org.apache.pig.data.InterSedes Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.pig.data;
import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import org.apache.pig.backend.executionengine.ExecException;
import org.apache.pig.classification.InterfaceAudience;
import org.apache.pig.classification.InterfaceStability;
/**
* A class to handle reading and writing of intermediate results of data
* types. The serialization format used by this class more efficient than
* what was used in DataReaderWriter .
* The format used by the functions in this class is subject to change, so it
* should be used ONLY to store intermediate results within a pig query.
*/
@InterfaceAudience.Private
@InterfaceStability.Evolving
public interface InterSedes {
/**
* Get the next object from DataInput in
* @param in
* @return Next object from DataInput in
* @throws IOException
* @throws ExecException
*/
public Object readDatum(DataInput in)
throws IOException, ExecException;
/**
* Get the next object from DataInput in of the type of type argument
* The type information has been read from DataInput.
* @param in
* @param type
* @return Next object from DataInput in
* @throws IOException
* @throws ExecException
*/
public Object readDatum(DataInput in, byte type)
throws IOException, ExecException;
/**
* The type of next object has been determined to be of type Tuple,
* add the columns that belong to the tuple to given tuple argument t
* @param in
* @param t
* @throws IOException
*/
public void addColsToTuple(DataInput in, Tuple t)
throws IOException;
/**
* Write given object val to DataOutput out
* @param out
* @param val
* @throws IOException
*/
public void writeDatum(DataOutput out, Object val)
throws IOException;
/**
* Write given object val of DataType type to DataOutput out
* @param out output
* @param val value to write
* @param type type, as defined in {@link DataType}
* @throws IOException
*/
public void writeDatum(DataOutput out, Object val, byte type)
throws IOException;
public Class getTupleRawComparatorClass();
}