001/*
002 * (C) Copyright 2017 Nuxeo SA (http://nuxeo.com/) and others.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *     http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 *
016 * Contributors:
017 *     bdelbosc
018 */
019package org.nuxeo.lib.stream.pattern.consumer.internals;
020
021import org.nuxeo.lib.stream.pattern.consumer.BatchPolicy;
022
023/**
024 * Keep state of a batch according to a batch policy.
025 *
026 * @since 9.1
027 */
028public class BatchState {
029    protected final BatchPolicy policy;
030
031    protected int counter;
032
033    protected long endMs;
034
035    public enum State {
036        FILLING, FULL, TIMEOUT, LAST
037    }
038
039    State state = State.FILLING;
040
041    public BatchState(BatchPolicy policy) {
042        this.policy = policy;
043    }
044
045    public void start() {
046        endMs = System.currentTimeMillis() + policy.getTimeThreshold().toMillis();
047        counter = 0;
048        state = State.FILLING;
049    }
050
051    public State inc() {
052        if (state != State.FILLING) {
053            throw new IllegalStateException("Try to add an item to a batch in non filling state:" + state);
054        }
055        counter++;
056        return getState();
057    }
058
059    public void force() {
060        state = State.FULL;
061    }
062
063    public void last() {
064        state = State.LAST;
065    }
066
067    public State getState() {
068        if (state != State.FILLING) {
069            return state;
070        }
071        if (counter >= policy.getCapacity()) {
072            state = State.FULL;
073        } else if (System.currentTimeMillis() > endMs) {
074            state = State.TIMEOUT;
075        }
076        return state;
077    }
078
079    public int getSize() {
080        return counter;
081    }
082
083}