bilaharith commented on a change in pull request #2548: URL: https://github.com/apache/hadoop/pull/2548#discussion_r568725718
########## File path: hadoop-tools/hadoop-azure/src/main/java/org/apache/hadoop/fs/azurebfs/services/AbfsListStatusRemoteIterator.java ########## @@ -0,0 +1,159 @@ +/** + * 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 + * <p> + * http://www.apache.org/licenses/LICENSE-2.0 + * <p> + * 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.hadoop.fs.azurebfs.services; + +import java.io.IOException; +import java.util.ArrayList; +import java.util.Collections; +import java.util.Iterator; +import java.util.List; +import java.util.NoSuchElementException; +import java.util.concurrent.ArrayBlockingQueue; +import java.util.concurrent.CompletableFuture; +import java.util.concurrent.TimeUnit; +import javax.activation.UnsupportedDataTypeException; + +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import org.apache.hadoop.fs.FileStatus; +import org.apache.hadoop.fs.RemoteIterator; + +public class AbfsListStatusRemoteIterator + implements RemoteIterator<FileStatus> { + + private static final Logger LOG = LoggerFactory + .getLogger(AbfsListStatusRemoteIterator.class); + + private static final boolean FETCH_ALL_FALSE = false; + private static final int MAX_QUEUE_SIZE = 10; + private static final long POLL_WAIT_TIME_IN_MS = 250; + + private final FileStatus fileStatus; + private final ListingSupport listingSupport; + private final ArrayBlockingQueue<Object> iteratorsQueue; + + private volatile boolean isAsyncInProgress = false; + private boolean isIterationComplete = false; + private String continuation; + private Iterator<FileStatus> currIterator; + + public AbfsListStatusRemoteIterator(final FileStatus fileStatus, + final ListingSupport listingSupport) { + this.fileStatus = fileStatus; + this.listingSupport = listingSupport; + iteratorsQueue = new ArrayBlockingQueue<>(MAX_QUEUE_SIZE); + currIterator = Collections.emptyIterator(); + fetchBatchesAsync(); + } + + @Override + public boolean hasNext() throws IOException { + if (currIterator.hasNext()) { + return true; + } + currIterator = getNextIterator(); + return currIterator.hasNext(); + } + + @Override + public FileStatus next() throws IOException { + if (!this.hasNext()) { + throw new NoSuchElementException(); + } + return currIterator.next(); + } + + private Iterator<FileStatus> getNextIterator() throws IOException { + fetchBatchesAsync(); + try { + Object obj = null; + while (obj == null + && (!isIterationComplete || !iteratorsQueue.isEmpty())) { + obj = iteratorsQueue.poll(POLL_WAIT_TIME_IN_MS, TimeUnit.MILLISECONDS); + } + if (obj == null) { + return Collections.emptyIterator(); + } else if (obj instanceof Iterator) { Review comment: Done ---------------------------------------------------------------- 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. For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
