liangyu-1 commented on code in PR #26681: URL: https://github.com/apache/flink/pull/26681#discussion_r2156625386
########## flink-core/src/main/java/org/apache/flink/core/fs/ContextWrapperFileSystem.java: ########## @@ -0,0 +1,32 @@ +/* + * 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.core.fs; + +import org.apache.flink.annotation.Experimental; + +/** + * A {@link ContextWrapperFileSystem} is a factory for wrapping a {@link FileSystem} with a {@link + * FileSystemContext}. This allows the file system to be aware of the context in which it is being + * used, such as caller context or other metadata. + */ +@Experimental +public interface ContextWrapperFileSystem { Review Comment: agree ########## flink-core/src/main/java/org/apache/flink/core/fs/FileSystemContext.java: ########## @@ -0,0 +1,84 @@ +/* + * 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.core.fs; + +import org.apache.flink.annotation.Experimental; +import org.apache.flink.annotation.Internal; + +import static org.apache.flink.util.Preconditions.checkState; + +/** + * A context for file system operations that can be used to set caller context or other metadata. + * This context is thread-local and can be initialized for each thread. + * + * <p>It is used to provide additional information to the file system operations, such as the caller + * context in Hadoop's HDFS. + */ +@Experimental +public class FileSystemContext { + private static final ThreadLocal<FileSystemContext> CONTEXTS = new InheritableThreadLocal<>(); + + @Internal + public static void initializeContextForThread(String context) { + final FileSystemContext oldContext = CONTEXTS.get(); + + checkState( + null == oldContext, + "Found an existing FileSystem context for this thread: %s " + + "This may indicate an accidental repeated initialization, or a leak of the" + + "(Inheritable)ThreadLocal through a ThreadPool.", + oldContext); + + final FileSystemContext newContext = new FileSystemContext(context); + + try { + Class<?> callerContextClass = Class.forName("org.apache.hadoop.ipc.CallerContext"); + Class<?> builderClass = Class.forName("org.apache.hadoop.ipc.CallerContext$Builder"); + Object builderInst = builderClass.getConstructor(String.class).newInstance(context); + Object hdfsContext = builderClass.getMethod("build").invoke(builderInst); + callerContextClass + .getMethod("setCurrent", callerContextClass) + .invoke(null, hdfsContext); + } catch (ClassNotFoundException + | java.lang.reflect.InvocationTargetException + | IllegalAccessException + | NoSuchMethodException + | InstantiationException e) { + throw new RuntimeException(e); + } + CONTEXTS.set(newContext); + } + + static FileSystem wrapWithContextWhenActivated(FileSystem fs) { Review Comment: agree -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: issues-unsubscr...@flink.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
