droponcommit.java

derby database source code.good for you.

/*

   Derby - Class org.apache.derby.impl.store.raw.data.DropOnCommit

   Copyright 1998, 2004 The Apache Software Foundation or its licensors, as applicable.

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

      http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.

 */

package org.apache.derby.impl.store.raw.data;


import org.apache.derby.iapi.store.raw.ContainerHandle;
import org.apache.derby.iapi.store.raw.ContainerLock;
import org.apache.derby.iapi.store.raw.Page;
import org.apache.derby.iapi.store.raw.LockingPolicy;
import org.apache.derby.iapi.store.raw.RecordHandle;

import org.apache.derby.iapi.store.raw.data.RawContainerHandle;
import org.apache.derby.iapi.store.raw.log.LogInstant;
import org.apache.derby.iapi.store.raw.xact.RawTransaction;

import org.apache.derby.iapi.services.locks.Lockable;

import org.apache.derby.catalog.UUID;

import org.apache.derby.iapi.error.StandardException;

import org.apache.derby.iapi.services.sanity.SanityManager;
import org.apache.derby.iapi.store.raw.ContainerKey;

import java.util.Observable;

/**
	Drop a table on a commit or abort
*/

public class DropOnCommit extends ContainerActionOnCommit {

	protected boolean isStreamContainer = false;

	/*
	**	Methods of Observer
	*/

	public DropOnCommit(ContainerKey identity) {

		super(identity);
	}

	public DropOnCommit(ContainerKey identity, boolean isStreamContainer) {

		super(identity);
		this.isStreamContainer = isStreamContainer;
	}

	/**
		Called when the transaction is about to complete.

		@see java.util.Observer#update
	*/
	public void update(Observable obj, Object arg) {
		if (SanityManager.DEBUG) {
			if (arg == null)
				SanityManager.THROWASSERT("still on observr list " + this);
		}

		if (arg.equals(RawTransaction.COMMIT) || arg.equals(RawTransaction.ABORT)) {

			RawTransaction xact = (RawTransaction) obj;

			try {
				if (this.isStreamContainer)
					xact.dropStreamContainer(identity.getSegmentId(), identity.getContainerId());
				else
					xact.dropContainer(identity);
			} catch (StandardException se) {
				xact.setObserverException(se);
			}

			obj.deleteObserver(this);
		}
	}
}