001 /** 002 * Licensed to the Apache Software Foundation (ASF) under one 003 * or more contributor license agreements. See the NOTICE file 004 * distributed with this work for additional information 005 * regarding copyright ownership. The ASF licenses this file 006 * to you under the Apache License, Version 2.0 (the 007 * "License"); you may not use this file except in compliance 008 * with the License. You may obtain a copy of the License at 009 * 010 * http://www.apache.org/licenses/LICENSE-2.0 011 * 012 * Unless required by applicable law or agreed to in writing, software 013 * distributed under the License is distributed on an "AS IS" BASIS, 014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 015 * See the License for the specific language governing permissions and 016 * limitations under the License. 017 */ 018 019 package org.apache.hadoop.record; 020 021 import java.io.IOException; 022 023 import org.apache.hadoop.classification.InterfaceAudience; 024 import org.apache.hadoop.classification.InterfaceStability; 025 026 /** 027 * Interface that all the Deserializers have to implement. 028 * 029 * @deprecated Replaced by <a href="https://hadoop.apache.org/avro/">Avro</a>. 030 */ 031 @Deprecated 032 @InterfaceAudience.Public 033 @InterfaceStability.Stable 034 public interface RecordInput { 035 /** 036 * Read a byte from serialized record. 037 * @param tag Used by tagged serialization formats (such as XML) 038 * @return value read from serialized record. 039 */ 040 byte readByte(String tag) throws IOException; 041 042 /** 043 * Read a boolean from serialized record. 044 * @param tag Used by tagged serialization formats (such as XML) 045 * @return value read from serialized record. 046 */ 047 boolean readBool(String tag) throws IOException; 048 049 /** 050 * Read an integer from serialized record. 051 * @param tag Used by tagged serialization formats (such as XML) 052 * @return value read from serialized record. 053 */ 054 int readInt(String tag) throws IOException; 055 056 /** 057 * Read a long integer from serialized record. 058 * @param tag Used by tagged serialization formats (such as XML) 059 * @return value read from serialized record. 060 */ 061 long readLong(String tag) throws IOException; 062 063 /** 064 * Read a single-precision float from serialized record. 065 * @param tag Used by tagged serialization formats (such as XML) 066 * @return value read from serialized record. 067 */ 068 float readFloat(String tag) throws IOException; 069 070 /** 071 * Read a double-precision number from serialized record. 072 * @param tag Used by tagged serialization formats (such as XML) 073 * @return value read from serialized record. 074 */ 075 double readDouble(String tag) throws IOException; 076 077 /** 078 * Read a UTF-8 encoded string from serialized record. 079 * @param tag Used by tagged serialization formats (such as XML) 080 * @return value read from serialized record. 081 */ 082 String readString(String tag) throws IOException; 083 084 /** 085 * Read byte array from serialized record. 086 * @param tag Used by tagged serialization formats (such as XML) 087 * @return value read from serialized record. 088 */ 089 Buffer readBuffer(String tag) throws IOException; 090 091 /** 092 * Check the mark for start of the serialized record. 093 * @param tag Used by tagged serialization formats (such as XML) 094 */ 095 void startRecord(String tag) throws IOException; 096 097 /** 098 * Check the mark for end of the serialized record. 099 * @param tag Used by tagged serialization formats (such as XML) 100 */ 101 void endRecord(String tag) throws IOException; 102 103 /** 104 * Check the mark for start of the serialized vector. 105 * @param tag Used by tagged serialization formats (such as XML) 106 * @return Index that is used to count the number of elements. 107 */ 108 Index startVector(String tag) throws IOException; 109 110 /** 111 * Check the mark for end of the serialized vector. 112 * @param tag Used by tagged serialization formats (such as XML) 113 */ 114 void endVector(String tag) throws IOException; 115 116 /** 117 * Check the mark for start of the serialized map. 118 * @param tag Used by tagged serialization formats (such as XML) 119 * @return Index that is used to count the number of map entries. 120 */ 121 Index startMap(String tag) throws IOException; 122 123 /** 124 * Check the mark for end of the serialized map. 125 * @param tag Used by tagged serialization formats (such as XML) 126 */ 127 void endMap(String tag) throws IOException; 128 }