1 /** 2 * Licensed to the Apache Software Foundation (ASF) under one 3 * or more contributor license agreements. See the NOTICE file 4 * distributed with this work for additional information 5 * regarding copyright ownership. The ASF licenses this file 6 * to you under the Apache License, Version 2.0 (the 7 * "License"); you may not use this file except in compliance 8 * with the License. You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, software 13 * distributed under the License is distributed on an "AS IS" BASIS, 14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 15 * See the License for the specific language governing permissions and 16 * limitations under the License. 17 */ 18 package org.apache.hadoop.hbase.codec; 19 20 import java.io.IOException; 21 import java.io.InputStream; 22 import java.io.OutputStream; 23 24 import org.apache.hadoop.classification.InterfaceAudience; 25 import org.apache.hadoop.hbase.Cell; 26 import org.apache.hadoop.hbase.KeyValue; 27 import org.apache.hadoop.hbase.KeyValueUtil; 28 29 /** 30 * Codec that does KeyValue version 1 serialization. 31 * 32 * <p>Encodes by casting Cell to KeyValue and writing out the backing array with a length prefix. 33 * This is how KVs were serialized in Puts, Deletes and Results pre-0.96. Its what would 34 * happen if you called the Writable#write KeyValue implementation. This encoder will fail 35 * if the passed Cell is not an old-school pre-0.96 KeyValue. Does not copy bytes writing. 36 * It just writes them direct to the passed stream. 37 * 38 * <p>If you wrote two KeyValues to this encoder, it would look like this in the stream: 39 * <pre> 40 * length-of-KeyValue1 // A java int with the length of KeyValue1 backing array 41 * KeyValue1 backing array filled with a KeyValue serialized in its particular format 42 * length-of-KeyValue2 43 * KeyValue2 backing array 44 * </pre> 45 */ 46 @InterfaceAudience.Private 47 public class KeyValueCodec implements Codec { 48 public static class KeyValueEncoder extends BaseEncoder { 49 public KeyValueEncoder(final OutputStream out) { 50 super(out); 51 } 52 53 @Override 54 public void write(Cell cell) throws IOException { 55 checkFlushed(); 56 // This is crass and will not work when KV changes. Also if passed a non-kv Cell, it will 57 // make expensive copy. 58 // Do not write tags over RPC 59 KeyValue.oswrite((KeyValue) KeyValueUtil.ensureKeyValue(cell), this.out, false); 60 } 61 } 62 63 public static class KeyValueDecoder extends BaseDecoder { 64 public KeyValueDecoder(final InputStream in) { 65 super(in); 66 } 67 68 protected Cell parseCell() throws IOException { 69 return KeyValue.iscreate(in); 70 } 71 } 72 73 /** 74 * Implementation depends on {@link InputStream#available()} 75 */ 76 @Override 77 public Decoder getDecoder(final InputStream is) { 78 return new KeyValueDecoder(is); 79 } 80 81 @Override 82 public Encoder getEncoder(OutputStream os) { 83 return new KeyValueEncoder(os); 84 } 85 }