ChannelOption: Allow types to be accessed with leading dot syntax (#2816

)

Motivation:

Since Swift 5.5 and [SE-0299](https://github.com/swiftlang/swift-evolution/blob/main/proposals/0299-extend-generic-static-member-lookup.md) it is possible to add static members to protocols which are discoverable through the shorthand dot syntax.
This change reduces type repetition and improves call-site legibility.

Modifications:

Added extensions for ChannelOption with static members where Self is bound to a concrete type.

Result:

ChannelOption types can be used with the leading dot syntax. For eg:

```
//before
.channelOption(ChannelOptions.explicitCongestionNotification, value: true)
.channelOption(ChannelOptions.socketOption(.so_reuseaddr), value: 1)

//after
.channelOption(.explicitCongestionNotification, value: true)
.channelOption(.socketOption(.so_reuseaddr), value: 1)
```

IntegrationTests/tests_04_performance/test_01_resources/shared.swift

@@ -109,7 +109,7 @@ private final class SimpleHTTPServer: ChannelInboundHandler {
 
 func doRequests(group: EventLoopGroup, number numberOfRequests: Int) throws -> Int {
  let serverChannel = try ServerBootstrap(group: group)
- .serverChannelOption(ChannelOptions.socketOption(.so_reuseaddr), value: 1)
+ .serverChannelOption(.socketOption(.so_reuseaddr), value: 1)
  .childChannelInitializer { channel in
  channel.pipeline.configureHTTPServerPipeline(
  withPipeliningAssistance: true,

IntegrationTests/tests_04_performance/test_01_resources/test_1000_autoReadGetAndSet.swift

@@ -32,8 +32,8 @@ func run(identifier: String) {
  let iterations = 1000
 
  for _ in 0..<iterations {
- let autoReadOption = try! server.getOption(ChannelOptions.autoRead).wait()
- try! server.setOption(ChannelOptions.autoRead, value: !autoReadOption).wait()
+ let autoReadOption = try! server.getOption(.autoRead).wait()
+ try! server.setOption(.autoRead, value: !autoReadOption).wait()
  }
 
  return iterations

IntegrationTests/tests_04_performance/test_01_resources/test_1000_autoReadGetAndSet_sync.swift

@@ -24,8 +24,8 @@ func run(identifier: String) {
  let syncOptions = server.syncOptions!
 
  for _ in 0..<iterations {
- let autoReadOption = try! syncOptions.getOption(ChannelOptions.autoRead)
- try! syncOptions.setOption(ChannelOptions.autoRead, value: !autoReadOption)
+ let autoReadOption = try! syncOptions.getOption(.autoRead)
+ try! syncOptions.setOption(.autoRead, value: !autoReadOption)
  }
 
  return iterations

IntegrationTests/tests_04_performance/test_01_resources/test_1000_tcpconnections.swift

@@ -51,7 +51,7 @@ func run(identifier: String) {
  }
 
  let serverChannel = try! ServerBootstrap(group: group)
- .serverChannelOption(ChannelOptions.socketOption(.so_reuseaddr), value: 1)
+ .serverChannelOption(.socketOption(.so_reuseaddr), value: 1)
  .childChannelInitializer { channel in
  channel.pipeline.addHandler(ReceiveAndCloseHandler())
  }.bind(host: "127.0.0.1", port: 0).wait()

IntegrationTests/tests_04_performance/test_01_resources/test_1000_udp_reqs.swift

@@ -92,7 +92,7 @@ private final class ClientHandler: ChannelInboundHandler {
 
 func run(identifier: String) {
  let serverChannel = try! DatagramBootstrap(group: group)
- .channelOption(ChannelOptions.explicitCongestionNotification, value: true)
+ .channelOption(.explicitCongestionNotification, value: true)
  // Set the handlers that are applied to the bound channel
  .channelInitializer { channel in
  channel.pipeline.addHandler(ServerEchoHandler())
@@ -106,7 +106,7 @@ func run(identifier: String) {
  let clientHandler = ClientHandler(remoteAddress: remoteAddress)
 
  let clientChannel = try! DatagramBootstrap(group: group)
- .channelOption(ChannelOptions.explicitCongestionNotification, value: true)
+ .channelOption(.explicitCongestionNotification, value: true)
  .channelInitializer { channel in
  channel.pipeline.addHandler(clientHandler)
  }

IntegrationTests/tests_04_performance/test_01_resources/test_ping_pong_1000_reqs_1_conn.swift

@@ -120,8 +120,8 @@ private final class PongHandler: ChannelInboundHandler {
 
 func doPingPongRequests(group: EventLoopGroup, number numberOfRequests: Int) throws -> Int {
  let serverChannel = try ServerBootstrap(group: group)
- .serverChannelOption(ChannelOptions.socketOption(.so_reuseaddr), value: 1)
- .childChannelOption(ChannelOptions.recvAllocator, value: FixedSizeRecvByteBufferAllocator(capacity: 4))
+ .serverChannelOption(.socketOption(.so_reuseaddr), value: 1)
+ .childChannelOption(.recvAllocator, value: FixedSizeRecvByteBufferAllocator(capacity: 4))
  .childChannelInitializer { channel in
  channel.pipeline.addHandler(ByteToMessageHandler(PongDecoder())).flatMap {
  channel.pipeline.addHandler(PongHandler())
@@ -137,7 +137,7 @@ func doPingPongRequests(group: EventLoopGroup, number numberOfRequests: Int) thr
  .channelInitializer { channel in
  channel.pipeline.addHandler(pingHandler)
  }
- .channelOption(ChannelOptions.recvAllocator, value: FixedSizeRecvByteBufferAllocator(capacity: 4))
+ .channelOption(.recvAllocator, value: FixedSizeRecvByteBufferAllocator(capacity: 4))
  .connect(to: serverChannel.localAddress!)
  .wait()
 

Sources/NIOChatClient/main.swift

@@ -45,7 +45,7 @@ private final class ChatHandler: ChannelInboundHandler {
 let group = MultiThreadedEventLoopGroup(numberOfThreads: 1)
 let bootstrap = ClientBootstrap(group: group)
  // Enable SO_REUSEADDR.
- .channelOption(ChannelOptions.socketOption(.so_reuseaddr), value: 1)
+ .channelOption(.socketOption(.so_reuseaddr), value: 1)
  .channelInitializer { channel in
  channel.pipeline.addHandler(ChatHandler())
  }

Sources/NIOChatServer/main.swift

@@ -130,8 +130,8 @@ let chatHandler = ChatHandler()
 let group = MultiThreadedEventLoopGroup(numberOfThreads: System.coreCount)
 let bootstrap = ServerBootstrap(group: group)
  // Specify backlog and enable SO_REUSEADDR for the server itself
- .serverChannelOption(ChannelOptions.backlog, value: 256)
- .serverChannelOption(ChannelOptions.socketOption(.so_reuseaddr), value: 1)
+ .serverChannelOption(.backlog, value: 256)
+ .serverChannelOption(.socketOption(.so_reuseaddr), value: 1)
 
  // Set the handlers that are applied to the accepted Channels
  .childChannelInitializer { channel in
@@ -143,9 +143,9 @@ let bootstrap = ServerBootstrap(group: group)
  }
 
  // Enable SO_REUSEADDR for the accepted Channels
- .childChannelOption(ChannelOptions.socketOption(.so_reuseaddr), value: 1)
- .childChannelOption(ChannelOptions.maxMessagesPerRead, value: 16)
- .childChannelOption(ChannelOptions.recvAllocator, value: AdaptiveRecvByteBufferAllocator())
+ .childChannelOption(.socketOption(.so_reuseaddr), value: 1)
+ .childChannelOption(.maxMessagesPerRead, value: 16)
+ .childChannelOption(.recvAllocator, value: AdaptiveRecvByteBufferAllocator())
 defer {
  try! group.syncShutdownGracefully()
 }

Sources/NIOCore/ChannelOption.swift

@@ -360,6 +360,97 @@ public struct ChannelOptions: Sendable {
  public static let receivePacketInfo = Types.ReceivePacketInfo()
 }
 
+/// - seealso: `SocketOption`.
+extension ChannelOption where Self == ChannelOptions.Types.SocketOption {
+ #if !(os(Windows))
+ public static func socket(_ level: SocketOptionLevel, _ name: SocketOptionName) -> Self {
+ .init(level: NIOBSDSocket.OptionLevel(rawValue: CInt(level)), name: NIOBSDSocket.Option(rawValue: CInt(name)))
+ }
+ #endif
+
+ public static func socketOption(_ name: NIOBSDSocket.Option) -> Self {
+ .init(level: .socket, name: name)
+ }
+
+ public static func ipOption(_ name: NIOBSDSocket.Option) -> Self {
+ .init(level: .ip, name: name)
+ }
+
+ public static func tcpOption(_ name: NIOBSDSocket.Option) -> Self {
+ .init(level: .tcp, name: name)
+ }
+}
+
+/// - seealso: `AllocatorOption`.
+extension ChannelOption where Self == ChannelOptions.Types.AllocatorOption {
+ public static var allocator: Self { .init() }
+}
+
+/// - seealso: `RecvAllocatorOption`.
+extension ChannelOption where Self == ChannelOptions.Types.RecvAllocatorOption {
+ public static var recvAllocator: Self { .init() }
+}
+
+/// - seealso: `AutoReadOption`.
+extension ChannelOption where Self == ChannelOptions.Types.AutoReadOption {
+ public static var autoRead: Self { .init() }
+}
+
+/// - seealso: `MaxMessagesPerReadOption`.
+extension ChannelOption where Self == ChannelOptions.Types.MaxMessagesPerReadOption {
+ public static var maxMessagesPerRead: Self { .init() }
+}
+
+/// - seealso: `BacklogOption`.
+extension ChannelOption where Self == ChannelOptions.Types.BacklogOption {
+ public static var backlog: Self { .init() }
+}
+
+/// - seealso: `WriteSpinOption`.
+extension ChannelOption where Self == ChannelOptions.Types.WriteSpinOption {
+ public static var writeSpin: Self { .init() }
+}
+
+/// - seealso: `WriteBufferWaterMarkOption`.
+extension ChannelOption where Self == ChannelOptions.Types.WriteBufferWaterMarkOption {
+ public static var writeBufferWaterMark: Self { .init() }
+}
+
+/// - seealso: `ConnectTimeoutOption`.
+extension ChannelOption where Self == ChannelOptions.Types.ConnectTimeoutOption {
+ public static var connectTimeout: Self { .init() }
+}
+
+/// - seealso: `AllowRemoteHalfClosureOption`.
+extension ChannelOption where Self == ChannelOptions.Types.AllowRemoteHalfClosureOption {
+ public static var allowRemoteHalfClosure: Self { .init() }
+}
+
+/// - seealso: `DatagramVectorReadMessageCountOption`.
+extension ChannelOption where Self == ChannelOptions.Types.DatagramVectorReadMessageCountOption {
+ public static var datagramVectorReadMessageCount: Self { .init() }
+}
+
+/// - seealso: `DatagramSegmentSize`.
+extension ChannelOption where Self == ChannelOptions.Types.DatagramSegmentSize {
+ public static var datagramSegmentSize: Self { .init() }
+}
+
+/// - seealso: `DatagramReceiveOffload`.
+extension ChannelOption where Self == ChannelOptions.Types.DatagramReceiveOffload {
+ public static var datagramReceiveOffload: Self { .init() }
+}
+
+/// - seealso: `ExplicitCongestionNotificationsOption`.
+extension ChannelOption where Self == ChannelOptions.Types.ExplicitCongestionNotificationsOption {
+ public static var explicitCongestionNotification: Self { .init() }
+}
+
+/// - seealso: `ReceivePacketInfo`.
+extension ChannelOption where Self == ChannelOptions.Types.ReceivePacketInfo {
+ public static var receivePacketInfo: Self { .init() }
+}
+
 extension ChannelOptions {
  /// A type-safe storage facility for `ChannelOption`s. You will only ever need this if you implement your own
  /// `Channel` that needs to store `ChannelOption`s.

Sources/NIOCore/ConvenienceOptionSupport.swift

@@ -176,13 +176,13 @@ extension ChannelOptions {
  mutating func applyFallbackMapping(_ universalBootstrap: NIOClientTCPBootstrap) -> NIOClientTCPBootstrap {
  var result = universalBootstrap
  if self.consumeAllowLocalEndpointReuse().isSet {
- result = result.channelOption(ChannelOptions.socketOption(.so_reuseaddr), value: 1)
+ result = result.channelOption(.socketOption(.so_reuseaddr), value: 1)
  }
  if self.consumeAllowRemoteHalfClosure().isSet {
- result = result.channelOption(ChannelOptions.allowRemoteHalfClosure, value: true)
+ result = result.channelOption(.allowRemoteHalfClosure, value: true)
  }
  if self.consumeDisableAutoRead().isSet {
- result = result.channelOption(ChannelOptions.autoRead, value: false)
+ result = result.channelOption(.autoRead, value: false)
  }
  return result
  }

Sources/NIOCrashTester/OutputGrepper.swift

@@ -29,7 +29,7 @@ internal struct OutputGrepper {
 
  // We gotta `dup` everything because Pipe is bad and closes file descriptors on `deinit` :(
  let channelFuture = NIOPipeBootstrap(group: group)
- .channelOption(ChannelOptions.allowRemoteHalfClosure, value: true)
+ .channelOption(.allowRemoteHalfClosure, value: true)
  .channelInitializer { channel in
  channel.eventLoop.makeCompletedFuture {
  try channel.pipeline.syncOperations.addHandlers([

Sources/NIOEchoClient/main.swift

@@ -56,7 +56,7 @@ private final class EchoHandler: ChannelInboundHandler {
 let group = MultiThreadedEventLoopGroup(numberOfThreads: 1)
 let bootstrap = ClientBootstrap(group: group)
  // Enable SO_REUSEADDR.
- .channelOption(ChannelOptions.socketOption(.so_reuseaddr), value: 1)
+ .channelOption(.socketOption(.so_reuseaddr), value: 1)
  .channelInitializer { channel in
  channel.pipeline.addHandler(EchoHandler())
  }

Sources/NIOEchoServer/main.swift

@@ -40,8 +40,8 @@ private final class EchoHandler: ChannelInboundHandler {
 let group = MultiThreadedEventLoopGroup(numberOfThreads: System.coreCount)
 let bootstrap = ServerBootstrap(group: group)
  // Specify backlog and enable SO_REUSEADDR for the server itself
- .serverChannelOption(ChannelOptions.backlog, value: 256)
- .serverChannelOption(ChannelOptions.socketOption(.so_reuseaddr), value: 1)
+ .serverChannelOption(.backlog, value: 256)
+ .serverChannelOption(.socketOption(.so_reuseaddr), value: 1)
 
  // Set the handlers that are appled to the accepted Channels
  .childChannelInitializer { channel in
@@ -53,9 +53,9 @@ let bootstrap = ServerBootstrap(group: group)
  }
 
  // Enable SO_REUSEADDR for the accepted Channels
- .childChannelOption(ChannelOptions.socketOption(.so_reuseaddr), value: 1)
- .childChannelOption(ChannelOptions.maxMessagesPerRead, value: 16)
- .childChannelOption(ChannelOptions.recvAllocator, value: AdaptiveRecvByteBufferAllocator())
+ .childChannelOption(.socketOption(.so_reuseaddr), value: 1)
+ .childChannelOption(.maxMessagesPerRead, value: 16)
+ .childChannelOption(.recvAllocator, value: AdaptiveRecvByteBufferAllocator())
 defer {
  try! group.syncShutdownGracefully()
 }

Sources/NIOHTTP1Client/main.swift

@@ -79,7 +79,7 @@ private final class HTTPEchoHandler: ChannelInboundHandler {
 let group = MultiThreadedEventLoopGroup(numberOfThreads: 1)
 let bootstrap = ClientBootstrap(group: group)
  // Enable SO_REUSEADDR.
- .channelOption(ChannelOptions.socketOption(.so_reuseaddr), value: 1)
+ .channelOption(.socketOption(.so_reuseaddr), value: 1)
  .channelInitializer { channel in
  channel.pipeline.addHTTPClientHandlers(
  position: .first,

Sources/NIOHTTP1Server/main.swift

@@ -604,22 +604,22 @@ func childChannelInitializer(channel: Channel) -> EventLoopFuture<Void> {
 let fileIO = NonBlockingFileIO(threadPool: .singleton)
 let socketBootstrap = ServerBootstrap(group: MultiThreadedEventLoopGroup.singleton)
  // Specify backlog and enable SO_REUSEADDR for the server itself
- .serverChannelOption(ChannelOptions.backlog, value: 256)
- .serverChannelOption(ChannelOptions.socketOption(.so_reuseaddr), value: 1)
+ .serverChannelOption(.backlog, value: 256)
+ .serverChannelOption(.socketOption(.so_reuseaddr), value: 1)
 
  // Set the handlers that are applied to the accepted Channels
  .childChannelInitializer(childChannelInitializer(channel:))
 
  // Enable SO_REUSEADDR for the accepted Channels
- .childChannelOption(ChannelOptions.socketOption(.so_reuseaddr), value: 1)
- .childChannelOption(ChannelOptions.maxMessagesPerRead, value: 1)
- .childChannelOption(ChannelOptions.allowRemoteHalfClosure, value: allowHalfClosure)
+ .childChannelOption(.socketOption(.so_reuseaddr), value: 1)
+ .childChannelOption(.maxMessagesPerRead, value: 1)
+ .childChannelOption(.allowRemoteHalfClosure, value: allowHalfClosure)
 let pipeBootstrap = NIOPipeBootstrap(group: MultiThreadedEventLoopGroup.singleton)
  // Set the handlers that are applied to the accepted Channels
  .channelInitializer(childChannelInitializer(channel:))
 
- .channelOption(ChannelOptions.maxMessagesPerRead, value: 1)
- .channelOption(ChannelOptions.allowRemoteHalfClosure, value: allowHalfClosure)
+ .channelOption(.maxMessagesPerRead, value: 1)
+ .channelOption(.allowRemoteHalfClosure, value: allowHalfClosure)
 print("htdocs = \(htdocs)")
 
 let channel = try { () -> Channel in

Sources/NIOMulticastChat/main.swift

@@ -69,7 +69,7 @@ let group = MultiThreadedEventLoopGroup(numberOfThreads: 1)
 
 // Begin by setting up the basics of the bootstrap.
 var datagramBootstrap = DatagramBootstrap(group: group)
- .channelOption(ChannelOptions.socketOption(.so_reuseaddr), value: 1)
+ .channelOption(.socketOption(.so_reuseaddr), value: 1)
  .channelInitializer { channel in
  channel.pipeline.addHandler(ChatMessageEncoder()).flatMap {
  channel.pipeline.addHandler(ChatMessageDecoder())

Sources/NIOPerformanceTester/UDPBenchmark.swift

@@ -45,7 +45,7 @@ extension UDPBenchmark: Benchmark {
  let address = try SocketAddress.makeAddressResolvingHost("127.0.0.1", port: 0)
  self.server = try DatagramBootstrap(group: group)
  // zero is the same as not applying the option.
- .channelOption(ChannelOptions.datagramVectorReadMessageCount, value: self.vectorReads)
+ .channelOption(.datagramVectorReadMessageCount, value: self.vectorReads)
  .channelInitializer { channel in
  channel.pipeline.addHandler(EchoHandler())
  }
@@ -56,7 +56,7 @@ extension UDPBenchmark: Benchmark {
 
  self.client = try DatagramBootstrap(group: group)
  // zero is the same as not applying the option.
- .channelOption(ChannelOptions.datagramVectorReadMessageCount, value: self.vectorReads)
+ .channelOption(.datagramVectorReadMessageCount, value: self.vectorReads)
  .channelInitializer { channel in
  let handler = EchoHandlerClient(
  eventLoop: channel.eventLoop,

Sources/NIOPerformanceTester/main.swift

@@ -160,7 +160,7 @@ defer {
 }
 
 let serverChannel = try ServerBootstrap(group: group)
- .serverChannelOption(ChannelOptions.socketOption(.so_reuseaddr), value: 1)
+ .serverChannelOption(.socketOption(.so_reuseaddr), value: 1)
  .childChannelInitializer { channel in
  channel.pipeline.configureHTTPServerPipeline(withPipeliningAssistance: true).flatMap {
  channel.pipeline.addHandler(SimpleHTTPServer())

Sources/NIOPosix/BaseSocketChannel.swift

@@ -1140,7 +1140,7 @@ class BaseSocketChannel<SocketType: BaseSocketProtocol>: SelectableChannel, Chan
  //
  // getOption0 can only fail if the channel is not active anymore but we assert further up that it is. If
  // that's not the case this is a precondition failure and we would like to know.
- let allowRemoteHalfClosure = try! self.getOption0(ChannelOptions.allowRemoteHalfClosure)
+ let allowRemoteHalfClosure = try! self.getOption0(.allowRemoteHalfClosure)
 
  // For EOF, we always fire read complete.
  self.pipeline.syncOperations.fireChannelReadComplete()