From c856f404e3fe8753e70c94a965c2419b4d523f96 Mon Sep 17 00:00:00 2001
From: Ben <thatbenbierens@gmail.com>
Date: Fri, 19 Apr 2024 11:40:32 +0200
Subject: [PATCH] Adds test to show from which hosts blocks are downloaded.

---
 Framework/Core/DownloadedLog.cs               | 14 ++++
 .../MultiPeerDownloadTests.cs                 | 72 +++++++++++++++++++
 2 files changed, 86 insertions(+)
 create mode 100644 Tests/CodexTests/ScalabilityTests/MultiPeerDownloadTests.cs

diff --git a/Framework/Core/DownloadedLog.cs b/Framework/Core/DownloadedLog.cs
index 923bcbc..fa4d559 100644
--- a/Framework/Core/DownloadedLog.cs
+++ b/Framework/Core/DownloadedLog.cs
@@ -4,6 +4,7 @@ namespace Core
 {
     public interface IDownloadedLog
     {
+        void IterateLines(Action<string> action);
         string[] GetLinesContaining(string expectedString);
         string[] FindLinesThatContain(params string[] tags);
         void DeleteFile();
@@ -18,6 +19,19 @@ namespace Core
             this.logFile = logFile;
         }
 
+        public void IterateLines(Action<string> action)
+        {
+            using var file = File.OpenRead(logFile.FullFilename);
+            using var streamReader = new StreamReader(file);
+
+            var line = streamReader.ReadLine();
+            while (line != null)
+            {
+                action(line);
+                line = streamReader.ReadLine();
+            }
+        }
+
         public string[] GetLinesContaining(string expectedString)
         {
             using var file = File.OpenRead(logFile.FullFilename);
diff --git a/Tests/CodexTests/ScalabilityTests/MultiPeerDownloadTests.cs b/Tests/CodexTests/ScalabilityTests/MultiPeerDownloadTests.cs
new file mode 100644
index 0000000..2ff5103
--- /dev/null
+++ b/Tests/CodexTests/ScalabilityTests/MultiPeerDownloadTests.cs
@@ -0,0 +1,72 @@
+using NUnit.Framework;
+using Utils;
+
+namespace CodexTests.ScalabilityTests
+{
+    [TestFixture]
+    public class MultiPeerDownloadTests : AutoBootstrapDistTest
+    {
+        [Test]
+        public void MultiPeerDownload()
+        {
+            var hosts = AddCodex(5, s => s.WithLogLevel(CodexPlugin.CodexLogLevel.Trace));
+            var file = GenerateTestFile(100.MB());
+            var cid = hosts[0].UploadFile(file);
+
+            var uploadLog = Ci.DownloadLog(hosts[0]);
+            var blockCids = uploadLog
+                .FindLinesThatContain("Putting block into network store")
+                .Select(s =>
+                {
+                    var start = s.IndexOf("cid=") + 4;
+                    var end = s.IndexOf(" count=");
+                    var len = end - start;
+                    return s.Substring(start, len);
+                })
+                .ToArray();
+
+            // Each host has the file.
+            foreach (var h in hosts) h.DownloadContent(cid);
+
+            var client = AddCodex(s => s.WithLogLevel(CodexPlugin.CodexLogLevel.Trace));
+            var resultFile = client.DownloadContent(cid);
+            resultFile!.AssertIsEqual(file);
+
+            var downloadLog = Ci.DownloadLog(client);
+            var blocksPerHost = new Dictionary<string, int>();
+            var seenBlocks = new List<string>();
+            var host = string.Empty;
+            downloadLog.IterateLines(line =>
+            {
+                if (line.Contains("peer=") && line.Contains(" len="))
+                {
+                    var start = line.IndexOf("peer=") + 5;
+                    var end = line.IndexOf(" len=");
+                    var len = end - start;
+                    host = line.Substring(start, len);
+                }
+                else if (!string.IsNullOrEmpty(host) && line.Contains("Storing block with key"))
+                {
+                    var start = line.IndexOf("cid=") + 4;
+                    var end = line.IndexOf(" count=");
+                    var len = end - start;
+                    var blockCid = line.Substring(start, len);
+
+                    if (!seenBlocks.Contains(blockCid))
+                    {
+                        seenBlocks.Add(blockCid);
+                        if (!blocksPerHost.ContainsKey(host)) blocksPerHost.Add(host, 1);
+                        else blocksPerHost[host]++;
+                    }
+                }
+            });
+
+            Log("Total number of blocks in dataset: " + blockCids.Length);
+            Log("Blocks fetched per host:");
+            foreach (var pair in blocksPerHost)
+            {
+                Log($"Host: {pair.Key} = {pair.Value}");
+            }
+        }
+    }
+}