TypeScript!

lib/scheduling.ts

@@ -0,0 +1,62 @@
+/**
+ * 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;
+}