def EstablishConnection(self, comportobj, guihandle, dbfilelocation):
global trc
trc.FunctionEntry("EstablishConnection")
self.ser = comportobj
self.toCancel = False
self.guicallback = guihandle
myparser = CurrentCostDataParser()
#
# we create our own connection to the database here
#
# we need our own connection to the database because we are running
# in a background thread, and pysqlite (used to implement the database)
# cannot reuse a connection across multiple threads
# the connection is relatively low cost, so having two connections open
# - one for the GUI thread and one for this background worker thread -
# doesn't seem like a burdensome extravagance :-)
#
dbconnection = CurrentCostDB()
dbconnection.InitialiseDB(dbfilelocation)
#
# look for the current reading in the data
#
line = ""
receivedHistory = False
while self.toCancel == False:
try:
line = self.ser.readUpdate()
# try to parse the XML
currentcoststruct = myparser.parseCurrentCostXML(line)
if currentcoststruct != None:
if 'hist' in currentcoststruct['msg']:
# we have received history data - parse and store the CurrentCost
# data in the datastore
# the parser will return the number of updates still expected
# (0 if this was the last or only expected update)
myparser.storeTimedCurrentCostData(dbconnection)
receivedHistory = True
elif receivedHistory == True:
# we received live data only
# if we have received un-graphed history data, we refresh the
# graphs now
trc.Trace(
"finished receiving history data - need to redraw graphs"
)
self.guicallback.updateGraphs()
receivedHistory = False
except Exception, exception:
if self.toCancel == False:
self.guicallback.exitOnError(
'Error reading from COM port: ' + str(exception))
trc.Error("Error when closing COM port")
trc.Error(str(exception))
trc.FunctionExit("EstablishConnection")
return
def run(s, db):
trc = CurrentCostTracer()
trc.EnableTrace(True)
trc.InitialiseTraceFile()
myparser = CurrentCostDataParser()
while True:
try:
line = s.readline()
except Exception, why:
print why
sleep(1)
else:
if line:
line = line.strip()
currentcoststruct = myparser.parseCurrentCostXML(line)
if currentcoststruct:
print currentcoststruct
if currentcoststruct["msg"].has_key("ch1"):
w1 = int(currentcoststruct["msg"]["ch1"]["watts"])
w2 = int(currentcoststruct["msg"]["ch2"]["watts"])
w3 = int(currentcoststruct["msg"]["ch3"]["watts"])
t = (w1**2 + w2**2 + w3**2)**0.5
print "watts are :", t
if currentcoststruct["msg"].has_key("hist"):
print "storing history data"
myparser.storeTimedCurrentCostData(db)
