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/*
* Copyright (c) 2000, 2020, Oracle and/or its affiliates.
*
* Licensed under the Universal Permissive License v 1.0 as shown at
* http://oss.oracle.com/licenses/upl.
*/
package com.tangosol.util.aggregator;
import com.tangosol.util.AsynchronousAgent;
import com.tangosol.util.InvocableMap;
import com.tangosol.util.InvocableMap.EntryAggregator;
import com.tangosol.util.InvocableMap.StreamingAggregator;
import com.tangosol.util.processor.AsynchronousProcessor;
import java.util.Set;
import javax.json.bind.annotation.JsonbProperty;
/**
* Abstract base class for asynchronous entry aggregators.
*
* @param the type of the Map entry keys
* @param the type of the Map entry values
* @param the type of the intermediate result during the parallel stage
* @param the type of the value returned by the StreamingAggregator
*
* @see AsynchronousAggregator
*
* @author gg/bb 2015.04.02
*/
public abstract class AbstractAsynchronousAggregator
extends AsynchronousAgent
implements EntryAggregator
{
/**
* Construct an AsynchronousAggregator for a given streaming aggregator.
*
* @param aggregator the underlying streaming aggregator
* @param iUnitOrderId the unit-of-order id for this aggregator
*/
protected AbstractAsynchronousAggregator(StreamingAggregator aggregator,
int iUnitOrderId)
{
super(iUnitOrderId);
m_aggregator = aggregator.supply();
}
// ----- AsynchronousAggregator API -------------------------------------
/**
* Called when there is a partial result of the asynchronous execution.
*
* For a given request, calls to this method and {@link #onException}
* may come concurrently.
*
* For ordering guarantees across different aggregator invocations see
* {@link #getUnitOfOrderId}.
*
* Note: Overriding implementations of this method must be non-blocking.
*
* @param result the partial result holder
*/
public abstract void onResult(P result);
/**
* Called after this asynchronous aggregator has been notified about all
* possible partial results or failures and no more are forthcoming.
*
* As long as this aggregator was submitted to any of {@link InvocableMap}'s methods,
* this method is guaranteed to be called once and only once.
*
* Possible call back sequences are:
*
* cache.aggregate
* ...
* onResult
* onComplete
*
* cache.aggregate
* ...
* onException
* onComplete
*
* cache.aggregate
* ...
* onResult
* onException
* onException
* onResult
* onComplete
*
*
* For ordering guarantees across processors see {@link #getUnitOfOrderId}.
*
* Note:
*
* Overriding implementations of this method must be non-blocking.
*
* If the StreamingAggregator signaled to short-circuit the aggregation
* while {@link StreamingAggregator#combine combining partial results},
* onComplete() could be called before all the results are received.
*/
public abstract void onComplete();
/**
* Called if the operation failed for any reason.
*
* For a given request, calls to this method and {@link #onResult}
* may come concurrently.
*
* Note: Overriding implementations of this method must be non-blocking.
*
* @param eReason the reason of failure
*/
public abstract void onException(Throwable eReason);
/**
* Return a unit-of-order id associated with this aggregator. By default,
* the unit-of-order id is assigned to the calling thread's hashCode.
*
* If two consecutive "aggregate" calls made using {@link
* AbstractAsynchronousAggregator AsynchronousAggregators} with the same order id
* and involve the same key set, then the corresponding {@link
* EntryAggregator#aggregate execution} and calls to {@link #onResult} are
* going to happen in the exact same order.
*
* Note 1: the ordering guarantee is respected between {@link
* AbstractAsynchronousAggregator}s and {@link AsynchronousProcessor}s with the same
* unit-of-order id;
*
* Note 2: there is no ordering guarantee between asynchronous and synchronous
* operations.
*
* @return the order id
*/
public int getUnitOfOrderId()
{
return m_iOrderId;
}
/**
* Return the underlying streaming aggregator.
*
* @return the underlying aggregator
*/
public StreamingAggregator getAggregator()
{
return m_aggregator;
}
// ---- not supported methods --------------------------------------------
/**
* Not supported.
*/
public R aggregate(Set> setEntries)
{
throw new UnsupportedOperationException();
}
// ----- data fields ----------------------------------------------------
/**
* The underlying aggregator.
*/
@JsonbProperty("aggregator")
protected StreamingAggregator m_aggregator;
}