app/Desktop/Main/Pages/DebugPageModel.cs

@@ -10,9 +10,8 @@ using DHT.Server;
 using DHT.Server.Data;
 using DHT.Server.Service;
 
-namespace DHT.Desktop.Main.Pages;
+namespace DHT.Desktop.Main.Pages {
-
+	sealed class DebugPageModel {
-sealed class DebugPageModel {
 		public string GenerateChannels { get; set; } = "0";
 		public string GenerateUsers { get; set; } = "0";
 		public string GenerateMessages { get; set; } = "0";
@@ -159,15 +158,16 @@ sealed class DebugPageModel {
 			int wordCount = 1 + (int) Math.Floor(maxWords * Math.Pow(rand.NextDouble(), 3));
 			return string.Join(' ', Enumerable.Range(0, wordCount).Select(_ => RandomWords[rand.Next(RandomWords.Length)]));
 		}
+	}
 }
 #else
-namespace DHT.Desktop.Main.Pages;
+namespace DHT.Desktop.Main.Pages {
-
+	sealed class DebugPageModel {
-sealed class DebugPageModel {
 		public string GenerateChannels { get; set; } = "0";
 		public string GenerateUsers { get; set; } = "0";
 		public string GenerateMessages { get; set; } = "0";
 
 		public void OnClickAddRandomDataToDatabase() {}
+	}
 }
 #endif

app/Server/Data/DownloadWithData.cs

@@ -0,0 +1,3 @@
+namespace DHT.Server.Data;
+
+public readonly record struct DownloadWithData(Download Download, byte[]? Data);

app/Server/Database/DatabaseExtensions.cs

@@ -26,9 +26,7 @@ public static class DatabaseExtensions {
 		await target.Messages.Add(batchedMessages);
 
 		await foreach (var download in source.Downloads.Get()) {
-			if (download.Status != DownloadStatus.Success || !await source.Downloads.GetDownloadData(download.NormalizedUrl, stream => target.Downloads.AddDownload(download, stream))) {
+			await target.Downloads.AddDownload(await source.Downloads.HydrateWithData(download));
-				await target.Downloads.AddDownload(download, stream: null);
-			}
 		}
 	}
 }

app/Server/Database/Import/LegacyArchiveImport.cs

@@ -161,7 +161,7 @@ public static class LegacyArchiveImport {
 
 		var messagesObj = data.HasKey(channelIdStr) ? data.RequireObject(channelIdStr, DataPath) : (JsonElement?) null;
 		if (messagesObj == null) {
-			return [];
+			return Array.Empty<Message>();
 		}
 
 		return messagesObj.Value.EnumerateObject().Select(item => {

app/Server/Database/Repositories/IDownloadRepository.cs

@@ -1,10 +1,10 @@
 using System;
 using System.Collections.Generic;
-using System.IO;
 using System.Linq;
 using System.Reactive.Linq;
 using System.Threading;
 using System.Threading.Tasks;
+using DHT.Server.Data;
 using DHT.Server.Data.Aggregations;
 using DHT.Server.Data.Filters;
 using DHT.Server.Download;
@@ -14,7 +14,7 @@ namespace DHT.Server.Database.Repositories;
 public interface IDownloadRepository {
 	IObservable<long> TotalCount { get; }
 
-	Task AddDownload(Data.Download item, Stream? stream);
+	Task AddDownload(DownloadWithData item);
 
 	Task<long> Count(DownloadItemFilter filter, CancellationToken cancellationToken = default);
 	
@@ -22,9 +22,9 @@ public interface IDownloadRepository {
 	
 	IAsyncEnumerable<Data.Download> Get();
 
-	Task<bool> GetDownloadData(string normalizedUrl, Func<Stream, Task> dataProcessor);
+	Task<DownloadWithData> HydrateWithData(Data.Download download);
 
-	Task<bool> GetSuccessfulDownloadWithData(string normalizedUrl, Func<Data.Download, Stream, Task> dataProcessor);
+	Task<DownloadWithData?> GetSuccessfulDownloadWithData(string normalizedUrl);
 
 	IAsyncEnumerable<DownloadItem> PullPendingDownloadItems(int count, DownloadItemFilter filter, CancellationToken cancellationToken = default);
 	
@@ -35,7 +35,7 @@ public interface IDownloadRepository {
 	internal sealed class Dummy : IDownloadRepository {
 		public IObservable<long> TotalCount { get; } = Observable.Return(0L);
 
-		public Task AddDownload(Data.Download item, Stream? stream) {
+		public Task AddDownload(DownloadWithData item) {
 			return Task.CompletedTask;
 		}
 
@@ -51,12 +51,12 @@ public interface IDownloadRepository {
 			return AsyncEnumerable.Empty<Data.Download>();
 		}
 
-		public Task<bool> GetDownloadData(string normalizedUrl, Func<Stream, Task> dataProcessor) {
+		public Task<DownloadWithData> HydrateWithData(Data.Download download) {
-			return Task.FromResult(false);
+			return Task.FromResult(new DownloadWithData(download, Data: null));
 		}
 
-		public Task<bool> GetSuccessfulDownloadWithData(string normalizedUrl, Func<Data.Download, Stream, Task> dataProcessor) {
+		public Task<DownloadWithData?> GetSuccessfulDownloadWithData(string normalizedUrl) {
-			return Task.FromResult(false);
+			return Task.FromResult<DownloadWithData?>(null);
 		}
 
 		public IAsyncEnumerable<DownloadItem> PullPendingDownloadItems(int count, DownloadItemFilter filter, CancellationToken cancellationToken) {

app/Server/Database/Sqlite/Repositories/SqliteChannelRepository.cs

@@ -19,9 +19,9 @@ sealed class SqliteChannelRepository : BaseSqliteRepository, IChannelRepository
 	}
 
 	public async Task Add(IReadOnlyList<Channel> channels) {
-		await using (var conn = await pool.Take()) {
+		await using var conn = await pool.Take();
-			await conn.BeginTransactionAsync();
 
+		await using (var tx = await conn.BeginTransactionAsync()) {
 			await using var cmd = conn.Upsert("channels", [
 				("id", SqliteType.Integer),
 				("server", SqliteType.Integer),
@@ -43,7 +43,7 @@ sealed class SqliteChannelRepository : BaseSqliteRepository, IChannelRepository
 				await cmd.ExecuteNonQueryAsync();
 			}
 
-			await conn.CommitTransactionAsync();
+			await tx.CommitAsync();
 		}
 
 		UpdateTotalCount();

app/Server/Database/Sqlite/Repositories/SqliteDownloadRepository.cs

@@ -1,6 +1,5 @@
 using System;
 using System.Collections.Generic;
-using System.IO;
 using System.Runtime.CompilerServices;
 using System.Threading;
 using System.Threading.Tasks;
@@ -15,9 +14,15 @@ using Microsoft.Data.Sqlite;
 
 namespace DHT.Server.Database.Sqlite.Repositories;
 
-sealed class SqliteDownloadRepository(SqliteConnectionPool pool) : BaseSqliteRepository(Log), IDownloadRepository {
+sealed class SqliteDownloadRepository : BaseSqliteRepository, IDownloadRepository {
 	private static readonly Log Log = Log.ForType<SqliteDownloadRepository>();
 	
+	private readonly SqliteConnectionPool pool;
+
+	public SqliteDownloadRepository(SqliteConnectionPool pool) : base(Log) {
+		this.pool = pool;
+	}
+
 	internal sealed class NewDownloadCollector : IAsyncDisposable {
 		private readonly SqliteDownloadRepository repository;
 		private bool hasAdded = false;
@@ -61,9 +66,11 @@ sealed class SqliteDownloadRepository(SqliteConnectionPool pool) : BaseSqliteRep
 		}
 	}
 
-	public async Task AddDownload(Data.Download item, Stream? stream) {
+	public async Task AddDownload(DownloadWithData item) {
+		var (download, data) = item;
+
 		await using (var conn = await pool.Take()) {
-			await conn.BeginTransactionAsync();
+			var tx = await conn.BeginTransactionAsync();
 
 			await using var metadataCmd = conn.Upsert("download_metadata", [
 				("normalized_url", SqliteType.Text),
@@ -73,37 +80,30 @@ sealed class SqliteDownloadRepository(SqliteConnectionPool pool) : BaseSqliteRep
 				("size", SqliteType.Integer),
 			]);
 
-			metadataCmd.Set(":normalized_url", item.NormalizedUrl);
+			metadataCmd.Set(":normalized_url", download.NormalizedUrl);
-			metadataCmd.Set(":download_url", item.DownloadUrl);
+			metadataCmd.Set(":download_url", download.DownloadUrl);
-			metadataCmd.Set(":status", (int) item.Status);
+			metadataCmd.Set(":status", (int) download.Status);
-			metadataCmd.Set(":type", item.Type);
+			metadataCmd.Set(":type", download.Type);
-			metadataCmd.Set(":size", item.Size);
+			metadataCmd.Set(":size", download.Size);
 			await metadataCmd.ExecuteNonQueryAsync();
 
-			if (stream == null) {
+			if (data == null) {
 				await using var deleteBlobCmd = conn.Command("DELETE FROM download_blobs WHERE normalized_url = :normalized_url");
-				deleteBlobCmd.AddAndSet(":normalized_url", SqliteType.Text, item.NormalizedUrl);
+				deleteBlobCmd.AddAndSet(":normalized_url", SqliteType.Text, download.NormalizedUrl);
 				await deleteBlobCmd.ExecuteNonQueryAsync();
 			}
 			else {
-				await using var upsertBlobCmd = conn.Command(
+				await using var upsertBlobCmd = conn.Upsert("download_blobs", [
-					"""
+					("normalized_url", SqliteType.Text),
-					INSERT INTO download_blobs (normalized_url, blob)
+					("blob", SqliteType.Blob)
-					VALUES (:normalized_url, ZEROBLOB(:blob_length))
+				]);
-					ON CONFLICT (normalized_url) DO UPDATE SET blob = excluded.blob
-					RETURNING rowid
-					"""
-				);
 
-				upsertBlobCmd.AddAndSet(":normalized_url", SqliteType.Text, item.NormalizedUrl);
+				upsertBlobCmd.Set(":normalized_url", download.NormalizedUrl);
-				upsertBlobCmd.AddAndSet(":blob_length", SqliteType.Integer, item.Size);
+				upsertBlobCmd.Set(":blob", data);
-				long rowid = await upsertBlobCmd.ExecuteLongScalarAsync();
+				await upsertBlobCmd.ExecuteNonQueryAsync();
-
-				await using var blob = new SqliteBlob(conn.InnerConnection, "download_blobs", "blob", rowid);
-				await stream.CopyToAsync(blob);
 			}
 
-			await conn.CommitTransactionAsync();
+			await tx.CommitAsync();
 		}
 
 		UpdateTotalCount();
@@ -187,35 +187,24 @@ sealed class SqliteDownloadRepository(SqliteConnectionPool pool) : BaseSqliteRep
 		}
 	}
 
-	public async Task<bool> GetDownloadData(string normalizedUrl, Func<Stream, Task> dataProcessor) {
+	public async Task<DownloadWithData> HydrateWithData(Data.Download download) {
 		await using var conn = await pool.Take();
 
-		await using var cmd = conn.Command("SELECT rowid FROM download_blobs WHERE normalized_url = :normalized_url");
+		await using var cmd = conn.Command("SELECT blob FROM download_blobs WHERE normalized_url = :url");
-		cmd.AddAndSet(":normalized_url", SqliteType.Text, normalizedUrl);
+		cmd.AddAndSet(":url", SqliteType.Text, download.NormalizedUrl);
 
-		long rowid;
+		await using var reader = await cmd.ExecuteReaderAsync();
+		var data = await reader.ReadAsync() && !reader.IsDBNull(0) ? (byte[]) reader["blob"] : null;
 		
-		await using (var reader = await cmd.ExecuteReaderAsync()) {
+		return new DownloadWithData(download, data);
-			if (!await reader.ReadAsync()) {
-				return false;
 	}
 
-			rowid = reader.GetInt64(0);
+	public async Task<DownloadWithData?> GetSuccessfulDownloadWithData(string normalizedUrl) {
-		}
-		
-		await using (var blob = new SqliteBlob(conn.InnerConnection, "download_blobs", "blob", rowid, readOnly: true)) {
-			await dataProcessor(blob);
-		}
-
-		return true;
-	}
-
-	public async Task<bool> GetSuccessfulDownloadWithData(string normalizedUrl, Func<Data.Download, Stream, Task> dataProcessor) {
 		await using var conn = await pool.Take();
 
 		await using var cmd = conn.Command(
 			"""
-			SELECT dm.download_url, dm.type, db.rowid FROM download_metadata dm
+			SELECT dm.download_url, dm.type, db.blob FROM download_metadata dm
 			JOIN download_blobs db ON dm.normalized_url = db.normalized_url
 			WHERE dm.normalized_url = :normalized_url AND dm.status = :success IS NOT NULL
 			"""
@@ -224,25 +213,19 @@ sealed class SqliteDownloadRepository(SqliteConnectionPool pool) : BaseSqliteRep
 		cmd.AddAndSet(":normalized_url", SqliteType.Text, normalizedUrl);
 		cmd.AddAndSet(":success", SqliteType.Integer, (int) DownloadStatus.Success);
 
-		string downloadUrl;
+		await using var reader = await cmd.ExecuteReaderAsync();
-		string? type;
-		long rowid;
 
-		await using (var reader = await cmd.ExecuteReaderAsync()) {
 		if (!await reader.ReadAsync()) {
-				return false;
+			return null;
 		}
 
-			downloadUrl = reader.GetString(0);
+		var downloadUrl = reader.GetString(0);
-			type = reader.IsDBNull(1) ? null : reader.GetString(1);
+		var type = reader.IsDBNull(1) ? null : reader.GetString(1);
-			rowid = reader.GetInt64(2);
+		var data = (byte[]) reader[2];
-		}
+		var size = (ulong) data.LongLength;
+		var download = new Data.Download(normalizedUrl, downloadUrl, DownloadStatus.Success, type, size);
 		
-		await using (var blob = new SqliteBlob(conn.InnerConnection, "download_blobs", "blob", rowid, readOnly: true)) {
+		return new DownloadWithData(download, data);
-			await dataProcessor(new Data.Download(normalizedUrl, downloadUrl, DownloadStatus.Success, type, (ulong) blob.Length), blob);
-		}
-
-		return true;
 	}
 
 	public async IAsyncEnumerable<DownloadItem> PullPendingDownloadItems(int count, DownloadItemFilter filter, [EnumeratorCancellation] CancellationToken cancellationToken) {

app/Server/Database/Sqlite/Repositories/SqliteMessageRepository.cs

@@ -39,7 +39,7 @@ sealed class SqliteMessageRepository : BaseSqliteRepository, IMessageRepository
 		}
 
 		await using (var conn = await pool.Take()) {
-			await conn.BeginTransactionAsync();
+			await using var tx = await conn.BeginTransactionAsync();
 
 			await using var messageCmd = conn.Upsert("messages", [
 				("message_id", SqliteType.Integer),
@@ -167,7 +167,7 @@ sealed class SqliteMessageRepository : BaseSqliteRepository, IMessageRepository
 				}
 			}
 
-			await conn.CommitTransactionAsync();
+			await tx.CommitAsync();
 			downloadCollector.OnCommitted();
 		}
 
@@ -183,11 +183,11 @@ sealed class SqliteMessageRepository : BaseSqliteRepository, IMessageRepository
 		return await conn.ExecuteReaderAsync("SELECT COUNT(*) FROM messages" + filter.GenerateConditions().BuildWhereClause(), static reader => reader?.GetInt64(0) ?? 0L, cancellationToken);
 	}
 
-	private sealed class MessageToManyCommand<T> : IAsyncDisposable {
+	private sealed class MesageToManyCommand<T> : IAsyncDisposable {
 		private readonly SqliteCommand cmd;
 		private readonly Func<SqliteDataReader, T> readItem;
 
-		public MessageToManyCommand(ISqliteConnection conn, string sql, Func<SqliteDataReader, T> readItem) {
+		public MesageToManyCommand(ISqliteConnection conn, string sql, Func<SqliteDataReader, T> readItem) {
 			this.cmd = conn.Command(sql);
 			this.cmd.Add(":message_id", SqliteType.Integer);
 
@@ -223,7 +223,7 @@ sealed class SqliteMessageRepository : BaseSqliteRepository, IMessageRepository
 			WHERE message_id = :message_id
 			""";
 
-		await using var attachmentCmd = new MessageToManyCommand<Attachment>(conn, AttachmentSql, static reader => new Attachment {
+		await using var attachmentCmd = new MesageToManyCommand<Attachment>(conn, AttachmentSql, static reader => new Attachment {
 			Id = reader.GetUint64(0),
 			Name = reader.GetString(1),
 			Type = reader.IsDBNull(2) ? null : reader.GetString(2),
@@ -241,7 +241,7 @@ sealed class SqliteMessageRepository : BaseSqliteRepository, IMessageRepository
 			WHERE message_id = :message_id
 			""";
 
-		await using var embedCmd = new MessageToManyCommand<Embed>(conn, EmbedSql, static reader => new Embed {
+		await using var embedCmd = new MesageToManyCommand<Embed>(conn, EmbedSql, static reader => new Embed {
 			Json = reader.GetString(0)
 		});
 
@@ -252,7 +252,7 @@ sealed class SqliteMessageRepository : BaseSqliteRepository, IMessageRepository
 			WHERE message_id = :message_id
 			""";
 
-		await using var reactionsCmd = new MessageToManyCommand<Reaction>(conn, ReactionSql, static reader => new Reaction {
+		await using var reactionsCmd = new MesageToManyCommand<Reaction>(conn, ReactionSql, static reader => new Reaction {
 			EmojiId = reader.IsDBNull(0) ? null : reader.GetUint64(0),
 			EmojiName = reader.IsDBNull(1) ? null : reader.GetString(1),
 			EmojiFlags = (EmojiFlags) reader.GetInt16(2),

app/Server/Database/Sqlite/Repositories/SqliteServerRepository.cs

@@ -19,9 +19,9 @@ sealed class SqliteServerRepository : BaseSqliteRepository, IServerRepository {
 	}
 
 	public async Task Add(IReadOnlyList<Data.Server> servers) {
-		await using (var conn = await pool.Take()) {
+		await using var conn = await pool.Take();
-			await conn.BeginTransactionAsync();
 
+		await using (var tx = await conn.BeginTransactionAsync()) {
 			await using var cmd = conn.Upsert("servers", [
 				("id", SqliteType.Integer),
 				("name", SqliteType.Text),
@@ -35,7 +35,7 @@ sealed class SqliteServerRepository : BaseSqliteRepository, IServerRepository {
 				await cmd.ExecuteNonQueryAsync();
 			}
 
-			await conn.CommitTransactionAsync();
+			await tx.CommitAsync();
 		}
 
 		UpdateTotalCount();

app/Server/Database/Sqlite/Repositories/SqliteUserRepository.cs

@@ -23,7 +23,7 @@ sealed class SqliteUserRepository : BaseSqliteRepository, IUserRepository {
 
 	public async Task Add(IReadOnlyList<User> users) {
 		await using (var conn = await pool.Take()) {
-			await conn.BeginTransactionAsync();
+			await using var tx = await conn.BeginTransactionAsync();
 
 			await using var cmd = conn.Upsert("users", [
 				("id", SqliteType.Integer),
@@ -46,7 +46,7 @@ sealed class SqliteUserRepository : BaseSqliteRepository, IUserRepository {
 				}
 			}
 
-			await conn.CommitTransactionAsync();
+			await tx.CommitAsync();
 			downloadCollector.OnCommitted();
 		}
 

app/Server/Database/Sqlite/Schema/SqliteSchemaUpgradeTo6.cs

@@ -1,4 +1,5 @@
 using System.Collections.Generic;
+using System.Data.Common;
 using System.Threading.Tasks;
 using DHT.Server.Database.Sqlite.Utils;
 using DHT.Server.Download;
@@ -38,7 +39,7 @@ sealed class SqliteSchemaUpgradeTo6 : ISchemaUpgrade {
 			}
 		}
 
-		await conn.BeginTransactionAsync();
+		await using var tx = await conn.BeginTransactionAsync();
 
 		int totalUrls = normalizedUrls.Count;
 		int processedUrls = -1;
@@ -60,7 +61,7 @@ sealed class SqliteSchemaUpgradeTo6 : ISchemaUpgrade {
 
 		await reporter.SubWork("Updating URLs...", totalUrls, totalUrls);
 
-		await conn.CommitTransactionAsync();
+		await tx.CommitAsync();
 	}
 
 	private async Task NormalizeDownloadUrls(ISqliteConnection conn, ISchemaUpgradeCallbacks.IProgressReporter reporter) {
@@ -83,8 +84,10 @@ sealed class SqliteSchemaUpgradeTo6 : ISchemaUpgrade {
 		}
 
 		await conn.ExecuteAsync("PRAGMA cache_size = -20000");
-		await conn.BeginTransactionAsync();
 
+		DbTransaction tx;
+
+		await using (tx = await conn.BeginTransactionAsync()) {
 			await reporter.SubWork("Deleting duplicates...", 0, 0);
 
 			await using (var deleteCmd = conn.Delete("downloads", ("url", SqliteType.Text))) {
@@ -94,12 +97,13 @@ sealed class SqliteSchemaUpgradeTo6 : ISchemaUpgrade {
 				}
 			}
 
-		await conn.CommitTransactionAsync();
+			await tx.CommitAsync();
+		}
 
 		int totalUrls = normalizedUrlsToOriginalUrls.Count;
 		int processedUrls = -1;
 
-		await conn.BeginTransactionAsync();
+		tx = await conn.BeginTransactionAsync();
 
 		await using (var updateCmd = conn.Command("UPDATE downloads SET download_url = :download_url, url = :normalized_url WHERE url = :download_url")) {
 			updateCmd.Add(":normalized_url", SqliteType.Text);
@@ -111,10 +115,11 @@ sealed class SqliteSchemaUpgradeTo6 : ISchemaUpgrade {
 
 					// Not proper way of dealing with transactions, but it avoids a long commit at the end.
 					// Schema upgrades are already non-atomic anyways, so this doesn't make it worse.
-					await conn.CommitTransactionAsync();
+					await tx.CommitAsync();
+					await tx.DisposeAsync();
 
-					await conn.BeginTransactionAsync();
+					tx = await conn.BeginTransactionAsync();
-					conn.AssignActiveTransaction(updateCmd);
+					updateCmd.Transaction = (SqliteTransaction) tx;
 				}
 
 				updateCmd.Set(":normalized_url", normalizedUrl);
@@ -125,7 +130,8 @@ sealed class SqliteSchemaUpgradeTo6 : ISchemaUpgrade {
 
 		await reporter.SubWork("Updating URLs...", totalUrls, totalUrls);
 
-		await conn.CommitTransactionAsync();
+		await tx.CommitAsync();
+		await tx.DisposeAsync();
 
 		await conn.ExecuteAsync("PRAGMA cache_size = -2000");
 	}

app/Server/Database/Sqlite/Schema/SqliteSchemaUpgradeTo7.cs

@@ -37,7 +37,7 @@ sealed class SqliteSchemaUpgradeTo7 : ISchemaUpgrade {
 
 		await reporter.SubWork("Processing downloaded files...", 0, totalFiles);
 		
-		await conn.BeginTransactionAsync();
+		var tx = await conn.BeginTransactionAsync();
 
 		await using (var insertCmd = conn.Command("INSERT INTO download_blobs (normalized_url, blob) SELECT normalized_url, blob FROM downloads WHERE normalized_url = :normalized_url"))
 		await using (var deleteCmd = conn.Command("DELETE FROM downloads WHERE normalized_url = :normalized_url")) {
@@ -50,11 +50,12 @@ sealed class SqliteSchemaUpgradeTo7 : ISchemaUpgrade {
 			
 					// Not proper way of dealing with transactions, but it avoids a long commit at the end.
 					// Schema upgrades are already non-atomic anyways, so this doesn't make it worse.
-					await conn.CommitTransactionAsync();
+					await tx.CommitAsync();
+					await tx.DisposeAsync();
 			
-					await conn.BeginTransactionAsync();
+					tx = await conn.BeginTransactionAsync();
-					conn.AssignActiveTransaction(insertCmd);
+					insertCmd.Transaction = (SqliteTransaction) tx;
-					conn.AssignActiveTransaction(deleteCmd);
+					deleteCmd.Transaction = (SqliteTransaction) tx;
 				}
 				
 				insertCmd.Set(":normalized_url", url);
@@ -67,7 +68,8 @@ sealed class SqliteSchemaUpgradeTo7 : ISchemaUpgrade {
 
 		await reporter.SubWork("Processing downloaded files...", totalFiles, totalFiles);
 
-		await conn.CommitTransactionAsync();
+		await tx.CommitAsync();
+		await tx.DisposeAsync();
 	}
 
 	private async Task<List<string>> GetDownloadedFileUrls(ISqliteConnection conn) {
@@ -109,8 +111,7 @@ sealed class SqliteSchemaUpgradeTo7 : ISchemaUpgrade {
 			await insertCmd.ExecuteNonQueryAsync();
 		}
 		
-		await conn.BeginTransactionAsync();
+		await using (var tx = await conn.BeginTransactionAsync()) {
-
 			await using var insertCmd = conn.Command("INSERT OR IGNORE INTO download_metadata (normalized_url, download_url, status, type, size) VALUES (:normalized_url, :download_url, :status, :type, :size)");
 			insertCmd.Add(":normalized_url", SqliteType.Text);
 			insertCmd.Add(":download_url", SqliteType.Text);
@@ -148,6 +149,7 @@ sealed class SqliteSchemaUpgradeTo7 : ISchemaUpgrade {
 				}
 			}
 			
-		await conn.CommitTransactionAsync();
+			await tx.CommitAsync();
+		}
 	}
 }

app/Server/Database/Sqlite/Utils/ISqliteConnection.cs

@@ -1,15 +1,8 @@
 using System;
-using System.Threading.Tasks;
 using Microsoft.Data.Sqlite;
 
 namespace DHT.Server.Database.Sqlite.Utils;
 
 interface ISqliteConnection : IAsyncDisposable {
 	SqliteConnection InnerConnection { get; }
-	
-	Task BeginTransactionAsync();
-	Task CommitTransactionAsync();
-	Task RollbackTransactionAsync();
-	
-	void AssignActiveTransaction(SqliteCommand command);
 }

app/Server/Database/Sqlite/Utils/SqliteConnectionPool.cs

@@ -1,6 +1,5 @@
 using System;
 using System.Collections.Generic;
-using System.Data.Common;
 using System.Threading;
 using System.Threading.Tasks;
 using DHT.Utils.Collections;
@@ -74,48 +73,17 @@ sealed class SqliteConnectionPool : IAsyncDisposable {
 		disposalTokenSource.Dispose();
 	}
 
-	private sealed class PooledConnection(SqliteConnectionPool pool, SqliteConnection conn) : ISqliteConnection {
+	private sealed class PooledConnection : ISqliteConnection {
-		public SqliteConnection InnerConnection { get; } = conn;
+		public SqliteConnection InnerConnection { get; }
 
-		private DbTransaction? activeTransaction;
+		private readonly SqliteConnectionPool pool;
 
-		public async Task BeginTransactionAsync() {
+		public PooledConnection(SqliteConnectionPool pool, SqliteConnection conn) {
-			if (activeTransaction != null) {
+			this.pool = pool;
-				throw new InvalidOperationException("A transaction is already active.");
+			this.InnerConnection = conn;
-			}
-			
-			activeTransaction = await InnerConnection.BeginTransactionAsync();
-		}
-
-		public async Task CommitTransactionAsync() {
-			if (activeTransaction == null) {
-				throw new InvalidOperationException("No active transaction to commit.");
-			}
-
-			await activeTransaction.CommitAsync();
-			await activeTransaction.DisposeAsync();
-			activeTransaction = null;
-		}
-
-		public async Task RollbackTransactionAsync() {
-			if (activeTransaction == null) {
-				throw new InvalidOperationException("No active transaction to rollback.");
-			}
-			
-			await activeTransaction.RollbackAsync();
-			await activeTransaction.DisposeAsync();
-			activeTransaction = null;
-		}
-
-		public void AssignActiveTransaction(SqliteCommand command) {
-			command.Transaction = (SqliteTransaction?) activeTransaction;
 		}
 
 		public async ValueTask DisposeAsync() {
-			if (activeTransaction != null) {
-				await RollbackTransactionAsync();
-			}
-			
 			await pool.Return(this);
 		}
 	}

app/Server/Database/Sqlite/Utils/SqliteExtensions.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Data.Common;
 using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
@@ -8,6 +9,10 @@ using Microsoft.Data.Sqlite;
 namespace DHT.Server.Database.Sqlite.Utils;
 
 static class SqliteExtensions {
+	public static ValueTask<DbTransaction> BeginTransactionAsync(this ISqliteConnection conn) {
+		return conn.InnerConnection.BeginTransactionAsync();
+	}
+
 	public static SqliteCommand Command(this ISqliteConnection conn, [LanguageInjection("sql")] string sql) {
 		var cmd = conn.InnerConnection.CreateCommand();
 		cmd.CommandText = sql;
@@ -26,10 +31,6 @@ static class SqliteExtensions {
 		return await reader.ReadAsync(cancellationToken) ? readFunction(reader) : readFunction(null);
 	}
 
-	public static async Task<long> ExecuteLongScalarAsync(this SqliteCommand command) {
-		return (long) (await command.ExecuteScalarAsync())!;
-	}
-
 	public static SqliteCommand Insert(this ISqliteConnection conn, string tableName, (string Name, SqliteType Type)[] columns) {
 		string columnNames = string.Join(',', columns.Select(static c => c.Name));
 		string columnParams = string.Join(',', columns.Select(static c => ':' + c.Name));

app/Server/Download/DownloadItem.cs

@@ -10,12 +10,13 @@ public readonly struct DownloadItem {
 	public string? Type { get; init; }
 	public ulong? Size { get; init; }
 	
-	internal Data.Download ToSuccess(long size) {
+	internal DownloadWithData ToSuccess(byte[] data) {
-		return new Data.Download(NormalizedUrl, DownloadUrl, DownloadStatus.Success, Type, (ulong) Math.Max(size, 0));
+		var size = (ulong) Math.Max(data.LongLength, 0);
+		return new DownloadWithData(new Data.Download(NormalizedUrl, DownloadUrl, DownloadStatus.Success, Type, size), data);
 	}
 	
-	internal Data.Download ToFailure(HttpStatusCode? statusCode = null) {
+	internal DownloadWithData ToFailure(HttpStatusCode? statusCode = null) {
 		var status = statusCode.HasValue ? (DownloadStatus) (int) statusCode : DownloadStatus.GenericError;
-		return new Data.Download(NormalizedUrl, DownloadUrl, status, Type, Size);
+		return new DownloadWithData(new Data.Download(NormalizedUrl, DownloadUrl, status, Type, Size), Data: null);
 	}
 }

app/Server/Download/DownloaderTask.cs

@@ -67,39 +67,28 @@ sealed class DownloaderTask : IAsyncDisposable {
 	private async Task RunDownloadTask(int taskIndex) {
 		var log = Log.ForType<DownloaderTask>("Task " + taskIndex);
 
-		var client = new HttpClient(new SocketsHttpHandler {
+		var client = new HttpClient();
-			ConnectTimeout = TimeSpan.FromSeconds(30)
-		});
-		
-		client.Timeout = Timeout.InfiniteTimeSpan;
 		client.DefaultRequestHeaders.UserAgent.ParseAdd(UserAgent);
+		client.Timeout = TimeSpan.FromSeconds(30);
 
 		while (!cancellationToken.IsCancellationRequested) {
 			var item = await downloadQueue.Reader.ReadAsync(cancellationToken);
 			log.Debug("Downloading " + item.DownloadUrl + "...");
 
 			try {
-				var response = await client.SendAsync(new HttpRequestMessage(HttpMethod.Get, item.DownloadUrl), HttpCompletionOption.ResponseHeadersRead, cancellationToken);
+				var downloadedBytes = await client.GetByteArrayAsync(item.DownloadUrl, cancellationToken);
-				response.EnsureSuccessStatusCode();
+				await db.Downloads.AddDownload(item.ToSuccess(downloadedBytes));
-
-				if (response.Content.Headers.ContentLength is {} contentLength) {
-					await using var stream = await response.Content.ReadAsStreamAsync(cancellationToken);
-					await db.Downloads.AddDownload(item.ToSuccess(contentLength), stream);
-				}
-				else {
-					await db.Downloads.AddDownload(item.ToFailure(), stream: null);
-					log.Error("Download response has no content length: " + item.DownloadUrl);
-				}
 			} catch (OperationCanceledException e) when (e.CancellationToken == cancellationToken) {
 				// Ignore.
-			} catch (TaskCanceledException e) when (e.InnerException is TimeoutException) {
+			} catch (TaskCanceledException e) {
-				await db.Downloads.AddDownload(item.ToFailure(), stream: null);
+				// HttpClient request timed out.
-				log.Error("Download timed out: " + item.DownloadUrl);
+				await db.Downloads.AddDownload(item.ToFailure());
+				log.Error(e.Message);
 			} catch (HttpRequestException e) {
-				await db.Downloads.AddDownload(item.ToFailure(e.StatusCode), stream: null);
+				await db.Downloads.AddDownload(item.ToFailure(e.StatusCode));
 				log.Error(e);
 			} catch (Exception e) {
-				await db.Downloads.AddDownload(item.ToFailure(), stream: null);
+				await db.Downloads.AddDownload(item.ToFailure());
 				log.Error(e);
 			} finally {
 				try {

app/Server/Endpoints/BaseEndpoint.cs

@@ -9,37 +9,37 @@ using Microsoft.AspNetCore.Http;
 
 namespace DHT.Server.Endpoints;
 
-abstract class BaseEndpoint(IDatabaseFile db) {
+abstract class BaseEndpoint {
 	private static readonly Log Log = Log.ForType<BaseEndpoint>();
 
-	protected IDatabaseFile Db { get; } = db;
+	protected IDatabaseFile Db { get; }
+
+	protected BaseEndpoint(IDatabaseFile db) {
+		this.Db = db;
+	}
 
 	public async Task Handle(HttpContext ctx) {
 		var response = ctx.Response;
 
 		try {
 			response.StatusCode = (int) HttpStatusCode.OK;
-			await Respond(ctx.Request, response);
+			var output = await Respond(ctx);
+			await output.WriteTo(response);
 		} catch (HttpException e) {
 			Log.Error(e);
 			response.StatusCode = (int) e.StatusCode;
-			if (response.HasStarted) {
-				Log.Warn("Response has already started, cannot write status message: " + e.Message);
-			}
-			else {
 			await response.WriteAsync(e.Message);
-			}
 		} catch (Exception e) {
 			Log.Error(e);
 			response.StatusCode = (int) HttpStatusCode.InternalServerError;
 		}
 	}
 
-	protected abstract Task Respond(HttpRequest request, HttpResponse response);
+	protected abstract Task<IHttpOutput> Respond(HttpContext ctx);
 
-	protected static async Task<JsonElement> ReadJson(HttpRequest request) {
+	protected static async Task<JsonElement> ReadJson(HttpContext ctx) {
 		try {
-			return await request.ReadFromJsonAsync(JsonElementContext.Default.JsonElement);
+			return await ctx.Request.ReadFromJsonAsync(JsonElementContext.Default.JsonElement);
 		} catch (JsonException) {
 			throw new HttpException(HttpStatusCode.UnsupportedMediaType, "This endpoint only accepts JSON.");
 		}

app/Server/Endpoints/GetDownloadedFileEndpoint.cs

@@ -7,13 +7,18 @@ using Microsoft.AspNetCore.Http;
 
 namespace DHT.Server.Endpoints;
 
-sealed class GetDownloadedFileEndpoint(IDatabaseFile db) : BaseEndpoint(db) {
+sealed class GetDownloadedFileEndpoint : BaseEndpoint {
-	protected override async Task Respond(HttpRequest request, HttpResponse response) {
+	public GetDownloadedFileEndpoint(IDatabaseFile db) : base(db) {}
-		string url = WebUtility.UrlDecode((string) request.RouteValues["url"]!);
+
+	protected override async Task<IHttpOutput> Respond(HttpContext ctx) {
+		string url = WebUtility.UrlDecode((string) ctx.Request.RouteValues["url"]!);
 		string normalizedUrl = DiscordCdn.NormalizeUrl(url);
 		
-		if (!await Db.Downloads.GetSuccessfulDownloadWithData(normalizedUrl, (download, stream) => response.WriteStreamAsync(download.Type, download.Size, stream))) {
+		if (await Db.Downloads.GetSuccessfulDownloadWithData(normalizedUrl) is { Download: {} download, Data: {} data }) {
-			response.Redirect(url, permanent: false);
+			return new HttpOutput.File(download.Type, data);
+		}
+		else {
+			return new HttpOutput.Redirect(url, permanent: false);
 		}
 	}
 }

app/Server/Endpoints/GetTrackingScriptEndpoint.cs

@@ -1,5 +1,5 @@
-using System.Net.Mime;
 using System.Reflection;
+using System.Text;
 using System.Threading.Tasks;
 using System.Web;
 using DHT.Server.Database;
@@ -10,19 +10,25 @@ using Microsoft.AspNetCore.Http;
 
 namespace DHT.Server.Endpoints;
 
-sealed class GetTrackingScriptEndpoint(IDatabaseFile db, ServerParameters parameters) : BaseEndpoint(db) {
+sealed class GetTrackingScriptEndpoint : BaseEndpoint {
 	private static ResourceLoader Resources { get; } = new (Assembly.GetExecutingAssembly());
 	
-	protected override async Task Respond(HttpRequest request, HttpResponse response) {
+	private readonly ServerParameters serverParameters;
+	
+	public GetTrackingScriptEndpoint(IDatabaseFile db, ServerParameters parameters) : base(db) {
+		serverParameters = parameters;
+	}
+
+	protected override async Task<IHttpOutput> Respond(HttpContext ctx) {
 		string bootstrap = await Resources.ReadTextAsync("Tracker/bootstrap.js");
-		string script = bootstrap.Replace("= 0; /*[PORT]*/", "= " + parameters.Port + ";")
+		string script = bootstrap.Replace("= 0; /*[PORT]*/", "= " + serverParameters.Port + ";")
-		                         .Replace("/*[TOKEN]*/", HttpUtility.JavaScriptStringEncode(parameters.Token))
+		                         .Replace("/*[TOKEN]*/", HttpUtility.JavaScriptStringEncode(serverParameters.Token))
 		                         .Replace("/*[IMPORTS]*/", await Resources.ReadJoinedAsync("Tracker/scripts/", '\n'))
 		                         .Replace("/*[CSS-CONTROLLER]*/", await Resources.ReadTextAsync("Tracker/styles/controller.css"))
 		                         .Replace("/*[CSS-SETTINGS]*/", await Resources.ReadTextAsync("Tracker/styles/settings.css"))
-		                         .Replace("/*[DEBUGGER]*/", request.Query.ContainsKey("debug") ? "debugger;" : "");
+		                         .Replace("/*[DEBUGGER]*/", ctx.Request.Query.ContainsKey("debug") ? "debugger;" : "");
 		
-		response.Headers.Append("X-DHT", "1");
+		ctx.Response.Headers.Append("X-DHT", "1");
-		await response.WriteTextAsync(MediaTypeNames.Text.JavaScript, script);
+		return new HttpOutput.File("text/javascript", Encoding.UTF8.GetBytes(script));
 	}
 }

app/Server/Endpoints/TrackChannelEndpoint.cs

@@ -8,14 +8,18 @@ using Microsoft.AspNetCore.Http;
 
 namespace DHT.Server.Endpoints;
 
-sealed class TrackChannelEndpoint(IDatabaseFile db) : BaseEndpoint(db) {
+sealed class TrackChannelEndpoint : BaseEndpoint {
-	protected override async Task Respond(HttpRequest request, HttpResponse response) {
+	public TrackChannelEndpoint(IDatabaseFile db) : base(db) {}
-		var root = await ReadJson(request);
+
+	protected override async Task<IHttpOutput> Respond(HttpContext ctx) {
+		var root = await ReadJson(ctx);
 		var server = ReadServer(root.RequireObject("server"), "server");
 		var channel = ReadChannel(root.RequireObject("channel"), "channel", server.Id);
 
 		await Db.Servers.Add([server]);
 		await Db.Channels.Add([channel]);
+
+		return HttpOutput.None;
 	}
 
 	private static Data.Server ReadServer(JsonElement json, string path) => new () {

app/Server/Endpoints/TrackMessagesEndpoint.cs

@@ -15,12 +15,14 @@ using Microsoft.AspNetCore.Http;
 
 namespace DHT.Server.Endpoints;
 
-sealed class TrackMessagesEndpoint(IDatabaseFile db) : BaseEndpoint(db) {
+sealed class TrackMessagesEndpoint : BaseEndpoint {
 	private const string HasNewMessages = "1";
 	private const string NoNewMessages = "0";
 
-	protected override async Task Respond(HttpRequest request, HttpResponse response) {
+	public TrackMessagesEndpoint(IDatabaseFile db) : base(db) {}
-		var root = await ReadJson(request);
+
+	protected override async Task<IHttpOutput> Respond(HttpContext ctx) {
+		var root = await ReadJson(ctx);
 
 		if (root.ValueKind != JsonValueKind.Array) {
 			throw new HttpException(HttpStatusCode.BadRequest, "Expected root element to be an array.");
@@ -41,7 +43,7 @@ sealed class TrackMessagesEndpoint(IDatabaseFile db) : BaseEndpoint(db) {
 
 		await Db.Messages.Add(messages);
 
-		await response.WriteTextAsync(anyNewMessages ? HasNewMessages : NoNewMessages);
+		return new HttpOutput.Text(anyNewMessages ? HasNewMessages : NoNewMessages);
 	}
 
 	private static Message ReadMessage(JsonElement json, string path) => new () {

app/Server/Endpoints/TrackUsersEndpoint.cs

@@ -8,9 +8,11 @@ using Microsoft.AspNetCore.Http;
 
 namespace DHT.Server.Endpoints;
 
-sealed class TrackUsersEndpoint(IDatabaseFile db) : BaseEndpoint(db) {
+sealed class TrackUsersEndpoint : BaseEndpoint {
-	protected override async Task Respond(HttpRequest request, HttpResponse response) {
+	public TrackUsersEndpoint(IDatabaseFile db) : base(db) {}
-		var root = await ReadJson(request);
+
+	protected override async Task<IHttpOutput> Respond(HttpContext ctx) {
+		var root = await ReadJson(ctx);
 
 		if (root.ValueKind != JsonValueKind.Array) {
 			throw new HttpException(HttpStatusCode.BadRequest, "Expected root element to be an array.");
@@ -24,6 +26,8 @@ sealed class TrackUsersEndpoint(IDatabaseFile db) : BaseEndpoint(db) {
 		}
 
 		await Db.Users.Add(users);
+
+		return HttpOutput.None;
 	}
 
 	private static User ReadUser(JsonElement json, string path) => new () {

app/Utils/Collections/LinqExtensions.cs

@@ -8,7 +8,7 @@ public static class LinqExtensions {
 		HashSet<TKey>? seenKeys = null;
 
 		foreach (var item in collection) {
-			seenKeys ??= [];
+			seenKeys ??= new HashSet<TKey>();
 
 			if (seenKeys.Add(getKeyFromItem(item))) {
 				yield return item;

app/Utils/Http/HttpExtensions.cs

@@ -1,33 +0,0 @@
-using System.IO;
-using System.Net.Mime;
-using System.Text;
-using System.Threading.Tasks;
-using Microsoft.AspNetCore.Http;
-
-namespace DHT.Utils.Http; 
-
-public static class HttpExtensions {
-	public static Task WriteTextAsync(this HttpResponse response, string text) {
-		return WriteTextAsync(response, MediaTypeNames.Text.Plain, text);
-	}
-	
-	public static async Task WriteTextAsync(this HttpResponse response, string contentType, string text) {
-		response.ContentType = contentType;
-		await response.StartAsync();
-		await response.WriteAsync(text, Encoding.UTF8);
-	}
-	
-	public static async Task WriteFileAsync(this HttpResponse response, string? contentType, byte[] bytes) {
-		response.ContentType = contentType ?? string.Empty;
-		response.ContentLength = bytes.Length;
-		await response.StartAsync();
-		await response.Body.WriteAsync(bytes);
-	}
-	
-	public static async Task WriteStreamAsync(this HttpResponse response, string? contentType, ulong? contentLength, Stream source) {
-		response.ContentType = contentType ?? string.Empty;
-		response.ContentLength = (long?) contentLength;
-		await response.StartAsync();
-		await source.CopyToAsync(response.Body);
-	}
-}

app/Utils/Http/HttpOutput.cs

@@ -0,0 +1,35 @@
+using System.Text;
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.Http;
+
+namespace DHT.Utils.Http;
+
+public static class HttpOutput {
+	public static IHttpOutput None { get; } = new NoneImpl();
+
+	private sealed class NoneImpl : IHttpOutput {
+		public Task WriteTo(HttpResponse response) {
+			return Task.CompletedTask;
+		}
+	}
+
+	public sealed class Text(string text) : IHttpOutput {
+		public Task WriteTo(HttpResponse response) {
+			return response.WriteAsync(text, Encoding.UTF8);
+		}
+	}
+
+	public sealed class File(string? contentType, byte[] bytes) : IHttpOutput {
+		public async Task WriteTo(HttpResponse response) {
+			response.ContentType = contentType ?? string.Empty;
+			await response.Body.WriteAsync(bytes);
+		}
+	}
+
+	public sealed class Redirect(string url, bool permanent) : IHttpOutput {
+		public Task WriteTo(HttpResponse response) {
+			response.Redirect(url, permanent);
+			return Task.CompletedTask;
+		}
+	}
+}

app/Utils/Http/IHttpOutput.cs

@@ -0,0 +1,8 @@
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.Http;
+
+namespace DHT.Utils.Http;
+
+public interface IHttpOutput {
+	Task WriteTo(HttpResponse response);
+}

app/Version.cs

@@ -8,5 +8,5 @@ using DHT.Utils;
 namespace DHT.Utils;
 
 static class Version {
-	public const string Tag = "41.2.0.0";
+	public const string Tag = "41.1.0.0";
 }