ccaominh commented on a change in pull request #9450: Skip empty files for local, hdfs, and cloud input sources URL: https://github.com/apache/druid/pull/9450#discussion_r387215952
########## File path: extensions-core/google-extensions/src/main/java/org/apache/druid/storage/google/ObjectStorageIterator.java ########## @@ -0,0 +1,129 @@ +/* + * 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.druid.storage.google; + +import com.google.api.services.storage.Storage; +import com.google.api.services.storage.model.Objects; +import com.google.api.services.storage.model.StorageObject; +import org.apache.druid.java.util.common.StringUtils; + +import java.io.IOException; +import java.net.URI; +import java.util.Iterator; +import java.util.NoSuchElementException; + +public class ObjectStorageIterator implements Iterator<StorageObject> +{ + private final GoogleStorage storage; + private final Iterator<URI> uris; + private final long maxListingLength; + + private Storage.Objects.List listRequest; + private Objects results; + private URI currentUri; + private String nextPageToken; + private Iterator<StorageObject> storageObjectsIterator; + private StorageObject currentObject; + + public ObjectStorageIterator(GoogleStorage storage, Iterator<URI> uris, long maxListingLength) + { + this.storage = storage; + this.uris = uris; + this.maxListingLength = maxListingLength; + this.nextPageToken = null; + + prepareNextRequest(); + fetchNextBatch(); + advanceStorageObject(); + } + + private void prepareNextRequest() + { + try { + currentUri = uris.next(); + String currentBucket = currentUri.getAuthority(); + String currentPrefix = StringUtils.maybeRemoveLeadingSlash(currentUri.getPath()); + nextPageToken = null; + listRequest = storage.list(currentBucket) + .setPrefix(currentPrefix) + .setMaxResults(maxListingLength); + + } + catch (IOException io) { + throw new RuntimeException(io); + } + } + + private void fetchNextBatch() + { + try { + listRequest.setPageToken(nextPageToken); + results = GoogleUtils.retryGoogleCloudStorageOperation(() -> listRequest.execute()); + storageObjectsIterator = results.getItems().iterator(); + nextPageToken = results.getNextPageToken(); + } + catch (Exception ex) { + throw new RuntimeException(ex); + } + } + + @Override + public boolean hasNext() + { + return currentObject != null; + } + + @Override + public StorageObject next() + { + if (!hasNext()) { + throw new NoSuchElementException(); + } + + final StorageObject retVal = currentObject; + advanceStorageObject(); + return retVal; + } + + private void advanceStorageObject() + { + while (storageObjectsIterator.hasNext() || nextPageToken != null || uris.hasNext()) { + while (storageObjectsIterator.hasNext()) { + final StorageObject next = storageObjectsIterator.next(); + // list with prefix can return directories, but they should always end with `/`, ignore them. + // also skips empty objects. + if (!next.getName().endsWith("/") && next.getSize().signum() > 0) { + currentObject = next; + return; + } + } + + if (nextPageToken != null) { + fetchNextBatch(); + } else if (uris.hasNext()) { + prepareNextRequest(); + fetchNextBatch(); Review comment: This branch is not covered by unit tests ---------------------------------------------------------------- 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] With regards, Apache Git Services --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
