Package com.tangosol.util.aggregator

Class PriorityAggregator<K,V,P,R>

java.lang.Object
com.tangosol.util.Base
com.tangosol.util.BitHelper
com.tangosol.util.ExternalizableHelper
com.tangosol.net.AbstractPriorityTask
com.tangosol.util.aggregator.PriorityAggregator<K,V,P,R>
Type Parameters:
K - the type of the Map entry keys
V - the type of the Map entry values
P - the type of the partial result
R - the type of the final result
All Implemented Interfaces:
ExternalizableLite, PortableObject, PriorityTask, InvocableMap.EntryAggregator<K,V,R>, InvocableMap.StreamingAggregator<K,V,P,R>, Serializable
public class PriorityAggregator<K,V,P,R> extends AbstractPriorityTask implements InvocableMap.StreamingAggregator<K,V,P,R>, ExternalizableLite, PortableObject
PriorityAggregator is used to explicitly control the scheduling priority and timeouts for execution of EntryAggregator-based methods.

For example, let's assume that there is an Orders cache that belongs to a partitioned cache service configured with a request-timeout and task-timeout of 5 seconds. Also assume that we are willing to wait longer for a particular aggregation request that scans the entire cache. Then we could override the default timeout values by using the PriorityAggregator as follows: 

   DoubleAverage      aggrStandard = new DoubleAverage("getPrice");
   PriorityAggregator aggrPriority = new PriorityAggregator(aggrStandard);
   aggrPriority.setExecutionTimeoutMillis(PriorityTask.TIMEOUT_NONE);
   aggrPriority.setRequestTimeoutMillis(PriorityTask.TIMEOUT_NONE);
   cacheOrders.aggregate((Filter) null, aggrPriority);

This is an advanced feature which should be used judiciously.

Since:
Coherence 3.3
Author:
gg 2007.03.20
See Also: