stabilizaiton work - projects rework for maintenanceability and ui livening

src/__Libraries/StellaOps.Provcache/WriteBehindQueue.Drain.cs

@@ -0,0 +1,34 @@
+using System;
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.Extensions.Logging;
+
+namespace StellaOps.Provcache;
+
+public sealed partial class WriteBehindQueue
+{
+    private async Task DrainAsync(CancellationToken cancellationToken)
+    {
+        var batch = new List<WriteBehindItem>();
+
+        while (_channel.Reader.TryRead(out var item))
+        {
+            batch.Add(item);
+            Interlocked.Decrement(ref _currentQueueDepth);
+
+            if (batch.Count >= _options.WriteBehindBatchSize)
+            {
+                await ProcessBatchAsync(batch, cancellationToken).ConfigureAwait(false);
+                batch.Clear();
+            }
+        }
+
+        if (batch.Count > 0)
+        {
+            await ProcessBatchAsync(batch, cancellationToken).ConfigureAwait(false);
+        }
+
+        _logger.LogInformation("Write-behind queue drained");
+    }
+}