Updated the logic for Stat/Metric tracking in the dashboard more robust. (#365)

* Updated the logic for Stat/Metric tracking in the dashboard more robust.

* Show used/total for stats.

* Added the ability to configure the update interval of metrics in the dashboard.

services/Ram.ts

@@ -0,0 +1,73 @@
+// TODO: Convert to a real service
+
+const GLib = imports.gi.GLib;
+
+import { pollVariable } from 'customModules/PollVar';
+import { GenericResourceData } from 'lib/types/customModules/generic';
+
+class Ram {
+    private updateFrequency = Variable(2000);
+    private shouldRound = false;
+
+    public ram = Variable<GenericResourceData>({ total: 0, used: 0, percentage: 0, free: 0 });
+
+    constructor() {
+        this.calculateUsage = this.calculateUsage.bind(this);
+        pollVariable(this.ram, [], this.updateFrequency.bind('value'), this.calculateUsage);
+    }
+
+    public calculateUsage(): GenericResourceData {
+        try {
+            const [success, meminfoBytes] = GLib.file_get_contents('/proc/meminfo');
+
+            if (!success || !meminfoBytes) {
+                throw new Error('Failed to read /proc/meminfo or file content is null.');
+            }
+
+            const meminfo = new TextDecoder('utf-8').decode(meminfoBytes);
+
+            const totalMatch = meminfo.match(/MemTotal:\s+(\d+)/);
+            const availableMatch = meminfo.match(/MemAvailable:\s+(\d+)/);
+
+            if (!totalMatch || !availableMatch) {
+                throw new Error('Failed to parse /proc/meminfo for memory values.');
+            }
+
+            const totalRamInBytes = parseInt(totalMatch[1], 10) * 1024;
+            const availableRamInBytes = parseInt(availableMatch[1], 10) * 1024;
+
+            let usedRam = totalRamInBytes - availableRamInBytes;
+            usedRam = isNaN(usedRam) || usedRam < 0 ? 0 : usedRam;
+
+            return {
+                percentage: this.divide([totalRamInBytes, usedRam]),
+                total: totalRamInBytes,
+                used: usedRam,
+                free: availableRamInBytes,
+            };
+        } catch (error) {
+            console.error('Error calculating RAM usage:', error);
+            return { total: 0, used: 0, percentage: 0, free: 0 };
+        }
+    }
+
+    public setShouldRound(round: boolean): void {
+        this.shouldRound = round;
+    }
+
+    private divide([total, used]: number[]): number {
+        const percentageTotal = (used / total) * 100;
+
+        if (this.shouldRound) {
+            return total > 0 ? Math.round(percentageTotal) : 0;
+        }
+
+        return total > 0 ? parseFloat(percentageTotal.toFixed(2)) : 0;
+    }
+
+    updateTimer(timerInMs: number): void {
+        this.updateFrequency.value = timerInMs;
+    }
+}
+
+export default Ram;