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 }