Pass callback results as dicts instead of tuples

scrapy/core/downloader/handlers/http11.py

@@ -384,7 +384,13 @@ class ScrapyAgent(object):
     def _cb_bodyready(self, txresponse, request):
         # deliverBody hangs for responses without body
         if txresponse.length == 0:
-            return txresponse, b'', None, None
+            return {
+                "txresponse": txresponse,
+                "body": b"",
+                "flags": None,
+                "certificate": None,
+                "ip_address": None,
+            }
 
         maxsize = request.meta.get('download_maxsize', self._maxsize)
         warnsize = request.meta.get('download_warnsize', self._warnsize)
@@ -420,12 +426,18 @@ class ScrapyAgent(object):
         return d
 
     def _cb_bodydone(self, result, request, url):
-        txresponse, body, flags, certificate, ip_address = result
-        status = int(txresponse.code)
-        headers = Headers(txresponse.headers.getAllRawHeaders())
-        respcls = responsetypes.from_args(headers=headers, url=url, body=body)
-        return respcls(url=url, status=status, headers=headers, body=body,
-                       flags=flags, certificate=certificate, ip_address=ip_address)
+        status = int(result["txresponse"].code)
+        headers = Headers(result["txresponse"].headers.getAllRawHeaders())
+        respcls = responsetypes.from_args(headers=headers, url=url, body=result["body"])
+        return respcls(
+            url=url,
+            status=status,
+            headers=headers,
+            body=result["body"],
+            flags=result["flags"],
+            certificate=result["certificate"],
+            ip_address=result["ip_address"],
+        )
 
 
 @implementer(IBodyProducer)
@@ -501,22 +513,34 @@ class _ResponseReader(protocol.Protocol):
 
         body = self._bodybuf.getvalue()
         if reason.check(ResponseDone):
-            self._finished.callback(
-                (self._txresponse, body, None, self._certificate, self._ip_address)
-            )
+            self._finished.callback({
+                "txresponse": self._txresponse,
+                "body": body,
+                "flags": None,
+                "certificate": self._certificate,
+                "ip_address": self._ip_address,
+            })
             return
 
         if reason.check(PotentialDataLoss):
-            self._finished.callback(
-                (self._txresponse, body, ['partial'], self._certificate, self._ip_address)
-            )
+            self._finished.callback({
+                "txresponse": self._txresponse,
+                "body": body,
+                "flags": ["partial"],
+                "certificate": self._certificate,
+                "ip_address": self._ip_address,
+            })
             return
 
         if reason.check(ResponseFailed) and any(r.check(_DataLoss) for r in reason.value.reasons):
             if not self._fail_on_dataloss:
-                self._finished.callback(
-                    (self._txresponse, body, ['dataloss'], self._certificate, self._ip_address)
-                )
+                self._finished.callback({
+                    "txresponse": self._txresponse,
+                    "body": body,
+                    "flags": ["dataloss"],
+                    "certificate": self._certificate,
+                    "ip_address": self._ip_address,
+                })
                 return
 
             elif not self._fail_on_dataloss_warned: