[Telemetry] Change trace_data to hold a list of raw trace data for each trace part

telemetry/telemetry/internal/backends/chrome_inspector/tracing_backend_unittest.py

Index: telemetry/telemetry/internal/backends/chrome_inspector/tracing_backend_unittest.py
diff --git a/telemetry/telemetry/internal/backends/chrome_inspector/tracing_backend_unittest.py b/telemetry/telemetry/internal/backends/chrome_inspector/tracing_backend_unittest.py
index 0cf3bd43a2b2da8661aacfc278a87e27804dd888..5162c1d84e99d5607558d4fb6910fae1e847b45d 100644
--- a/telemetry/telemetry/internal/backends/chrome_inspector/tracing_backend_unittest.py
+++ b/telemetry/telemetry/internal/backends/chrome_inspector/tracing_backend_unittest.py
@@ -67,8 +67,9 @@ class TracingBackendTest(tab_test_case.TabTestCase):
 
     # Check that clock sync data is in tracing data.
     clock_sync_found = False
-    trace = tracing_data.GetTraceFor(trace_data.CHROME_TRACE_PART)
-    for event in trace['traceEvents']:
+    traces = tracing_data.GetTracesFor(trace_data.CHROME_TRACE_PART)
+    self.assertEqual(len(traces), 1)
+    for event in traces[0]['traceEvents']:
       if event['name'] == 'clock_sync' or 'ClockSyncEvent' in event['name']:
         clock_sync_found = True
         break
@@ -121,9 +122,9 @@ class TracingBackendUnitTest(unittest.TestCase):
 
   def testCollectTracingDataTimeout(self):
     self._inspector_socket.AddEvent(
-        'Tracing.dataCollected', {'value': [{'ph': 'B'}]}, 9)
+        'Tracing.dataCollected', {'value': {'traceEvents': [{'ph': 'B'}]}}, 9)
     self._inspector_socket.AddEvent(
-        'Tracing.dataCollected', {'value': [{'ph': 'E'}]}, 19)
+        'Tracing.dataCollected', {'value': {'traceEvents': [{'ph': 'E'}]}}, 19)
     self._inspector_socket.AddEvent('Tracing.tracingComplete', {}, 35)
     backend = tracing_backend.TracingBackend(self._inspector_socket)
 
@@ -132,37 +133,41 @@ class TracingBackendUnitTest(unittest.TestCase):
     # a TracingTimeoutException.
     with self.assertRaises(tracing_backend.TracingTimeoutException):
       backend._CollectTracingData(trace_data_builder, 10)
-    trace_events = trace_data_builder.AsData().GetTraceFor(
-        trace_data.CHROME_TRACE_PART).get('traceEvents', [])
-    self.assertEqual(2, len(trace_events))
+    traces = trace_data_builder.AsData().GetTracesFor(
+        trace_data.CHROME_TRACE_PART)
+    self.assertEqual(2, len(traces))
+    self.assertEqual(1, len(traces[0].get('traceEvents', [])))
+    self.assertEqual(1, len(traces[1].get('traceEvents', [])))
     self.assertFalse(backend._has_received_all_tracing_data)
 
   def testCollectTracingDataNoTimeout(self):
     self._inspector_socket.AddEvent(
-        'Tracing.dataCollected', {'value': [{'ph': 'B'}]}, 9)
+        'Tracing.dataCollected', {'value': {'traceEvents': [{'ph': 'B'}]}}, 9)
     self._inspector_socket.AddEvent(
-        'Tracing.dataCollected', {'value': [{'ph': 'E'}]}, 14)
+        'Tracing.dataCollected', {'value': {'traceEvents': [{'ph': 'E'}]}}, 14)
     self._inspector_socket.AddEvent('Tracing.tracingComplete', {}, 19)
     backend = tracing_backend.TracingBackend(self._inspector_socket)
     trace_data_builder = trace_data.TraceDataBuilder()
     backend._CollectTracingData(trace_data_builder, 10)
-    trace_events = trace_data_builder.AsData().GetTraceFor(
-        trace_data.CHROME_TRACE_PART).get('traceEvents', [])
-    self.assertEqual(2, len(trace_events))
+    traces = trace_data_builder.AsData().GetTracesFor(
+        trace_data.CHROME_TRACE_PART)
+    self.assertEqual(2, len(traces))
+    self.assertEqual(1, len(traces[0].get('traceEvents', [])))
+    self.assertEqual(1, len(traces[1].get('traceEvents', [])))
     self.assertTrue(backend._has_received_all_tracing_data)
 
   def testCollectTracingDataFromStreamNoContainer(self):
     self._inspector_socket.AddEvent(
         'Tracing.tracingComplete', {'stream': '42'}, 1)
     self._inspector_socket.AddAsyncResponse(
-        'IO.read', {'data': '[{},{},{'}, 2)
+        'IO.read', {'data': '{"traceEvents": [{},{},{'}, 2)
     self._inspector_socket.AddAsyncResponse(
-        'IO.read', {'data': '},{},{}]', 'eof': True}, 3)
+        'IO.read', {'data': '},{},{}]}', 'eof': True}, 3)
     backend = tracing_backend.TracingBackend(self._inspector_socket)
     trace_data_builder = trace_data.TraceDataBuilder()
     backend._CollectTracingData(trace_data_builder, 10)
-    trace_events = trace_data_builder.AsData().GetTraceFor(
-        trace_data.CHROME_TRACE_PART).get('traceEvents', [])
+    trace_events = trace_data_builder.AsData().GetTracesFor(
+        trace_data.CHROME_TRACE_PART)[0].get('traceEvents', [])

[perezju, 2017/01/13 10:17:01]

this seems to be a common pattern: GetTracesFor(...)[0], how about adding an
API: GetSingleTraceFor(...) that:
- checks that len(traces) == 1
- returns that single trace

[nednguyen, 2017/01/13 15:53:21]

Umm, this is only exists because we have legacy trace parser in Python. I think
we need not make it easier to use the legacy one & transition to JS instead :-)

     self.assertEqual(5, len(trace_events))
     self.assertTrue(backend._has_received_all_tracing_data)
 
@@ -179,7 +184,7 @@ class TracingBackendUnitTest(unittest.TestCase):
     trace_data_builder = trace_data.TraceDataBuilder()
     backend._CollectTracingData(trace_data_builder, 10)
     data = trace_data_builder.AsData()
-    chrome_trace = data.GetTraceFor(trace_data.CHROME_TRACE_PART)
+    chrome_trace = data.GetTracesFor(trace_data.CHROME_TRACE_PART)[0]
 
     self.assertEqual(3, len(chrome_trace.get('traceEvents', [])))
     self.assertEqual(dict, type(chrome_trace.get('metadata')))