1 package org.apache.lucene.store;
4 * Licensed to the Apache Software Foundation (ASF) under one or more
5 * contributor license agreements. See the NOTICE file distributed with
6 * this work for additional information regarding copyright ownership.
7 * The ASF licenses this file to You under the Apache License, Version 2.0
8 * (the "License"); you may not use this file except in compliance with
9 * the License. You may obtain a copy of the License at
11 * http://www.apache.org/licenses/LICENSE-2.0
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14 * distributed under the License is distributed on an "AS IS" BASIS,
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16 * See the License for the specific language governing permissions and
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20 import java.io.IOException;
23 * <p>Base class for Locking implementation. {@link Directory} uses
24 * instances of this class to implement locking.</p>
26 * <p>Note that there are some useful tools to verify that
27 * your LockFactory is working correctly: {@link
28 * VerifyingLockFactory}, {@link LockStressTest}, {@link
29 * LockVerifyServer}.</p>
31 * @see LockVerifyServer
33 * @see VerifyingLockFactory
36 public abstract class LockFactory {
38 protected String lockPrefix = null;
41 * Set the prefix in use for all locks created in this
42 * LockFactory. This is normally called once, when a
43 * Directory gets this LockFactory instance. However, you
44 * can also call this (after this instance is assigned to
45 * a Directory) to override the prefix in use. This
46 * is helpful if you're running Lucene on machines that
47 * have different mount points for the same shared
50 public void setLockPrefix(String lockPrefix) {
51 this.lockPrefix = lockPrefix;
55 * Get the prefix in use for all locks created in this LockFactory.
57 public String getLockPrefix() {
58 return this.lockPrefix;
62 * Return a new Lock instance identified by lockName.
63 * @param lockName name of the lock to be created.
65 public abstract Lock makeLock(String lockName);
68 * Attempt to clear (forcefully unlock and remove) the
69 * specified lock. Only call this at a time when you are
70 * certain this lock is no longer in use.
71 * @param lockName name of the lock to be cleared.
73 abstract public void clearLock(String lockName) throws IOException;