1 files changed, 120 insertions, 0 deletions
diff --git a/catapult/telemetry/telemetry/internal/platform/power_monitor/monsoon_power_monitor.py b/catapult/telemetry/telemetry/internal/platform/power_monitor/monsoon_power_monitor.py
new file mode 100644
index 00000000..abbd9f4d
--- /dev/null
+++ b/catapult/telemetry/telemetry/internal/platform/power_monitor/monsoon_power_monitor.py
@@ -0,0 +1,120 @@
+# Copyright 2014 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 json
+import logging
+import multiprocessing
+import tempfile
+import time
+
+from telemetry.core import exceptions
+from telemetry.internal.platform.power_monitor import android_power_monitor_base
+from telemetry.internal.platform.profiler import monsoon
+
+
+def _MonitorPower(device, is_collecting, output):
+  """Monitoring process
+     Args:
+       device: A profiler.monsoon object to collect samples from.
+       is_collecting: the event to synchronize on.
+       output: opened file to write the samples.
+  """
+  with output:
+    samples = []
+    start_time = None
+    end_time = None
+    try:
+      device.StartDataCollection()
+      is_collecting.set()
+      # First sample also calibrate the computation.
+      device.CollectData()
+      start_time = time.time()
+      while is_collecting.is_set():
+        new_data = device.CollectData()
+        assert new_data, 'Unable to collect data from device'
+        samples += new_data
+      end_time = time.time()
+    finally:
+      device.StopDataCollection()
+    result = {
+      'duration_s': end_time - start_time,
+      'samples': samples
+    }
+    json.dump(result, output)
+
+
+class MonsoonPowerMonitor(android_power_monitor_base.AndroidPowerMonitorBase):
+  def __init__(self, _, platform_backend):
+    super(MonsoonPowerMonitor, self).__init__()
+    self._powermonitor_process = None
+    self._powermonitor_output_file = None
+    self._is_collecting = None
+    self._monsoon = None
+    self._platform = platform_backend
+    try:
+      self._monsoon = monsoon.Monsoon(wait=False)
+      # Nominal Li-ion voltage is 3.7V, but it puts out 4.2V at max capacity.
+      # Use 4.0V to simulate a "~80%" charged battery. Google "li-ion voltage
+      # curve". This is true only for a single cell. (Most smartphones, some
+      # tablets.)
+      self._monsoon.SetVoltage(4.0)
+    except EnvironmentError:
+      self._monsoon = None
+
+  def CanMonitorPower(self):
+    return self._monsoon is not None
+
+  def StartMonitoringPower(self, browser):
+    self._CheckStart()
+    self._powermonitor_output_file = tempfile.TemporaryFile()
+    self._is_collecting = multiprocessing.Event()
+    self._powermonitor_process = multiprocessing.Process(
+        target=_MonitorPower,
+        args=(self._monsoon,
+              self._is_collecting,
+              self._powermonitor_output_file))
+    # Ensure child is not left behind: parent kills daemonic children on exit.
+    self._powermonitor_process.daemon = True
+    self._powermonitor_process.start()
+    if not self._is_collecting.wait(timeout=0.5):
+      self._powermonitor_process.terminate()
+      raise exceptions.ProfilingException('Failed to start data collection.')
+
+  def StopMonitoringPower(self):
+    self._CheckStop()
+    try:
+      # Tell powermonitor to take an immediate sample and join.
+      self._is_collecting.clear()
+      self._powermonitor_process.join()
+      with self._powermonitor_output_file:
+        self._powermonitor_output_file.seek(0)
+        powermonitor_output = self._powermonitor_output_file.read()
+      assert powermonitor_output, 'PowerMonitor produced no output'
+      return MonsoonPowerMonitor.ParseSamplingOutput(powermonitor_output)
+    finally:
+      self._powermonitor_output_file = None
+      self._powermonitor_process = None
+      self._is_collecting = None
+
+  @staticmethod
+  def ParseSamplingOutput(powermonitor_output):
+    """Parse the output of of the samples collector process.
+
+    Returns:
+        Dictionary in the format returned by StopMonitoringPower().
+    """
+    result = json.loads(powermonitor_output)
+    if result['samples']:
+      timedelta_h = (result['duration_s'] / len(result['samples'])) / 3600.0
+      power_samples = [current_a * voltage_v * 10**3
+                       for (current_a, voltage_v) in result['samples']]
+      total_energy_consumption_mwh = sum(power_samples) * timedelta_h
+    else:
+      logging.warning('Sample information not available.')
+      power_samples = []
+      total_energy_consumption_mwh = 0
+
+    return {'identifier':'monsoon',
+            'power_samples_mw':power_samples,
+            'monsoon_energy_consumption_mwh':total_energy_consumption_mwh}