package org.apache.lucene.store;
/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.
*/
import java.io.IOException;
/**
* <p>Base class for Locking implementation. {@link Directory} uses
* instances of this class to implement locking.</p>
*
* <p>Note that there are some useful tools to verify that
* your LockFactory is working correctly: {@link
* VerifyingLockFactory}, {@link LockStressTest}, {@link
* LockVerifyServer}.</p>
*
* @see LockVerifyServer
* @see LockStressTest
* @see VerifyingLockFactory
*/
public abstract class LockFactory {
protected String lockPrefix = null;
/**
* Set the prefix in use for all locks created in this
* LockFactory. This is normally called once, when a
* Directory gets this LockFactory instance. However, you
* can also call this (after this instance is assigned to
* a Directory) to override the prefix in use. This
* is helpful if you're running Lucene on machines that
* have different mount points for the same shared
* directory.
*/
public void setLockPrefix(String lockPrefix) {
this.lockPrefix = lockPrefix;
}
/**
* Get the prefix in use for all locks created in this LockFactory.
*/
public String getLockPrefix() {
return this.lockPrefix;
}
/**
* Return a new Lock instance identified by lockName.
* @param lockName name of the lock to be created.
*/
public abstract Lock makeLock(String lockName);
/**
* Attempt to clear (forcefully unlock and remove) the
* specified lock. Only call this at a time when you are
* certain this lock is no longer in use.
* @param lockName name of the lock to be cleared.
*/
abstract public void clearLock(String lockName) throws IOException;
}