| /* |
| * 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.hadoop.hbase.ipc; |
| |
| import java.io.IOException; |
| import java.nio.ByteBuffer; |
| import java.nio.channels.GatheringByteChannel; |
| import org.apache.yetus.audience.InterfaceAudience; |
| |
| /** |
| * Chain of ByteBuffers. Used writing out an array of byte buffers. |
| */ |
| @InterfaceAudience.Private |
| class BufferChain { |
| private final ByteBuffer[] buffers; |
| private int remaining = 0; |
| private int size; |
| |
| BufferChain(ByteBuffer... buffers) { |
| for (ByteBuffer b : buffers) { |
| this.remaining += b.remaining(); |
| } |
| this.size = remaining; |
| this.buffers = buffers; |
| } |
| |
| /** |
| * Expensive. Makes a new buffer to hold a copy of what is in contained ByteBuffers. This call |
| * drains this instance; it cannot be used subsequent to the call. |
| * @return A new byte buffer with the content of all contained ByteBuffers. |
| */ |
| byte[] getBytes() { |
| if (!hasRemaining()) throw new IllegalAccessError(); |
| byte[] bytes = new byte[this.remaining]; |
| int offset = 0; |
| for (ByteBuffer bb : this.buffers) { |
| int length = bb.remaining(); |
| bb.get(bytes, offset, length); |
| offset += length; |
| } |
| return bytes; |
| } |
| |
| boolean hasRemaining() { |
| return remaining > 0; |
| } |
| |
| long write(GatheringByteChannel channel) throws IOException { |
| if (!hasRemaining()) { |
| return 0; |
| } |
| long written = 0; |
| for (ByteBuffer bb : this.buffers) { |
| if (bb.hasRemaining()) { |
| final int pos = bb.position(); |
| final int result = channel.write(bb); |
| if (result <= 0) { |
| // Write error. Return how much we were able to write until now. |
| return written; |
| } |
| // Adjust the position of buffers already written so we don't write out |
| // duplicate data upon retry of incomplete write with the same buffer chain. |
| bb.position(pos + result); |
| remaining -= result; |
| written += result; |
| } |
| } |
| return written; |
| } |
| |
| int size() { |
| return size; |
| } |
| |
| ByteBuffer[] getBuffers() { |
| return this.buffers; |
| } |
| } |