/*
***************************************************************************************
* Copyright (C) 2006 EsperTech, Inc. All rights reserved. *
* http://www.espertech.com/esper *
* http://www.espertech.com *
* ---------------------------------------------------------------------------------- *
* The software in this package is published under the terms of the GPL license *
* a copy of which has been included with this distribution in the license.txt file. *
***************************************************************************************
*/
package com.espertech.esper.schedule;
/**
* This class acts as a buckets for sorting schedule service callbacks that are scheduled to occur at the same
* time. Each buckets constists of slots that callbacks are assigned to.
* <p>
* At the time of timer evaluation, callbacks that become triggerable are ordered using the bucket
* as the first-level order, and slot as the second-level order.
* <p>
* Each statement at statement creation time allocates a buckets, and each timer within the
* statement allocates a slot. Thus statements that depend on other statements (such as for insert-into),
* and timers within their statement (such as time window or output rate limit timers) behave
* deterministically.
*/
public class ScheduleBucket {
private final int bucketNum;
private int lastSlot;
/**
* Ctor.
*
* @param bucketNum is a simple integer number for this bucket by which buckets can be sorted
*/
public ScheduleBucket(int bucketNum) {
this.bucketNum = bucketNum;
lastSlot = 0;
}
public long allocateSlot() {
return toLong(bucketNum, lastSlot++);
}
public long allocateSlot(int slotNumber) {
return toLong(bucketNum, slotNumber);
}
public static long toLong(int bucket, int slot) {
return ((long) bucket << 32) | slot & 0xFFFFFFFFL;
}
}