Converted Chapter2 to C#

c#/Chapter1/Chapter1.cs

@@ -0,0 +1,132 @@
+// See https://aka.ms/new-console-template for more information
+
+using System.Diagnostics;
+using StackExchange.Redis;
+
+namespace Chapter1;
+
+public class Chapter1 {
+	private const int OneWeekInSeconds = 7 * 86400;
+	private const int VoteScore = 432;
+	private const int ArticlesPerPage = 25;
+
+	public static void Main() {
+		new Chapter1().run();
+	}
+
+	private void run() {
+		var con = ConnectionMultiplexer.Connect("localhost");
+		var db = con.GetDatabase();
+
+		var articleId = postArticle(db, "username", "A title", "https://www.google.com");
+		Console.WriteLine("We posted a new article with id: " + articleId);
+		Console.WriteLine("Its HASH looks like:");
+		var articleData = db.HashGetAll("article:" + articleId);
+
+		foreach (var entry in articleData) {
+			Console.WriteLine(" " + entry.Name + ": " + entry.Value);
+		}
+
+		Console.WriteLine();
+
+		articleVote(db, "other_user", "article:" + articleId);
+		var votes = (int?)db.HashGet("article:" + articleId, "votes") ?? 0;
+		Console.WriteLine("We voted for the article, it now has votes: " + votes);
+		Debug.Assert(votes > 1, "Vote count is less than 1");
+
+		Console.WriteLine("The currently highest-scoring articles are:");
+		var articles = getArticles(db, 1);
+		printArticles(articles);
+		Debug.Assert(articles.Count >= 1, "Article count is less than 1");
+
+		addGroups(db, articleId, new[]{"new-group"});
+		Console.WriteLine("We added the article to a new group, other articles include:");
+		var groupArticles = getGroupArticles(db, "new-group", 1);
+		printArticles(groupArticles);
+		Debug.Assert(groupArticles.Count >= 1, "Article group count is less than 1");
+	}
+
+	private string postArticle(IDatabase db, string user, string title, string link) {
+		var articleId = db.StringIncrement("article:").ToString();
+
+		var voted = "voted:" + articleId;
+		db.SetAdd(voted, user);
+		db.KeyExpire(voted, TimeSpan.FromSeconds(OneWeekInSeconds));
+
+		var now = DateTimeOffset.Now.ToUnixTimeSeconds();
+		var article = "article:" + articleId;
+		var articleData = new List<HashEntry> {
+			new("title", title),
+			new("link", link),
+			new("user", user),
+			new("now", now.ToString()),
+			new("votes", "1")
+		};
+		db.HashSet(article, articleData.ToArray());
+
+		db.SortedSetAdd("score:", article, now + VoteScore);
+		db.SortedSetAdd("time:", article, now);
+
+		return articleId;
+	}
+
+	private void articleVote(IDatabase db, string user, string article) {
+		var cutoff = DateTimeOffset.Now.ToUnixTimeSeconds() - OneWeekInSeconds;
+		var articleScore = db.SortedSetScore("time:", article) ?? 0;
+
+		if (articleScore < cutoff) {
+			return;
+		}
+
+		var articleId = article.Substring(article.IndexOf(':') + 1);
+
+		if (db.SetAdd("voted:" + articleId, user)) {
+			db.SortedSetIncrement("score:", article, VoteScore);
+			db.HashIncrement(article, "votes");
+		}
+	}
+
+	private List<Dictionary<RedisValue, RedisValue>>
+		getArticles(IDatabase db, int page, string order = "score:") {
+		var start = (page - 1) * ArticlesPerPage;
+		var end = start + ArticlesPerPage - 1;
+
+		var ids = db.SortedSetRangeByRank(order, start, end, order: Order.Descending);
+		var articles = new List<Dictionary<RedisValue, RedisValue>>();
+
+		foreach (var id in ids) {
+			var articleData = db.HashGetAll(id.ToString())
+				.ToDictionary(c => c.Name, c => c.Value);
+			articleData["id"] = id;
+			articles.Add(articleData);
+		}
+
+		return articles;
+	}
+
+	private void printArticles(List<Dictionary<RedisValue, RedisValue>> articles) {
+		foreach (var article in articles) {
+			Console.WriteLine(" id: " + article["id"]);
+			foreach (var articleData in article.Where(c => !c.Key.Equals("id"))) {
+				Console.WriteLine("    " + articleData.Key + ": " + articleData.Value);
+			}
+		}
+	}
+
+	private void addGroups(IDatabase db, string articleId, string[] toAdd) {
+		var article = "article:" + articleId;
+		foreach (var group in toAdd) {
+			db.SetAdd("group:" + group, article);
+		}
+	}
+
+	private List<Dictionary<RedisValue, RedisValue>> getGroupArticles(IDatabase db, string group, int page, string order = "score:") {
+		var key = order + group;
+		if (!db.KeyExists(key)) {
+			db.SortedSetCombineAndStore(SetOperation.Intersect, key, "group:" + group, order, aggregate: Aggregate.Max);
+			db.KeyExpire(key, TimeSpan.FromSeconds(60));
+		}
+
+		return getArticles(db, page, key);
+	}
+}

c#/Chapter1/Chapter1.csproj

@@ -0,0 +1,14 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <OutputType>Exe</OutputType>
+        <TargetFramework>net6.0</TargetFramework>
+        <ImplicitUsings>enable</ImplicitUsings>
+        <Nullable>enable</Nullable>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <PackageReference Include="StackExchange.Redis" Version="2.6.90" />
+    </ItemGroup>
+
+</Project>

c#/Chapter1/Chapter1.sln

@@ -0,0 +1,16 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Chapter1", "Chapter1.csproj", "{F01C7220-1D82-4691-8EB2-DB79842BEC82}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{F01C7220-1D82-4691-8EB2-DB79842BEC82}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{F01C7220-1D82-4691-8EB2-DB79842BEC82}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{F01C7220-1D82-4691-8EB2-DB79842BEC82}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{F01C7220-1D82-4691-8EB2-DB79842BEC82}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+EndGlobal

c#/Chapter2/CacheRowsThread.cs

@@ -0,0 +1,63 @@
+using StackExchange.Redis;
+using System.Text.Json;
+
+namespace Chapter2;
+
+public class CacheRowsThread {
+	private readonly IDatabase _db;
+	private bool _quit;
+	private readonly Thread _thread;
+
+	public CacheRowsThread(IDatabase db) {
+		_db = db;
+		_thread = new Thread(run);
+		_quit = false;
+	}
+
+	public void Start() {
+		_thread.Start();
+	}
+
+	public void Quit() {
+		_quit = true;
+	}
+
+	public bool IsAlive() {
+		return _thread.IsAlive;
+	}
+
+	private void run() {
+		while (!_quit) {
+			var range = _db.SortedSetRangeByRankWithScores("schedule:", 0, 0);
+			var enumerator = range.GetEnumerator();
+			var next = (SortedSetEntry?)(enumerator.MoveNext() ? enumerator.Current : null);
+			var now = DateTimeOffset.UtcNow.ToUnixTimeSeconds();
+			if (next == null || next.Value.Score > now) {
+				try {
+					Thread.Sleep(50);
+				} catch (Exception ex) {
+					Console.WriteLine("error at thread:" + ex);
+				}
+
+				continue;
+			}
+
+			var rowId = next.Value.Element.ToString();
+			var delay = _db.SortedSetScore("delay:", rowId) ?? 0;
+			if (delay <= 0) {
+				_db.SortedSetRemove("delay:", rowId);
+				_db.SortedSetRemove("schedule:", rowId);
+				_db.KeyDelete("inv:" + rowId);
+				continue;
+			}
+
+			var row = new Inventory(rowId);
+			if (row == null) {
+				throw new ArgumentNullException(nameof(row));
+			}
+
+			_db.SortedSetAdd("schedule:", rowId, now + delay);
+			_db.StringSet("inv:" + rowId, JsonSerializer.Serialize(row));
+		}
+	}
+}