org.apache.pig.LoadCaster Maven / Gradle / Ivy
/* 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;
import java.io.IOException;
import java.util.Map;
import org.apache.pig.ResourceSchema.ResourceFieldSchema;
import org.apache.pig.classification.InterfaceAudience;
import org.apache.pig.classification.InterfaceStability;
import org.apache.pig.data.DataBag;
import org.apache.pig.data.Tuple;
/**
* An interface that provides cast implementations for load functions. For casts between
* bytearray objects and internal types, Pig relies on the load function that loaded the data to
* provide the cast. This is because Pig does not understand the binary representation of the
* data and thus cannot cast it. This interface provides functions to cast from bytearray to each
* of Pig's internal types.
* @since Pig 0.7
*/
@InterfaceAudience.Public
@InterfaceStability.Evolving // Because we still don't have the map casts quite right
public interface LoadCaster {
/**
* Cast data from bytearray to long value.
* @param b bytearray to be cast.
* @return Long value.
* @throws IOException if the value cannot be cast.
*/
public Long bytesToLong(byte[] b) throws IOException;
/**
* Cast data from bytearray to float value.
* @param b bytearray to be cast.
* @return Float value.
* @throws IOException if the value cannot be cast.
*/
public Float bytesToFloat(byte[] b) throws IOException;
/**
* Cast data from bytearray to double value.
* @param b bytearray to be cast.
* @return Double value.
* @throws IOException if the value cannot be cast.
*/
public Double bytesToDouble(byte[] b) throws IOException;
/**
* Cast data from bytearray to integer value.
* @param b bytearray to be cast.
* @return Double value.
* @throws IOException if the value cannot be cast.
*/
public Integer bytesToInteger(byte[] b) throws IOException;
/**
* Cast data from bytearray to chararray value.
* @param b bytearray to be cast.
* @return String value.
* @throws IOException if the value cannot be cast.
*/
public String bytesToCharArray(byte[] b) throws IOException;
/**
* Cast data from bytearray to map value.
* @param b bytearray to be cast.
* @return Map value.
* @throws IOException if the value cannot be cast.
*/
@Deprecated
public Map bytesToMap(byte[] b) throws IOException;
/**
* Cast data from bytearray to map value.
* @param b bytearray to be cast.
* @param fieldSchema field schema for the output map
* @return Map value.
* @throws IOException if the value cannot be cast.
*/
public Map bytesToMap(byte[] b, ResourceFieldSchema fieldSchema) throws IOException;
/**
* Cast data from bytearray to tuple value.
* @param b bytearray to be cast.
* @param fieldSchema field schema for the output tuple
* @return Tuple value.
* @throws IOException if the value cannot be cast.
*/
public Tuple bytesToTuple(byte[] b, ResourceFieldSchema fieldSchema) throws IOException;
/**
* Cast data from bytearray to bag value.
* @param b bytearray to be cast.
* @param fieldSchema field schema for the output bag
* @return Bag value.
* @throws IOException if the value cannot be cast.
*/
public DataBag bytesToBag(byte[] b, ResourceFieldSchema fieldSchema) throws IOException;
}