问题描述
我有一个 http4s HttpRoutes
和一个我的效果类型的任务(ZIO,如果这很重要)。效果是副作用,不返回任何值。我想将两者组合在一起,创建一个新的 HttpRoutes
,它将在 HttpRoutes
中的任何匹配路由之前运行效果。
import zio.Task
val httpRoutes: HttpRoutes[Task] = ...
val effect: Task[Unit] = ...
val combined: HttpRoutes[Task] = ???
如何将 HttpRoutes
和效果结合在一起?
解决方法
根据 https://http4s.org/v0.21/middleware
的简单实现对我有用
@accessible
trait HttpServer {
def bindHttp: UIO[Server[Task]]
}
object HttpServer {
def make(
httpRoutes: HttpRoutes[Task],cpuPool: ExecutionContext@Id("zio.cpu"),) = {
for {
implicit0(rts: Runtime[Any]) <- ZIO.runtime[Any].toManaged_
combined = Kleisli { (req: Request[Task]) =>
val effect: Task[Unit] = Task.effectTotal(println("123"))
OptionT.liftF(effect).flatMap { _ =>
httpRoutes(req)
}
}
srv <- BlazeServerBuilder[Task](cpuPool)
.withHttpApp(combined.orNotFound)
.bindHttp(host = "0.0.0.0")
.resource
.toManaged
} yield new HttpServer {
val bindHttp = IO.succeed(srv)
}
}
}