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/*******************************************************************************
* Copyright (c) 2010-2019, Tamas Szabo, itemis AG, Gabor Bergmann, IncQuery Labs Ltd.
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0 which is available at
* http://www.eclipse.org/legal/epl-v20.html.
*
* SPDX-License-Identifier: EPL-2.0
*******************************************************************************/
package tools.refinery.viatra.runtime.rete.aggregation.timely;
import java.util.Objects;
import java.util.TreeMap;
import tools.refinery.viatra.runtime.matchers.psystem.aggregations.IMultisetAggregationOperator;
import tools.refinery.viatra.runtime.matchers.tuple.Tuple;
import tools.refinery.viatra.runtime.matchers.tuple.TupleMask;
import tools.refinery.viatra.runtime.matchers.util.Direction;
import tools.refinery.viatra.runtime.rete.network.ReteContainer;
import tools.refinery.viatra.runtime.rete.network.communication.Timestamp;
/**
* First-only column aggregator with sequential aggregation architecture.
*
* @author Tamas Szabo
* @since 2.4
*/
public class FirstOnlySequentialTimelyColumnAggregatorNode<Domain, Accumulator, AggregateResult>
extends FirstOnlyTimelyColumnAggregatorNode<Domain, Accumulator, AggregateResult> {
public FirstOnlySequentialTimelyColumnAggregatorNode(final ReteContainer reteContainer,
final IMultisetAggregationOperator<Domain, Accumulator, AggregateResult> operator,
final TupleMask groupMask, final TupleMask columnMask) {
super(reteContainer, operator, groupMask, columnMask);
}
/**
* Accumulator gets modified only at the timestamp where the update happened. During the folding, accumulators are
* never changed at higher timestamps. Aggregate results at higher timestamps may change due to the change at the
* input timestamp. Uniqueness enforcement may require from aggregate results to jump up/down on demand during the
* folding.
*/
@Override
public void update(final Direction direction, final Tuple update, final Timestamp timestamp) {
final Tuple group = groupMask.transform(update);
final Tuple value = columnMask.transform(update);
@SuppressWarnings("unchecked")
final Domain aggregand = (Domain) runtimeContext.unwrapElement(value.get(0));
final boolean isInsertion = direction == Direction.INSERT;
final AggregateResult previousResult = getResultRaw(group, timestamp, true);
final Accumulator oldAccumulator = getAccumulator(group, timestamp);
final AggregateResult oldResult = previousResult == null ? operator.getAggregate(oldAccumulator)
: operator.combine(previousResult, oldAccumulator);
final Accumulator newAccumulator = operator.update(oldAccumulator, aggregand, isInsertion);
final AggregateResult newResult = previousResult == null ? operator.getAggregate(newAccumulator)
: operator.combine(previousResult, newAccumulator);
storeIfNotNeutral(group, newAccumulator, newResult, timestamp);
propagateWithChecks(group, timestamp, previousResult, previousResult, oldResult, newResult);
// fold up the state towards higher timestamps
if (!Objects.equals(oldResult, newResult)) {
AggregateResult previousOldResult = oldResult;
AggregateResult previousNewResult = newResult;
AggregateResult currentOldResult = null;
AggregateResult currentNewResult = null;
final TreeMap<Timestamp, CumulativeAggregate<Accumulator, AggregateResult>> groupEntries = this.memory
.get(group);
Timestamp currentTimestamp = groupEntries == null ? null : groupEntries.higherKey(timestamp);
while (currentTimestamp != null) {
// they cannot be the same, otherwise we would not even be here
assert !Objects.equals(previousOldResult, previousNewResult);
final Accumulator accumulator = getAccumulator(group, currentTimestamp);
currentOldResult = groupEntries.get(currentTimestamp).result;
currentNewResult = operator.combine(previousNewResult, accumulator);
// otherwise we would not be iterating over this timestamp
assert !operator.isNeutral(accumulator);
propagateWithChecks(group, currentTimestamp, previousOldResult, previousNewResult, currentOldResult,
currentNewResult);
if (!Objects.equals(currentOldResult, currentNewResult)) {
storeIfNotNeutral(group, accumulator, currentNewResult, currentTimestamp);
previousOldResult = currentOldResult;
previousNewResult = currentNewResult;
currentTimestamp = groupEntries.higherKey(currentTimestamp);
} else {
// we can stop the folding from here
break;
}
}
}
}
@Override
protected Accumulator getAccumulator(final Tuple group, final Timestamp timestamp) {
final TreeMap<Timestamp, CumulativeAggregate<Accumulator, AggregateResult>> entryMap = this.memory.get(group);
if (entryMap == null) {
return operator.createNeutral();
} else {
final CumulativeAggregate<Accumulator, AggregateResult> entry = entryMap.get(timestamp);
if (entry == null) {
return operator.createNeutral();
} else {
return entry.accumulator;
}
}
}
}
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