org.apache.flink.runtime.execution.librarycache.LibraryCacheManager 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.flink.runtime.execution.librarycache;
import org.apache.flink.api.common.JobID;
import org.apache.flink.runtime.blob.PermanentBlobKey;
import org.apache.flink.util.UserCodeClassLoader;
import java.io.IOException;
import java.net.URL;
import java.util.Collection;
/**
* The LibraryCacheManager is responsible for creating and managing the user code class loaders.
*
* In order to obtain a user code class loader, one first needs to obtain a {@link
* ClassLoaderLease} for a given {@link JobID}. At first, the {@link ClassLoaderLease} is
* unresolved. In order to obtain the user class loader one needs to resolve it by specifying the
* required jar files and class paths. The user code class loader for a job is valid as long as
* there exists a valid {@link ClassLoaderLease}. A {@link ClassLoaderLease} becomes invalid once it
* gets released.
*/
public interface LibraryCacheManager {
/**
* Registers a new class loader lease for the given jobId. The user code class loader for this
* job will be valid as long as there exists a valid lease for this job.
*
* @param jobId jobId for which to register a new class loader lease
* @return a new class loader lease for the given job
*/
ClassLoaderLease registerClassLoaderLease(JobID jobId);
/**
* Shuts the library cache manager down. Thereby it will close all open {@link ClassLoaderLease}
* and release all registered user code class loaders.
*/
void shutdown();
/** Handle to retrieve a user code class loader for the associated job. */
interface ClassLoaderHandle {
/**
* Gets or resolves the user code class loader for the associated job.
*
*
In order to retrieve the user code class loader the caller has to specify the required
* jars and class paths. Upon calling this method first for a job, it will make sure that
* the required jars are present and potentially cache the created user code class loader.
* Every subsequent call to this method, will ensure that created user code class loader can
* fulfill the required jar files and class paths.
*
* @param requiredJarFiles requiredJarFiles the user code class loader needs to load
* @param requiredClasspaths requiredClasspaths the user code class loader needs to be
* started with
* @return the user code class loader fulfilling the requirements
* @throws IOException if the required jar files cannot be downloaded
* @throws IllegalStateException if the cached user code class loader does not fulfill the
* requirements
*/
UserCodeClassLoader getOrResolveClassLoader(
Collection requiredJarFiles, Collection requiredClasspaths)
throws IOException;
}
/** Lease which allows to signal when the user code class loader is no longer needed. */
interface ClassLoaderLease extends ClassLoaderHandle {
/**
* Releases the lease to the user code class loader for the associated job.
*
* This method signals that the lease holder not longer needs the user code class loader
* for the associated job. Once all leases for a job are released, the library cache manager
* is allowed to release the associated user code class loader.
*/
void release();
}
}