iperf3: Add compatibility for servers pre version 3.2.

Result message from servers pre version 3.2 do not encode start or end
time, so workaround this by using the t3, t0 timestamps used elsewhere for
sending.

Fixes issue micropython#665.

Author: graeme-winter

python-ecosys/iperf3/iperf3.py

@@ -147,10 +147,14 @@ def stop(self):
 
     def report_receiver(self, stats):
         st = stats["streams"][0]
-        dt = st["end_time"] - st["start_time"]
+
+        # iperf servers pre 3.2 do not transmit start or end time,
+        # so use local as fallback if not available.
+        dt = ticks_diff(self.t3, self.t0)
+
         self.print_line(
-            st["start_time"],
-            st["end_time"],
+            st.get("start_time", 0.0),
+            st.get("end_time", dt * 1e-6),
             st["bytes"],
             st["packets"],
             st["errors"],

python-ecosys/iperf3/manifest.py

@@ -1,3 +1,3 @@
-metadata(version="0.1.3", pypi="iperf3", pypi_publish="uiperf3")
+metadata(version="0.1.4", pypi="iperf3", pypi_publish="uiperf3")
 
 module("iperf3.py")