From ec9359d15296eaaeac65056eb1b934a85680c898 Mon Sep 17 00:00:00 2001
From: Lessley Dennington <ldennington@github.com>
Date: Thu, 2 Mar 2023 15:36:35 -0700
Subject: [PATCH 1/4] trace2: move formattargettypes

Move the FormatTargetTypes enum from the specific Trace2StreamWriter class
to the shared Trace2Writer class, since the Trace2FileWriter class also
uses values from this enum.
---
 src/shared/Core/ITrace2Writer.cs      | 10 ++++++++++
 src/shared/Core/Trace2StreamWriter.cs | 10 ----------
 2 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/src/shared/Core/ITrace2Writer.cs b/src/shared/Core/ITrace2Writer.cs
index 6dd302add..fbe1b2297 100644
--- a/src/shared/Core/ITrace2Writer.cs
+++ b/src/shared/Core/ITrace2Writer.cs
@@ -3,6 +3,16 @@
 
 namespace GitCredentialManager;
 
+/// <summary>
+/// The different format targets supported in the TRACE2 tracing
+/// system.
+/// </summary>
+public enum Trace2FormatTarget
+{
+    Event,
+    Normal
+}
+
 public interface ITrace2Writer : IDisposable
 {
     bool Failed { get; }
diff --git a/src/shared/Core/Trace2StreamWriter.cs b/src/shared/Core/Trace2StreamWriter.cs
index 5ef88bd1b..c41f45ec8 100644
--- a/src/shared/Core/Trace2StreamWriter.cs
+++ b/src/shared/Core/Trace2StreamWriter.cs
@@ -3,16 +3,6 @@
 
 namespace GitCredentialManager;
 
-/// <summary>
-/// The different format targets supported in the TRACE2 tracing
-/// system.
-/// </summary>
-public enum Trace2FormatTarget
-{
-    Event,
-    Normal
-}
-
 public class Trace2StreamWriter : Trace2Writer
 {
     private readonly TextWriter _writer;

From 7c9328c8e035917f1cfd7ff11d465989f911e99d Mon Sep 17 00:00:00 2001
From: Lessley Dennington <ldennington@github.com>
Date: Tue, 14 Mar 2023 09:40:50 -0600
Subject: [PATCH 2/4] trace2: write normal format events in snake case

A previous patch [1] added the ability to write strings in snake case.
However, this was not applied to writing events in the normal format -
events that should be written as child_start or child_exit are currently
written as childstart and childexit. This patch corrects this issue.

[1]: 7d2a8cc583a8aeae104c6cb144fde1328ef50cae
---
 src/shared/Core/Trace2.cs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/shared/Core/Trace2.cs b/src/shared/Core/Trace2.cs
index 7ba44d3d2..6317654fe 100644
--- a/src/shared/Core/Trace2.cs
+++ b/src/shared/Core/Trace2.cs
@@ -467,7 +467,7 @@ protected string BuildNormalString(string message)
 
         // Git's TRACE2 normal format is:
         // [<time> SP <filename>:<line> SP+] <event-name> [[SP] <event-message>] LF
-        return $"{time} {source,-33} {Event.ToString().ToLower()} {message}";
+        return $"{time} {source,-33} {Event.ToString().ToSnakeCase()} {message}";
     }
 }
 

From c0a3a0366854d466bd6ce1fbc30b76d4e21802eb Mon Sep 17 00:00:00 2001
From: Lessley Dennington <ldennington@github.com>
Date: Tue, 14 Mar 2023 11:48:26 -0600
Subject: [PATCH 3/4] trace2: add process depth calculation

The performance format target requires recording of process depth. We use
the number of forward slashes in the process's sid as a convenient way to
determine this. Because the sid and the depth are process-related
concepts, this change also moves sid/depth related properties into
ProcessManager.cs and removes the SidManager.cs class.
---
 .../Program.cs                                |  2 +-
 src/shared/Core.Tests/ProcessManagerTests.cs  | 33 ++++++++++++
 src/shared/Core/ProcessManager.cs             | 51 ++++++++++++++++++-
 src/shared/Core/SidManager.cs                 | 27 ----------
 src/shared/Core/Trace2.cs                     |  2 +-
 .../Program.cs                                |  2 +-
 src/shared/Git-Credential-Manager/Program.cs  |  2 +-
 src/shared/GitHub.UI.Avalonia/Program.cs      |  2 +-
 src/shared/GitLab.UI.Avalonia/Program.cs      |  2 +-
 .../Atlassian.Bitbucket.UI.Windows/Program.cs |  2 +-
 .../Program.cs                                |  2 +-
 src/windows/GitHub.UI.Windows/Program.cs      |  2 +-
 src/windows/GitLab.UI.Windows/Program.cs      |  2 +-
 13 files changed, 93 insertions(+), 38 deletions(-)
 create mode 100644 src/shared/Core.Tests/ProcessManagerTests.cs
 delete mode 100644 src/shared/Core/SidManager.cs

diff --git a/src/shared/Atlassian.Bitbucket.UI.Avalonia/Program.cs b/src/shared/Atlassian.Bitbucket.UI.Avalonia/Program.cs
index b715486e3..8bc3a6571 100644
--- a/src/shared/Atlassian.Bitbucket.UI.Avalonia/Program.cs
+++ b/src/shared/Atlassian.Bitbucket.UI.Avalonia/Program.cs
@@ -47,7 +47,7 @@ private static void AppMain(object o)
 
             // Set the session id (sid) for the helper process, to be
             // used when TRACE2 tracing is enabled.
-            SidManager.CreateSid();
+            ProcessManager.CreateSid();
             using (var context = new CommandContext())
             using (var app = new HelperApplication(context))
             {
diff --git a/src/shared/Core.Tests/ProcessManagerTests.cs b/src/shared/Core.Tests/ProcessManagerTests.cs
new file mode 100644
index 000000000..8e96c41f0
--- /dev/null
+++ b/src/shared/Core.Tests/ProcessManagerTests.cs
@@ -0,0 +1,33 @@
+using GitCredentialManager;
+using Xunit;
+
+namespace Core.Tests;
+
+public class ProcessManagerTests
+{
+    [Theory]
+    [InlineData("", 0)]
+    [InlineData("foo", 0)]
+    [InlineData("foo/bar", 1)]
+    [InlineData("foo/bar/baz", 2)]
+    public void CreateSid_Envar_Returns_Expected_Sid(string input, int expected)
+    {
+        ProcessManager.Sid = input;
+        var actual = ProcessManager.GetProcessDepth();
+
+        Assert.Equal(expected, actual);
+    }
+
+    [Theory]
+    [InlineData("", 0)]
+    [InlineData("foo", 0)]
+    [InlineData("foo/bar", 1)]
+    [InlineData("foo/bar/baz", 2)]
+    public void TryGetProcessDepth_Returns_Expected_Depth(string input, int expected)
+    {
+        ProcessManager.Sid = input;
+        var actual = ProcessManager.GetProcessDepth();
+
+        Assert.Equal(expected, actual);
+    }
+}
\ No newline at end of file
diff --git a/src/shared/Core/ProcessManager.cs b/src/shared/Core/ProcessManager.cs
index 78b0e2c9c..8f0e542ad 100644
--- a/src/shared/Core/ProcessManager.cs
+++ b/src/shared/Core/ProcessManager.cs
@@ -1,3 +1,4 @@
+using System;
 using System.Diagnostics;
 using System.Threading.Tasks;
 
@@ -27,8 +28,14 @@ public interface IProcessManager
 
 public class ProcessManager : IProcessManager
 {
+    private const string SidEnvar = "GIT_TRACE2_PARENT_SID";
+
     protected readonly ITrace2 Trace2;
 
+    public static string Sid { get; internal set; }
+
+    public static int Depth { get; internal set; }
+
     public ProcessManager(ITrace2 trace2)
     {
         EnsureArgument.NotNull(trace2, nameof(trace2));
@@ -50,9 +57,51 @@ public virtual ChildProcess CreateProcess(string path, string args, bool useShel
         return CreateProcess(psi);
     }
 
-
     public virtual ChildProcess CreateProcess(ProcessStartInfo psi)
     {
         return new ChildProcess(Trace2, psi);
     }
+
+    /// <summary>
+    /// Create a TRACE2 "session id" (sid) for this process.
+    /// </summary>
+    public static void CreateSid()
+    {
+        Sid = Environment.GetEnvironmentVariable(SidEnvar);
+
+        if (!string.IsNullOrEmpty(Sid))
+        {
+            // Use trim to ensure no accidental leading or trailing slashes
+            Sid = $"{Sid.Trim('/')}/{Guid.NewGuid():D}";
+            // Only check for process depth if there is a parent.
+            // If there is not a parent, depth defaults to 0.
+            Depth = GetProcessDepth();
+        }
+        else
+        {
+            // We are the root process; create our own 'root' SID
+            Sid = Guid.NewGuid().ToString("D");
+        }
+
+        Environment.SetEnvironmentVariable(SidEnvar, Sid);
+    }
+
+    /// <summary>
+    /// Get "depth" of current process relative to top-level GCM process.
+    /// </summary>
+    /// <returns>Depth of current process.</returns>
+    internal static int GetProcessDepth()
+    {
+        char processSeparator = '/';
+
+        int count = 0;
+        // Use AsSpan() for slight performance bump over traditional foreach loop.
+        foreach (var c in Sid.AsSpan())
+        {
+            if (c == processSeparator)
+                count++;
+        }
+
+        return count;
+    }
 }
diff --git a/src/shared/Core/SidManager.cs b/src/shared/Core/SidManager.cs
deleted file mode 100644
index 6ccfb72ed..000000000
--- a/src/shared/Core/SidManager.cs
+++ /dev/null
@@ -1,27 +0,0 @@
-using System;
-
-namespace GitCredentialManager;
-
-public class SidManager
-{
-    private const string SidEnvar = "GIT_TRACE2_PARENT_SID";
-
-    public static string Sid { get; private set; }
-
-    public static void CreateSid()
-    {
-        Sid = Environment.GetEnvironmentVariable(SidEnvar);
-
-        if (!string.IsNullOrEmpty(Sid))
-        {
-            Sid = $"{Sid}/{Guid.NewGuid():D}";
-        }
-        else
-        {
-            // We are the root process; create our own 'root' SID
-            Sid = Guid.NewGuid().ToString("D");
-        }
-
-        Environment.SetEnvironmentVariable(SidEnvar, Sid);
-    }
-}
diff --git a/src/shared/Core/Trace2.cs b/src/shared/Core/Trace2.cs
index 6317654fe..ecfd43c61 100644
--- a/src/shared/Core/Trace2.cs
+++ b/src/shared/Core/Trace2.cs
@@ -146,7 +146,7 @@ public void Initialize(DateTimeOffset startTime)
 
         _applicationStartTime = startTime;
         _settings = _commandContext.Settings.GetTrace2Settings();
-        _sid = SidManager.Sid;
+        _sid = ProcessManager.Sid;
 
         InitializeWriters();
 
diff --git a/src/shared/Git-Credential-Manager.UI.Avalonia/Program.cs b/src/shared/Git-Credential-Manager.UI.Avalonia/Program.cs
index 0360591de..124bc775d 100644
--- a/src/shared/Git-Credential-Manager.UI.Avalonia/Program.cs
+++ b/src/shared/Git-Credential-Manager.UI.Avalonia/Program.cs
@@ -45,7 +45,7 @@ private static void AppMain(object o)
 
             // Set the session id (sid) for the helper process, to be
             // used when TRACE2 tracing is enabled.
-            SidManager.CreateSid();
+            ProcessManager.CreateSid();
             using (var context = new CommandContext())
             using (var app = new HelperApplication(context))
             {
diff --git a/src/shared/Git-Credential-Manager/Program.cs b/src/shared/Git-Credential-Manager/Program.cs
index 34494d1df..8b3ae260a 100644
--- a/src/shared/Git-Credential-Manager/Program.cs
+++ b/src/shared/Git-Credential-Manager/Program.cs
@@ -14,7 +14,7 @@ public static void Main(string[] args)
             var startTime = DateTimeOffset.UtcNow;
             // Set the session id (sid) and start time for the GCM process, to be
             // used when TRACE2 tracing is enabled.
-            SidManager.CreateSid();
+            ProcessManager.CreateSid();
 
             using (var context = new CommandContext())
             using (var app = new Application(context))
diff --git a/src/shared/GitHub.UI.Avalonia/Program.cs b/src/shared/GitHub.UI.Avalonia/Program.cs
index bc7db3a6b..5fd62eb8e 100644
--- a/src/shared/GitHub.UI.Avalonia/Program.cs
+++ b/src/shared/GitHub.UI.Avalonia/Program.cs
@@ -47,7 +47,7 @@ private static void AppMain(object o)
 
             // Set the session id (sid) for the helper process, to be
             // used when TRACE2 tracing is enabled.
-            SidManager.CreateSid();
+            ProcessManager.CreateSid();
             using (var context = new CommandContext())
             using (var app = new HelperApplication(context))
             {
diff --git a/src/shared/GitLab.UI.Avalonia/Program.cs b/src/shared/GitLab.UI.Avalonia/Program.cs
index d2016f465..a3ce47799 100644
--- a/src/shared/GitLab.UI.Avalonia/Program.cs
+++ b/src/shared/GitLab.UI.Avalonia/Program.cs
@@ -47,7 +47,7 @@ private static void AppMain(object o)
 
             // Set the session id (sid) for the helper process, to be
             // used when TRACE2 tracing is enabled.
-            SidManager.CreateSid();
+            ProcessManager.CreateSid();
             using (var context = new CommandContext())
             using (var app = new HelperApplication(context))
             {
diff --git a/src/windows/Atlassian.Bitbucket.UI.Windows/Program.cs b/src/windows/Atlassian.Bitbucket.UI.Windows/Program.cs
index 96440e17a..d53d374bb 100644
--- a/src/windows/Atlassian.Bitbucket.UI.Windows/Program.cs
+++ b/src/windows/Atlassian.Bitbucket.UI.Windows/Program.cs
@@ -14,7 +14,7 @@ public static async Task Main(string[] args)
         {
             // Set the session id (sid) for the helper process, to be
             // used when TRACE2 tracing is enabled.
-            SidManager.CreateSid();
+            ProcessManager.CreateSid();
             using (var context = new CommandContext())
             using (var app = new HelperApplication(context))
             {
diff --git a/src/windows/Git-Credential-Manager.UI.Windows/Program.cs b/src/windows/Git-Credential-Manager.UI.Windows/Program.cs
index 9cc6d5c6a..2c7fc3cdb 100644
--- a/src/windows/Git-Credential-Manager.UI.Windows/Program.cs
+++ b/src/windows/Git-Credential-Manager.UI.Windows/Program.cs
@@ -12,7 +12,7 @@ public static async Task Main(string[] args)
         {
             // Set the session id (sid) for the helper process, to be
             // used when TRACE2 tracing is enabled.
-            SidManager.CreateSid();
+            ProcessManager.CreateSid();
             using (var context = new CommandContext())
             using (var app = new HelperApplication(context))
             {
diff --git a/src/windows/GitHub.UI.Windows/Program.cs b/src/windows/GitHub.UI.Windows/Program.cs
index 7a79030fc..0c334c9e0 100644
--- a/src/windows/GitHub.UI.Windows/Program.cs
+++ b/src/windows/GitHub.UI.Windows/Program.cs
@@ -14,7 +14,7 @@ public static async Task Main(string[] args)
         {
             // Set the session id (sid) for the helper process, to be
             // used when TRACE2 tracing is enabled.
-            SidManager.CreateSid();
+            ProcessManager.CreateSid();
             using (var context = new CommandContext())
             using (var app = new HelperApplication(context))
             {
diff --git a/src/windows/GitLab.UI.Windows/Program.cs b/src/windows/GitLab.UI.Windows/Program.cs
index 67bdcfedc..6a7c8ebc3 100644
--- a/src/windows/GitLab.UI.Windows/Program.cs
+++ b/src/windows/GitLab.UI.Windows/Program.cs
@@ -14,7 +14,7 @@ public static async Task Main(string[] args)
         {
             // Set the session id (sid) for the helper process, to be
             // used when TRACE2 tracing is enabled.
-            SidManager.CreateSid();
+            ProcessManager.CreateSid();
             using (var context = new CommandContext())
             using (var app = new HelperApplication(context))
             {

From 59a2692614fb3f1a8afdfeaa03f4d7e38318e648 Mon Sep 17 00:00:00 2001
From: Lessley Dennington <ldennington@github.com>
Date: Thu, 2 Mar 2023 15:30:01 -0700
Subject: [PATCH 4/4] trace2: add performance format target

Add the performance format target for TRACE2 tracing. This change
includes a few notable components:

1. A new GetMessage method to ensure message strings written to normal and
performance targets are not duplicated.
2. A new PerformanceFormatComponent class to track sizing of optional
properties of performance format messages.
3. A BuildSpan method that Trace2Message children use to create
correctly-sized "spans" for optional properties of performance format
messages. A span is a piece of the message beginning with a pipe (|) and
ending just before the next pipe or the end of the message.
4. A BuildTimeSpan method that adjusts spans for long/short times. In
future, when we have events that include performance format string span
components, we will need to add an additional method to handle them.
---
 src/shared/Core.Tests/Trace2Tests.cs |  13 +-
 src/shared/Core/Constants.cs         |   8 +-
 src/shared/Core/ITrace2Writer.cs     |   6 +-
 src/shared/Core/Settings.cs          |   6 +
 src/shared/Core/Trace2.cs            | 240 ++++++++++++++++++++++++---
 5 files changed, 243 insertions(+), 30 deletions(-)

diff --git a/src/shared/Core.Tests/Trace2Tests.cs b/src/shared/Core.Tests/Trace2Tests.cs
index 9816a0d3e..445c177e2 100644
--- a/src/shared/Core.Tests/Trace2Tests.cs
+++ b/src/shared/Core.Tests/Trace2Tests.cs
@@ -1,6 +1,3 @@
-using System;
-using System.Text.RegularExpressions;
-using GitCredentialManager.Tests.Objects;
 using Xunit;
 
 namespace GitCredentialManager.Tests;
@@ -30,4 +27,14 @@ public void TryGetPipeName_Windows_Returns_Expected_Value(string input, string e
         Assert.True(isSuccessful);
         Assert.Matches(actual, expected);
     }
+
+    [Theory]
+    [InlineData(0.013772,    "  0.013772 ")]
+    [InlineData(26.316083,   " 26.316083 ")]
+    [InlineData(100.316083,  "100.316083 ")]
+    public void BuildTimeSpan_Match_Returns_Expected_String(double input, string expected)
+    {
+        var actual = Trace2Message.BuildTimeSpan(input);
+        Assert.Equal(expected, actual);
+    }
 }
diff --git a/src/shared/Core/Constants.cs b/src/shared/Core/Constants.cs
index 617aed645..e5f283b47 100644
--- a/src/shared/Core/Constants.cs
+++ b/src/shared/Core/Constants.cs
@@ -56,6 +56,7 @@ public static class EnvironmentVariables
             public const string GcmAllowWia           = "GCM_ALLOW_WINDOWSAUTH";
             public const string GitTrace2Event        = "GIT_TRACE2_EVENT";
             public const string GitTrace2Normal       = "GIT_TRACE2";
+            public const string GitTrace2Performance  = "GIT_TRACE2_PERF";
 
             /*
              * Unlike other environment variables, these proxy variables are normally lowercase only.
@@ -169,9 +170,10 @@ public static class Remote
 
             public static class Trace2
             {
-                public const string SectionName = "trace2";
-                public const string EventTarget = "eventtarget";
-                public const string NormalTarget = "normaltarget";
+                public const string SectionName       = "trace2";
+                public const string EventTarget       = "eventtarget";
+                public const string NormalTarget      = "normaltarget";
+                public const string PerformanceTarget = "perftarget";
             }
         }
 
diff --git a/src/shared/Core/ITrace2Writer.cs b/src/shared/Core/ITrace2Writer.cs
index fbe1b2297..426c69f1e 100644
--- a/src/shared/Core/ITrace2Writer.cs
+++ b/src/shared/Core/ITrace2Writer.cs
@@ -10,7 +10,8 @@ namespace GitCredentialManager;
 public enum Trace2FormatTarget
 {
     Event,
-    Normal
+    Normal,
+    Performance
 }
 
 public interface ITrace2Writer : IDisposable
@@ -44,6 +45,9 @@ protected string Format(Trace2Message message)
             case Trace2FormatTarget.Normal:
                 sb.Append(message.ToNormalString());
                 break;
+            case Trace2FormatTarget.Performance:
+                sb.Append(message.ToPerformanceString());
+                break;
             default:
                 Console.WriteLine($"warning: unrecognized format target '{_formatTarget}', disabling TRACE2 tracing.");
                 Failed = true;
diff --git a/src/shared/Core/Settings.cs b/src/shared/Core/Settings.cs
index 55069d63b..79935f957 100644
--- a/src/shared/Core/Settings.cs
+++ b/src/shared/Core/Settings.cs
@@ -533,6 +533,12 @@ public Trace2Settings GetTrace2Settings()
                 settings.FormatTargetsAndValues.Add(Trace2FormatTarget.Normal, value);
             }
 
+            if (TryGetSetting(Constants.EnvironmentVariables.GitTrace2Performance, KnownGitCfg.Trace2.SectionName,
+                    Constants.GitConfiguration.Trace2.PerformanceTarget, out value))
+            {
+                settings.FormatTargetsAndValues.Add(Trace2FormatTarget.Performance, value);
+            }
+
             return settings;
         }
 
diff --git a/src/shared/Core/Trace2.cs b/src/shared/Core/Trace2.cs
index ecfd43c61..813ebbf3b 100644
--- a/src/shared/Core/Trace2.cs
+++ b/src/shared/Core/Trace2.cs
@@ -1,10 +1,8 @@
 using System;
-using System.Collections;
 using System.Collections.Generic;
+using System.ComponentModel;
 using System.IO;
 using System.IO.Pipes;
-using System.Linq;
-using System.Runtime.Serialization;
 using System.Text;
 using Newtonsoft.Json;
 using Newtonsoft.Json.Converters;
@@ -42,6 +40,15 @@ public class Trace2Settings
         new Dictionary<Trace2FormatTarget, string>();
 }
 
+public class PerformanceFormatSpan
+{
+    public int Size { get; set; }
+
+    public int BeginPadding { get; set; }
+
+    public int EndPadding { get; set; }
+}
+
 /// <summary>
 /// Represents the application's TRACE2 tracing system.
 /// </summary>
@@ -212,7 +219,8 @@ public void WriteChildStart(DateTimeOffset startTime,
             Id = ++_childProcCounter,
             Classification = processClass,
             UseShell = useShell,
-            Argv = procArgs
+            Argv = procArgs,
+            Depth = ProcessManager.Depth
         });
     }
 
@@ -242,7 +250,8 @@ public void WriteChildExit(
             Id = _childProcCounter,
             Pid = pid,
             Code = code,
-            ElapsedTime = elapsedTime
+            ElapsedTime = elapsedTime,
+            Depth = ProcessManager.Depth
         });
     }
 
@@ -426,8 +435,11 @@ private void WriteMessage(Trace2Message message)
 
 public abstract class Trace2Message
 {
-    protected const string TimeFormat = "yyyy'-'MM'-'dd'T'HH':'mm':'ss'.'ffffff'Z'";
     private const int SourceColumnMaxWidth = 23;
+    private const string NormalPerfTimeFormat = "HH:mm:ss.ffffff";
+
+    protected const string EmptyPerformanceSpan =  "|     |           |           |             ";
+    protected const string TimeFormat = "yyyy'-'MM'-'dd'T'HH':'mm':'ss'.'ffffff'Z'";
 
     [JsonProperty("event", Order = 1)]
     public Trace2Event Event { get; set; }
@@ -449,34 +461,122 @@ public abstract class Trace2Message
     [JsonProperty("line", Order = 6)]
     public int Line { get; set; }
 
+    [JsonProperty("depth", Order = 7)]
+    public int Depth { get; set; }
+
     public abstract string ToJson();
 
     public abstract string ToNormalString();
 
-    protected string BuildNormalString(string message)
+    public abstract string ToPerformanceString();
+
+    protected abstract string BuildPerformanceSpan();
+
+    protected string BuildNormalString()
     {
+        string message = GetEventMessage(Trace2FormatTarget.Normal);
+
         // The normal format uses local time rather than UTC time.
-        string time = Time.ToLocalTime().ToString("HH:mm:ss.ffffff");
+        string time = Time.ToLocalTime().ToString(NormalPerfTimeFormat);
+        string source = GetSource();
 
+        // Git's TRACE2 normal format is:
+        // [<time> SP <filename>:<line> SP+] <event-name> [[SP] <event-message>] LF
+        return $"{time} {source,-33} {Event.ToString().ToSnakeCase()} {message}";
+    }
+
+    protected string BuildPerformanceString()
+    {
+        string message = GetEventMessage(Trace2FormatTarget.Performance);
+
+        // The performance format uses local time rather than UTC time.
+        var time = Time.ToLocalTime().ToString(NormalPerfTimeFormat);
+        var source = GetSource();
+
+        // Git's TRACE2 performance format is:
+        // [<time> SP <filename>:<line> SP+
+        //     BAR SP] d<depth> SP
+        //     BAR SP <thread-name> SP+
+        //     BAR SP <event-name> SP+
+        //     BAR SP [r<repo-id>] SP+
+        //     BAR SP [<t_abs>] SP+
+        //     BAR SP [<t_rel>] SP+
+        //     BAR SP [<category>] SP+
+        //     BAR SP DOTS* <perf-event-message>
+        //     LF
+        return $"{time} {source,-29}| d{Depth} | {Thread,-24} | {Event.ToString().ToSnakeCase(),-12} {BuildPerformanceSpan()} | {message}";
+    }
+
+    protected abstract string GetEventMessage(Trace2FormatTarget formatTarget);
+
+    protected void AddDots(StringBuilder sb)
+    {
+        var dotCount = Depth;
+        while (dotCount > 0)
+        {
+            sb.Append("..");
+            dotCount--;
+        }
+    }
+
+    internal static string BuildTimeSpan(double time)
+    {
+        var timeString = time.ToString("F6");
+        var component = new PerformanceFormatSpan()
+        {
+            Size = 11,
+            BeginPadding = 2,
+            EndPadding = 1
+        };
+        AdjustPadding(component, timeString);
+
+        var beginPadding = new string(' ', component.BeginPadding);
+        var endPadding = new string(' ', component.EndPadding);
+
+        return $"{beginPadding}{timeString}{endPadding}";
+    }
+
+    private string GetSource()
+    {
         // Source column format is file:line
         string source = $"{File.ToLower()}:{Line}";
         if (source.Length > SourceColumnMaxWidth)
         {
-            source = TraceUtils.FormatSource(source, SourceColumnMaxWidth);
+            return TraceUtils.FormatSource(source, SourceColumnMaxWidth);
         }
 
-        // Git's TRACE2 normal format is:
-        // [<time> SP <filename>:<line> SP+] <event-name> [[SP] <event-message>] LF
-        return $"{time} {source,-33} {Event.ToString().ToSnakeCase()} {message}";
+        return source;
+    }
+
+    private static void AdjustPadding(PerformanceFormatSpan span, string data)
+    {
+        var paddingTotal = span.BeginPadding + span.EndPadding;
+        // Size difference between the expected size and the actual size of the data
+        var sizeDifference = span.Size - paddingTotal - data.Length;
+
+        if (sizeDifference < 0)
+        {
+            // Remove all padding for values that take up the entire span
+            if (Math.Abs(sizeDifference) == paddingTotal)
+            {
+                span.BeginPadding = 0;
+                span.EndPadding = 0;
+            }
+            else
+            {
+                // Decrease BeginPadding for large time values that don't occupy entire span
+                span.BeginPadding += sizeDifference;
+            }
+        }
     }
 }
 
 public class VersionMessage : Trace2Message
 {
-    [JsonProperty("evt", Order = 7)]
+    [JsonProperty("evt", Order = 8)]
     public string Evt { get; set; }
 
-    [JsonProperty("exe", Order = 8)]
+    [JsonProperty("exe", Order = 9)]
     public string Exe { get; set; }
 
     public override string ToJson()
@@ -491,16 +591,31 @@ public override string ToJson()
 
     public override string ToNormalString()
     {
-        return BuildNormalString(Exe.ToLower());
+        return BuildNormalString();
+    }
+
+    public override string ToPerformanceString()
+    {
+        return BuildPerformanceString();
+    }
+
+    protected override string BuildPerformanceSpan()
+    {
+        return EmptyPerformanceSpan;
+    }
+
+    protected override string GetEventMessage(Trace2FormatTarget formatTarget)
+    {
+        return Exe.ToLower();
     }
 }
 
 public class StartMessage : Trace2Message
 {
-    [JsonProperty("t_abs", Order = 7)]
+    [JsonProperty("t_abs", Order = 8)]
     public double ElapsedTime { get; set; }
 
-    [JsonProperty("argv", Order = 8)]
+    [JsonProperty("argv", Order = 9)]
     public List<string> Argv { get; set; }
 
     public override string ToJson()
@@ -515,16 +630,31 @@ public override string ToJson()
 
     public override string ToNormalString()
     {
-        return BuildNormalString(string.Join(" ", Argv));
+        return BuildNormalString();
+    }
+
+    public override string ToPerformanceString()
+    {
+        return BuildPerformanceString();
+    }
+
+    protected override string BuildPerformanceSpan()
+    {
+        return $"|     |{BuildTimeSpan(ElapsedTime)}|           |             ";
+    }
+
+    protected override string GetEventMessage(Trace2FormatTarget formatTarget)
+    {
+        return string.Join(" ", Argv);
     }
 }
 
 public class ExitMessage : Trace2Message
 {
-    [JsonProperty("t_abs", Order = 7)]
+    [JsonProperty("t_abs", Order = 8)]
     public double ElapsedTime { get; set; }
 
-    [JsonProperty("code", Order = 8)]
+    [JsonProperty("code", Order = 9)]
     public int Code { get; set; }
 
     public override string ToJson()
@@ -539,7 +669,22 @@ public override string ToJson()
 
     public override string ToNormalString()
     {
-        return BuildNormalString($"elapsed:{ElapsedTime} code:{Code}");
+        return BuildNormalString();
+    }
+
+    public override string ToPerformanceString()
+    {
+        return BuildPerformanceString();
+    }
+
+    protected override string BuildPerformanceSpan()
+    {
+        return $"|     |{BuildTimeSpan(ElapsedTime)}|           |             ";
+    }
+
+    protected override string GetEventMessage(Trace2FormatTarget formatTarget)
+    {
+        return $"elapsed:{ElapsedTime} code:{Code}";
     }
 }
 
@@ -569,7 +714,32 @@ public override string ToJson()
 
     public override string ToNormalString()
     {
-        return BuildNormalString($"[{Id}] {string.Join(" ", Argv)}");
+        return BuildNormalString();
+    }
+
+    public override string ToPerformanceString()
+    {
+        return BuildPerformanceString();
+    }
+
+    protected override string BuildPerformanceSpan()
+    {
+        return EmptyPerformanceSpan;
+    }
+
+    protected override string GetEventMessage(Trace2FormatTarget formatTarget)
+    {
+        var sb = new StringBuilder();
+        AddDots(sb);
+
+        if (formatTarget == Trace2FormatTarget.Performance)
+            sb.Append($"[ch{Id}]");
+        else
+            sb.Append($"[{Id}]");
+
+        sb.Append($" {string.Join(" ", Argv)}");
+
+        return sb.ToString();
     }
 }
 
@@ -599,6 +769,30 @@ public override string ToJson()
 
     public override string ToNormalString()
     {
-        return BuildNormalString($"[{Id}] pid:{Pid} code:{Code} elapsed:{ElapsedTime}");
+        return BuildNormalString();
+    }
+
+    public override string ToPerformanceString()
+    {
+        return BuildPerformanceString();
+    }
+
+    protected override string BuildPerformanceSpan()
+    {
+        return $"|     |{BuildTimeSpan(ElapsedTime)}|           |             ";
+    }
+
+    protected override string GetEventMessage(Trace2FormatTarget formatTarget)
+    {
+        var sb = new StringBuilder();
+        AddDots(sb);
+
+        if (formatTarget == Trace2FormatTarget.Performance)
+            sb.Append($"[ch{Id}]");
+        else
+            sb.Append($"[{Id}]");
+
+        sb.Append($" pid:{Pid} code:{Code} elapsed:{ElapsedTime}");
+        return sb.ToString();
     }
 }