Fixed an incomplete plugin start with extensive enterprise configurations (#1033)

app/MindWork AI Studio/Settings/SettingsManager.cs

@@ -1,4 +1,6 @@
+using System.Diagnostics;
 using System.Linq.Expressions;
+using System.Text;
 using System.Text.Json;
 
 using AIStudio.Provider;
@@ -30,6 +32,16 @@ public sealed class SettingsManager
         Converters = { new TolerantEnumConverter() },
     };
 
+    /// <summary>
+    /// From this duration on, storing the settings is reported as slow.
+    /// </summary>
+    /// <remarks>
+    /// The settings file is a few hundred kilobytes at most, so storing it usually takes some
+    /// milliseconds. Far beyond that, something is blocking: on one machine, every store took 18
+    /// seconds, and each one held up the start of AI Studio.
+    /// </remarks>
+    private static readonly TimeSpan SLOW_STORE_THRESHOLD = TimeSpan.FromSeconds(1);
+
     private readonly ILogger<SettingsManager> logger;
     private readonly RustService rustService;
 
@@ -337,10 +349,24 @@ public sealed class SettingsManager
                 return;
             }
 
+            //
+            // Serializing and writing are measured on their own, because a slow store has two
+            // different causes: a property which asks the file system or the network while it is
+            // serialized, or a file system which is slow to write, e.g., because of a virus scanner
+            // or a synchronized profile folder. Only the two durations tell them apart:
+            //
+            var serializingStartedAt = Stopwatch.GetTimestamp();
             var settingsJson = JsonSerializer.Serialize(this.ConfigurationData, JSON_OPTIONS);
+            var serializingDuration = Stopwatch.GetElapsedTime(serializingStartedAt);
+
+            var writingStartedAt = Stopwatch.GetTimestamp();
             var settingsPath = Path.Combine(ConfigDirectory!, SETTINGS_FILENAME);
             await this.StoreSerializedSettings(settingsJson, settingsPath);
             await this.StoreSerializedVersionBackup(this.ConfigurationData.Version, settingsJson);
+            var writingDuration = Stopwatch.GetElapsedTime(writingStartedAt);
+
+            if (serializingDuration + writingDuration >= SLOW_STORE_THRESHOLD)
+                this.logger.LogWarning($"Storing the settings took {(serializingDuration + writingDuration).TotalMilliseconds:F0} ms, which is unusually long: serializing took {serializingDuration.TotalMilliseconds:F0} ms, writing took {writingDuration.TotalMilliseconds:F0} ms. The settings are {Encoding.UTF8.GetByteCount(settingsJson) / 1024} KB. A slow serialization points to a setting which reaches out to the file system or the network while it is serialized; slow writing points to the file system itself, e.g., a virus scanner or a synchronized profile folder.");
         }
         finally
         {