| /* |
| * 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.io.util; |
| |
| import java.io.File; |
| import java.io.IOException; |
| import java.nio.ByteBuffer; |
| import java.nio.MappedByteBuffer; |
| import java.nio.channels.FileChannel; |
| import java.nio.channels.WritableByteChannel; |
| import java.nio.file.StandardOpenOption; |
| |
| import org.apache.cassandra.io.FSReadError; |
| import org.apache.cassandra.utils.CLibrary; |
| import org.apache.cassandra.utils.concurrent.RefCounted; |
| import org.apache.cassandra.utils.concurrent.SharedCloseableImpl; |
| |
| /** |
| * A proxy of a FileChannel that: |
| * |
| * - implements reference counting |
| * - exports only thread safe FileChannel operations |
| * - wraps IO exceptions into runtime exceptions |
| * |
| * Tested by RandomAccessReaderTest. |
| */ |
| public final class ChannelProxy extends SharedCloseableImpl |
| { |
| private final String filePath; |
| private final FileChannel channel; |
| |
| public static FileChannel openChannel(File file) |
| { |
| try |
| { |
| return FileChannel.open(file.toPath(), StandardOpenOption.READ); |
| } |
| catch (IOException e) |
| { |
| throw new RuntimeException(e); |
| } |
| } |
| |
| public ChannelProxy(String path) |
| { |
| this (new File(path)); |
| } |
| |
| public ChannelProxy(File file) |
| { |
| this(file.getPath(), openChannel(file)); |
| } |
| |
| public ChannelProxy(String filePath, FileChannel channel) |
| { |
| super(new Cleanup(filePath, channel)); |
| |
| this.filePath = filePath; |
| this.channel = channel; |
| } |
| |
| public ChannelProxy(ChannelProxy copy) |
| { |
| super(copy); |
| |
| this.filePath = copy.filePath; |
| this.channel = copy.channel; |
| } |
| |
| private final static class Cleanup implements RefCounted.Tidy |
| { |
| final String filePath; |
| final FileChannel channel; |
| |
| Cleanup(String filePath, FileChannel channel) |
| { |
| this.filePath = filePath; |
| this.channel = channel; |
| } |
| |
| public String name() |
| { |
| return filePath; |
| } |
| |
| public void tidy() |
| { |
| try |
| { |
| channel.close(); |
| } |
| catch (IOException e) |
| { |
| throw new FSReadError(e, filePath); |
| } |
| } |
| } |
| |
| public ChannelProxy sharedCopy() |
| { |
| return new ChannelProxy(this); |
| } |
| |
| public String filePath() |
| { |
| return filePath; |
| } |
| |
| public int read(ByteBuffer buffer, long position) |
| { |
| try |
| { |
| return channel.read(buffer, position); |
| } |
| catch (IOException e) |
| { |
| throw new FSReadError(e, filePath); |
| } |
| } |
| |
| public long transferTo(long position, long count, WritableByteChannel target) |
| { |
| try |
| { |
| return channel.transferTo(position, count, target); |
| } |
| catch (IOException e) |
| { |
| throw new FSReadError(e, filePath); |
| } |
| } |
| |
| public MappedByteBuffer map(FileChannel.MapMode mode, long position, long size) |
| { |
| try |
| { |
| return channel.map(mode, position, size); |
| } |
| catch (IOException e) |
| { |
| throw new FSReadError(e, filePath); |
| } |
| } |
| |
| public long size() |
| { |
| try |
| { |
| return channel.size(); |
| } |
| catch (IOException e) |
| { |
| throw new FSReadError(e, filePath); |
| } |
| } |
| |
| public int getFileDescriptor() |
| { |
| return CLibrary.getfd(channel); |
| } |
| |
| @Override |
| public String toString() |
| { |
| return filePath(); |
| } |
| } |