TwitchIrcMessageHighLevelDeconstructionBenchmark.cs

using System;
using System.Text.RegularExpressions;
using BenchmarkDotNet.Attributes;

namespace CatCoreBenchmarkSandbox.Benchmarks.TwitchIRCMessageDeconstruction
{
	[MemoryDiagnoser]
	[CategoriesColumn, AllStatisticsColumn, BaselineColumn, MinColumn, Q1Column, MeanColumn, Q3Column, MaxColumn, MedianColumn]
	public class TwitchIrcMessageHighLevelDeconstructionBenchmark
	{
		private readonly Regex _twitchMessageRegex =
			new Regex(
				@"^(?:@(?<Tags>[^\r\n ]*) +|())(?::(?<HostName>[^\r\n ]+) +|())(?<MessageType>[^\r\n ]+)(?: +(?<ChannelName>[^:\r\n ]+[^\r\n ]*(?: +[^:\r\n ]+[^\r\n ]*)*)|())?(?: +:(?<Message>[^\r\n]*)| +())?[\r\n]*$",
				RegexOptions.Compiled);

		[Params(
			":tmi.twitch.tv 376 realeris :>",
			":realeris!realeris@realeris.tmi.twitch.tv JOIN #realeris",
			":realeris.tmi.twitch.tv 353 realeris = #realeris :realeris",
			":realeris.tmi.twitch.tv 366 realeris #realeris :End of /NAMES list",
			":tmi.twitch.tv CAP * ACK :twitch.tv/tags twitch.tv/commands twitch.tv/membership",
			"@badge-info=subscriber/1;badges=broadcaster/1,subscriber/0;client-nonce=1ef9899702c12a2081fa33899d7e8465;color=#FF69B4;display-name=RealEris;emotes=;flags=;id=b4595e1c-dd1b-4e45-b7df-a3403c945ad6;mod=0;room-id=405499635;subscriber=1;tmi-sent-ts=1614390981294;turbo=0;user-id=405499635;user-type= :realeris!realeris@realeris.tmi.twitch.tv PRIVMSG #realeris :Heya",
			"@badge-info=founder/13;badges=moderator/1,founder/0,bits/1000;client-nonce=05e5fe0b80aadc4c5035303b99d6762a;color=#DAA520;display-name=Scarapter;emotes=;flags=;id=7317d5aa-38ae-4191-88d7-d4d54a3c27bc;mod=1;room-id=62975335;subscriber=0;tmi-sent-ts=1617644034348;turbo=0;user-id=51591450;user-type=mod :scarapter!scarapter@scarapter.tmi.twitch.tv PRIVMSG #lnterz :i definitely dont miss the mass of random charging ports that existed",
			"@badge-info=;badges=;color=;display-name=bonkeybob;emotes=;flags=;id=108b80a1-7829-4879-86cc-953c3a6b122b;mod=0;room-id=62975335;subscriber=0;tmi-sent-ts=1617644112658;turbo=0;user-id=549616012;user-type= :bonkeybob!bonkeybob@bonkeybob.tmi.twitch.tv PRIVMSG #lnterz :The phrase “it’s just a game” is such a weak mindset. You are ok with what happened, losing, imperfection of a craft. When you stop getting angry after losing, you’ve lost twice.   There’s always something to learn, and always room for improvement, never settle.",
			"@badge-info=subscriber/1;badges=broadcaster/1,subscriber/0;client-nonce=1ef9899702c12a2081fa33899d7e8465;color=#FF69B4;display-name=RealEris;emotes=;flags=;id=b4595e1c-dd1b-4e45-b7df-a3403c945ad6;mod=0;room-id=405499635;subscriber=1;tmi-sent-ts=1614390981294;turbo=0;user-id=405499635;user-type= :realeris!realeris@realeris.tmi.twitch.tv PRIVMSG #realeris :Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop p")]
		public string IrcMessage = null!;

		[Benchmark(Baseline = true)]
		public void RegexBenchmark()
		{
			var match = _twitchMessageRegex.Match(IrcMessage);

			var tags = match.Groups["Tags"].Success ? match.Groups["Tags"].Value : null;
			var userName = match.Groups["HostName"].Success ? match.Groups["HostName"].Value.Split('!')[0] : null;
			var messageType = match.Groups["MessageType"].Value;
			var channelName = match.Groups["ChannelName"].Success ? match.Groups["ChannelName"].Value.Trim('#') : null;
			var message = match.Groups["Message"].Success ? match.Groups["Message"].Value : null;
		}

		[Benchmark]
		// ReSharper disable once CognitiveComplexity
		public void SpanDissectionBenchmark()
		{
			// Null-ing this here as I can't do that in the method signature
			string? tags = null;
			string? prefix = null;
			string commandType;
			string? channelName = null;
			string? message = null;

			// Twitch IRC Message spec
			// https://ircv3.net/specs/extensions/message-tags

			var position = 0;
			var nextSpacePosition = 0;

			var messageAsSpan = IrcMessage.AsSpan();

			void SkipToNextNonSpaceCharacter(ref ReadOnlySpan<char> msg)
			{
				while (position < msg.Length && msg[position] == ' ')
				{
					position++;
				}
			}

			// Check for message tags
			if (messageAsSpan[0] == '@')
			{
				nextSpacePosition = messageAsSpan.IndexOf(' ');
				if (nextSpacePosition == -1)
				{
					throw new Exception("Invalid IRC Message");
				}

				tags = messageAsSpan.Slice(1, nextSpacePosition - 1).ToString();

				position = nextSpacePosition + 1;
				SkipToNextNonSpaceCharacter(ref messageAsSpan);
				messageAsSpan = messageAsSpan.Slice(position);
				position = 0;
			}


			// Handle prefix
			if (messageAsSpan[position] == ':')
			{
				nextSpacePosition = messageAsSpan.IndexOf(' ');
				if (nextSpacePosition == -1)
				{
					throw new Exception("Invalid IRC Message");
				}

				prefix = messageAsSpan.Slice(1, (nextSpacePosition) - 1).ToString();

				position = nextSpacePosition + 1;
				SkipToNextNonSpaceCharacter(ref messageAsSpan);
				messageAsSpan = messageAsSpan.Slice(position);
				position = 0;
			}


			// Handle MessageType
			nextSpacePosition = messageAsSpan.IndexOf(' ');
			if (nextSpacePosition == -1)
			{
				if (messageAsSpan.Length > position)
				{
					commandType = messageAsSpan.ToString();
					return;
				}
			}

			commandType = messageAsSpan.Slice(0, nextSpacePosition).ToString();

			position = nextSpacePosition + 1;
			SkipToNextNonSpaceCharacter(ref messageAsSpan);
			messageAsSpan = messageAsSpan.Slice(position);
			position = 0;


			// Handle channelname and message
			var handledInLoop = false;
			while (position < messageAsSpan.Length)
			{
				if (messageAsSpan[position] == ':')
				{
					handledInLoop = true;

					// Handle message (extracting this first as we're going to do a lookback in order to determine the previous part)
					message = messageAsSpan.Slice(position + 1).ToString();

					// Handle everything before the colon as the channelname parameter
					while (--position > 0 && messageAsSpan[position] == ' ')
					{
					}

					if (position > 0)
					{
						var offset = messageAsSpan[0] == '#' ? 1 : 0;
						channelName = messageAsSpan.Slice(offset, position + 1 - offset).ToString();
					}

					break;
				}

				position++;
			}

			if (handledInLoop)
			{
				return;
			}

			if (messageAsSpan[0] == '#')
			{
				messageAsSpan = messageAsSpan.Slice(1);
			}

			channelName = messageAsSpan.ToString();
		}
	}
}