From b4f144a7fbfbcb551eacad38115111b629370116 Mon Sep 17 00:00:00 2001
From: benbierens <thatbenbierens@gmail.com>
Date: Wed, 7 Jun 2023 10:56:25 +0200
Subject: [PATCH] Speeds up file-equal assertions hugely

---
 DistTestCore/FileManager.cs | 40 ++++++++++++++++++++++++++++---------
 1 file changed, 31 insertions(+), 9 deletions(-)

diff --git a/DistTestCore/FileManager.cs b/DistTestCore/FileManager.cs
index d4d893b..69e0ef3 100644
--- a/DistTestCore/FileManager.cs
+++ b/DistTestCore/FileManager.cs
@@ -1,5 +1,6 @@
 using Logging;
 using NUnit.Framework;
+using System.Runtime.InteropServices;
 using Utils;
 
 namespace DistTestCore
@@ -154,11 +155,33 @@ namespace DistTestCore
         public string Label { get; }
 
         public void AssertIsEqual(TestFile? actual)
+        {
+            var sw = Stopwatch.Begin(log);
+            try
+            {
+                AssertEqual(actual);
+            }
+            finally
+            {
+                sw.End($"{nameof(TestFile)}.{nameof(AssertIsEqual)}");
+            }
+        }
+
+        public string Describe()
+        {
+            if (!string.IsNullOrEmpty(Label)) return Label;
+            return $"'{Filename}' ({Formatter.FormatByteSize(GetFileSize())})";
+        }
+
+        private void AssertEqual(TestFile? actual)
         {
             if (actual == null) Assert.Fail("TestFile is null.");
             if (actual == this || actual!.Filename == Filename) Assert.Fail("TestFile is compared to itself.");
 
-            Assert.That(actual.GetFileSize(), Is.EqualTo(GetFileSize()), "Files are not of equal length.");
+            Stopwatch.Measure(log, "sizes", () =>
+            {
+                Assert.That(actual.GetFileSize(), Is.EqualTo(GetFileSize()), "Files are not of equal length.");
+            });
 
             using var streamExpected = new FileStream(Filename, FileMode.Open, FileAccess.Read);
             using var streamActual = new FileStream(actual.Filename, FileMode.Open, FileAccess.Read);
@@ -179,15 +202,14 @@ namespace DistTestCore
                     log.Log($"OK: '{Describe()}' is equal to '{actual.Describe()}'.");
                     return;
                 }
-                Assert.That(readActual, Is.EqualTo(readExpected), "Unable to read buffers of equal length.");
-                CollectionAssert.AreEqual(bytesExpected, bytesActual, "Files are not binary-equal.");
-            }
-        }
 
-        public string Describe()
-        {
-            if (!string.IsNullOrEmpty(Label)) return Label;
-            return $"'{Filename}' ({Formatter.FormatByteSize(GetFileSize())})";
+                Assert.That(readActual, Is.EqualTo(readExpected), "Unable to read buffers of equal length.");
+
+                for (var i = 0; i < readActual; i++)
+                {
+                    if (bytesExpected[i] != bytesActual[i]) Assert.Fail("File contents not equal.");
+                }
+            }
         }
 
         private long GetFileSize()