bilaharith commented on a change in pull request #2548: URL: https://github.com/apache/hadoop/pull/2548#discussion_r565222229
########## File path: hadoop-tools/hadoop-azure/src/main/java/org/apache/hadoop/fs/azurebfs/services/AbfsListStatusRemoteIterator.java ########## @@ -0,0 +1,151 @@ +/** + * 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 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 final FileStatus fileStatus; + private final ListingSupport listingSupport; + private final ArrayBlockingQueue<Iterator<FileStatus>> iteratorsQueue; + private final Object asyncOpLock = new Object(); + + private volatile boolean isAsyncInProgress = false; + private boolean firstBatch = true; + private String continuation; + private Iterator<FileStatus> currIterator; + private IOException ioException; + + 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; + } + updateCurrentIterator(); + return currIterator.hasNext(); + } + + @Override + public FileStatus next() throws IOException { + if (!this.hasNext()) { + throw new NoSuchElementException(); + } + return currIterator.next(); + } + + private void updateCurrentIterator() throws IOException { + fetchBatchesAsync(); + synchronized (this) { + if (iteratorsQueue.isEmpty()) { + if (ioException != null) { + throw ioException; + } + if (isListingComplete()) { + return; + } + } + } + try { + currIterator = iteratorsQueue.take(); + if (!currIterator.hasNext() && !isListingComplete()) { + updateCurrentIterator(); Review comment: Moved away fro recursion ---------------------------------------------------------------- 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: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: common-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: common-issues-h...@hadoop.apache.org
