EventLoopFuture: use Result type (#734)

Motivation: Now that the stdlib has introduced the Result type, we can use it in the implementation (and the whenComplete) function of EventLoopFuture Modifications: - replace EventLoopValue with Result - make whenComplete provide the Result Result: use the new shiny stuff
apple · Jan 5, 2019 · 684cad3 · 684cad3
1 parent 08eb325
commit 684cad3
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Showing 21 changed files with 74 additions and 86 deletions.
diff --git a/Sources/NIO/Bootstrap.swift b/Sources/NIO/Bootstrap.swift
@@ -440,7 +440,7 @@ public final class ClientBootstrap {
                 channel.close(promise: nil)
             }
 
-            connectPromise.futureResult.whenComplete {
+            connectPromise.futureResult.whenComplete { (_: Result<Void, Error>) in
                 cancelTask.cancel()
             }
             return connectPromise.futureResult

diff --git a/Sources/NIO/ChannelHandlers.swift b/Sources/NIO/ChannelHandlers.swift
@@ -223,7 +223,7 @@ public class IdleStateHandler: ChannelDuplexHandler {
         }
 
         let writePromise = promise ?? ctx.eventLoop.makePromise()
-        writePromise.futureResult.whenComplete {
+        writePromise.futureResult.whenComplete { (_: Result<Void, Error>) in
             self.lastWriteCompleteTime = DispatchTime.now()
         }
         ctx.write(data, promise: writePromise)

diff --git a/Sources/NIO/EventLoop.swift b/Sources/NIO/EventLoop.swift
@@ -116,7 +116,7 @@ public final class RepeatedTask {
         }
 
         scheduled.futureResult.whenSuccess { future in
-            future.whenComplete {
+            future.whenComplete { (_: Result<Void, Error>) in
                 self.reschedule0()
             }
         }
@@ -957,7 +957,7 @@ final public class MultiThreadedEventLoopGroup: EventLoopGroup {
             g.enter()
             loop.closeGently().mapIfError { err in
                 q.sync { error = err }
-            }.whenComplete {
+            }.whenComplete { (_: Result<Void, Error>) in
                 g.leave()
             }
         }

diff --git a/Sources/NIO/EventLoopFuture.swift b/Sources/NIO/EventLoopFuture.swift
@@ -14,14 +14,6 @@
 
 import NIOConcurrencyHelpers
 
-
-/// A `Result`-like type that is used to track the data through the
-/// callback pipeline.
-private enum EventLoopFutureValue<T> {
-    case success(T)
-    case failure(Error)
-}
-
 /// Internal list of callbacks.
 ///
 /// Most of these are closures that pull a value from one future, call a user callback, push the
@@ -187,7 +179,7 @@ public struct EventLoopPromise<T> {
     ///
     /// - parameters:
     ///     - value: The value to fire the future with.
-    private func _resolve(value: EventLoopFutureValue<T>) {
+    private func _resolve(value: Result<T, Error>) {
         if futureResult.eventLoop.inEventLoop {
             _setValue(value: value)._run()
         } else {
@@ -202,7 +194,7 @@ public struct EventLoopPromise<T> {
     /// - parameters:
     ///     - value: The result of the promise.
     /// - returns: The callback list to run.
-    fileprivate func _setValue(value: EventLoopFutureValue<T>) -> CallbackList {
+    fileprivate func _setValue(value: Result<T, Error>) -> CallbackList {
         return futureResult._setValue(value: value)
     }
 }
@@ -333,7 +325,7 @@ public struct EventLoopPromise<T> {
 /// `EventLoopFuture` should be sufficient to guarantee thread-safety.
 public final class EventLoopFuture<T> {
     // TODO: Provide a tracing facility.  It would be nice to be able to set '.debugTrace = true' on any EventLoopFuture or EventLoopPromise and have every subsequent chained EventLoopFuture report the success result or failure error.  That would simplify some debugging scenarios.
-    fileprivate var value: EventLoopFutureValue<T>? {
+    fileprivate var value: Result<T, Error>? {
         didSet {
             _isFulfilled.store(true)
         }
@@ -356,7 +348,7 @@ public final class EventLoopFuture<T> {
     /// the entire chain from the top without recursing.
     fileprivate var callbacks: CallbackList = CallbackList()
 
-    private init(eventLoop: EventLoop, value: EventLoopFutureValue<T>?, file: StaticString, line: UInt) {
+    private init(eventLoop: EventLoop, value: Result<T, Error>?, file: StaticString, line: UInt) {
         self.eventLoop = eventLoop
         self.value = value
         self._isFulfilled = UnsafeEmbeddedAtomic(value: value != nil)
@@ -608,7 +600,7 @@ extension EventLoopFuture {
         }
     }
 
-    fileprivate func _whenCompleteWithValue(_ callback: @escaping (EventLoopFutureValue<T>) -> Void) {
+    fileprivate func _whenCompleteWithValue(_ callback: @escaping (Result<T, Error>) -> Void) {
         _whenComplete {
             callback(self.value!)
             return CallbackList()
@@ -662,16 +654,16 @@ extension EventLoopFuture {
     ///
     /// - parameters:
     ///     - callback: The callback that is called when the `EventLoopFuture` is fulfilled.
-    public func whenComplete(_ callback: @escaping () -> Void) {
+    public func whenComplete(_ callback: @escaping (Result<T, Error>) -> Void) {
         _whenComplete {
-            callback()
+            callback(self.value!)
             return CallbackList()
         }
     }
 
 
     /// Internal:  Set the value and return a list of callbacks that should be invoked as a result.
-    fileprivate func _setValue(value: EventLoopFutureValue<T>) -> CallbackList {
+    fileprivate func _setValue(value: Result<T, Error>) -> CallbackList {
         self.eventLoop.assertInEventLoop()
         if self.value == nil {
             self.value = value
@@ -813,7 +805,7 @@ Further information:
             precondition(MultiThreadedEventLoopGroup.currentEventLoop == nil, explainer(), file: file, line: line)
         }
 
-        var v: EventLoopFutureValue <T>? = nil
+        var v: Result<T, Error>? = nil
         let lock = ConditionLock(value: 0)
         _whenComplete { () -> CallbackList in
             lock.lock()

diff --git a/Sources/NIO/HappyEyeballs.swift b/Sources/NIO/HappyEyeballs.swift
@@ -606,7 +606,7 @@ internal class HappyEyeballsConnector {
             self.targets.aResultsAvailable(results)
         }.mapIfError { err in
             self.error.dnsAError = err
-        }.whenComplete {
+        }.whenComplete { (_: Result<Void, Error>) in
             self.dnsResolutions += 1
             self.processInput(.resolverACompleted)
         }
@@ -618,7 +618,7 @@ internal class HappyEyeballsConnector {
             self.targets.aaaaResultsAvailable(results)
         }.mapIfError { err in
             self.error.dnsAAAAError = err
-        }.whenComplete {
+        }.whenComplete { (_: Result<Void, Error>) in
             // It's possible that we were waiting to time out here, so if we were we should
             // cancel that.
             self.resolutionTask?.cancel()

diff --git a/Sources/NIOHTTP1/HTTPUpgradeHandler.swift b/Sources/NIOHTTP1/HTTPUpgradeHandler.swift
@@ -206,7 +206,7 @@ public class HTTPServerUpgradeHandler: ChannelInboundHandler {
                     if bufferedMessages.count > 0 {
                         ctx.fireChannelReadComplete()
                     }
-                }.whenComplete {
+                }.whenComplete { (_: Result<Void, Error>) in
                     ctx.pipeline.remove(ctx: ctx, promise: nil)
                 }
             }

diff --git a/Sources/NIOHTTP1Server/main.swift b/Sources/NIOHTTP1Server/main.swift
@@ -358,7 +358,7 @@ private final class HTTPHandler: ChannelInboundHandler {
                         } else {
                             return ctx.close()
                         }
-                    }.whenComplete {
+                    }.whenComplete { (_: Result<Void, Error>) in
                         _ = try? file.close()
                     }
                 case .sendfile:
@@ -370,7 +370,7 @@ private final class HTTPHandler: ChannelInboundHandler {
                         return p.futureResult
                     }.thenIfError { (_: Error) in
                         ctx.close()
-                    }.whenComplete {
+                    }.whenComplete { (_: Result<Void, Error>) in
                         _ = try? file.close()
                     }
                 }
@@ -387,7 +387,7 @@ private final class HTTPHandler: ChannelInboundHandler {
 
         let promise = self.keepAlive ? promise : (promise ?? ctx.eventLoop.makePromise())
         if !self.keepAlive {
-            promise!.futureResult.whenComplete { ctx.close(promise: nil) }
+            promise!.futureResult.whenComplete { (_: Result<Void, Error>) in ctx.close(promise: nil) }
         }
         self.handler = nil
 

diff --git a/Sources/NIOTLS/ApplicationProtocolNegotiationHandler.swift b/Sources/NIOTLS/ApplicationProtocolNegotiationHandler.swift
@@ -118,7 +118,7 @@ public class ApplicationProtocolNegotiationHandler: ChannelInboundHandler {
         }
 
         let switchFuture = completionHandler(result)
-        switchFuture.whenComplete {
+        switchFuture.whenComplete { (_: Result<Void, Error>) in
             self.unbuffer(context: context)
             context.pipeline.remove(handler: self, promise: nil)
         }

diff --git a/Sources/NIOWebSocket/WebSocketFrameDecoder.swift b/Sources/NIOWebSocket/WebSocketFrameDecoder.swift
@@ -309,7 +309,7 @@ public final class WebSocketFrameDecoder: ByteToMessageDecoder {
             let frame = WebSocketFrame(fin: true,
                                        opcode: .connectionClose,
                                        data: data)
-            ctx.writeAndFlush(self.wrapInboundOut(frame)).whenComplete {
+            ctx.writeAndFlush(self.wrapInboundOut(frame)).whenComplete { (_: Result<Void, Error>) in
                 ctx.close(promise: nil)
             }
         }

diff --git a/Sources/NIOWebSocket/WebSocketProtocolErrorHandler.swift b/Sources/NIOWebSocket/WebSocketProtocolErrorHandler.swift
@@ -32,7 +32,7 @@ public final class WebSocketProtocolErrorHandler: ChannelInboundHandler {
             let frame = WebSocketFrame(fin: true,
                                        opcode: .connectionClose,
                                        data: data)
-            ctx.writeAndFlush(self.wrapOutboundOut(frame)).whenComplete {
+            ctx.writeAndFlush(self.wrapOutboundOut(frame)).whenComplete { (_: Result<Void, Error>) in
                 ctx.close(promise: nil)
             }
         }

diff --git a/Sources/NIOWebSocketServer/main.swift b/Sources/NIOWebSocketServer/main.swift
@@ -81,7 +81,7 @@ private final class HTTPHandler: ChannelInboundHandler {
                                     headers: headers)
         ctx.write(self.wrapOutboundOut(.head(responseHead)), promise: nil)
         ctx.write(self.wrapOutboundOut(.body(.byteBuffer(self.responseBody))), promise: nil)
-        ctx.write(self.wrapOutboundOut(.end(nil))).whenComplete {
+        ctx.write(self.wrapOutboundOut(.end(nil))).whenComplete { (_: Result<Void, Error>) in
             ctx.close(promise: nil)
         }
         ctx.flush()
@@ -95,7 +95,7 @@ private final class HTTPHandler: ChannelInboundHandler {
                                     status: .methodNotAllowed,
                                     headers: headers)
         ctx.write(self.wrapOutboundOut(.head(head)), promise: nil)
-        ctx.write(self.wrapOutboundOut(.end(nil))).whenComplete {
+        ctx.write(self.wrapOutboundOut(.end(nil))).whenComplete { (_: Result<Void, Error>) in
             ctx.close(promise: nil)
         }
         ctx.flush()
@@ -194,7 +194,7 @@ private final class WebSocketTimeHandler: ChannelInboundHandler {
         var data = ctx.channel.allocator.buffer(capacity: 2)
         data.write(webSocketErrorCode: .protocolError)
         let frame = WebSocketFrame(fin: true, opcode: .connectionClose, data: data)
-        ctx.write(self.wrapOutboundOut(frame)).whenComplete {
+        ctx.write(self.wrapOutboundOut(frame)).whenComplete { (_: Result<Void, Error>) in
             ctx.close(mode: .output, promise: nil)
         }
         awaitingClose = true

diff --git a/Tests/NIOHTTP1Tests/HTTPResponseCompressorTest.swift b/Tests/NIOHTTP1Tests/HTTPResponseCompressorTest.swift
@@ -36,7 +36,7 @@ private class PromiseOrderer {
         let thisPromiseIndex = promiseArray.count
         promiseArray.append(promise)
 
-        promise.futureResult.whenComplete {
+        promise.futureResult.whenComplete { (_: Result<Void, Error>) in
             let priorFutures = self.promiseArray[0..<thisPromiseIndex]
             let subsequentFutures = self.promiseArray[(thisPromiseIndex + 1)...]
             let allPriorFuturesFired = priorFutures.map { $0.futureResult.isFulfilled }.allSatisfy { $0 }

diff --git a/Tests/NIOHTTP1Tests/HTTPServerClientTest.swift b/Tests/NIOHTTP1Tests/HTTPServerClientTest.swift
@@ -124,12 +124,12 @@ class HTTPServerClientTest : XCTestCase {
                     b.write(string: replyString)
 
                     let outbound = self.outboundBody(b)
-                    ctx.write(self.wrapOutboundOut(outbound.body)).whenComplete {
+                    ctx.write(self.wrapOutboundOut(outbound.body)).whenComplete { (_: Result<Void, Error>) in
                         outbound.destructor()
                     }
                     ctx.write(self.wrapOutboundOut(.end(nil))).mapIfError { error in
                         XCTFail("unexpected error \(error)")
-                    }.whenComplete {
+                    }.whenComplete { (_: Result<Void, Error>) in
                         self.sentEnd = true
                         self.maybeClose(ctx: ctx)
                     }
@@ -148,13 +148,13 @@ class HTTPServerClientTest : XCTestCase {
                         let outbound = self.outboundBody(b)
                         ctx.write(self.wrapOutboundOut(outbound.body)).mapIfError { error in
                             XCTFail("unexpected error \(error)")
-                        }.whenComplete {
+                        }.whenComplete { (_: Result<Void, Error>) in
                             outbound.destructor()
                         }
                     }
                     ctx.write(self.wrapOutboundOut(.end(nil))).mapIfError { error in
                         XCTFail("unexpected error \(error)")
-                    }.whenComplete {
+                    }.whenComplete { (_: Result<Void, Error>) in
                         self.sentEnd = true
                         self.maybeClose(ctx: ctx)
                     }
@@ -174,7 +174,7 @@ class HTTPServerClientTest : XCTestCase {
                         let outbound = self.outboundBody(b)
                         ctx.write(self.wrapOutboundOut(outbound.body)).mapIfError { error in
                             XCTFail("unexpected error \(error)")
-                        }.whenComplete {
+                        }.whenComplete { (_: Result<Void, Error>) in
                             outbound.destructor()
                         }
                     }
@@ -184,7 +184,7 @@ class HTTPServerClientTest : XCTestCase {
                     trailers.add(name: "X-Should-Trail", value: "sure")
                     ctx.write(self.wrapOutboundOut(.end(trailers))).mapIfError { error in
                         XCTFail("unexpected error \(error)")
-                    }.whenComplete {
+                    }.whenComplete { (_: Result<Void, Error>) in
                         self.sentEnd = true
                         self.maybeClose(ctx: ctx)
                     }
@@ -209,12 +209,12 @@ class HTTPServerClientTest : XCTestCase {
                     let outbound = self.outboundBody(buf)
                     ctx.writeAndFlush(self.wrapOutboundOut(outbound.body)).mapIfError { error in
                         XCTFail("unexpected error \(error)")
-                    }.whenComplete {
+                    }.whenComplete { (_: Result<Void, Error>) in
                         outbound.destructor()
                     }
                     ctx.write(self.wrapOutboundOut(.end(nil))).mapIfError { error in
                         XCTFail("unexpected error \(error)")
-                    }.whenComplete {
+                    }.whenComplete { (_: Result<Void, Error>) in
                         self.sentEnd = true
                         self.maybeClose(ctx: ctx)
                     }
@@ -227,7 +227,7 @@ class HTTPServerClientTest : XCTestCase {
                     }
                     ctx.write(self.wrapOutboundOut(.end(nil))).mapIfError { error in
                         XCTFail("unexpected error \(error)")
-                    }.whenComplete {
+                    }.whenComplete { (_: Result<Void, Error>) in
                         self.sentEnd = true
                         self.maybeClose(ctx: ctx)
                     }
@@ -239,7 +239,7 @@ class HTTPServerClientTest : XCTestCase {
                     }
                     ctx.write(self.wrapOutboundOut(.end(nil))).mapIfError { error in
                         XCTFail("unexpected error \(error)")
-                    }.whenComplete {
+                    }.whenComplete { (_: Result<Void, Error>) in
                         self.sentEnd = true
                         self.maybeClose(ctx: ctx)
                     }

diff --git a/Tests/NIOTests/ChannelTests.swift b/Tests/NIOTests/ChannelTests.swift
@@ -972,7 +972,7 @@ public class ChannelTests: XCTestCase {
             pwm.markFlushCheckpoint()
             _ = pwm.add(data: .byteBuffer(buffer), promise: ps[2])
 
-            ps[0].futureResult.whenComplete {
+            ps[0].futureResult.whenComplete { (_: Result<Void, Error>) in
                 pwm.failAll(error: ChannelError.inputClosed, close: true)
             }
 

diff --git a/Tests/NIOTests/EchoServerClientTest.swift b/Tests/NIOTests/EchoServerClientTest.swift
@@ -350,7 +350,7 @@ class EchoServerClientTest : XCTestCase {
                     default:
                         XCTFail("unexpected error: \(err)")
                     }
-                }.whenComplete {
+                }.whenComplete { (_: Result<Void, Error>) in
                     self.channelInactivePromise.succeed(result: ())
                 }
             }
@@ -370,7 +370,7 @@ class EchoServerClientTest : XCTestCase {
                     default:
                         XCTFail("unexpected error: \(err)")
                     }
-                }.whenComplete {
+                }.whenComplete { (_: Result<Void, Error>) in
                     self.channelUnregisteredPromise.succeed(result: ())
                 }
             }
@@ -603,7 +603,7 @@ class EchoServerClientTest : XCTestCase {
             }
 
             private func writeUntilFailed(_ ctx: ChannelHandlerContext, _ buffer: ByteBuffer) {
-                ctx.writeAndFlush(NIOAny(buffer)).whenComplete {
+                ctx.writeAndFlush(NIOAny(buffer)).whenComplete { (_: Result<Void, Error>) in
                     ctx.eventLoop.execute {
                         self.writeUntilFailed(ctx, buffer)
                     }
@@ -635,7 +635,7 @@ class EchoServerClientTest : XCTestCase {
                     ctx.writeAndFlush(NIOAny(buffer))
                 }.then {
                     ctx.close()
-                }.whenComplete {
+                }.whenComplete { (_: Result<Void, Error>) in
                     self.dpGroup.leave()
                 }
             }

diff --git a/Tests/NIOTests/EmbeddedChannelTest.swift b/Tests/NIOTests/EmbeddedChannelTest.swift
@@ -160,14 +160,14 @@ class EmbeddedChannelTest: XCTestCase {
         let channel = EmbeddedChannel()
         XCTAssertFalse(channel.isActive)
         let connectPromise = channel.eventLoop.makePromise(of: Void.self)
-        connectPromise.futureResult.whenComplete {
+        connectPromise.futureResult.whenComplete { (_: Result<Void, Error>) in
             XCTAssertTrue(channel.isActive)
         }
         channel.connect(to: try SocketAddress(ipAddress: "127.0.0.1", port: 0), promise: connectPromise)
         try connectPromise.futureResult.wait()
 
         let closePromise = channel.eventLoop.makePromise(of: Void.self)
-        closePromise.futureResult.whenComplete {
+        closePromise.futureResult.whenComplete { (_: Result<Void, Error>) in
             XCTAssertFalse(channel.isActive)
         }
 

diff --git a/Tests/NIOTests/EmbeddedEventLoopTest.swift b/Tests/NIOTests/EmbeddedEventLoopTest.swift
@@ -215,7 +215,7 @@ public class EmbeddedEventLoopTest: XCTestCase {
             XCTFail("Scheduled future completed")
         }.mapIfError { caughtErr in
             XCTAssertTrue(err === caughtErr as? EmbeddedTestError)
-        }.whenComplete {
+        }.whenComplete { (_: Result<Void, Error>) in
             fired = true
         }