Changes between Initial Version and Version 1 of P8

Timestamp:

04/28/26 13:55:00 (4 days ago)

Author:

211099

Comment:

--

P8

@@ +1 @@
+= Advanced Application Development =
+
+== Transactions ==
+
+=== User Registration ===
+
+{{{
+public async Task<RegisterResponse> Handle(RegisterRequest request, CancellationToken cancellationToken)
+{
+    var existing = await _userRepository.GetByEmailAsync(request.Email, cancellationToken);
+    if (existing != null)
+        throw new InvalidOperationException("Email already in use.");
+
+    await using var transaction = await _context.BeginTransactionAsync(cancellationToken);
+    try
+    {
+        var user = new Domain.Entities.User
+        {
+            Username = request.Username,
+            Email = request.Email,
+            Name = request.Name,
+            Surname = request.Surname,
+            Password = BCrypt.Net.BCrypt.HashPassword(request.Password),
+            CreatedAt = DateTime.UtcNow,
+            UpdatedAt = DateTime.UtcNow
+        };
+
+        await _userRepository.AddAsync(user, cancellationToken);
+
+        var writer = new Domain.Entities.Writer { Id = user.Id };
+        await _writerRepository.AddAsync(writer, cancellationToken);
+
+        await transaction.CommitAsync(cancellationToken);
+        return new RegisterResponse(user.Id, user.Username, user.Email);
+    }
+    catch
+    {
+        await transaction.RollbackAsync(cancellationToken);
+        throw;
+    }
+}
+}}}
+
+=== Publishing a Story ===
+
+{{{
+public async Task<AddResponse> Handle(AddRequest request, CancellationToken cancellationToken)
+{
+    await using var transaction = await _context.BeginTransactionAsync(cancellationToken);
+    try
+    {
+        var story = new Domain.Entities.Story
+        {
+            MatureContent = request.MatureContent,
+            ShortDescription = request.ShortDescription,
+            Image = request.Image,
+            Content = request.Content,
+            UserId = request.UserId,
+            CreatedAt = DateTime.UtcNow,
+            UpdatedAt = DateTime.UtcNow
+        };
+
+        await _storyRepository.AddAsync(story, cancellationToken);
+
+        foreach (var genreName in request.Genres ?? [])
+        {
+            var genre = await _genreRepository.GetByNameAsync(genreName, cancellationToken);
+            if (genre == null) continue;
+            await _hasGenreRepository.AddAsync(new Domain.Entities.HasGenre { StoryId = story.Id, GenreId = genre.Id }, cancellationToken);
+        }
+
+        await transaction.CommitAsync(cancellationToken);
+        return new AddResponse(story.Id);
+    }
+    catch
+    {
+        await transaction.RollbackAsync(cancellationToken);
+        throw;
+    }
+}
+}}}
+
+== Database Connection Pooling ==
+
+Because we use .NET 9 with EF Core and Npgsql for the backend, we do not manage database connections manually. Connection pooling in Npgsql is handled automatically by the driver.
+
+Npgsql is a transitive dependency of `Npgsql.EntityFrameworkCore.PostgreSQL`, so adding the following to the project is sufficient:
+
+{{{
+<PackageReference Include="Npgsql.EntityFrameworkCore.PostgreSQL" Version="9.0.4" />
+}}}
+
+The EF Core context is registered using `AddDbContextPool` instead of `AddDbContext`, which enables context instance pooling on top of Npgsql's own connection pool:
+
+{{{
+services.AddDbContextPool<ApplicationDbContext>(options =>
+    options.UseNpgsql(connectionString));
+}}}
+
+The pool parameters are read from `appsettings.json` at startup and appended to the Npgsql connection string:
+
+{{{
+"ConnectionPool": {
+  "MinPoolSize": 1,
+  "MaxPoolSize": 20,
+  "ConnectionIdleLifetime": 300,
+  "ConnectionPruningInterval": 10,
+  "CommandTimeout": 30,
+  "Timeout": 15
+}
+}}}
+
+These values can be changed as needed. The established connections can be observed in the SSH tunnel logs when the application starts:
+
+{{{
+debug1: Connection to port 9999 forwarding to localhost port 5432 requested.
+debug1: channel 2: new direct-tcpip [direct-tcpip] (inactive timeout: 0)
+debug1: Connection to port 9999 forwarding to localhost port 5432 requested.
+debug1: channel 3: new direct-tcpip [direct-tcpip] (inactive timeout: 0)
+debug1: Connection to port 9999 forwarding to localhost port 5432 requested.
+debug1: channel 4: new direct-tcpip [direct-tcpip] (inactive timeout: 0)
+debug1: Connection to port 9999 forwarding to localhost port 5432 requested.
+debug1: channel 5: new direct-tcpip [direct-tcpip] (inactive timeout: 0)
+debug1: Connection to port 9999 forwarding to localhost port 5432 requested.
+debug1: channel 6: new direct-tcpip [direct-tcpip] (inactive timeout: 0)
+debug1: Connection to port 9999 forwarding to localhost port 5432 requested.
+debug1: channel 7: new direct-tcpip [direct-tcpip] (inactive timeout: 0)
+debug1: Connection to port 9999 forwarding to localhost port 5432 requested.
+debug1: channel 8: new direct-tcpip [direct-tcpip] (inactive timeout: 0)
+debug1: Connection to port 9999 forwarding to localhost port 5432 requested.
+debug1: channel 9: new direct-tcpip [direct-tcpip] (inactive timeout: 0)
+debug1: Connection to port 9999 forwarding to localhost port 5432 requested.
+debug1: channel 10: new direct-tcpip [direct-tcpip] (inactive timeout: 0)
+debug1: Connection to port 9999 forwarding to localhost port 5432 requested.
+debug1: channel 11: new direct-tcpip [direct-tcpip] (inactive timeout: 0)
+}}}