BREAKING CHANGE(smartmetrics): add system-wide metrics collection, Prometheus gauges, and normalized CPU reporting

ts/smartmetrics.sysusage.ts

@@ -0,0 +1,94 @@
+import * as fs from 'fs';
+import * as os from 'os';
+
+export interface ISystemUsageResult {
+  cpuPercent: number;          // 0-100% system-wide CPU utilization
+  memTotalBytes: number;       // total physical RAM
+  memAvailableBytes: number;   // available memory
+  memUsedBytes: number;        // memTotal - memAvailable
+  memUsedPercent: number;      // 0-100%
+  loadAvg1: number;            // 1-min load average
+  loadAvg5: number;            // 5-min load average
+  loadAvg15: number;           // 15-min load average
+}
+
+// History for system CPU delta tracking
+interface ICpuSnapshot {
+  idle: number;
+  total: number;
+}
+
+let prevCpuSnapshot: ICpuSnapshot | null = null;
+
+function readProcStat(): ICpuSnapshot | null {
+  try {
+    const content = fs.readFileSync('/proc/stat', 'utf8');
+    const firstLine = content.split('\n')[0]; // "cpu  user nice system idle iowait irq softirq steal ..."
+    const parts = firstLine.split(/\s+/).slice(1).map(Number);
+    // parts: [user, nice, system, idle, iowait, irq, softirq, steal, ...]
+    const idle = parts[3] + (parts[4] || 0); // idle + iowait
+    const total = parts.reduce((sum, v) => sum + v, 0);
+    return { idle, total };
+  } catch {
+    return null;
+  }
+}
+
+function getMemoryInfo(): { totalBytes: number; availableBytes: number } {
+  try {
+    const content = fs.readFileSync('/proc/meminfo', 'utf8');
+    let memTotal = 0;
+    let memAvailable = 0;
+    for (const line of content.split('\n')) {
+      if (line.startsWith('MemTotal:')) {
+        memTotal = parseInt(line.split(/\s+/)[1], 10) * 1024; // kB to bytes
+      } else if (line.startsWith('MemAvailable:')) {
+        memAvailable = parseInt(line.split(/\s+/)[1], 10) * 1024;
+      }
+    }
+    if (memTotal > 0 && memAvailable > 0) {
+      return { totalBytes: memTotal, availableBytes: memAvailable };
+    }
+  } catch {
+    // fall through to os fallback
+  }
+  // Fallback using os module
+  const totalBytes = os.totalmem();
+  const availableBytes = os.freemem();
+  return { totalBytes, availableBytes };
+}
+
+export async function getSystemUsage(): Promise<ISystemUsageResult> {
+  // CPU
+  let cpuPercent = 0;
+  const currentSnapshot = readProcStat();
+  if (currentSnapshot && prevCpuSnapshot) {
+    const totalDelta = currentSnapshot.total - prevCpuSnapshot.total;
+    const idleDelta = currentSnapshot.idle - prevCpuSnapshot.idle;
+    if (totalDelta > 0) {
+      cpuPercent = ((totalDelta - idleDelta) / totalDelta) * 100;
+    }
+  }
+  if (currentSnapshot) {
+    prevCpuSnapshot = currentSnapshot;
+  }
+
+  // Memory
+  const mem = getMemoryInfo();
+  const memUsedBytes = mem.totalBytes - mem.availableBytes;
+  const memUsedPercent = mem.totalBytes > 0 ? (memUsedBytes / mem.totalBytes) * 100 : 0;
+
+  // Load averages
+  const [loadAvg1, loadAvg5, loadAvg15] = os.loadavg();
+
+  return {
+    cpuPercent,
+    memTotalBytes: mem.totalBytes,
+    memAvailableBytes: mem.availableBytes,
+    memUsedBytes,
+    memUsedPercent,
+    loadAvg1,
+    loadAvg5,
+    loadAvg15,
+  };
+}