Initial commit (history squashed)

src/StellaOps.Cli/Telemetry/CliMetrics.cs

@@ -0,0 +1,62 @@
+using System;
+using System.Diagnostics.Metrics;
+
+namespace StellaOps.Cli.Telemetry;
+
+internal static class CliMetrics
+{
+    private static readonly Meter Meter = new("StellaOps.Cli", "1.0.0");
+
+    private static readonly Counter<long> ScannerDownloadCounter = Meter.CreateCounter<long>("stellaops.cli.scanner.download.count");
+    private static readonly Counter<long> ScannerInstallCounter = Meter.CreateCounter<long>("stellaops.cli.scanner.install.count");
+    private static readonly Counter<long> ScanRunCounter = Meter.CreateCounter<long>("stellaops.cli.scan.run.count");
+    private static readonly Histogram<double> CommandDurationHistogram = Meter.CreateHistogram<double>("stellaops.cli.command.duration.ms");
+
+    public static void RecordScannerDownload(string channel, bool fromCache)
+        => ScannerDownloadCounter.Add(1, new KeyValuePair<string, object?>[]
+        {
+            new("channel", channel),
+            new("cache", fromCache ? "hit" : "miss")
+        });
+
+    public static void RecordScannerInstall(string channel)
+        => ScannerInstallCounter.Add(1, new KeyValuePair<string, object?>[] { new("channel", channel) });
+
+    public static void RecordScanRun(string runner, int exitCode)
+        => ScanRunCounter.Add(1, new KeyValuePair<string, object?>[]
+        {
+            new("runner", runner),
+            new("exit_code", exitCode)
+        });
+
+    public static IDisposable MeasureCommandDuration(string command)
+    {
+        var start = DateTime.UtcNow;
+        return new DurationScope(command, start);
+    }
+
+    private sealed class DurationScope : IDisposable
+    {
+        private readonly string _command;
+        private readonly DateTime _start;
+        private bool _disposed;
+
+        public DurationScope(string command, DateTime start)
+        {
+            _command = command;
+            _start = start;
+        }
+
+        public void Dispose()
+        {
+            if (_disposed)
+            {
+                return;
+            }
+
+            _disposed = true;
+            var elapsed = (DateTime.UtcNow - _start).TotalMilliseconds;
+            CommandDurationHistogram.Record(elapsed, new KeyValuePair<string, object?>[] { new("command", _command) });
+        }
+    }
+}