In preparation for the next two posts, I want to offer a cute IDisposable that applies a Stopwatch to whatever body of code it encloses. It is not as robust as it could be (see the TODOs), but here it is for what it's worth.

/// <summary>
/// Times the execution of a body of code.
/// Timing begins when this object is constructed,
/// and ends when it is Disposed.
/// </summary>
public sealed class CodeTimer : IDisposable
{
    // Tracks the indent level through nested CodeTimers.
    // TODO - Track the indent level by thread ID.
    static int _indentLevelStatic;

    readonly string _description;
    readonly Stopwatch _stopwatch = new Stopwatch();
    readonly int _indentLevel;

    // Actions that can write the results of this timer.
    // TODO - Dependency-inject these Actions.
    readonly Action<int, string> _writeStartingMessage = (indentLevel, descr) =>
        Console.WriteLine(@"{0}{1}: Starting.", new String(' ', indentLevel * 4), descr);
    readonly Action<int, string, TimeSpan> _writeFinishedMessage = (indentLevel, descr, elapsed) =>
        Console.WriteLine(@"{0}{1}: Finished in {2:s\.ffff} seconds.", new String(' ', indentLevel * 4), descr, elapsed);

    /// <summary>
    /// Construct a CodeTimer.
    /// </summary>
    /// <param name="description">Describes the code being timed.</param>
    public CodeTimer(string description)
    {
        _description = description;
        _indentLevel = _indentLevelStatic++;
        _writeStartingMessage(_indentLevel, _description);
        _stopwatch.Start();
    }

    /// <summary>
    /// Disposes the object and writes the results.
    /// </summary>
    public void Dispose()
    {
        _stopwatch.Stop();
        _writeFinishedMessage(_indentLevel, _description, _stopwatch.Elapsed);
        --_indentLevelStatic;
    }
}

In the next post, you'll see the CodeTimer at work.