galenwarren commented on a change in pull request #15599: URL: https://github.com/apache/flink/pull/15599#discussion_r781315443
########## File path: flink-filesystems/flink-gs-fs-hadoop/src/test/java/org/apache/flink/fs/gs/storage/MockBlobStorage.java ########## @@ -0,0 +1,205 @@ +/* + * 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.fs.gs.storage; + +import org.apache.flink.configuration.MemorySize; +import org.apache.flink.fs.gs.utils.BlobUtils; +import org.apache.flink.fs.gs.utils.ChecksumUtils; + +import com.google.cloud.storage.StorageException; + +import javax.annotation.Nullable; + +import java.io.ByteArrayOutputStream; +import java.io.IOException; +import java.nio.channels.ClosedChannelException; +import java.util.HashMap; +import java.util.List; +import java.util.Map; +import java.util.Optional; +import java.util.stream.Collectors; +import java.util.stream.StreamSupport; + +/** Mock blob storage implementation, using in-memory structures. */ +public class MockBlobStorage implements GSBlobStorage { + + /** Mock blob value with metadata. */ + public static class BlobValue { + + public final byte[] content; + + public BlobValue(byte[] content) { + this.content = content; + } + } + + /** The mock blob metadata. */ + static class BlobMetadata implements GSBlobStorage.BlobMetadata { + + private final BlobValue blobValue; + + private final String forcedChecksum; + + BlobMetadata(BlobValue blobValue, String forcedChecksum) { + this.blobValue = blobValue; + this.forcedChecksum = forcedChecksum; + } + + @Override + public String getChecksum() { + if (forcedChecksum != null) { + return forcedChecksum; + } else { + int checksum = ChecksumUtils.CRC_HASH_FUNCTION.hashBytes(blobValue.content).asInt(); + return ChecksumUtils.convertChecksumToString(checksum); + } + } + } + + /** The mock write channel, which writes to the memory-based storage. */ + public class WriteChannel implements GSBlobStorage.WriteChannel { + + private final GSBlobIdentifier blobIdentifier; + + @Nullable public final MemorySize chunkSize; + + private final ByteArrayOutputStream stream; + + private boolean closed; + + WriteChannel(GSBlobIdentifier blobIdentifier, @Nullable MemorySize chunkSize) { + this.blobIdentifier = blobIdentifier; + this.stream = new ByteArrayOutputStream(); + this.closed = false; + this.chunkSize = chunkSize; + } + + @Override + public int write(byte[] content, int start, int length) throws IOException { + if (closed) { + throw new ClosedChannelException(); + } + + int writeCount = Math.min(length, maxWriteCount); + stream.write(content, start, writeCount); + return writeCount; + } + + @Override + public void close() throws IOException { + if (!closed) { + stream.close(); + blobs.put(blobIdentifier, new BlobValue(stream.toByteArray())); + closed = true; + } + } + } + + /** The blobs in the mock storage. */ + public final Map<GSBlobIdentifier, BlobValue> blobs; + + /** Set this to force a checksum value to be returned. */ + public String forcedChecksum; + + /** Set this to cause writes to be truncated at this length. */ + public int maxWriteCount = Integer.MAX_VALUE; + + public MockBlobStorage() { + this.blobs = new HashMap<>(); + } + + @Override + public GSBlobStorage.WriteChannel writeBlob(GSBlobIdentifier blobId) { + return new WriteChannel(blobId, null); + } + + @Override + public GSBlobStorage.WriteChannel writeBlob(GSBlobIdentifier blobId, MemorySize chunkSize) { + return new WriteChannel(blobId, chunkSize); + } + + @Override + public void createBlob(GSBlobIdentifier blobIdentifier) { + blobs.put(blobIdentifier, new BlobValue(new byte[0])); + } + + @Override + public Optional<GSBlobStorage.BlobMetadata> getMetadata(GSBlobIdentifier blobIdentifier) { + BlobValue blobValue = blobs.get(blobIdentifier); + if (blobValue != null) { + return Optional.of(new BlobMetadata(blobValue, forcedChecksum)); + } else { + return Optional.empty(); + } + } + + @Override + public List<GSBlobIdentifier> list(String bucketName, String prefix) { + return blobs.keySet().stream() + .filter( + blobId -> + blobId.bucketName.equals(bucketName) + && blobId.objectName.startsWith(prefix)) + .collect(Collectors.toList()); + } + + @Override + public void copy(GSBlobIdentifier sourceBlobIdentifier, GSBlobIdentifier targetBlobIdentifier) { + BlobValue blobValue = blobs.get(sourceBlobIdentifier); + if (blobValue == null) { + throw new StorageException(404, "Copy source not found"); + } + blobs.put(targetBlobIdentifier, blobValue); + } + + @Override + public void compose( + List<GSBlobIdentifier> sourceBlobIdentifiers, GSBlobIdentifier targetBlobIdentifier) { + + if (sourceBlobIdentifiers.size() > BlobUtils.COMPOSE_MAX_BLOBS) { + throw new UnsupportedOperationException(); + } + + try (ByteArrayOutputStream stream = new ByteArrayOutputStream()) { + + // write all the source blobs into the stream + for (GSBlobIdentifier blobIdentifier : sourceBlobIdentifiers) { + BlobValue sourceBlobValue = blobs.get(blobIdentifier); + if (sourceBlobValue == null) { + throw new StorageException(404, "Compose source not found"); + } + stream.write(sourceBlobValue.content); + } + + // write the resulting blob + BlobValue targetBlobValue = new BlobValue(stream.toByteArray()); + blobs.put(targetBlobIdentifier, targetBlobValue); + + } catch (IOException ex) { + throw new RuntimeException(ex); + } + } Review comment: Correct, and the non-deleting behavior of `compose` is documented [here](https://cloud.google.com/storage/docs/composing-objects). -- This is an automated message from the Apache Git Service. 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