| /* |
| * 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.jackrabbit.oak.upgrade.cli.blob; |
| |
| import org.apache.jackrabbit.oak.spi.blob.BlobOptions; |
| import org.apache.jackrabbit.oak.spi.blob.BlobStore; |
| import org.jetbrains.annotations.NotNull; |
| |
| import java.io.ByteArrayInputStream; |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.nio.charset.StandardCharsets; |
| import static com.google.common.base.Preconditions.checkNotNull; |
| |
| /** |
| * Utility BlobStore implementation to be used in tooling that can work with a |
| * FileStore without the need of the DataStore being present locally. |
| * |
| * Additionally instead of failing it tries to mimic and return blob reference |
| * passed in by <b>caller</b> by passing it back as a binary. |
| * |
| * Example: requesting <code>blobId = e7c22b994c59d9</code> it will return the |
| * <code>e7c22b994c59d9</code> text as a UTF-8 encoded binary file. |
| */ |
| public class LoopbackBlobStore implements BlobStore { |
| |
| @Override |
| public String writeBlob(InputStream in) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| @Override |
| public String writeBlob(InputStream in, BlobOptions options) throws IOException { |
| return writeBlob(in); |
| } |
| |
| @Override |
| public int readBlob(String blobId, long pos, byte[] buff, int off, |
| int length) { |
| // Only a part of binary can be requested! |
| final int binaryLength = blobId.length(); |
| checkBinaryOffsetInRange(pos, binaryLength); |
| final int effectiveSrcPos = Math.toIntExact(pos); |
| final int effectiveBlobLengthToBeRead = Math.min( |
| binaryLength - effectiveSrcPos, length); |
| checkForBufferOverflow(buff, off, effectiveBlobLengthToBeRead); |
| final byte[] blobIdBytes = getBlobIdStringAsByteArray(blobId); |
| System.arraycopy(blobIdBytes, effectiveSrcPos, buff, off, |
| effectiveBlobLengthToBeRead); |
| return effectiveBlobLengthToBeRead; |
| } |
| |
| private void checkForBufferOverflow(final byte[] buff, final int off, |
| final int effectiveBlobLengthToBeRead) { |
| if (buff.length < effectiveBlobLengthToBeRead + off) { |
| // We cannot recover if buffer used to write is too small |
| throw new UnsupportedOperationException("Edge case: cannot fit " + |
| "blobId in a buffer (buffer too small)"); |
| } |
| } |
| |
| private void checkBinaryOffsetInRange(final long pos, final int binaryLength) { |
| if (pos > binaryLength) { |
| throw new IllegalArgumentException( |
| String.format("Offset %d out of range of %d", pos, |
| binaryLength)); |
| } |
| } |
| |
| private byte[] getBlobIdStringAsByteArray(final String blobId) { |
| return blobId.getBytes(StandardCharsets.UTF_8); |
| } |
| |
| @Override |
| public long getBlobLength(String blobId) throws IOException { |
| return blobId.length(); |
| } |
| |
| @Override |
| public InputStream getInputStream(String blobId) throws IOException { |
| checkNotNull(blobId); |
| return new ByteArrayInputStream(getBlobIdStringAsByteArray(blobId)); |
| } |
| |
| @Override |
| public String getBlobId(@NotNull String reference) { |
| return checkNotNull(reference); |
| } |
| |
| @Override |
| public String getReference(@NotNull String blobId) { |
| return checkNotNull(blobId); |
| } |
| } |