[RFC] ConnectionPool rewrite and http/2 support

Package.swift

@@ -21,7 +21,8 @@ let package = Package(
         .library(name: "AsyncHTTPClient", targets: ["AsyncHTTPClient"]),
     ],
     dependencies: [
-        .package(url: "https://github.com/apple/swift-nio.git", from: "2.27.0"),
+        .package(url: "https://github.com/apple/swift-nio.git", from: "2.29.0"),
+        .package(url: "https://github.com/apple/swift-nio-http2.git", from: "1.7.0"),
         .package(url: "https://github.com/apple/swift-nio-ssl.git", from: "2.13.0"),
         .package(url: "https://github.com/apple/swift-nio-extras.git", from: "1.3.0"),
         .package(url: "https://github.com/apple/swift-nio-transport-services.git", from: "1.5.1"),
@@ -30,7 +31,7 @@ let package = Package(
     targets: [
         .target(
             name: "AsyncHTTPClient",
-            dependencies: ["NIO", "NIOHTTP1", "NIOSSL", "NIOConcurrencyHelpers", "NIOHTTPCompression",
+            dependencies: ["NIO", "NIOHTTP1", "NIOHTTP2", "NIOSSL", "NIOConcurrencyHelpers", "NIOHTTPCompression",
                            "NIOFoundationCompat", "NIOTransportServices", "Logging"]
         ),
         .testTarget(

Sources/AsyncHTTPClient/ConnectionPool.swift

@@ -86,7 +86,9 @@ final class ConnectionPool {
                 let provider = HTTP1ConnectionProvider(key: key,
                                                        eventLoop: taskEventLoop,
                                                        configuration: key.config(overriding: self.configuration),
+                                                       tlsConfiguration: request.tlsConfiguration,
                                                        pool: self,
+                                                       sslContextCache: self.sslContextCache,
                                                        backgroundActivityLogger: self.backgroundActivityLogger)
                 let enqueued = provider.enqueue()
                 assert(enqueued)
@@ -213,6 +215,8 @@ class HTTP1ConnectionProvider {
 
     private let backgroundActivityLogger: Logger
 
+    private let factory: HTTPConnectionPool.ConnectionFactory
+
     /// Creates a new `HTTP1ConnectionProvider`
     ///
     /// - parameters:
@@ -225,7 +229,9 @@ class HTTP1ConnectionProvider {
     init(key: ConnectionPool.Key,
          eventLoop: EventLoop,
          configuration: HTTPClient.Configuration,
+         tlsConfiguration: TLSConfiguration?,
          pool: ConnectionPool,
+         sslContextCache: SSLContextCache,
          backgroundActivityLogger: Logger) {
         self.eventLoop = eventLoop
         self.configuration = configuration
@@ -234,6 +240,13 @@ class HTTP1ConnectionProvider {
         self.closePromise = eventLoop.makePromise()
         self.state = .init(eventLoop: eventLoop)
         self.backgroundActivityLogger = backgroundActivityLogger
+
+        self.factory = HTTPConnectionPool.ConnectionFactory(
+            key: self.key,
+            tlsConfiguration: tlsConfiguration ?? configuration.tlsConfiguration ?? .forClient(),
+            clientConfiguration: self.configuration,
+            sslContextCache: sslContextCache
+        )
     }
 
     deinit {
@@ -440,12 +453,25 @@ class HTTP1ConnectionProvider {
 
     private func makeChannel(preference: HTTPClient.EventLoopPreference,
                              logger: Logger) -> EventLoopFuture<Channel> {
-        return NIOClientTCPBootstrap.makeHTTP1Channel(destination: self.key,
-                                                      eventLoop: self.eventLoop,
-                                                      configuration: self.configuration,
-                                                      sslContextCache: self.pool.sslContextCache,
-                                                      preference: preference,
-                                                      logger: logger)
+        let connectionID = HTTPConnectionPool.Connection.ID.globalGenerator.next()
+        let eventLoop = preference.bestEventLoop ?? self.eventLoop
+        return self.factory.makeBestChannel(connectionID: connectionID, eventLoop: eventLoop, logger: logger).flatMapThrowing {
+            (channel, _) -> Channel in
+
+            // add the http1.1 channel handlers
+            let syncOperations = channel.pipeline.syncOperations
+            try syncOperations.addHTTPClientHandlers(leftOverBytesStrategy: .forwardBytes)
+
+            switch self.configuration.decompression {
+            case .disabled:
+                ()
+            case .enabled(let limit):
+                let decompressHandler = NIOHTTPResponseDecompressor(limit: limit)
+                try syncOperations.addHandler(decompressHandler)
+            }
+
+            return channel
+        }
     }
 
     /// A `Waiter` represents a request that waits for a connection when none is