From fa31c471d24532c3acd55e1a8f2fc411e7e09ec0 Mon Sep 17 00:00:00 2001
From: Matthias Mohr <m.mohr@uni-muenster.de>
Date: Thu, 3 Sep 2020 12:29:50 +0200
Subject: [PATCH] Run monitorFn if data is outdated #26 + bugfix

---
 src/baseentity.js | 11 +++++++++++
 src/job.js        |  8 +++++---
 src/service.js    |  8 +++++---
 3 files changed, 21 insertions(+), 6 deletions(-)

diff --git a/src/baseentity.js b/src/baseentity.js
index 6d0e8e90..94de4cef 100644
--- a/src/baseentity.js
+++ b/src/baseentity.js
@@ -17,6 +17,7 @@ class BaseEntity {
 		this.connection = connection;
 		this.apiToClientNames = {};
 		this.clientToApiNames = {};
+		this.lastRefreshTime = 0;
 		this.extra = {};
 		for(let i in properties) {
 			let backend, client;
@@ -59,9 +60,19 @@ class BaseEntity {
 				this[this.apiToClientNames[name]] = metadata[name];
 			}
 		}
+		this.lastRefreshTime = Date.now();
 		return this;
 	}
 
+	/**
+	 * Returns the age of the data in seconds.
+	 * 
+	 * @returns {integer}
+	 */
+	getDataAge() {
+		return (Date.now() - this.lastRefreshTime) / 1000;
+	}
+
 	/**
 	 * Returns all data in the model.
 	 * 
diff --git a/src/job.js b/src/job.js
index b0f7d55d..adae1625 100644
--- a/src/job.js
+++ b/src/job.js
@@ -95,7 +95,7 @@ class Job extends BaseEntity {
 	 * Checks for status changes and new log entries every x seconds.
 	 * 
 	 * On every status change observed or on new log entries (if supported by the back-end),
-	 * the callback is executed. It is also executed once at the beginning.
+	 * the callback is executed. It may also be executed once at the beginning.
 	 * The callback receives the updated job (this object) and the logs (array) passed.
 	 * 
 	 * The monitoring stops once the job has finished, was canceled or errored out.
@@ -118,14 +118,16 @@ class Job extends BaseEntity {
 			throw new Error('Monitoring Jobs not supported by the back-end.');
 		}
 
-		let lastStatus = null;
+		let lastStatus = this.status;
 		let intervalId = null;
 		let logIterator = null;
 		if (capabilities.hasFeature('debugJob')) {
 			logIterator = this.debugJob();
 		}
 		let monitorFn = async () => {
-			await this.describeJob();
+			if (this.getDataAge() >= interval-1) {
+				await this.describeJob();
+			}
 			let logs = logIterator ? await logIterator.nextLogs() : [];
 			if (lastStatus !== this.status || logs.length > 0) {
 				callback(this, logs);
diff --git a/src/service.js b/src/service.js
index b72462ee..446817e6 100644
--- a/src/service.js
+++ b/src/service.js
@@ -81,7 +81,7 @@ class Service extends BaseEntity {
 	 * Checks for new log entries every x seconds.
 	 * 
 	 * On every status change (enabled/disabled) observed or on new log entries (if supported by the back-end),
-	 * the callback is executed. It is also executed once at the beginning.
+	 * the callback is executed. It may also be executed once at the beginning.
 	 * The callback receives the updated service (this object) and the logs (array) passed.
 	 * 
 	 * Returns a function that can be called to stop monitoring the service manually.
@@ -103,14 +103,16 @@ class Service extends BaseEntity {
 			throw new Error('Monitoring Services not supported by the back-end.');
 		}
 
-		let wasEnabled = null;
+		let wasEnabled = this.enabled;
 		let intervalId = null;
 		let logIterator = null;
 		if (capabilities.hasFeature('debugService')) {
 			logIterator = this.debugService();
 		}
 		let monitorFn = async () => {
-			await this.describeService();
+			if (this.getDataAge() >= interval-1) {
+				await this.describeService();
+			}
 			let logs = logIterator ? await logIterator.nextLogs() : [];
 			if (wasEnabled !== this.enabled || logs.length > 0) {
 				callback(this, logs);