modules/webdatabase/Database.cpp

/*
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#include "config.h"
#include "modules/webdatabase/Database.h"

#include "core/dom/CrossThreadTask.h"
#include "core/dom/Document.h"
#include "core/dom/ExecutionContext.h"
#include "core/html/VoidCallback.h"
#include "core/page/Page.h"
#include "platform/Logging.h"
#include "modules/webdatabase/sqlite/SQLiteStatement.h"
#include "modules/webdatabase/ChangeVersionData.h"
#include "modules/webdatabase/DatabaseCallback.h"
#include "modules/webdatabase/DatabaseContext.h"
#include "modules/webdatabase/DatabaseManager.h"
#include "modules/webdatabase/DatabaseTask.h"
#include "modules/webdatabase/DatabaseThread.h"
#include "modules/webdatabase/DatabaseTracker.h"
#include "modules/webdatabase/SQLError.h"
#include "modules/webdatabase/SQLTransaction.h"
#include "modules/webdatabase/SQLTransactionCallback.h"
#include "modules/webdatabase/SQLTransactionErrorCallback.h"
#include "platform/weborigin/SecurityOrigin.h"
#include "wtf/OwnPtr.h"
#include "wtf/PassOwnPtr.h"
#include "wtf/PassRefPtr.h"
#include "wtf/RefPtr.h"
#include "wtf/StdLibExtras.h"
#include "wtf/text/CString.h"

namespace WebCore {

PassRefPtr<Database> Database::create(ExecutionContext*, PassRefPtr<DatabaseBackendBase> backend)
{
    // FIXME: Currently, we're only simulating the backend by return the
    // frontend database as its own the backend. When we split the 2 apart,
    // this create() function should be changed to be a factory method for
    // instantiating the backend.
    return static_cast<Database*>(backend.get());
}

Database::Database(PassRefPtr<DatabaseContext> databaseContext,
    const String& name, const String& expectedVersion, const String& displayName, unsigned long estimatedSize)
    : DatabaseBase(databaseContext->executionContext())
    , DatabaseBackend(databaseContext, name, expectedVersion, displayName, estimatedSize)
    , m_databaseContext(DatabaseBackend::databaseContext())
{
    ScriptWrappable::init(this);
    m_databaseThreadSecurityOrigin = m_contextThreadSecurityOrigin->isolatedCopy();
    setFrontend(this);

    ASSERT(m_databaseContext->databaseThread());
}

class DerefContextTask : public ExecutionContextTask {
public:
    static PassOwnPtr<DerefContextTask> create(PassRefPtr<ExecutionContext> context)
    {
        return adoptPtr(new DerefContextTask(context));
    }

    virtual void performTask(ExecutionContext* context)
    {
        ASSERT_UNUSED(context, context == m_context);
        m_context.clear();
    }

    virtual bool isCleanupTask() const { return true; }

private:
    DerefContextTask(PassRefPtr<ExecutionContext> context)
        : m_context(context)
    {
    }

    RefPtr<ExecutionContext> m_context;
};

Database::~Database()
{
    // The reference to the ExecutionContext needs to be cleared on the JavaScript thread. If we're on that thread already, we can just let the RefPtr's destruction do the dereffing.
    if (!m_executionContext->isContextThread()) {
        // Grab a pointer to the script execution here because we're releasing it when we pass it to
        // DerefContextTask::create.
        ExecutionContext* executionContext = m_executionContext.get();

        executionContext->postTask(DerefContextTask::create(m_executionContext.release()));
    }
}

Database* Database::from(DatabaseBackend* backend)
{
    return static_cast<Database*>(backend->m_frontend);
}

PassRefPtr<DatabaseBackend> Database::backend()
{
    return this;
}

String Database::version() const
{
    return DatabaseBackendBase::version();
}

void Database::closeImmediately()
{
    ASSERT(m_executionContext->isContextThread());
    DatabaseThread* databaseThread = databaseContext()->databaseThread();
    if (databaseThread && !databaseThread->terminationRequested() && opened()) {
        logErrorMessage("forcibly closing database");
        databaseThread->scheduleTask(DatabaseCloseTask::create(this, 0));
    }
}

void Database::changeVersion(const String& oldVersion, const String& newVersion, PassOwnPtr<SQLTransactionCallback> callback, PassOwnPtr<SQLTransactionErrorCallback> errorCallback, PassOwnPtr<VoidCallback> successCallback)
{
    ChangeVersionData data(oldVersion, newVersion);
    runTransaction(callback, errorCallback, successCallback, false, &data);
}

void Database::transaction(PassOwnPtr<SQLTransactionCallback> callback, PassOwnPtr<SQLTransactionErrorCallback> errorCallback, PassOwnPtr<VoidCallback> successCallback)
{
    runTransaction(callback, errorCallback, successCallback, false);
}

void Database::readTransaction(PassOwnPtr<SQLTransactionCallback> callback, PassOwnPtr<SQLTransactionErrorCallback> errorCallback, PassOwnPtr<VoidCallback> successCallback)
{
    runTransaction(callback, errorCallback, successCallback, true);
}

static void callTransactionErrorCallback(ExecutionContext*, PassOwnPtr<SQLTransactionErrorCallback> callback, PassRefPtr<SQLError> error)
{
    callback->handleEvent(error.get());
}

void Database::runTransaction(PassOwnPtr<SQLTransactionCallback> callback, PassOwnPtr<SQLTransactionErrorCallback> errorCallback,
    PassOwnPtr<VoidCallback> successCallback, bool readOnly, const ChangeVersionData* changeVersionData)
{
    // FIXME: Rather than passing errorCallback to SQLTransaction and then sometimes firing it ourselves,
    // this code should probably be pushed down into DatabaseBackend so that we only create the SQLTransaction
    // if we're actually going to run it.
#if !ASSERT_DISABLED
    SQLTransactionErrorCallback* originalErrorCallback = errorCallback.get();
#endif
    RefPtr<SQLTransaction> transaction = SQLTransaction::create(this, callback, successCallback, errorCallback, readOnly);
    RefPtr<SQLTransactionBackend> transactionBackend = backend()->runTransaction(transaction, readOnly, changeVersionData);
    if (!transactionBackend) {
        OwnPtr<SQLTransactionErrorCallback> callback = transaction->releaseErrorCallback();
        ASSERT(callback == originalErrorCallback);
        if (callback) {
            RefPtr<SQLError> error = SQLError::create(SQLError::UNKNOWN_ERR, "database has been closed");
            executionContext()->postTask(createCallbackTask(&callTransactionErrorCallback, callback.release(), error.release()));
        }
    }
}

class DeliverPendingCallbackTask : public ExecutionContextTask {
public:
    static PassOwnPtr<DeliverPendingCallbackTask> create(PassRefPtr<SQLTransaction> transaction)
    {
        return adoptPtr(new DeliverPendingCallbackTask(transaction));
    }

    virtual void performTask(ExecutionContext*)
    {
        m_transaction->performPendingCallback();
    }

private:
    DeliverPendingCallbackTask(PassRefPtr<SQLTransaction> transaction)
        : m_transaction(transaction)
    {
    }

    RefPtr<SQLTransaction> m_transaction;
};

void Database::scheduleTransactionCallback(SQLTransaction* transaction)
{
    m_executionContext->postTask(DeliverPendingCallbackTask::create(transaction));
}

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

    SQLiteStatement statement(sqliteDatabase(), "SELECT name FROM sqlite_master WHERE type='table';");
    if (statement.prepare() != SQLResultOk) {
        WTF_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) {
        WTF_LOG_ERROR("Error getting tables for database %s", databaseDebugName().ascii().data());
        return Vector<String>();
    }

    return tableNames;
}

Vector<String> Database::tableNames()
{
    // FIXME: Not using isolatedCopy on these strings looks ok since threads take strict turns
    // in dealing with them. However, if the code changes, this may not be true anymore.
    Vector<String> result;
    DatabaseTaskSynchronizer synchronizer;
    if (!databaseContext()->databaseThread() || databaseContext()->databaseThread()->terminationRequested(&synchronizer))
        return result;

    OwnPtr<DatabaseTableNamesTask> task = DatabaseTableNamesTask::create(this, &synchronizer, result);
    databaseContext()->databaseThread()->scheduleTask(task.release());
    synchronizer.waitForTaskCompletion();

    return result;
}

SecurityOrigin* Database::securityOrigin() const
{
    if (m_executionContext->isContextThread())
        return m_contextThreadSecurityOrigin.get();
    if (databaseContext()->databaseThread()->isDatabaseThread())
        return m_databaseThreadSecurityOrigin.get();
    return 0;
}

void Database::reportStartTransactionResult(int errorSite, int webSqlErrorCode, int sqliteErrorCode)
{
    backend()->reportStartTransactionResult(errorSite, webSqlErrorCode, sqliteErrorCode);
}

void Database::reportCommitTransactionResult(int errorSite, int webSqlErrorCode, int sqliteErrorCode)
{
    backend()->reportCommitTransactionResult(errorSite, webSqlErrorCode, sqliteErrorCode);
}


} // namespace WebCore