Moving EntityCache files to separate directory

EntityCache/Module.cs

@@ -7,37 +7,26 @@ using System;
 using System.Collections.Generic;
 using System.Threading.Tasks;
 
-namespace Noikoio.RegexBot.Module.EntityCache
+namespace Noikoio.RegexBot.EntityCache
 {
     /// <summary>
-    /// Caches information regarding all known guilds, channels, and users.
+    /// Bot module portion of the entity cache. Caches information regarding all known guilds, channels, and users.
     /// The function of this module should be transparent to the user, and thus no configuration is needed.
     /// This module should be initialized BEFORE any other modules that make use of guild and user cache.
     /// </summary>
-    class EntityCache : BotModule
+    class Module : BotModule
     {
-        /*
-         * Future plans:
-         * Have this, or something connected to this class, be accessible throughout the bot.
-         * 
-         * There should be a system that holds a small in-memory cache of users (as EntityCache objects)
-         * for quick lookups by other parts of the bot.
-         * Without this system, we'll be having future bot features constantly querying the database
-         * on their own to look up entity cache records, which (among other things) could result in
-         * a race conditions where an event becomes aware of a user before it has been recorded.
-         */
-
         private readonly DatabaseConfig _db;
 
         public override string Name => nameof(EntityCache);
 
-        public EntityCache(DiscordSocketClient client) : base(client)
+        public Module(DiscordSocketClient client) : base(client)
         {
             _db = RegexBot.Config.Database;
 
             if (_db.Available)
             {
-                Sql.CreateCacheTables();
+                SqlHelper.CreateCacheTables();
 
                 client.GuildAvailable += Client_GuildAvailable;
                 client.GuildUpdated += Client_GuildUpdated;
@@ -54,7 +43,7 @@ namespace Noikoio.RegexBot.Module.EntityCache
 
         #region Event handling
         // Guild and guild member information has become available.
-        // This is a very expensive operation, when joining larger guilds for the first time.
+        // This is a very expensive operation, especially when joining larger guilds.
         private async Task Client_GuildAvailable(SocketGuild arg)
         {
             await Task.Run(async () =>

EntityCache/SqlHelper.cs

@@ -0,0 +1,98 @@
+using Npgsql;
+using System;
+using System.Collections.Generic;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Noikoio.RegexBot.EntityCache
+{
+    /// <summary>
+    /// Helper methods for database operations.
+    /// </summary>
+    static class SqlHelper
+    {
+        public const string TableGuild = "cache_guild";
+        public const string TableTextChannel = "cache_textchannel";
+        public const string TableUser = "cache_users";
+
+        private static async Task<NpgsqlConnection> OpenDB()
+        {
+            if (!RegexBot.Config.Database.Available) return null;
+            return await RegexBot.Config.Database.GetOpenConnectionAsync();
+        }
+
+        public static async Task CreateCacheTables()
+        {
+            var db = await OpenDB();
+            if (db == null) return;
+            using (db)
+            {
+                // Guild cache
+                using (var c = db.CreateCommand())
+                {
+                    c.CommandText = "CREATE TABLE IF NOT EXISTS " + TableGuild + " ("
+                        + "guild_id bigint primary key, "
+                        + "cache_date timestamptz not null, "
+                        + "current_name text not null, "
+                        + "display_name text null"
+                        + ")";
+                    await c.ExecuteNonQueryAsync();
+                }
+                // May not require other indexes. Add here if they become necessary.
+
+                // Text channel cache
+                using (var c = db.CreateCommand())
+                {
+                    c.CommandText = "CREATE TABLE IF NOT EXISTS " + TableTextChannel + " ("
+                        + "channel_id bigint not null primary key, "
+                        + $"guild_id bigint not null references {TableGuild}, "
+                        + "cache_date timestamptz not null, "
+                        + "name text not null";
+                    await c.ExecuteNonQueryAsync();
+                }
+                // As of the time of this commit, Discord doesn't allow any uppercase characters
+                // in channel names. No lowercase name index needed.
+
+                // User cache
+                using (var c = db.CreateCommand())
+                {
+                    c.CommandText = "CREATE TABLE IF NOT EXISTS " + TableUser + " ("
+                        + "user_id bigint not null, "
+                        + $"guild_id bigint not null references {TableGuild}, "
+                        + "cache_date timestamptz not null, "
+                        + "username text not null, "
+                        + "discriminator text not null, "
+                        + "nickname text null, "
+                        + "avatar_url text null"
+                        + ")";
+                    await c.ExecuteNonQueryAsync();
+                }
+                using (var c = db.CreateCommand())
+                {
+                    // guild_id is a foreign key, and also one half of the primary key here
+                    c.CommandText = "CREATE UNIQUE INDEX IF NOT EXISTS "
+                        + $"{TableUser}_ck_idx on {TableUser} (user_id, guild_id)";
+                    await c.ExecuteNonQueryAsync();
+                }
+                using (var c = db.CreateCommand())
+                {
+                    c.CommandText = "CREATE INDEX IF NOT EXISTS "
+                        + $"{TableUser}_usersearch_idx on {TableUser} LOWER(username)";
+                    await c.ExecuteNonQueryAsync();
+                }
+            }
+        }
+
+        #region Insertions and updates
+        static async Task UpdateGuild()
+        {
+            var db = await OpenDB();
+            if (db == null) return;
+            using (db)
+            {
+
+            }
+        }
+        #endregion
+    }
+}

Module/EntityCache/Sql.cs

@@ -1,56 +0,0 @@
-using Npgsql;
-using System;
-using System.Collections.Generic;
-using System.Text;
-
-namespace Noikoio.RegexBot.Module.EntityCache
-{
-    /// <summary>
-    /// Contains common constants and static methods for cache access.
-    /// </summary>
-    class Sql
-    {
-        public const string TableGuild = "cache_guild";
-        public const string TableUser = "cache_users";
-
-        private static NpgsqlConnection OpenDB() =>
-            RegexBot.Config.Database.GetOpenConnectionAsync().GetAwaiter().GetResult();
-
-        public static void CreateCacheTables()
-        {
-            using (var db = OpenDB())
-            {
-                using (var c = db.CreateCommand())
-                {
-                    c.CommandText = "CREATE TABLE IF NOT EXISTS " + TableGuild + "("
-                        + "guild_id bigint primary key, "
-                        + "current_name text not null, "
-                        + "display_name text null"
-                        + ")";
-                    c.ExecuteNonQuery();
-                }
-
-                using (var c = db.CreateCommand())
-                {
-                    c.CommandText = "CREATE TABLE IF NOT EXISTS " + TableUser + "("
-                        + "user_id bigint not null, "
-                        + $"guild_id bigint not null references {TableGuild}, "
-                        + "cache_date timestamptz not null, "
-                        + "username text not null, "
-                        + "discriminator text not null, "
-                        + "nickname text null, "
-                        + "avatar_url text null"
-                        + ")";
-                    c.ExecuteNonQuery();
-                }
-                using (var c = db.CreateCommand())
-                {
-                    c.CommandText = "CREATE UNIQUE INDEX IF NOT EXISTS "
-                        + $"{TableUser}_idx on {TableUser} (user_id, guild_id)";
-                    c.ExecuteNonQuery();
-                }
-                // TODO create indexes for string-based queries
-            }
-        }
-    }
-}

RegexBot.cs

@@ -48,7 +48,7 @@ namespace Noikoio.RegexBot
                 new Module.AutoMod.AutoMod(_client),
                 new Module.ModTools.ModTools(_client),
                 new Module.AutoRespond.AutoRespond(_client),
-                new Module.EntityCache.EntityCache(_client) // EntityCache goes before anything else that uses its data
+                new EntityCache.Module(_client) // EntityCache goes before anything else that uses its data
             };
             var dlog = Logger.GetLogger("Discord.Net");
             _client.Log += async (arg) =>