--- /dev/null
+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;
+}