Experiment with HttpClient HTTP request/response API method design th…

…at provides non racy methods when called outside event-loop.

src/main/java/io/vertx/core/http/HttpClient.java

@@ -15,6 +15,7 @@
 import io.vertx.core.Future;
 
 import java.util.concurrent.TimeUnit;
+import java.util.function.Function;
 
 /**
  * The API to interacts with an HTTP server.
@@ -41,6 +42,10 @@ default Future<HttpClientRequest> request() {
    */
   Future<HttpClientRequest> request(RequestOptions options);
 
+  default <T> Future<T> request(RequestOptions options, Function<HttpClientRequest, Future<T>> handler) {
+    return request(options).compose(handler);
+  }
+
   /**
    * Create an HTTP request to send to the server at the {@code host} and {@code port}.
    *
@@ -54,6 +59,10 @@ default Future<HttpClientRequest> request(HttpMethod method, int port, String ho
     return request(new RequestOptions().setMethod(method).setPort(port).setHost(host).setURI(requestURI));
   }
 
+  default <T> Future<T> request(HttpMethod method, int port, String host, String requestURI, Function<HttpClientRequest, Future<T>> handler) {
+    return request(method, port, host, requestURI).compose(handler);
+  }
+
   /**
    * Create an HTTP request to send to the server at the {@code host} and default port.
    *
@@ -66,6 +75,10 @@ default Future<HttpClientRequest> request(HttpMethod method, String host, String
     return request(new RequestOptions().setMethod(method).setHost(host).setURI(requestURI));
   }
 
+  default <T> Future<T> request(HttpMethod method, String host, String requestURI , Function<HttpClientRequest, Future<T>> handler) {
+    return request(method, host, requestURI).compose(handler);
+  }
+
   /**
    * Create an HTTP request to send to the server at the default host and port.
    *
@@ -77,6 +90,10 @@ default Future<HttpClientRequest> request(HttpMethod method, String requestURI)
     return request(new RequestOptions().setMethod(method).setURI(requestURI));
   }
 
+  default <T> Future<T> request(HttpMethod method, String requestURI, Function<HttpClientRequest, Future<T>> handler) {
+    return request(method, requestURI).compose(handler);
+  }
+
   /**
    * Shutdown with a 30 seconds timeout ({@code shutdown(30, TimeUnit.SECONDS)}).
    *

src/test/java/io/vertx/core/http/HttpTest.java

@@ -6604,10 +6604,11 @@ public void shouldThrowISEIfSendingResponseFromHeadersEndHandler() throws Except
       }
     );
     startServer(testAddress);
-    client.request(requestOptions)
-      .compose(req -> req.send()
+    client.request(requestOptions, req -> req
+        .send()
         .andThen(onSuccess(resp -> assertEquals(200, resp.statusCode())))
-        .compose(HttpClientResponse::end))
+        .compose(HttpClientResponse::end)
+      )
       .onComplete(onSuccess(nothing -> complete()));
     await();
   }