Add optimization to apache async client instrumentation

dd-java-agent/instrumentation/apache-httpasyncclient-4/src/main/java/datadog/trace/instrumentation/apachehttpasyncclient/ApacheHttpAsyncClientDecorator.java

@@ -7,6 +7,7 @@ import org.apache.http.HttpRequest;
 import org.apache.http.HttpResponse;
 import org.apache.http.RequestLine;
 import org.apache.http.StatusLine;
+import org.apache.http.client.methods.HttpUriRequest;
 import org.apache.http.protocol.HttpContext;
 import org.apache.http.protocol.HttpCoreContext;
 
@@ -26,41 +27,56 @@ public class ApacheHttpAsyncClientDecorator extends HttpClientDecorator<HttpRequ
 
   @Override
   protected String method(final HttpRequest request) {
+    if (request instanceof HttpUriRequest) {
+      return ((HttpUriRequest) request).getMethod();
+    } else {
       final RequestLine requestLine = request.getRequestLine();
       return requestLine == null ? null : requestLine.getMethod();
     }
+  }
 
   @Override
   protected URI url(final HttpRequest request) throws URISyntaxException {
+    /*
+     * Note: this is essentially an optimization: HttpUriRequest allows quicker access to required information.
+     * The downside is that we need to load HttpUriRequest which essentially means we depend on httpasyncclient
+     * library depending on httpclient library. Currently this seems to be the case.
+     */
+    if (request instanceof HttpUriRequest) {
+      return ((HttpUriRequest) request).getURI();
+    } else {
       final RequestLine requestLine = request.getRequestLine();
       return requestLine == null ? null : new URI(requestLine.getUri());
     }
+  }
 
   @Override
   protected String hostname(final HttpRequest request) {
-    final RequestLine requestLine = request.getRequestLine();
-    if (requestLine != null) {
     try {
-        return new URI(requestLine.getUri()).getHost();
+      final URI uri = url(request);
+      if (uri != null) {
+        return uri.getHost();
+      } else {
+        return null;
+      }
     } catch (final URISyntaxException e) {
       return null;
     }
   }
-    return null;
-  }
 
   @Override
   protected Integer port(final HttpRequest request) {
-    final RequestLine requestLine = request.getRequestLine();
-    if (requestLine != null) {
     try {
-        return new URI(requestLine.getUri()).getPort();
+      final URI uri = url(request);
+      if (uri != null) {
+        return uri.getPort();
+      } else {
+        return null;
+      }
     } catch (final URISyntaxException e) {
       return null;
     }
   }
-    return null;
-  }
 
   @Override
   protected Integer status(final HttpContext context) {