import speed improvements

DtoImporterService/BookImporter.cs

@@ -19,13 +19,13 @@ namespace DtoImporterService
 			new ContributorImporter(DbContext).Import(importItems);
 			new SeriesImporter(DbContext).Import(importItems);
 			new CategoryImporter(DbContext).Import(importItems);
-
+			
 			// get distinct
-			var productIds = importItems.Select(i => i.DtoItem.ProductId).ToList();
-
+			var productIds = importItems.Select(i => i.DtoItem.ProductId).Distinct().ToList();
+			
 			// load db existing => .Local
 			loadLocal_books(productIds);
-
+			
 			// upsert
 			var qtyNew = upsertBooks(importItems);
 			return qtyNew;
@@ -33,9 +33,9 @@ namespace DtoImporterService
 
 		private void loadLocal_books(List<string> productIds)
 		{
-			var localProductIds = DbContext.Books.Local.Select(b => b.AudibleProductId);
+			// if this context has already loaded books, don't need to reload them. vestige from when context was long-lived. in practice, we now typically use a fresh context. this is quick though so no harm in leaving it.
+			var localProductIds = DbContext.Books.Local.Select(b => b.AudibleProductId).ToList();
 			var remainingProductIds = productIds
-				.Distinct()
 				.Except(localProductIds)
 				.ToList();
 

DtoImporterService/CategoryImporter.cs

@@ -35,7 +35,7 @@ namespace DtoImporterService
 
 		private void loadLocal_categories(List<string> categoryIds)
 		{
-			var localIds = DbContext.Categories.Local.Select(c => c.AudibleCategoryId);
+			var localIds = DbContext.Categories.Local.Select(c => c.AudibleCategoryId).ToList();
 			var remainingCategoryIds = categoryIds
 				.Distinct()
 				.Except(localIds)

DtoImporterService/PerfLogger.cs

@@ -0,0 +1,34 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Linq;
+
+namespace DtoImporterService
+{
+	public record timeLogEntry(string msg, long totalElapsed, long delta);
+	public static class PerfLogger
+	{
+		private static Stopwatch sw = new Stopwatch();
+		private static List<timeLogEntry> __log { get; } = new List<timeLogEntry>();
+
+		public static void logTime(string s)
+		{
+			var totalElapsed = sw.ElapsedMilliseconds;
+
+			var prev = __log.Last().totalElapsed;
+			var delta = totalElapsed - prev;
+
+			__log.Add(new(s, totalElapsed, delta));
+		}
+		public static void logRestart()
+		{
+			__log.Clear();
+			__log.Add(new("begin", 0, 0));
+			sw.Restart();
+		}
+		public static void stop() => sw.Stop();
+		public static string logOutput =>
+			$"{nameof(timeLogEntry.msg)}\t{nameof(timeLogEntry.totalElapsed)}\t{nameof(timeLogEntry.delta)}\r\n"
+			+ __log.Select(t => $"{t.msg}\t{t.totalElapsed}\t{t.delta}").Aggregate((a, b) => $"{a}\r\n{b}");
+	}
+}