sqltransaction.cpp

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            // Reset the maximum size here, as it was increased to allow us to retry this statement
            m_database->m_sqliteDatabase.setMaximumSize(m_database->maximumSize());
        } else {
            // If the current statement has already been run, failed due to quota constraints, and we're not retrying it,
            // that means it ended in an error.  Handle it now
            if (m_currentStatement && m_currentStatement->lastExecutionFailedDueToQuota()) {
                handleCurrentStatementError();
                break;
            }
            
            // Otherwise, advance to the next statement
            getNextStatement();
        }
    } while (runCurrentStatement());
    
    // If runCurrentStatement() returned false, that means either there was no current statement to run,
    // or the current statement requires a callback to complete.  In the later case, it also scheduled 
    // the callback or performed any other additional work so we can return
    if (!m_currentStatement)
        postflightAndCommit();
}

void SQLTransaction::getNextStatement()
{
    m_currentStatement = 0;
    
    MutexLocker locker(m_statementMutex);
    if (!m_statementQueue.isEmpty()) {
        m_currentStatement = m_statementQueue.first();
        m_statementQueue.removeFirst();
    }
}

bool SQLTransaction::runCurrentStatement()
{
    if (!m_currentStatement)
        return false;
        
    m_database->m_databaseAuthorizer->reset();
    
    if (m_currentStatement->execute(m_database.get())) {
        if (m_database->m_databaseAuthorizer->lastActionChangedDatabase()) {
            // Flag this transaction as having changed the database for later delegate notification
            m_modifiedDatabase = true;
            // Also dirty the size of this database file for calculating quota usage
            OriginQuotaManager& manager(DatabaseTracker::tracker().originQuotaManager());
            Locker<OriginQuotaManager> locker(manager);
            
            manager.markDatabase(m_database.get());
        }
            
        if (m_currentStatement->hasStatementCallback()) {
            m_nextStep = &SQLTransaction::deliverStatementCallback;
            LOG(StorageAPI, "Scheduling deliverStatementCallback for transaction %p\n", this);
            m_database->scheduleTransactionCallback(this);
            return false;
        }
        return true;
    }
    
    if (m_currentStatement->lastExecutionFailedDueToQuota()) {
        m_nextStep = &SQLTransaction::deliverQuotaIncreaseCallback;
        LOG(StorageAPI, "Scheduling deliverQuotaIncreaseCallback for transaction %p\n", this);
        m_database->scheduleTransactionCallback(this);
        return false;
    }
    
    handleCurrentStatementError();
    
    return false;
}

void SQLTransaction::handleCurrentStatementError()
{
    // Transaction Steps 6.error - Call the statement's error callback, but if there was no error callback,
    // jump to the transaction error callback
    if (m_currentStatement->hasStatementErrorCallback()) {
        m_nextStep = &SQLTransaction::deliverStatementCallback;
        LOG(StorageAPI, "Scheduling deliverStatementCallback for transaction %p\n", this);
        m_database->scheduleTransactionCallback(this);
    } else {
        m_transactionError = m_currentStatement->sqlError();
        if (!m_transactionError)
            m_transactionError = SQLError::create(1, "the statement failed to execute");
        handleTransactionError(false);
    }
}

void SQLTransaction::deliverStatementCallback()
{
    ASSERT(m_currentStatement);
    
    // Transaction Step 6.6 and 6.3(error) - If the statement callback went wrong, jump to the transaction error callback
    // Otherwise, continue to loop through the statement queue
    m_executeSqlAllowed = true;
    bool result = m_currentStatement->performCallback(this);
    m_executeSqlAllowed = false;

    if (result) {
        m_transactionError = SQLError::create(0, "the statement callback raised an exception or statement error callback did not return false");
        handleTransactionError(true);
    } else
        scheduleToRunStatements();
}

void SQLTransaction::deliverQuotaIncreaseCallback()
{
    ASSERT(m_currentStatement);
    ASSERT(!m_shouldRetryCurrentStatement);
    
    Page* page = m_database->document()->page();
    ASSERT(page);
    
    RefPtr<SecurityOrigin> origin = m_database->securityOriginCopy();
    
    unsigned long long currentQuota = DatabaseTracker::tracker().quotaForOrigin(origin.get());
    page->chrome()->client()->exceededDatabaseQuota(m_database->document()->frame(), m_database->stringIdentifier());
    unsigned long long newQuota = DatabaseTracker::tracker().quotaForOrigin(origin.get());
    
    // If the new quota ended up being larger than the old quota, we will retry the statement.
    if (newQuota > currentQuota)
        m_shouldRetryCurrentStatement = true;
        
    m_nextStep = &SQLTransaction::runStatements;
    LOG(StorageAPI, "Scheduling runStatements for transaction %p\n", this);
    m_database->scheduleTransactionStep(this);
}

void SQLTransaction::postflightAndCommit()
{    
    // Transaction Step 7 - Peform postflight steps, jumping to the error callback if they fail
    if (m_wrapper && !m_wrapper->performPostflight(this)) {
        m_transactionError = m_wrapper->sqlError();
        if (!m_transactionError)
            m_transactionError = SQLError::create(0, "unknown error occured setting up transaction");
        handleTransactionError(false);
        return;
    }
    
    // Transacton Step 8+9 - Commit the transaction, jumping to the error callback if that fails
    ASSERT(m_sqliteTransaction);
    
    m_database->m_databaseAuthorizer->disable();
    m_sqliteTransaction->commit();
    m_database->m_databaseAuthorizer->enable();

    // If the commit failed, the transaction will still be marked as "in progress"
    if (m_sqliteTransaction->inProgress()) {
        m_shouldCommitAfterErrorCallback = false;
        m_transactionError = SQLError::create(0, "failed to commit the transaction");
        handleTransactionError(false);
        return;
    }
    
    // The commit was successful, notify the delegates if the transaction modified this database
    if (m_modifiedDatabase)
        DatabaseTracker::tracker().scheduleNotifyDatabaseChanged(m_database->m_securityOrigin.get(), m_database->m_name);
    
    // Now release our unneeded callbacks, to break reference cycles.
    m_callback = 0;
    m_errorCallback = 0;
    
    // Transaction Step 10 - Deliver success callback, if there is one
    if (m_successCallback) {
        m_nextStep = &SQLTransaction::deliverSuccessCallback;
        LOG(StorageAPI, "Scheduling deliverSuccessCallback for transaction %p\n", this);
        m_database->scheduleTransactionCallback(this);
    } else 
        cleanupAfterSuccessCallback();
}

void SQLTransaction::deliverSuccessCallback()
{
    // Transaction Step 10 - Deliver success callback
    ASSERT(m_successCallback);
    m_successCallback->handleEvent();
    
    // Release the last callback to break reference cycle
    m_successCallback = 0;

    // Schedule a "post-success callback" step to return control to the database thread in case there
    // are further transactions queued up for this Database
    m_nextStep = &SQLTransaction::cleanupAfterSuccessCallback;
    LOG(StorageAPI, "Scheduling cleanupAfterSuccessCallback for transaction %p\n", this);
    m_database->scheduleTransactionStep(this);
}

void SQLTransaction::cleanupAfterSuccessCallback()
{
    // Transaction Step 11 - End transaction steps
    // There is no next step
    LOG(StorageAPI, "Transaction %p is complete\n", this);
    ASSERT(!m_database->m_sqliteDatabase.transactionInProgress());
    m_nextStep = 0;
}

void SQLTransaction::handleTransactionError(bool inCallback)
{
    if (m_errorCallback) {
        if (inCallback)
            deliverTransactionErrorCallback();
        else {
            m_nextStep = &SQLTransaction::deliverTransactionErrorCallback;
            LOG(StorageAPI, "Scheduling deliverTransactionErrorCallback for transaction %p\n", this);
            m_database->scheduleTransactionCallback(this);
        }
        return;
    }
    
    // Transaction Step 12 - If the callback couldn't be called, then rollback the transaction.
    m_shouldCommitAfterErrorCallback = false;
    if (inCallback) {
        m_nextStep = &SQLTransaction::cleanupAfterTransactionErrorCallback;
        LOG(StorageAPI, "Scheduling cleanupAfterTransactionErrorCallback for transaction %p\n", this);
        m_database->scheduleTransactionStep(this);
    } else {
        cleanupAfterTransactionErrorCallback();
    }
}

void SQLTransaction::deliverTransactionErrorCallback()
{
    ASSERT(m_transactionError);
    
    // Transaction Step 12 - If the callback didn't return false, then rollback the transaction.
    // This includes the callback not existing, returning true, or throwing an exception
    if (!m_errorCallback || m_errorCallback->handleEvent(m_transactionError.get()))
        m_shouldCommitAfterErrorCallback = false;

    m_nextStep = &SQLTransaction::cleanupAfterTransactionErrorCallback;
    LOG(StorageAPI, "Scheduling cleanupAfterTransactionErrorCallback for transaction %p\n", this);
    m_database->scheduleTransactionStep(this);
}

void SQLTransaction::cleanupAfterTransactionErrorCallback()
{
    m_database->m_databaseAuthorizer->disable();
    if (m_sqliteTransaction) {
        // Transaction Step 12 -If the error callback returned false, and the last error wasn't itself a 
        // failure when committing the transaction, then try to commit the transaction
        if (m_shouldCommitAfterErrorCallback)
            m_sqliteTransaction->commit();
        
        if (m_sqliteTransaction->inProgress()) {
            // Transaction Step 12 - If that fails, or if the callback couldn't be called 
            // or if it didn't return false, then rollback the transaction.
            m_sqliteTransaction->rollback();
        } else if (m_modifiedDatabase) {
            // But if the commit was successful, notify the delegates if the transaction modified this database
            DatabaseTracker::tracker().scheduleNotifyDatabaseChanged(m_database->m_securityOrigin.get(), m_database->m_name);
        }
        
        ASSERT(!m_database->m_sqliteDatabase.transactionInProgress());
        m_sqliteTransaction.clear();
    }
    m_database->m_databaseAuthorizer->enable();
    
    // Transaction Step 12 - Any still-pending statements in the transaction are discarded.
    {
        MutexLocker locker(m_statementMutex);
        m_statementQueue.clear();
    }
    
    // Transaction is complete!  There is no next step
    LOG(StorageAPI, "Transaction %p is complete with an error\n", this);
    ASSERT(!m_database->m_sqliteDatabase.transactionInProgress());
    m_nextStep = 0;

    // Now release our callbacks, to break reference cycles.
    m_callback = 0;
    m_errorCallback = 0;
}

} // namespace WebCore