| /* |
| * 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.IOException; |
| import java.io.OutputStream; |
| import java.nio.ByteBuffer; |
| import java.nio.channels.WritableByteChannel; |
| |
| import org.apache.cassandra.config.Config; |
| import org.apache.cassandra.utils.ByteBufferUtil; |
| |
| /** |
| * Abstract base class for DataOutputStreams that accept writes from ByteBuffer or Memory and also provide |
| * access to the underlying WritableByteChannel associated with their output stream. |
| * |
| * If no channel is provided by derived classes then a wrapper channel is provided. |
| */ |
| public abstract class DataOutputStreamPlus extends OutputStream implements DataOutputPlus |
| { |
| //Dummy wrapper channel for derived implementations that don't have a channel |
| protected final WritableByteChannel channel; |
| |
| protected DataOutputStreamPlus() |
| { |
| this.channel = newDefaultChannel(); |
| } |
| |
| protected DataOutputStreamPlus(WritableByteChannel channel) |
| { |
| this.channel = channel; |
| } |
| |
| private static int MAX_BUFFER_SIZE = |
| Integer.getInteger(Config.PROPERTY_PREFIX + "data_output_stream_plus_temp_buffer_size", 8192); |
| |
| /* |
| * Factored out into separate method to create more flexibility around inlining |
| */ |
| protected static byte[] retrieveTemporaryBuffer(int minSize) |
| { |
| byte[] bytes = tempBuffer.get(); |
| if (bytes.length < Math.min(minSize, MAX_BUFFER_SIZE)) |
| { |
| // increase in powers of 2, to avoid wasted repeat allocations |
| bytes = new byte[Math.min(MAX_BUFFER_SIZE, 2 * Integer.highestOneBit(minSize))]; |
| tempBuffer.set(bytes); |
| } |
| return bytes; |
| } |
| |
| private static final ThreadLocal<byte[]> tempBuffer = new ThreadLocal<byte[]>() |
| { |
| @Override |
| public byte[] initialValue() |
| { |
| return new byte[16]; |
| } |
| }; |
| |
| // Derived classes can override and *construct* a real channel, if it is not possible to provide one to the constructor |
| protected WritableByteChannel newDefaultChannel() |
| { |
| return new WritableByteChannel() |
| { |
| |
| @Override |
| public boolean isOpen() |
| { |
| return true; |
| } |
| |
| @Override |
| public void close() throws IOException |
| { |
| } |
| |
| @Override |
| public int write(ByteBuffer src) throws IOException |
| { |
| int toWrite = src.remaining(); |
| |
| if (src.hasArray()) |
| { |
| DataOutputStreamPlus.this.write(src.array(), src.arrayOffset() + src.position(), src.remaining()); |
| src.position(src.limit()); |
| return toWrite; |
| } |
| |
| if (toWrite < 16) |
| { |
| int offset = src.position(); |
| for (int i = 0 ; i < toWrite ; i++) |
| DataOutputStreamPlus.this.write(src.get(i + offset)); |
| src.position(src.limit()); |
| return toWrite; |
| } |
| |
| byte[] buf = retrieveTemporaryBuffer(toWrite); |
| |
| int totalWritten = 0; |
| while (totalWritten < toWrite) |
| { |
| int toWriteThisTime = Math.min(buf.length, toWrite - totalWritten); |
| |
| ByteBufferUtil.arrayCopy(src, src.position() + totalWritten, buf, 0, toWriteThisTime); |
| |
| DataOutputStreamPlus.this.write(buf, 0, toWriteThisTime); |
| |
| totalWritten += toWriteThisTime; |
| } |
| |
| src.position(src.limit()); |
| return totalWritten; |
| } |
| |
| }; |
| } |
| |
| } |