| /* |
| * 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.cassandra.db.streaming; |
| |
| import com.google.common.collect.ImmutableSet; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| import org.apache.cassandra.io.sstable.Component; |
| import org.apache.cassandra.io.sstable.Descriptor; |
| import org.apache.cassandra.io.util.FileUtils; |
| |
| import java.io.File; |
| import java.io.IOException; |
| import java.io.RandomAccessFile; |
| import java.nio.channels.FileChannel; |
| import java.util.HashMap; |
| import java.util.Map; |
| import java.util.Set; |
| |
| /** |
| * Mutable SSTable components and their hardlinks to avoid concurrent sstable component modification |
| * during entire-sstable-streaming. |
| */ |
| public class ComponentContext implements AutoCloseable |
| { |
| private static final Logger logger = LoggerFactory.getLogger(ComponentContext.class); |
| |
| private static final Set<Component> MUTABLE_COMPONENTS = ImmutableSet.of(Component.STATS, Component.SUMMARY); |
| |
| private final Map<Component, File> hardLinks; |
| private final ComponentManifest manifest; |
| |
| private ComponentContext(Map<Component, File> hardLinks, ComponentManifest manifest) |
| { |
| this.hardLinks = hardLinks; |
| this.manifest = manifest; |
| } |
| |
| public static ComponentContext create(Descriptor descriptor) |
| { |
| Map<Component, File> hardLinks = new HashMap<>(1); |
| |
| for (Component component : MUTABLE_COMPONENTS) |
| { |
| File file = new File(descriptor.filenameFor(component)); |
| if (!file.exists()) |
| continue; |
| |
| File hardlink = new File(descriptor.tmpFilenameForStreaming(component)); |
| FileUtils.createHardLink(file, hardlink); |
| hardLinks.put(component, hardlink); |
| } |
| |
| return new ComponentContext(hardLinks, ComponentManifest.create(descriptor)); |
| } |
| |
| public ComponentManifest manifest() |
| { |
| return manifest; |
| } |
| |
| /** |
| * @return file channel to be streamed, either original component or hardlinked component. |
| */ |
| public FileChannel channel(Descriptor descriptor, Component component, long size) throws IOException |
| { |
| String toTransfer = hardLinks.containsKey(component) ? hardLinks.get(component).getPath() : descriptor.filenameFor(component); |
| @SuppressWarnings("resource") // file channel will be closed by Caller |
| FileChannel channel = new RandomAccessFile(toTransfer, "r").getChannel(); |
| |
| assert size == channel.size() : String.format("Entire sstable streaming expects %s file size to be %s but got %s.", |
| component, size, channel.size()); |
| return channel; |
| } |
| |
| @Override |
| public void close() |
| { |
| Throwable accumulate = null; |
| for (File file : hardLinks.values()) |
| accumulate = FileUtils.deleteWithConfirm(file, accumulate); |
| |
| hardLinks.clear(); |
| |
| if (accumulate != null) |
| logger.warn("Failed to remove hard link files", accumulate); |
| } |
| } |