java.lang.Object
- org.apache.geode.modules.util.RegionSizeFunction

All Implemented Interfaces:

java.io.Serializable, Declarable, Function, DataSerializable, Identifiable
```
public class RegionSizeFunction
extends java.lang.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 Description

static java.lang.String ID

Constructor Summary

Constructors
Constructor Description

RegionSizeFunction()

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`execute(FunctionContext context)`	The method which contains the logic to be executed.
`void`	`fromData(java.io.DataInput in)`	Reads the state of this object as primitive data from the given `DataInput`.
`java.lang.String`	`getId()`	Return a unique function identifier, used to register the function with `FunctionService`
`java.util.Collection<ResourcePermission>`	`getRequiredPermissions(java.lang.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(java.io.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.Declarable
init, initialize

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

- Field Detail
  - ID
```
public static final java.lang.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 java.util.Collection<ResourcePermission> getRequiredPermissions(java.lang.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 java.lang.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(java.io.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(java.io.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

Gemfire JavaDocs

Class RegionSizeFunction

Nested Class Summary

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

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

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

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

Field Detail

ID

Constructor Detail

RegionSizeFunction

Method Detail

execute

getRequiredPermissions

getId

hasResult

optimizeForWrite

isHA

toData

fromData