Files
genieacs/lib/scheduling.ts
T
2019-02-20 03:36:52 -08:00

63 lines
1.9 KiB
TypeScript

/**
* Copyright 2013-2018 Zaid Abdulla
*
* This file is part of GenieACS.
*
* GenieACS is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* GenieACS is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with GenieACS. If not, see <http://www.gnu.org/licenses/>.
*/
import * as crypto from "crypto";
import * as later from "later";
function md532(str): number {
const digest = crypto
.createHash("md5")
.update(str)
.digest();
return (
digest.readUInt32LE(0) ^
digest.readUInt32LE(4) ^
digest.readUInt32LE(8) ^
digest.readUInt32LE(12)
);
}
export function variance(deviceId, vrnc): number {
return (md532(deviceId) >>> 0) % vrnc;
}
export function interval(timestamp, intrvl, offset = 0): number {
return Math.trunc((timestamp + offset) / intrvl) * intrvl - offset;
}
export function parseCron(cronExp): any {
const parts = cronExp.trim().split(/\s+/);
if (parts.length === 5) parts.unshift("*");
return later.schedule(later.parse.cron(parts.join(" "), true));
}
export function cron(timestamp, schedule, offset = 0): number[] {
// TODO later.js doesn't throw erorr if expression is invalid!
const ret = [0, 0];
const prev = schedule.prev(1, new Date(timestamp + offset));
if (prev) ret[0] = prev.setMilliseconds(0) - offset;
const next = schedule.next(1, new Date(timestamp + offset + 1000));
if (next) ret[1] = next.setMilliseconds(0) - offset;
return ret;
}