Clean up dependencies and imports. (#1935)

Motivation:

As we've largely completed our move to split out our core abstractions,
we now have an opportunity to clean up our dependencies and imports. We
should arrange for everything to only import NIO if it actually needs
it, and to correctly express dependencies on NIOCore and NIOEmbedded
where they exist.

We aren't yet splitting out tests that only test functionality in
NIOCore, that will follow in a separate patch.

Modifications:

- Fixed up imports
- Made sure our protocols only require NIOCore.

Result:

Better expression of dependencies.

Co-authored-by: George Barnett <[email protected]>

Author: Lukasa

Package.swift

@@ -29,8 +29,8 @@ var targets: [PackageDescription.Target] = [
                            "_NIODataStructures",
                            "NIOEmbedded"]),
     .target(name: "_NIOConcurrency",
-            dependencies: ["NIO"]),
-    .target(name: "NIOFoundationCompat", dependencies: ["NIO"]),
+            dependencies: ["NIOCore"]),
+    .target(name: "NIOFoundationCompat", dependencies: ["NIOCore"]),
     .target(name: "CNIOAtomics", dependencies: []),
     .target(name: "CNIOSHA1", dependencies: []),
     .target(name: "CNIOLinux", dependencies: []),
@@ -39,59 +39,59 @@ var targets: [PackageDescription.Target] = [
     .target(name: "NIOConcurrencyHelpers",
             dependencies: ["CNIOAtomics"]),
     .target(name: "NIOHTTP1",
-            dependencies: ["NIO", "NIOConcurrencyHelpers", "CNIOHTTPParser"]),
+            dependencies: ["NIOCore", "NIOConcurrencyHelpers", "CNIOHTTPParser"]),
     .target(name: "NIOEchoServer",
-            dependencies: ["NIO", "NIOConcurrencyHelpers"]),
+            dependencies: ["NIO", "NIOCore", "NIOConcurrencyHelpers"]),
     .target(name: "NIOEchoClient",
-            dependencies: ["NIO", "NIOConcurrencyHelpers"]),
+            dependencies: ["NIO", "NIOCore", "NIOConcurrencyHelpers"]),
     .target(name: "NIOHTTP1Server",
-            dependencies: ["NIO", "NIOHTTP1", "NIOConcurrencyHelpers"]),
+            dependencies: ["NIO", "NIOCore", "NIOHTTP1", "NIOConcurrencyHelpers"]),
     .target(name: "NIOHTTP1Client",
-            dependencies: ["NIO", "NIOHTTP1", "NIOConcurrencyHelpers"]),
+            dependencies: ["NIO", "NIOCore", "NIOHTTP1", "NIOConcurrencyHelpers"]),
     .target(name: "CNIOHTTPParser"),
-    .target(name: "NIOTLS", dependencies: ["NIO"]),
+    .target(name: "NIOTLS", dependencies: ["NIOCore"]),
     .target(name: "NIOChatServer",
-            dependencies: ["NIO", "NIOConcurrencyHelpers"]),
+            dependencies: ["NIO", "NIOCore", "NIOConcurrencyHelpers"]),
     .target(name: "NIOChatClient",
-            dependencies: ["NIO", "NIOConcurrencyHelpers"]),
+            dependencies: ["NIO", "NIOCore", "NIOConcurrencyHelpers"]),
     .target(name: "NIOWebSocket",
-            dependencies: ["NIO", "NIOHTTP1", "CNIOSHA1"]),
+            dependencies: ["NIOCore", "NIOHTTP1", "CNIOSHA1"]),
     .target(name: "NIOWebSocketServer",
-            dependencies: ["NIO", "NIOHTTP1", "NIOWebSocket"]),
+            dependencies: ["NIO", "NIOCore", "NIOHTTP1", "NIOWebSocket"]),
     .target(name: "NIOWebSocketClient",
-            dependencies: ["NIO", "NIOHTTP1", "NIOWebSocket"]),
+            dependencies: ["NIO", "NIOCore", "NIOHTTP1", "NIOWebSocket"]),
     .target(name: "NIOPerformanceTester",
-            dependencies: ["NIO", "NIOHTTP1", "NIOFoundationCompat", "NIOWebSocket"]),
+            dependencies: ["NIO", "NIOCore", "NIOEmbedded", "NIOHTTP1", "NIOFoundationCompat", "NIOWebSocket"]),
     .target(name: "NIOMulticastChat",
-            dependencies: ["NIO"]),
+            dependencies: ["NIO", "NIOCore"]),
     .target(name: "NIOUDPEchoServer",
-            dependencies: ["NIO"]),
+            dependencies: ["NIO", "NIOCore"]),
     .target(name: "NIOUDPEchoClient",
-            dependencies: ["NIO"]),
+            dependencies: ["NIO", "NIOCore"]),
     .target(name: "NIOTestUtils",
-            dependencies: ["NIO", "NIOHTTP1"]),
+            dependencies: ["NIO", "NIOCore", "NIOEmbedded", "NIOHTTP1"]),
     .target(name: "NIOCrashTester",
-            dependencies: ["NIO", "NIOHTTP1", "NIOWebSocket", "NIOFoundationCompat"]),
+            dependencies: ["NIO", "NIOCore", "NIOEmbedded", "NIOHTTP1", "NIOWebSocket", "NIOFoundationCompat"]),
     .target(name: "NIOAsyncAwaitDemo",
-            dependencies: ["NIO", "NIOHTTP1", "_NIOConcurrency"]),
+            dependencies: ["NIO", "NIOCore", "NIOHTTP1", "_NIOConcurrency"]),
     .testTarget(name: "NIOEmbeddedTests",
                 dependencies: ["NIOConcurrencyHelpers", "NIOCore", "NIOEmbedded"]),
     .testTarget(name: "NIOTests",
-                dependencies: ["NIO", "NIOFoundationCompat", "NIOTestUtils", "NIOConcurrencyHelpers", "NIOEmbedded"]),
+                dependencies: ["NIO", "NIOCore", "NIOFoundationCompat", "NIOTestUtils", "NIOConcurrencyHelpers", "NIOEmbedded"]),
     .testTarget(name: "NIOConcurrencyHelpersTests",
-                dependencies: ["NIOConcurrencyHelpers", "NIO"]),
+                dependencies: ["NIOConcurrencyHelpers", "NIOCore"]),
     .testTarget(name: "NIODataStructuresTests",
                 dependencies: ["_NIODataStructures"]),
     .testTarget(name: "NIOHTTP1Tests",
-                dependencies: ["NIOHTTP1", "NIOFoundationCompat", "NIOTestUtils"]),
+                dependencies: ["NIOCore", "NIOEmbedded", "NIO", "NIOHTTP1", "NIOFoundationCompat", "NIOTestUtils"]),
     .testTarget(name: "NIOTLSTests",
-                dependencies: ["NIO", "NIOTLS", "NIOFoundationCompat"]),
+                dependencies: ["NIOCore", "NIOEmbedded", "NIOTLS", "NIOFoundationCompat"]),
     .testTarget(name: "NIOWebSocketTests",
-                dependencies: ["NIO", "NIOWebSocket"]),
+                dependencies: ["NIOCore", "NIOEmbedded", "NIOWebSocket"]),
     .testTarget(name: "NIOTestUtilsTests",
                 dependencies: ["NIOTestUtils"]),
     .testTarget(name: "NIOFoundationCompatTests",
-                dependencies: ["NIO", "NIOFoundationCompat"]),
+                dependencies: ["NIOCore", "NIOFoundationCompat"]),
 ]
 
 let package = Package(

Sources/NIOAsyncAwaitDemo/AsyncChannelIO.swift

@@ -12,7 +12,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-import NIO
+import NIOCore
 import NIOHTTP1
 
 #if compiler(>=5.5) // we cannot write this on one line with `&&` because Swift 5.0 doesn't like it...

Sources/NIOAsyncAwaitDemo/FullRequestResponse.swift

@@ -14,7 +14,7 @@
 
 // THIS FILE IS MOSTLY COPIED FROM swift-nio-extras
 
-import NIO
+import NIOCore
 import NIOHTTP1
 
 public final class MakeFullRequestHandler: ChannelOutboundHandler {

Sources/NIOAsyncAwaitDemo/main.swift

@@ -11,7 +11,7 @@
 // SPDX-License-Identifier: Apache-2.0
 //
 //===----------------------------------------------------------------------===//
-
+import NIOCore
 import NIO
 import _NIOConcurrency
 import NIOHTTP1

Sources/NIOChatClient/main.swift

@@ -2,7 +2,7 @@
 //
 // This source file is part of the SwiftNIO open source project
 //
-// Copyright (c) 2017-2018 Apple Inc. and the SwiftNIO project authors
+// Copyright (c) 2017-2021 Apple Inc. and the SwiftNIO project authors
 // Licensed under Apache License v2.0
 //
 // See LICENSE.txt for license information
@@ -11,6 +11,7 @@
 // SPDX-License-Identifier: Apache-2.0
 //
 //===----------------------------------------------------------------------===//
+import NIOCore
 import NIO
 
 private final class ChatHandler: ChannelInboundHandler {

Sources/NIOChatServer/main.swift

@@ -2,7 +2,7 @@
 //
 // This source file is part of the SwiftNIO open source project
 //
-// Copyright (c) 2017-2018 Apple Inc. and the SwiftNIO project authors
+// Copyright (c) 2017-2021 Apple Inc. and the SwiftNIO project authors
 // Licensed under Apache License v2.0
 //
 // See LICENSE.txt for license information
@@ -11,6 +11,7 @@
 // SPDX-License-Identifier: Apache-2.0
 //
 //===----------------------------------------------------------------------===//
+import NIOCore
 import NIO
 import Dispatch
 

Sources/NIOCrashTester/CrashTests+ByteBuffer.swift

@@ -2,7 +2,7 @@
 //
 // This source file is part of the SwiftNIO open source project
 //
-// Copyright (c) 2020 Apple Inc. and the SwiftNIO project authors
+// Copyright (c) 2020-2021 Apple Inc. and the SwiftNIO project authors
 // Licensed under Apache License v2.0
 //
 // See LICENSE.txt for license information
@@ -12,7 +12,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-import NIO
+import NIOCore
 
 struct ByteBufferCrashTests {
     let testMovingReaderIndexPastWriterIndex = CrashTest(

Sources/NIOCrashTester/CrashTests+EventLoop.swift

@@ -2,7 +2,7 @@
 //
 // This source file is part of the SwiftNIO open source project
 //
-// Copyright (c) 2020 Apple Inc. and the SwiftNIO project authors
+// Copyright (c) 2020-2021 Apple Inc. and the SwiftNIO project authors
 // Licensed under Apache License v2.0
 //
 // See LICENSE.txt for license information
@@ -11,7 +11,7 @@
 // SPDX-License-Identifier: Apache-2.0
 //
 //===----------------------------------------------------------------------===//
-
+import NIOCore
 import NIO
 
 fileprivate let group = MultiThreadedEventLoopGroup(numberOfThreads: 2)

Sources/NIOCrashTester/CrashTests+HTTP.swift

@@ -2,7 +2,7 @@
 //
 // This source file is part of the SwiftNIO open source project
 //
-// Copyright (c) 2020 Apple Inc. and the SwiftNIO project authors
+// Copyright (c) 2020-2021 Apple Inc. and the SwiftNIO project authors
 // Licensed under Apache License v2.0
 //
 // See LICENSE.txt for license information
@@ -11,8 +11,8 @@
 // SPDX-License-Identifier: Apache-2.0
 //
 //===----------------------------------------------------------------------===//
-
-import NIO
+import NIOEmbedded
+import NIOCore
 import NIOHTTP1
 
 struct HTTPCrashTests {

Sources/NIOCrashTester/OutputGrepper.swift

@@ -2,7 +2,7 @@
 //
 // This source file is part of the SwiftNIO open source project
 //
-// Copyright (c) 2020 Apple Inc. and the SwiftNIO project authors
+// Copyright (c) 2020-2021 Apple Inc. and the SwiftNIO project authors
 // Licensed under Apache License v2.0
 //
 // See LICENSE.txt for license information
@@ -11,7 +11,7 @@
 // SPDX-License-Identifier: Apache-2.0
 //
 //===----------------------------------------------------------------------===//
-
+import NIOCore
 import NIO
 import NIOFoundationCompat
 import class Foundation.Pipe