[Telemetry] Add battor tracing agent

telemetry/telemetry/internal/platform/tracing_agent/battor_tracing_agent.py

+# Copyright 2016 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import logging
+
+from battor import battor_error
+from battor import battor_wrapper
+from py_trace_event import trace_time
+from telemetry.internal.platform import tracing_agent
+from telemetry.timeline import trace_data
+
+
+class BattOrTracingAgent(tracing_agent.TracingAgent):
+  """A tracing agent for getting power data from a BattOr device.
+
+  BattOrTracingAgent allows Telemetry to issue high-level tracing commands
+  (StartTracing, StopTracing, RecordClockSyncMarker) to BattOrs, which are
+  high-frequency power monitors used for battery testing.
+  """
+
+  def __init__(self, platform_backend):
+    super(BattOrTracingAgent, self).__init__(platform_backend)
+    self._platform_backend = platform_backend
+    android_device = (
+        platform_backend.device if platform_backend.GetOSName() == 'android'
+        else None)
+    self._battor = battor_wrapper.BattorWrapper(platform_backend.GetOSName(),

[charliea (OOO until 10-5), 2016/05/09 21:30:32]

We should change this from BattorWrapper to BattOrWrapper so that we're
consistent w/ capitalization across all of our code (not really relevant here,
but just pointing it out)

[rnephew (Reviews Here), 2016/05/10 15:51:44]

Also need to change battor_error, I will do this in a seperate CL after this one
lands.

+                                                android_device=android_device)
+
+  @classmethod
+  def IsSupported(cls, platform_backend):
+    """Returns True if BattOr tracing is available."""
+    if platform_backend.GetOSName() == 'android':
+      # TODO(rnephew): When we pass BattOr device map into telemetry, change

[charliea (OOO until 10-5), 2016/05/09 21:30:32]

nit: s/telemetry/Telemetry

[rnephew (Reviews Here), 2016/05/10 15:51:44]

Done.

+      # this to reflect that.
+      return battor_wrapper.IsBattOrConnected(
+          'android', android_device=platform_backend.device)
+    return battor_wrapper.IsBattOrConnected(platform_backend.GetOSName())
+
+  def StartAgentTracing(self, config, timeout):
+    """Start tracing on the BattOr.
+
+    Args:
+      config: A TracingConfig instance.
+      timeout: number of seconds that this tracing agent should try to start
+        tracing until timing out.
+
+    Returns:
+      True if the tracing agent started successfully.
+    """
+    if not config.enable_battor_trace:
+      return False
+    try:
+      self._battor.StartShell()
+      self._battor.StartTracing()
+      return True
+    except battor_error.BattorError:
+      logging.exception('Failure in starting tracing on BattOr.')
+      return False
+
+  def StopAgentTracing(self):
+    """Stops tracing on the BattOr."""
+    self._battor.StopTracing()
+
+  def SupportsExplicitClockSync(self):
+    return self._battor.SupportsExplicitClockSync()
+
+  def RecordClockSyncMarker(self, sync_id,
+                            record_controller_clock_sync_marker_callback):
+    """Records a clock sync marker in the BattOr trace.
+
+    Args:
+      sync_id: Unique id for sync event.
+      record_controller_clock_sync_marker_callback: Function that takes a sync
+        ID and a timestamp as arguments. This function typically will record the
+        tracing controller clock sync marker.
+    """
+    timestamp = trace_time.Now()
+    self._battor.RecordClockSyncMarker(sync_id)
+    record_controller_clock_sync_marker_callback(sync_id, timestamp)
+
+  def CollectAgentTraceData(self, trace_data_builder, timeout=None):
+    data = '\n'.join(self._battor.CollectTraceData(timeout=timeout))
+    trace_data_builder.AddEventsTo(trace_data.BATTOR_TRACE_PART, [data])