com.scaleoutsoftware.soss.client.map

Class NamedMapInvokable<KEY,VALUE,PARAMETER,RESULT>

java.lang.Object

com.scaleoutsoftware.soss.client.map.NamedMapInvokable<KEY,VALUE,PARAMETER,RESULT>

Type Parameters:

KEY - key type

VALUE - value type

PARAMETER - invocation parameter type

RESULT - result type

All Implemented Interfaces:

java.io.Serializable

public abstract class NamedMapInvokable<KEY,VALUE,PARAMETER,RESULT>
extends java.lang.Object
implements java.io.Serializable

Base class for implementing parallel invocations, which are executed on all keys in the map across the cluster in a distributed manner. Instances of NamedMapInvokable are submitted to the map by calling NamedMap.invoke(NamedMapInvokable, Object).

Warning: an instance of NamedMapInvokable can be used concurrently by several threads, so implementations should not access any inner variables in a non-thread safe manner.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
NamedMapInvokable()

Method Summary

Modifier and Type	Method and Description
RESULT	eval(KEY key, VALUE value, PARAMETER parameter) This method is called for each key in the map.
RESULT	evalPartialKeySet(NamedMapInvokableContext<KEY,VALUE> context, PARAMETER parameter) This method is called for a group of keys in the map.
CustomSerializer<RESULT>	getParameterCustomSerializer() Returns the CustomSerializer used for serializing/deserializing invocation parameter objects.
CustomSerializer<RESULT>	getResultCustomSerializer() Returns the CustomSerializer used for serializing/deserializing result objects.
abstract RESULT	merge(RESULT firstResult, RESULT secondResult, PARAMETER parameter) This method is used for merging two invocation results into one.

Methods inherited from class java.lang.Object

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

Constructor Detail

NamedMapInvokable

public NamedMapInvokable()

Method Detail

eval

public RESULT eval(KEY key,
                   VALUE value,
                   PARAMETER parameter)
            throws InvokeException

This method is called for each key in the map.

Parameters:

key - key to process

value - value to process

parameter - invocation parameter object

Returns:

result or null if this key does not have a result.

Throws:

InvokeException - when a server invocation error has occurred.

evalPartialKeySet

public RESULT evalPartialKeySet(NamedMapInvokableContext<KEY,VALUE> context,
                                PARAMETER parameter)
                         throws InvokeException

This method is called for a group of keys in the map. It is expected that it will iterate through all keys and values by calling next(...) on the context and getting the current key and value through context.getKey() and context.getValue().

It is important that the context only iterates through a subset of the keys in the map. The final result is produced by calling merge(Object, Object, Object) to perform a pairwise merge of all subset results.

This method can be called concurrently by several threads, but with different context objects, so care should be taken not to store any non-thread safe state in class variables.

Parameters:

context - operation context with methods to iterate through keys and values; can also be used to modify the current value or remove the current key from the map

parameter - invocation parameter object

Returns:

result or null if this group of keys does not have a result.

Throws:

InvokeException - when a server invocation error has occurred.

merge

public abstract RESULT merge(RESULT firstResult,
                             RESULT secondResult,
                             PARAMETER parameter)
                      throws InvokeException

This method is used for merging two invocation results into one.

Note: if the result objects are mutable, modifying and returning one of the provided results as a merged result can improve performance and memory efficiency by eliminating the need to allocate a new result object for each merge.

Parameters:

firstResult - first result to merge

secondResult - second result to merge

parameter - invocation parameter object

Returns:

merged result or null if there is no such result

Throws:

InvokeException - when a server invocation error has occurred.

getResultCustomSerializer

public CustomSerializer<RESULT> getResultCustomSerializer()

Returns the CustomSerializer used for serializing/deserializing result objects. This method can be overridden to define custom serialization for the result object. By default, standard serialization is used.

Returns:

custom serializer instance

getParameterCustomSerializer

public CustomSerializer<RESULT> getParameterCustomSerializer()

Returns the CustomSerializer used for serializing/deserializing invocation parameter objects. This method can be overridden to define custom serialization for the parameter object. By default, standard serialization is used.

Returns:

custom serializer instance