org.apache.flink.cep.nfa.NFAState Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.flink.cep.nfa;
import java.util.Arrays;
import java.util.Comparator;
import java.util.Objects;
import java.util.PriorityQueue;
import java.util.Queue;
/** State kept for a {@link NFA}. */
public class NFAState {
/**
* Current set of {@link ComputationState computation states} within the state machine. These
* are the "active" intermediate states that are waiting for new matching events to transition
* to new valid states.
*/
private Queue partialMatches;
private Queue completedMatches;
/** Flag indicating whether the matching status of the state machine has changed. */
private boolean stateChanged;
/** Flag indicating whether the current matching status is new partial matched. */
private boolean isNewStartPartialMatch;
public static final Comparator COMPUTATION_STATE_COMPARATOR =
Comparator.comparingLong(
c ->
c.getStartEventID() != null
? c.getStartEventID().getTimestamp()
: Long.MAX_VALUE)
.thenComparingInt(
c ->
c.getStartEventID() != null
? c.getStartEventID().getId()
: Integer.MAX_VALUE);
public NFAState(Iterable states) {
this.partialMatches = new PriorityQueue<>(COMPUTATION_STATE_COMPARATOR);
for (ComputationState startingState : states) {
partialMatches.add(startingState);
}
this.completedMatches = new PriorityQueue<>(COMPUTATION_STATE_COMPARATOR);
}
public NFAState(
Queue partialMatches, Queue completedMatches) {
this.partialMatches = partialMatches;
this.completedMatches = completedMatches;
}
/**
* Check if the matching status of the NFA has changed so far.
*
* @return {@code true} if matching status has changed, {@code false} otherwise
*/
public boolean isStateChanged() {
return stateChanged;
}
/** Reset the changed bit checked via {@link #isStateChanged()} to {@code false}. */
public void resetStateChanged() {
this.stateChanged = false;
}
/** Set the changed bit checked via {@link #isStateChanged()} to {@code true}. */
public void setStateChanged() {
this.stateChanged = true;
}
public Queue getPartialMatches() {
return partialMatches;
}
public Queue getCompletedMatches() {
return completedMatches;
}
public void setNewPartialMatches(PriorityQueue newPartialMatches) {
this.partialMatches = newPartialMatches;
}
public boolean isNewStartPartialMatch() {
return isNewStartPartialMatch;
}
public void resetNewStartPartialMatch() {
this.isNewStartPartialMatch = false;
}
public void setNewStartPartiailMatch() {
this.isNewStartPartialMatch = true;
}
@Override
public boolean equals(Object o) {
if (this == o) {
return true;
}
if (o == null || getClass() != o.getClass()) {
return false;
}
NFAState nfaState = (NFAState) o;
return Arrays.equals(partialMatches.toArray(), nfaState.partialMatches.toArray())
&& Arrays.equals(completedMatches.toArray(), nfaState.completedMatches.toArray());
}
@Override
public int hashCode() {
return Objects.hash(partialMatches, completedMatches);
}
@Override
public String toString() {
return "NFAState{"
+ "partialMatches="
+ partialMatches
+ ", completedMatches="
+ completedMatches
+ ", stateChanged="
+ stateChanged
+ '}';
}
}
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