCallback().
}

Vector<String> Database::tableNames()
{
    if (!m_document->databaseThread())
        return Vector<String>();
    RefPtr<DatabaseTableNamesTask> task = DatabaseTableNamesTask::create(this);

    task->lockForSynchronousScheduling();
    m_document->databaseThread()->scheduleImmediateTask(task);
    task->waitForSynchronousCompletion();

    return task->tableNames();
}

void Database::setExpectedVersion(const String& version)
{
    m_expectedVersion = version.copy();
}

PassRefPtr<SecurityOrigin> Database::securityOriginCopy() const
{
    return m_securityOrigin->copy();
}

String Database::stringIdentifier() const
{
    // Return a deep copy for ref counting thread safety
    return m_name.copy();
}

}