def fetch_sensor(platformID: str, name: str,
units: str = None, parser: str = None, tags: list = None,
startime: int = None, endtime: int = None, truncate = True,
db: str = DB, connection: MongoClient = CONN ) -> Sensor:
"""
Fetches a specified Sensor from MongoDB, truncated by startime and endtime
Args:
platformID (str): name of the target collection, typically a platformID
name (str): Sensor name, eg 'm_depth' or 'salinity'
units (str=None): sensor units, eg 'rad' or 'deg' or 'nodim'
parser (str=None): parser-tag, eg mima or xbd or suflog
tags (list=None): sensor's tags. #TODO, currently UNIMPLIMENTED
startime (int=None): epoch query start time
endtime (int=None): epoch query end time
truncate (bool=True): True -> Sensor data range is exactly the requested range
False -> Sensor data returned in 24hr chunks, as saved in database
db (str=<default>): name of the target database
connection (MongoClient=<default>): specifies host and port of target mongodb server
Returns:
a Sensor
"""
collection = connection[db][platformID]
doc = {'name': name}
if units:
doc['units'] = units
if parser:
doc['parser'] = parser
if startime:
startday = MSensor.epoch2epochday(startime)
else:
startday = 0
startime = -inf
if endtime:
enday = endtime
else:
enday = time() #no future data
endtime = inf
doc['epochday'] = {'$gte':startday, '$lt':enday}
cursor = collection.find(doc).sort('epochday',1)
msensors = []
for doc in cursor:
msensors.append(CLASSON.decode(doc))
# sensor.xy.extend(doc['xy'])
sensor = MSensor.to_sensor(msensors)
if truncate:
sensor.xy = list(filter(lambda xy_tup: startime <= xy_tup[0] < endtime, sensor.xy))
return sensor
