Allow 0 RTT measurements

To speed up the scanner.
RTT is not being used at the moment, set the default to 0.

sbws/config.default.ini

@@ -42,7 +42,7 @@ download_min = 5
 download_target = 6
 download_max = 10
 # How many RTT measurements to make
-num_rtts = 10
+num_rtts = 0
 # Number of downloads with acceptable times we must have for a relay before
 # moving on
 num_downloads = 5

sbws/lib/resultdump.py

@@ -476,7 +476,7 @@ class ResultSuccess(Result):
     def from_dict(d):
         assert isinstance(d, dict)
         return ResultSuccess(
-            d['rtts'], d['downloads'],
+            d['rtts'] or [], d['downloads'],
             Result.Relay(
                 d['fingerprint'], d['nickname'], d['address'],
                 d['master_key_ed25519'], d['relay_average_bandwidth'],

sbws/lib/v3bwfile.py

@@ -302,7 +302,9 @@ class V3BWLine(object):
                 return None
             kwargs['desc_avg_bw_bs'] = \
                 results_recent[-1].relay_average_bandwidth
-            kwargs['rtt'] = cls.rtt_from_results(results_recent)
+            rtt = cls.rtt_from_results(results_recent)
+            if rtt:
+                kwargs['rtt'] = rtt
             bw = cls.bw_bs_median_from_results(results_recent)
             kwargs['bw_bs_mean'] = cls.bw_bs_mean_from_results(results_recent)
             kwargs['bw_bs_median'] = cls.bw_bs_median_from_results(
@@ -380,7 +382,7 @@ class V3BWLine(object):
     def rtt_from_results(results):
         # convert from miliseconds to seconds
         rtts = [(round(rtt * 1000)) for r in results for rtt in r.rtts]
-        rtt = round(median(rtts))
+        rtt = round(median(rtts)) if rtts else None
         return rtt
 
     @staticmethod

sbws/util/config.py

@@ -236,7 +236,7 @@ def _validate_scanner(conf):
     sec = 'scanner'
     err_tmpl = Template('$sec/$key ($val): $e')
     ints = {
-        'num_rtts': {'minimum': 1, 'maximum': 100},
+        'num_rtts': {'minimum': 0, 'maximum': 100},
         'num_downloads': {'minimum': 1, 'maximum': 100},
         'initial_read_request': {'minimum': 1, 'maximum': None},
         'measurement_threads': {'minimum': 1, 'maximum': None},