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    }