| /* |
| * 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.DataOutput; |
| import java.io.IOException; |
| import java.nio.ByteBuffer; |
| |
| import org.apache.cassandra.utils.vint.VIntCoding; |
| |
| /** |
| * Extension to DataOutput that provides for writing ByteBuffer and Memory, potentially with an efficient |
| * implementation that is zero copy or at least has reduced bounds checking overhead. |
| */ |
| public interface DataOutputPlus extends DataOutput |
| { |
| // write the buffer without modifying its position |
| void write(ByteBuffer buffer) throws IOException; |
| |
| default void write(Memory memory, long offset, long length) throws IOException |
| { |
| for (ByteBuffer buffer : memory.asByteBuffers(offset, length)) |
| write(buffer); |
| } |
| |
| default void writeVInt(long i) throws IOException |
| { |
| VIntCoding.writeVInt(i, this); |
| } |
| |
| /** |
| * This is more efficient for storing unsigned values, both in storage and CPU burden. |
| * |
| * Note that it is still possible to store negative values, they just take up more space. |
| * So this method doesn't forbid e.g. negative sentinel values in future, if they need to be snuck in. |
| * A protocol version bump can then be introduced to improve efficiency. |
| */ |
| default void writeUnsignedVInt(long i) throws IOException |
| { |
| VIntCoding.writeUnsignedVInt(i, this); |
| } |
| |
| /** |
| * Returns the current position of the underlying target like a file-pointer |
| * or the position withing a buffer. Not every implementation may support this |
| * functionality. Whether or not this functionality is supported can be checked |
| * via the {@link #hasPosition()}. |
| * |
| * @throws UnsupportedOperationException if the implementation does not support |
| * position |
| */ |
| default long position() |
| { |
| throw new UnsupportedOperationException(); |
| } |
| |
| /** |
| * If the implementation supports providing a position, this method returns |
| * {@code true}, otherwise {@code false}. |
| */ |
| default boolean hasPosition() |
| { |
| return false; |
| } |
| } |