org.apache.geode.modules.util

Class RegionSizeFunction

java.lang.Object

org.apache.geode.modules.util.RegionSizeFunction

All Implemented Interfaces:

Serializable, Declarable, Function, DataSerializable, Identifiable

public class RegionSizeFunction
extends Object
implements Function, Declarable, DataSerializable

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.geode.DataSerializable

DataSerializable.Replaceable

Field Summary

Fields

Modifier and Type	Field and Description
static String	ID

Constructor Summary

Constructors

Constructor and Description
RegionSizeFunction()

Method Summary

Modifier and Type	Method and Description
void	execute(FunctionContext context) The method which contains the logic to be executed.
void	fromData(DataInput in) Reads the state of this object as primitive data from the given DataInput.
String	getId() Return a unique function identifier, used to register the function with FunctionService
Collection<ResourcePermission>	getRequiredPermissions(String regionName) Returns the list of ResourcePermission this function requires.
boolean	hasResult() Specifies whether the function sends results while executing.
boolean	isHA() Specifies whether the function is eligible for re-execution (in case of failure).
boolean	optimizeForWrite() Return true to indicate to GemFire the method requires optimization for writing the targeted FunctionService.onRegion(org.apache.geode.cache.Region) and any associated routing objects.
void	toData(DataOutput out) Writes the state of this object as primitive data to the given DataOutput.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.geode.cache.execute.Function

getRequiredPermissions

Methods inherited from interface org.apache.geode.lang.Identifiable

exists, find, remove

Methods inherited from interface org.apache.geode.cache.Declarable

init, initialize

Field Detail

ID

public static final String ID

See Also:

Constant Field Values

Constructor Detail

RegionSizeFunction

public RegionSizeFunction()

Method Detail

execute

public void execute(FunctionContext context)

Description copied from interface: Function

The method which contains the logic to be executed. This method should be thread safe and may be invoked more than once on a given member for a single Execution. The context provided to this function is the one which was built using Execution. The contexts can be data dependent or data-independent so user should check to see if the context provided in parameter is instance of RegionFunctionContext.

Specified by:

execute in interface Function

Parameters:

context - as created by Execution

getRequiredPermissions

public Collection<ResourcePermission> getRequiredPermissions(String regionName)

Description copied from interface: Function

Returns the list of ResourcePermission this function requires.

By default, functions require DATA:WRITE permission. If your function requires other permissions, you will need to override this method.

Please be as specific as possible when you set the required permissions for your function e.g. if your function reads from a region, it would be good to include the region name in your permission. It's better to return "DATA:READ:regionName" as the required permission other than "DATA:READ", because the latter means only users with read permission on ALL regions can execute your function.

All the permissions returned from this method will be ANDed together.

Specified by:

getRequiredPermissions in interface Function

Parameters:

regionName - the region this function will be executed on. The regionName is optional and will only be present when the function is executed by an onRegion() executor. In other cases, it will be null. This method returns permissions appropriate to the context, independent of the presence of the regionName parameter.

Returns:

a collection of ResourcePermissions indicating the permissions required to execute the function.

getId

public String getId()

Description copied from interface: Function

Return a unique function identifier, used to register the function with FunctionService

Specified by:

getId in interface Function

Specified by:

getId in interface Identifiable

Returns:

string identifying this function

hasResult

public boolean hasResult()

Description copied from interface: Function

Specifies whether the function sends results while executing. The method returns false if no result is expected.

If this method returns false, ResultCollector.getResult() throws FunctionException.

If this method returns true, ResultCollector.getResult() blocks and waits for the result of function execution

Specified by:

hasResult in interface Function

Returns:

whether this function returns a Result back to the caller.

optimizeForWrite

public boolean optimizeForWrite()

Description copied from interface: Function

Return true to indicate to GemFire the method requires optimization for writing the targeted FunctionService.onRegion(org.apache.geode.cache.Region) and any associated routing objects.

Returning false will optimize for read behavior on the targeted FunctionService.onRegion(org.apache.geode.cache.Region) and any associated routing objects.

This method is only consulted when Region passed to FunctionService#onRegion(org.apache.geode.cache.Region) is a partitioned region

Specified by:

optimizeForWrite in interface Function

Returns:

false if the function is read only, otherwise returns true

See Also:

FunctionService

isHA

public boolean isHA()

Description copied from interface: Function

Specifies whether the function is eligible for re-execution (in case of failure).

Specified by:

isHA in interface Function

Returns:

whether the function is eligible for re-execution.

See Also:

FunctionContext.isPossibleDuplicate()

toData

public void toData(DataOutput out)

Description copied from interface: DataSerializable

Writes the state of this object as primitive data to the given DataOutput.

Since 5.7 it is possible for any method call to the specified DataOutput to throw GemFireRethrowable. It should not be caught by user code. If it is it must be rethrown.

Specified by:

toData in interface DataSerializable

Parameters:

out - the DataOutput to write to

fromData

public void fromData(DataInput in)

Description copied from interface: DataSerializable

Reads the state of this object as primitive data from the given DataInput.

Specified by:

fromData in interface DataSerializable

Parameters:

in - the DataInput to read from