move database utils to Database/Utils, create DatabaseMigrator

PluralKit.Core/Database/Database.cs

@@ -18,21 +18,21 @@ namespace PluralKit.Core
 {
     internal class Database: IDatabase
     {
-        private const string RootPath = "PluralKit.Core.Database"; // "resource path" root for SQL files
-        private const int TargetSchemaVersion = 14;
         
         private readonly CoreConfig _config;
         private readonly ILogger _logger;
         private readonly IMetrics _metrics;
         private readonly DbConnectionCountHolder _countHolder;
+        private readonly DatabaseMigrator _migrator;
         private readonly string _connectionString;
 
         public Database(CoreConfig config, DbConnectionCountHolder countHolder, ILogger logger,
-                        IMetrics metrics)
+                        IMetrics metrics, DatabaseMigrator migrator)
         {
             _config = config;
             _countHolder = countHolder;
             _metrics = metrics;
+            _migrator = migrator;
             _logger = logger.ForContext<Database>();
             
             _connectionString = new NpgsqlConnectionStringBuilder(_config.Database)
@@ -92,65 +92,8 @@ namespace PluralKit.Core
         
         public async Task ApplyMigrations()
         {
-            // Run everything in a transaction
+            using var conn = await Obtain();
-            await using var conn = await Obtain();
+            await _migrator.ApplyMigrations(conn);
-            await using var tx = await conn.BeginTransactionAsync();
-            
-            // Before applying migrations, clean out views/functions to prevent type errors
-            await ExecuteSqlFile($"{RootPath}.clean.sql", conn, tx);
-
-            // Apply all migrations between the current database version and the target version
-            await ApplyMigrations(conn, tx);
-
-            // Now, reapply views/functions (we deleted them above, no need to worry about conflicts)
-            await ExecuteSqlFile($"{RootPath}.Views.views.sql", conn, tx);
-            await ExecuteSqlFile($"{RootPath}.Functions.functions.sql", conn, tx);
-
-            // Finally, commit tx
-            await tx.CommitAsync();
-        }
-        
-        private async Task ApplyMigrations(IPKConnection conn, IDbTransaction tx)
-        {
-            var currentVersion = await GetCurrentDatabaseVersion(conn);
-            _logger.Information("Current schema version: {CurrentVersion}", currentVersion);
-            for (var migration = currentVersion + 1; migration <= TargetSchemaVersion; migration++)
-            {
-                _logger.Information("Applying schema migration {MigrationId}", migration);
-                await ExecuteSqlFile($"{RootPath}.Migrations.{migration}.sql", conn, tx);
-            }
-        }
-        
-        private async Task ExecuteSqlFile(string resourceName, IPKConnection conn, IDbTransaction tx = null)
-        {
-            await using var stream = typeof(Database).Assembly.GetManifestResourceStream(resourceName);
-            if (stream == null) throw new ArgumentException($"Invalid resource name  '{resourceName}'");
-
-            using var reader = new StreamReader(stream);
-            var query = await reader.ReadToEndAsync();
-
-            await conn.ExecuteAsync(query, transaction: tx);
-
-            // If the above creates new enum/composite types, we must tell Npgsql to reload the internal type caches
-            // This will propagate to every other connection as well, since it marks the global type mapper collection dirty.
-            ((PKConnection) conn).ReloadTypes();
-        }
-
-        private async Task<int> GetCurrentDatabaseVersion(IPKConnection conn)
-        {
-            // First, check if the "info" table exists (it may not, if this is a *really* old database)
-            var hasInfoTable =
-                await conn.QuerySingleOrDefaultAsync<int>(
-                    "select count(*) from information_schema.tables where table_name = 'info'") == 1;
-
-            // If we have the table, read the schema version
-            if (hasInfoTable)
-                return await conn.QuerySingleOrDefaultAsync<int>("select schema_version from info");
-
-            // If not, we return version "-1"
-            // This means migration 0 will get executed, getting us into a consistent state
-            // Then, migration 1 gets executed, which creates the info table and sets version to 1
-            return -1;
         }
 
         private class PassthroughTypeHandler<T>: SqlMapper.TypeHandler<T>

PluralKit.Core/Database/Utils/DatabaseMigrator.cs

@@ -0,0 +1,85 @@
+using System;
+using System.Data;
+using System.IO;
+using System.Threading.Tasks;
+
+using Dapper;
+
+using Serilog;
+
+namespace PluralKit.Core
+{
+    internal class DatabaseMigrator
+    {
+        private const string RootPath = "PluralKit.Core.Database"; // "resource path" root for SQL files
+        private const int TargetSchemaVersion = 14;
+        private readonly ILogger _logger;
+
+        public DatabaseMigrator(ILogger logger)
+        {
+            _logger = logger;
+        }
+
+        public async Task ApplyMigrations(IPKConnection conn)
+        {
+            // Run everything in a transaction
+            await using var tx = await conn.BeginTransactionAsync();
+
+            // Before applying migrations, clean out views/functions to prevent type errors
+            await ExecuteSqlFile($"{RootPath}.clean.sql", conn, tx);
+
+            // Apply all migrations between the current database version and the target version
+            await ApplyMigrations(conn, tx);
+
+            // Now, reapply views/functions (we deleted them above, no need to worry about conflicts)
+            await ExecuteSqlFile($"{RootPath}.Views.views.sql", conn, tx);
+            await ExecuteSqlFile($"{RootPath}.Functions.functions.sql", conn, tx);
+
+            // Finally, commit tx
+            await tx.CommitAsync();
+        }
+
+        private async Task ApplyMigrations(IPKConnection conn, IDbTransaction tx)
+        {
+            var currentVersion = await GetCurrentDatabaseVersion(conn);
+            _logger.Information("Current schema version: {CurrentVersion}", currentVersion);
+            for (var migration = currentVersion + 1; migration <= TargetSchemaVersion; migration++)
+            {
+                _logger.Information("Applying schema migration {MigrationId}", migration);
+                await ExecuteSqlFile($"{RootPath}.Migrations.{migration}.sql", conn, tx);
+            }
+        }
+
+        private async Task ExecuteSqlFile(string resourceName, IPKConnection conn, IDbTransaction tx = null)
+        {
+            await using var stream = typeof(Database).Assembly.GetManifestResourceStream(resourceName);
+            if (stream == null) throw new ArgumentException($"Invalid resource name  '{resourceName}'");
+
+            using var reader = new StreamReader(stream);
+            var query = await reader.ReadToEndAsync();
+
+            await conn.ExecuteAsync(query, transaction: tx);
+
+            // If the above creates new enum/composite types, we must tell Npgsql to reload the internal type caches
+            // This will propagate to every other connection as well, since it marks the global type mapper collection dirty.
+            ((PKConnection) conn).ReloadTypes();
+        }
+
+        private async Task<int> GetCurrentDatabaseVersion(IPKConnection conn)
+        {
+            // First, check if the "info" table exists (it may not, if this is a *really* old database)
+            var hasInfoTable =
+                await conn.QuerySingleOrDefaultAsync<int>(
+                    "select count(*) from information_schema.tables where table_name = 'info'") == 1;
+
+            // If we have the table, read the schema version
+            if (hasInfoTable)
+                return await conn.QuerySingleOrDefaultAsync<int>("select schema_version from info");
+
+            // If not, we return version "-1"
+            // This means migration 0 will get executed, getting us into a consistent state
+            // Then, migration 1 gets executed, which creates the info table and sets version to 1
+            return -1;
+        }
+    }
+}

PluralKit.Core/Modules/DataStoreModule.cs

@@ -10,6 +10,7 @@ namespace PluralKit.Core
         protected override void Load(ContainerBuilder builder)
         {
             builder.RegisterType<DbConnectionCountHolder>().SingleInstance();
+            builder.RegisterType<DatabaseMigrator>().SingleInstance();
             builder.RegisterType<Database>().As<IDatabase>().SingleInstance();
             builder.RegisterType<ModelRepository>().AsSelf().SingleInstance();