org.apache.flink.api.common.accumulators

Class AccumulatorHelper

java.lang.Object

org.apache.flink.api.common.accumulators.AccumulatorHelper

@Internal
public class AccumulatorHelper
extends Object

Helper functions for the interaction with Accumulator.

Constructor Summary

Constructors

Constructor and Description
AccumulatorHelper()

Method Summary

Modifier and Type	Method and Description
static void	compareAccumulatorTypes(Object name, Class<? extends Accumulator> first, Class<? extends Accumulator> second) Compare both classes and throw UnsupportedOperationException if they differ.
static Map<String,Accumulator<?,?>>	copy(Map<String,Accumulator<?,?>> accumulators)
static Map<String,OptionalFailure<Object>>	deserializeAccumulators(Map<String,SerializedValue<OptionalFailure<Object>>> serializedAccumulators, ClassLoader loader) Takes the serialized accumulator results and tries to deserialize them using the provided class loader.
static Map<String,Object>	deserializeAndUnwrapAccumulators(Map<String,SerializedValue<OptionalFailure<Object>>> serializedAccumulators, ClassLoader loader) Takes the serialized accumulator results and tries to deserialize them using the provided class loader, and then try to unwrap the value unchecked.
static String	getResultsFormatted(Map<String,Object> map)
static void	mergeInto(Map<String,OptionalFailure<Accumulator<?,?>>> target, Map<String,Accumulator<?,?>> toMerge) Merge two collections of accumulators.
static Map<String,OptionalFailure<Object>>	toResultMap(Map<String,Accumulator<?,?>> accumulators) Transform the Map with accumulators into a Map containing only the results.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

AccumulatorHelper

public AccumulatorHelper()

Method Detail

mergeInto

public static void mergeInto(Map<String,OptionalFailure<Accumulator<?,?>>> target,
                             Map<String,Accumulator<?,?>> toMerge)

Merge two collections of accumulators. The second will be merged into the first.

Parameters:

target - The collection of accumulators that will be updated

toMerge - The collection of accumulators that will be merged into the other

compareAccumulatorTypes

public static void compareAccumulatorTypes(Object name,
                                           Class<? extends Accumulator> first,
                                           Class<? extends Accumulator> second)
                                    throws UnsupportedOperationException

Compare both classes and throw UnsupportedOperationException if they differ.

Throws:

UnsupportedOperationException

toResultMap

public static Map<String,OptionalFailure<Object>> toResultMap(Map<String,Accumulator<?,?>> accumulators)

Transform the Map with accumulators into a Map containing only the results.

getResultsFormatted

public static String getResultsFormatted(Map<String,Object> map)

copy

public static Map<String,Accumulator<?,?>> copy(Map<String,Accumulator<?,?>> accumulators)

deserializeAccumulators

public static Map<String,OptionalFailure<Object>> deserializeAccumulators(Map<String,SerializedValue<OptionalFailure<Object>>> serializedAccumulators,
                                                                          ClassLoader loader)
                                                                   throws IOException,
                                                                          ClassNotFoundException

Takes the serialized accumulator results and tries to deserialize them using the provided class loader.

Parameters:

serializedAccumulators - The serialized accumulator results.

loader - The class loader to use.

Returns:

The deserialized accumulator results.

Throws:

IOException

ClassNotFoundException

deserializeAndUnwrapAccumulators

public static Map<String,Object> deserializeAndUnwrapAccumulators(Map<String,SerializedValue<OptionalFailure<Object>>> serializedAccumulators,
                                                                  ClassLoader loader)
                                                           throws IOException,
                                                                  ClassNotFoundException

Takes the serialized accumulator results and tries to deserialize them using the provided class loader, and then try to unwrap the value unchecked.

Parameters:

serializedAccumulators - The serialized accumulator results.

loader - The class loader to use.

Returns:

The deserialized and unwrapped accumulator results.

Throws:

IOException

ClassNotFoundException