org.apache.flink.table.functions

Class ConstantFunctionContext

java.lang.Object

org.apache.flink.table.functions.FunctionContext

org.apache.flink.table.functions.ConstantFunctionContext

@Internal
public final class ConstantFunctionContext
extends FunctionContext

A FunctionContext for constant expression reduction. It is used when a function is called with constant expressions or constant expressions can be derived from the given statement.

Since constant expression reduction happens during planning, methods that reference Flink's runtime context are not available.

See Also:

FunctionDefinition.isDeterministic()

Constructor Summary

Constructors

Constructor and Description
ConstantFunctionContext(org.apache.flink.configuration.Configuration configuration)

Method Summary

Modifier and Type	Method and Description
File	getCachedFile(String name) Gets the local temporary file copy of a distributed cache files.
Set<org.apache.flink.api.common.externalresource.ExternalResourceInfo>	getExternalResourceInfos(String resourceName) Get the external resource information.
String	getJobParameter(String key, String defaultValue) Gets the global job parameter value associated with the given key as a string.
org.apache.flink.metrics.MetricGroup	getMetricGroup() Returns the metric group for this parallel subtask.

Methods inherited from class java.lang.Object

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

Constructor Detail

ConstantFunctionContext

public ConstantFunctionContext(org.apache.flink.configuration.Configuration configuration)

Method Detail

getMetricGroup

public org.apache.flink.metrics.MetricGroup getMetricGroup()

Description copied from class: FunctionContext

Returns the metric group for this parallel subtask.

Overrides:

getMetricGroup in class FunctionContext

Returns:

metric group for this parallel subtask.

getCachedFile

public File getCachedFile(String name)

Description copied from class: FunctionContext

Gets the local temporary file copy of a distributed cache files.

Overrides:

getCachedFile in class FunctionContext

Parameters:

name - distributed cache file name

Returns:

local temporary file copy of a distributed cache file.

getJobParameter

public String getJobParameter(String key,
                              String defaultValue)

Description copied from class: FunctionContext

Gets the global job parameter value associated with the given key as a string.

Overrides:

getJobParameter in class FunctionContext

Parameters:

key - key pointing to the associated value

defaultValue - default value which is returned in case global job parameter is null or there is no value associated with the given key

Returns:

(default) value associated with the given key

getExternalResourceInfos

public Set<org.apache.flink.api.common.externalresource.ExternalResourceInfo> getExternalResourceInfos(String resourceName)

Description copied from class: FunctionContext

Get the external resource information.

Overrides:

getExternalResourceInfos in class FunctionContext