From e908c5069b891d550a0334fe2efe04c9a127884f Mon Sep 17 00:00:00 2001
From: Hornwitser <github@hornwitser.no>
Date: Mon, 6 Apr 2020 18:56:21 +0200
Subject: [PATCH] Add autosave tracking and statistics

Detect when autosaves are made and track the size in a Prometheus gague.
---
 CHANGELOG.md               |  1 +
 lib/factorio/server.js     | 29 +++++++++++++++++++++++++++++
 slave.js                   | 17 +++++++++++++++++
 test/lib/factorio/lines.js | 22 ++++++++++++++++++++++
 4 files changed, 69 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 19f2d8c4..59365897 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -38,6 +38,7 @@ Version 2.0.0
 - Added WebSocket usage statistics.
 - Added commands sent statistic.
 - Added Factorio server CPU and memory usage statistic.
+- Added Factorio autosave size statistic.
 
 ### Changes
 
diff --git a/lib/factorio/server.js b/lib/factorio/server.js
index e8414fac..8f7a6540 100644
--- a/lib/factorio/server.js
+++ b/lib/factorio/server.js
@@ -349,6 +349,18 @@ const outputHeuristics = [
 		}
 	},
 
+	// Message indicating the server has started an autosave
+	{
+		filter: {
+			type: 'log',
+			message: /^Saving to _autosave\d+ \((non-)?blocking\)\.$/,
+		},
+		action: function(output) {
+			let name = /^Saving to (_autosave\d+) /.exec(output.message)[1];
+			this.emit('_autosave', name);
+		},
+	},
+
 	// Message indicating the server has finished saving
 	{
 		filter: {
@@ -419,6 +431,8 @@ const outputHeuristics = [
  * output - invoked with parsed output from Factorio
  * rcon-ready - invoked when the RCON client has connected
  * game-ready - invoked when the server is finished starting up
+ * autosave-start - invoked when the server starts an autosave
+ * autosave-fnished - invoked when the autosave finished
  * exit - invoked when the sterver has exited
  */
 class FactorioServer extends events.EventEmitter {
@@ -454,6 +468,20 @@ class FactorioServer extends events.EventEmitter {
 
 		this._stdout = new LineSplitter((line) => { this._handleOutput(line, 'stdout'); });
 		this._stderr = new LineSplitter((line) => { this._handleOutput(line, 'stderr'); });
+
+		// Track autosaving
+		this._runningAutosave = null;
+		this.on("_autosave", function(name) {
+			this.emit("autosave-start", name);
+			this._runningAutosave = name;
+		})
+
+		this.on("_saved", function() {
+			if (this._runningAutosave) {
+				this.emit("autosave-finished", this._runningAutosave);
+				this._runningAutosave = null;
+			}
+		})
 	}
 
 	_check(expectedStates) {
@@ -645,6 +673,7 @@ class FactorioServer extends events.EventEmitter {
 			this._rconReady = false;
 			this._gameReady = false;
 			this._unexpected = [];
+			this._runningAutosave = null;
 
 			this.emit("exit");
 		});
diff --git a/slave.js b/slave.js
index 1d34b0e3..ce9adfc3 100644
--- a/slave.js
+++ b/slave.js
@@ -35,6 +35,12 @@ const instanceFactorioMemoryUsage = new prometheus.Gauge(
 	{ labels: ["instance_id"] }
 );
 
+const instanceFactorioAutosaveSize = new prometheus.Gauge(
+	"clusterio_instance_factorio_autosave_bytes",
+	"Size of Factorio server autosave in bytes.",
+	{ labels: ["instance_id"] }
+);
+
 /**
  * Keeps track of the runtime parameters of an instance
  */
@@ -78,6 +84,17 @@ class Instance extends link.Link{
 		this.server.on("error", err => {
 			console.log(`Error in instance ${this.name}:`, err);
 		});
+
+		this.server.on("autosave-finished", name => {
+			this._autosave(name).catch(err => {
+				console.error("Error handling autosave-finished:", err);
+			});
+		});
+	}
+
+	async _autosave(name) {
+		let stat = await fs.stat(this.path("saves", `${name}.zip`));
+		instanceFactorioAutosaveSize.labels(String(this.config.get("instance.id"))).set(stat.size);
 	}
 
 	notifyExit() {
diff --git a/test/lib/factorio/lines.js b/test/lib/factorio/lines.js
index eb6159ba..2e316ac0 100644
--- a/test/lib/factorio/lines.js
+++ b/test/lib/factorio/lines.js
@@ -109,6 +109,28 @@ let testLines = new Map([
 			message: "Error while running event level::on_nth_tick(1)",
 		}
 	],
+	[
+		"4802.763 Info AppManager.cpp:287: Saving to _autosave4 (blocking).",
+		{
+			format: "seconds",
+			time: "4802.763",
+			type: "log",
+			level: "Info",
+			file: "AppManager.cpp:287",
+			message: "Saving to _autosave4 (blocking).",
+		}
+	],
+	[
+		"4202.780 Info AppManagerStates.cpp:1802: Saving finished",
+		{
+			format: "seconds",
+			time: "4202.780",
+			type: "log",
+			level: "Info",
+			file: "AppManagerStates.cpp:1802",
+			message: "Saving finished",
+		}
+	],
 ])
 
 module.exports = {