class DataCollector(object):
"""The DataCollector collects and stores all data.
The stored data includes:
- Time
- GPS data
- OBD2 data
"""
def __init__(self):
"""Initializes the DataCollector."""
super(DataCollector, self).__init__()
obd2readerClass = getattr(obd2reader, CONFIGURATION["obd2reader"])
self._obd2reader = obd2readerClass(CONFIGURATION["device"], CONFIGURATION["speed"])
self._obd2reader.open_connection()
self._gpsreader = GPSReader(CONFIGURATION["gpsdPort"])
def shutdown(self):
"""Shuts down the DataCollector and all of its Threads."""
self._obd2reader.shutdown()
self._gpsreader.shutdown()
def write_data_log(self, logFileName, nbrOfOBDFrames, messagesPerTimestamp):
"""Stores an data log file to the given location.
:param String logFileName: Path to store the log file.
:param Integer nbrOfOBDFrames: Number of OBD frames to be stored inside the log.
This parameter does NOT affect the number of time
stamps or GPS reports.
:param Integer messagesPerTimestamp: Number of OBD2 frames share the same time stamp.
:return: Returns the number of bytes stored in the log.
:rtype: Integer
"""
## create the log file
logf = file(logFileName, "ab")
## performance optimization
## reduces the __getattr__ calls for the major instances
write = logf.write
gpsreader = self._gpsreader
obd2reader = self._obd2reader
## number of bytes written
bytes = 0
## collect the requested number of OBD2 frames
for idx in xrange(0, nbrOfOBDFrames, messagesPerTimestamp):
## time stamp
timestamp = "#TIME__%s\n" % _getCurrentTime()
write(timestamp)
bytes += len(timestamp)
## read the number of frames requested
try:
logEntries = obd2reader.read_frames(nbrOfOBDFrames)
except:
obd2reader.reconnect()
continue
## store the frames in the log
logEntries = "\n".join(logEntries)
write("%s\n" % logEntries)
bytes += len(logEntries) + 1
## append the gpslog entries, when there are any
gpsreports = ["#GPS__%s\n" % entry for entry in gpsreader.get_current_gps_entries()]
## no GPS report collected since last run
if not gpsreports:
continue
## store the reports in the log
gpsreports = "\n".join([str(r) for r in gpsreports])
write("%s\n" % gpsreports)
bytes += len(gpsreports) + 1
# close the log file
logf.close()
## return the number of bytes written
return bytes
