Remove swift-service-lifecycle dependency (#96)

We have only single service in the project, so we don't need to
orchestrate multiple services to gracefully shutdown. We can just
run the single service and let it run until it finishes.

Author: kateinoigakukun

Package.resolved

@@ -24,7 +24,6 @@ let package = Package(
     .package(url: "https://github.com/apple/swift-crypto.git", from: "3.1.0"),
     .package(url: "https://github.com/apple/swift-nio.git", from: "2.63.0"),
     .package(url: "https://github.com/apple/swift-log.git", from: "1.5.3"),
-    .package(url: "https://github.com/swift-server/swift-service-lifecycle.git", from: "2.3.0"),
   ],
   targets: [
     // Targets are the basic building blocks of a package. A target can define a module or a test suite.
@@ -34,7 +33,6 @@ let package = Package(
       dependencies: [
         "SwiftSDKGenerator",
         .product(name: "ArgumentParser", package: "swift-argument-parser"),
-        .product(name: "ServiceLifecycle", package: "swift-service-lifecycle"),
       ],
       swiftSettings: [
         .enableExperimentalFeature("StrictConcurrency=complete"),
@@ -47,7 +45,6 @@ let package = Package(
         .product(name: "AsyncAlgorithms", package: "swift-async-algorithms"),
         .product(name: "AsyncHTTPClient", package: "async-http-client"),
         .product(name: "Logging", package: "swift-log"),
-        .product(name: "ServiceLifecycle", package: "swift-service-lifecycle"),
         .product(name: "SystemPackage", package: "swift-system"),
         "GeneratorEngine",
         "Helpers",

Package.swift

@@ -12,7 +12,6 @@
 
 import ArgumentParser
 import Logging
-import ServiceLifecycle
 import SwiftSDKGenerator
 import struct SystemPackage.FilePath
 
@@ -40,18 +39,22 @@ struct GeneratorCLI: AsyncParsableCommand {
         logger: logger
       )
 
-      let serviceGroup = ServiceGroup(
-        configuration: .init(
-          services: [.init(
-            service: SwiftSDKGeneratorService(recipe: recipe, generator: generator),
-            successTerminationBehavior: .gracefullyShutdownGroup
-          )],
-          cancellationSignals: [.sigint],
-          logger: logger
-        )
-      )
+      let generatorTask = Task {
+        try await generator.run(recipe: recipe)
+      }
 
-      try await serviceGroup.run()
+      #if canImport(Darwin)
+      // On Darwin platforms Dispatch's signal source uses kqueue and EVFILT_SIGNAL for
+      // delivering signals. This exists alongside but with lower precedence than signal and
+      // sigaction: ignore signal handling here to kqueue can deliver signals.
+      signal(SIGINT, SIG_IGN)
+      #endif
+      let signalSource = DispatchSource.makeSignalSource(signal: SIGINT)
+      signalSource.setEventHandler {
+        generatorTask.cancel()
+      }
+      signalSource.resume()
+      try await generatorTask.value
     }
 
     print("\nTime taken for this generator run: \(elapsed.intervalString).")
@@ -303,15 +306,6 @@ extension Duration {
   }
 }
 
-struct SwiftSDKGeneratorService: Service {
-    let recipe: SwiftSDKRecipe
-    let generator: SwiftSDKGenerator
-
-    func run() async throws {
-        try await generator.run(recipe: recipe)
-    }
-}
-
 struct StringError: Error, CustomStringConvertible {
   let description: String
   init(_ description: String) {