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.hbase.Cell; 25 import org.apache.hadoop.hbase.KeyValue; 26 import org.apache.hadoop.hbase.KeyValueUtil; 27 28 /** 29 * Codec that does KeyValue version 1 serialization. 30 * 31 * <p>Encodes by casting Cell to KeyValue and writing out the backing array with a length prefix. 32 * This is how KVs were serialized in Puts, Deletes and Results pre-0.96. Its what would 33 * happen if you called the Writable#write KeyValue implementation. This encoder will fail 34 * if the passed Cell is not an old-school pre-0.96 KeyValue. Does not copy bytes writing. 35 * It just writes them direct to the passed stream. 36 * 37 * <p>If you wrote two KeyValues to this encoder, it would look like this in the stream: 38 * <pre> 39 * length-of-KeyValue1 // A java int with the length of KeyValue1 backing array 40 * KeyValue1 backing array filled with a KeyValue serialized in its particular format 41 * length-of-KeyValue2 42 * KeyValue2 backing array 43 * </pre> 44 */ 45 public class KeyValueCodec implements Codec { 46 static class KeyValueEncoder extends BaseEncoder { 47 KeyValueEncoder(final OutputStream out) { 48 super(out); 49 } 50 51 @Override 52 public void write(Cell cell) throws IOException { 53 checkFlushed(); 54 // This is crass and will not work when KV changes. Also if passed a non-kv Cell, it will 55 // make expensive copy. 56 try { 57 KeyValue.oswrite((KeyValue)KeyValueUtil.ensureKeyValue(cell), this.out); 58 } catch (IOException e) { 59 throw new CodecException(e); 60 } 61 } 62 } 63 64 static class KeyValueDecoder extends BaseDecoder { 65 KeyValueDecoder(final InputStream in) { 66 super(in); 67 } 68 69 protected Cell parseCell() throws IOException { 70 return KeyValue.iscreate(in); 71 } 72 } 73 74 /** 75 * Implementation depends on {@link InputStream#available()} 76 */ 77 @Override 78 public Decoder getDecoder(final InputStream is) { 79 return new KeyValueDecoder(is); 80 } 81 82 @Override 83 public Encoder getEncoder(OutputStream os) { 84 return new KeyValueEncoder(os); 85 } 86 }