Java tutorial
/* * 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.backup; import static org.apache.jackrabbit.oak.segment.file.FileStoreBuilder.fileStoreBuilder; import java.io.File; import java.io.IOException; import javax.annotation.Nonnull; import com.google.common.base.Stopwatch; import com.google.common.base.Suppliers; import org.apache.jackrabbit.oak.segment.Compactor; import org.apache.jackrabbit.oak.segment.Revisions; import org.apache.jackrabbit.oak.segment.SegmentBufferWriter; import org.apache.jackrabbit.oak.segment.SegmentNodeState; import org.apache.jackrabbit.oak.segment.SegmentReader; import org.apache.jackrabbit.oak.segment.SegmentWriter; import org.apache.jackrabbit.oak.segment.WriterCacheManager; import org.apache.jackrabbit.oak.segment.compaction.SegmentGCOptions; import org.apache.jackrabbit.oak.segment.file.FileStore; import org.apache.jackrabbit.oak.segment.file.FileStoreBuilder; import org.apache.jackrabbit.oak.segment.file.tooling.BasicReadOnlyBlobStore; import org.slf4j.Logger; import org.slf4j.LoggerFactory; public class FileStoreBackup { private static final Logger log = LoggerFactory.getLogger(FileStoreBackup.class); public static boolean USE_FAKE_BLOBSTORE = Boolean.getBoolean("oak.backup.UseFakeBlobStore"); public static void backup(@Nonnull SegmentReader reader, @Nonnull Revisions revisions, @Nonnull File destination) throws IOException { Stopwatch watch = Stopwatch.createStarted(); SegmentGCOptions gcOptions = SegmentGCOptions.defaultGCOptions().setOffline(); FileStoreBuilder builder = fileStoreBuilder(destination).withDefaultMemoryMapping(); if (USE_FAKE_BLOBSTORE) { builder.withBlobStore(new BasicReadOnlyBlobStore()); } builder.withGCOptions(gcOptions); FileStore backup = builder.build(); SegmentNodeState current = reader.readHeadState(revisions); try { int gen = 0; gen = current.getRecordId().getSegment().getGcGeneration(); SegmentBufferWriter bufferWriter = new SegmentBufferWriter(backup, backup.getTracker(), backup.getReader(), "b", gen); SegmentWriter writer = new SegmentWriter(backup, backup.getReader(), backup.getBlobStore(), new WriterCacheManager.Default(), bufferWriter); Compactor compactor = new Compactor(backup.getReader(), writer, backup.getBlobStore(), Suppliers.ofInstance(false), gcOptions); compactor.setContentEqualityCheck(true); SegmentNodeState head = backup.getHead(); SegmentNodeState after = compactor.compact(head, current, head); if (after != null) { backup.getRevisions().setHead(head.getRecordId(), after.getRecordId()); } } finally { backup.close(); backup = null; } FileStoreBuilder builder2 = fileStoreBuilder(destination).withDefaultMemoryMapping(); builder2.withGCOptions(gcOptions); backup = builder2.build(); try { cleanup(backup); } finally { backup.close(); } watch.stop(); log.info("Backup finished in {}.", watch); } static boolean cleanup(FileStore f) throws IOException { boolean ok = true; for (File file : f.cleanup()) { ok = ok && file.delete(); } return true; } }