| /* |
| * 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<ComputationState> partialMatches; |
| |
| private Queue<ComputationState> completedMatches; |
| |
| /** |
| * Flag indicating whether the matching status of the state machine has changed. |
| */ |
| private boolean stateChanged; |
| |
| public static final Comparator<ComputationState> COMPUTATION_STATE_COMPARATOR = |
| Comparator.<ComputationState>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<ComputationState> 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<ComputationState> partialMatches, Queue<ComputationState> 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<ComputationState> getPartialMatches() { |
| return partialMatches; |
| } |
| |
| public Queue<ComputationState> getCompletedMatches() { |
| return completedMatches; |
| } |
| |
| public void setNewPartialMatches(PriorityQueue<ComputationState> newPartialMatches) { |
| this.partialMatches = newPartialMatches; |
| } |
| |
| @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 + |
| '}'; |
| } |
| } |