org.apache.pulsar.metadata.api.coordination.LockManager Maven / Gradle / Ivy
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* 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.
*/
package org.apache.pulsar.metadata.api.coordination;
import java.util.List;
import java.util.Optional;
import java.util.concurrent.CompletableFuture;
import org.apache.pulsar.metadata.api.MetadataStoreException;
import org.apache.pulsar.metadata.api.MetadataStoreException.LockBusyException;
import org.apache.pulsar.metadata.api.MetadataStoreException.NotFoundException;
/**
* Controller for acquiring distributed lock on resources.
*/
public interface LockManager extends AutoCloseable {
/**
* Read the content of an existing lock.
*
* If the lock is already taken, this operation will fail immediately.
*
* Warning: because of the distributed nature of the lock, having acquired a lock will never provide a strong
* guarantee that no one else also think it owns the same resource. The caller will have to deal with these race
* conditions when using the resource itself (eg. using compareAndSet() or fencing mechanisms).
*
* @param path
* the path of the resource on which to acquire the lock
* @return a future that will track the completion of the operation
* @throws NotFoundException
* if the lock is not taken
* @throws MetadataStoreException
* if there's a failure in reading the lock
*/
CompletableFuture> readLock(String path);
/**
* Acquire a lock on a shared resource.
*
* If the lock is already taken, this operation will fail immediately.
*
* Warning: because of the distributed nature of the lock, having acquired a lock will never provide a strong
* guarantee that no one else also think it owns the same resource. The caller will have to deal with these race
* conditions when using the resource itself (eg. using compareAndSet() or fencing mechanisms).
*
* @param path
* the path of the resource on which to acquire the lock
* @param value
* the value of the lock
* @return a future that will track the completion of the operation
* @throws LockBusyException
* if the lock is already taken
* @throws MetadataStoreException
* if there's a failure in acquiring the lock
*/
CompletableFuture> acquireLock(String path, T value);
/**
* List all the locks that are children of a specific path.
*
* For example, given locks: /a/b/lock-1 and /a/b/lock-2, the
* listLocks("/a/b") will return a list of ["lock-1", "lock-2"].
*
* @param path
* the prefix path to get the list of locks
* @return a future that will track the completion of the operation
* @throws MetadataStoreException
* if there's a failure in getting the list of locks
*/
CompletableFuture> listLocks(String path);
/**
* Close the LockManager and release all the locks.
*
* @return a future that will track the completion of the operation
* @throws MetadataStoreException
* if there's a failure in closing the LockManager
*/
CompletableFuture asyncClose();
}