Added initial benchmarks

.gitignore

@@ -9,3 +9,4 @@ DerivedData/
 /Package.resolved
 .ci/
 .docc-build/
+Package.resolved

Benchmarks/.gitignore

@@ -0,0 +1,8 @@
+.DS_Store
+/.build
+/Packages
+xcuserdata/
+DerivedData/
+.swiftpm/xcode/package.xcworkspace/contents.xcworkspacedata
+.netrc
+.benchmarkBaselines/

Benchmarks/Package.swift

@@ -0,0 +1,30 @@
+// swift-tools-version: 5.9
+
+import PackageDescription
+
+let package = Package(
+    name: "benchmarks",
+    platforms: [
+        .macOS(.v14),
+    ],
+    products: [
+        .executable(name: "Benchmarks", targets: ["Benchmarks"]),
+    ],
+    dependencies: [
+        .package(name: "swift-openapi-async-http-client", path: "../"),
+        .package(url: "https://github.com/ordo-one/package-benchmark.git", from: "1.26.0"),
+    ],
+    targets: [
+        .executableTarget(
+            name: "Benchmarks",
+            dependencies: [
+                .product(name: "Benchmark", package: "package-benchmark"),
+                .product(name: "OpenAPIAsyncHTTPClient", package: "swift-openapi-async-http-client")
+            ],
+            path: "Sources",
+            plugins: [
+                .plugin(name: "BenchmarkPlugin", package: "package-benchmark")
+            ]
+        ),
+    ]
+)

Benchmarks/README.md

@@ -0,0 +1,23 @@
+# Benchmarks
+
+## Running
+
+Run and check results.
+
+```zsh
+swift package benchmark
+```
+
+## Checking against baselines
+
+Run for a specific Swift version, for example:
+```zsh
+swift package benchmark baseline check --check-absolute-path Thresholds/5.10/
+```
+
+## Updating baselines
+
+Update for a specific Swift version, for example:
+```zsh
+swift package --allow-writing-to-package-directory benchmark --format metricP90AbsoluteThresholds --path Thresholds/5.10/
+```

Benchmarks/Sources/Benchmarks.swift

@@ -0,0 +1,77 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the SwiftOpenAPIGenerator open source project
+//
+// Copyright (c) YEARS Apple Inc. and the SwiftOpenAPIGenerator project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of SwiftOpenAPIGenerator project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+
+import Benchmark
+@_spi(Benchmarks) import OpenAPIAsyncHTTPClient
+import AsyncHTTPClient
+import NIOCore
+import HTTPTypes
+import OpenAPIRuntime
+import Foundation
+
+let benchmarks = {
+    let defaultMetrics: [BenchmarkMetric] = [
+        .mallocCountTotal,
+        .cpuTotal
+    ]
+    let config: Benchmark.Configuration = .init(
+        metrics: defaultMetrics,
+        scalingFactor: .kilo,
+        maxDuration: .seconds(10)
+    )
+
+    Benchmark("Creation.Default", configuration: config) { benchmark in
+        for _ in benchmark.scaledIterations {
+            blackHole({
+                AsyncHTTPClientTransport()
+            }())
+        }
+    }
+
+    Benchmark("Conversion", configuration: config) { benchmark in
+        let request = HTTPRequest(
+            method: .post,
+            scheme: nil,
+            authority: nil,
+            path: "/stuff",
+            headerFields: [
+                .init("x-stuff")!: "things"
+            ]
+        )
+        let requestBody = HTTPBody("Hello world")
+        let baseURL = URL(string: "https://example.com")!
+        let response = HTTPClientResponse(
+            status: .ok,
+            headers: [
+                "x-stuff": "things"
+            ],
+            body: .bytes(ByteBuffer(string: "Hello world"))
+        )
+        let transport = AsyncHTTPClientTransport(
+            configuration: .init(),
+            requestSenderClosure: { _, _, _ in
+                response
+            }
+        )
+        for _ in benchmark.scaledIterations {
+            let (response, responseBody) = try await transport.send(
+                request,
+                body: requestBody,
+                baseURL: baseURL,
+                operationID: "postThings"
+            )
+            blackHole((response, responseBody))
+        }
+    }
+}

Sources/OpenAPIAsyncHTTPClient/AsyncHTTPClientTransport.swift

@@ -127,6 +127,27 @@ public struct AsyncHTTPClientTransport: ClientTransport {
         self.requestSender = requestSender
     }
 
+    /// Creates a new transport.
+    /// - Parameters:
+    ///   - configuration: A set of configuration values used by the transport.
+    ///   - requestSenderClosure: The underlying request sender closure.
+    @_spi(Benchmarks) public init(
+        configuration: Configuration,
+        requestSenderClosure: @Sendable @escaping (HTTPClientRequest, HTTPClient, TimeAmount) async throws ->
+            HTTPClientResponse
+    ) {
+        struct ClosureRequestSender: HTTPRequestSending {
+            var sendClosure:
+                @Sendable (AsyncHTTPClientTransport.Request, HTTPClient, TimeAmount) async throws ->
+                    AsyncHTTPClientTransport.Response
+            func send(request: AsyncHTTPClientTransport.Request, with client: HTTPClient, timeout: TimeAmount)
+                async throws -> AsyncHTTPClientTransport.Response
+            { try await sendClosure(request, client, timeout) }
+        }
+        self.configuration = configuration
+        self.requestSender = ClosureRequestSender(sendClosure: requestSenderClosure)
+    }
+
     /// Creates a new transport.
     /// - Parameter configuration: A set of configuration values used by the transport.
     public init(configuration: Configuration = .init()) {

scripts/check-license-headers.sh

@@ -43,6 +43,9 @@ read -ra PATHS_TO_CHECK_FOR_LICENSE <<< "$( \
   ":(exclude).gitignore" \
   ":(exclude).spi.yml" \
   ":(exclude).swift-format" \
+  ":(exclude)Benchmarks/.gitignore" \
+  ":(exclude)Benchmarks/Package.swift" \
+  ":(exclude)Benchmarks/README.md" \
   ":(exclude)CODE_OF_CONDUCT.md" \
   ":(exclude)CONTRIBUTING.md" \
   ":(exclude)CONTRIBUTORS.txt" \