Make http-imports faster to load, by hinting persistent connection on request.

runtime/bin/builtin.dart

Index: runtime/bin/builtin.dart
diff --git a/runtime/bin/builtin.dart b/runtime/bin/builtin.dart
index be17c3f919576b178b06d3748da33e5a68efeb43..ab6eb07ff1a7e249fbb0a7ab366cd00208392c63 100644
--- a/runtime/bin/builtin.dart
+++ b/runtime/bin/builtin.dart
@@ -79,16 +79,32 @@ void _makeHttpRequest(String uri) {
   try {
     Uri requestUri = Uri.parse(uri);
     _client.getUrl(requestUri)
-        .then((HttpClientRequest request) => request.close())
+        .then((HttpClientRequest request) {
+          request.persistentConnection = false;
+          return request.close();
+        })
         .then((HttpClientResponse response) {
-          return response
-              .fold(new BytesBuilder(), (b, d) => b..add(d))
-              .then((builder) {
-                _requestCompleted(builder.takeBytes(), response);
-                // This client is only used for a single request. Force closing
-                // it now otherwise we wait around until it times out.

[Ivan Posva, 2014/03/18 12:13:43]

This comment was crucial in understanding why the client had to be closed.
Please restore it.

[Anders Johnsen, 2014/03/18 12:22:33]

No, it was crucial to why we were using `force: true`.

The comment now could be:

  Close the client to stop any timers currently held alive.

-                _client.close(force:true);
-              });
+          // Only create a ByteBuilder, if multiple chunks is received.

[floitsch, 2014/03/18 12:26:24]

are received.

[Anders Johnsen, 2014/03/18 12:33:24]

Done.

+          var bufferOrBuilder;
+          response.listen(
+            (data) {
+              if (bufferOrBuilder == null) {
+                bufferOrBuilder = data;
+              } else {
+                if (bufferOrBuilder is! BytesBuilder) {
+                  bufferOrBuilder = new BytesBuilder()
+                      ..add(bufferOrBuilder);
+                }
+                bufferOrBuilder.add(data);
+              }
+            },
+            onDone: () {
+              var data = bufferOrBuilder;
+              if (data is BytesBuilder) data = data.takeBytes();
+              _requestCompleted(data, response);
+              _client.close();
+            },
+            onError: _requestFailed);
         }).catchError((error) {
           _requestFailed(error);
         });