Example client that connects to the messaging, listens for event objects and dumps the event IDs.
Illustrate the basic messaging concepts.
This script was demonstrated at the SeisComP3 workshop in Erice. It should be relatively self-explaining, but full understanding does require certain knowlege of Python.
The script does nothing but
No actual real-world use case but a truly minimum example for a SeisComP3 application.
import sys, traceback, seiscomp3.Client
class EventListener(seiscomp3.Client.Application):
def __init__(self):
seiscomp3.Client.Application.__init__(self, len(sys.argv), sys.argv)
self.setMessagingEnabled(True)
self.setDatabaseEnabled(True, True)
self.setPrimaryMessagingGroup(seiscomp3.Communication.Protocol.LISTENER_GROUP)
self.addMessagingSubscription("EVENT")
def doSomethingWithEvent(self, event):
try:
#######################################
#### Include your custom code here ####
print "event.publicID = %s" % event.publicID()
#######################################
except:
info = traceback.format_exception(*sys.exc_info())
for i in info: sys.stderr.write(i)
def updateObject(self, parentID, object):
# called if an updated object is received
event = seiscomp3.DataModel.Event.Cast(object)
if event:
print "received update for event %s" % event.publicID()
self.doSomethingWithEvent(event)
def addObject(self, parentID, object):
# called if a new object is received
event = seiscomp3.DataModel.Event.Cast(object)
if event:
print "received new event %s" % event.publicID()
self.doSomethingWithEvent(event)
def run(self):
# needs not be re-implemented
print "Hi! The EventListener is now running."
return seiscomp3.Client.Application.run(self)
app = EventListener()
sys.exit(app())
Note that the EventListener class is derived from the application class seiscomp3.Client.Application from which it inherits most of the functionality. For instance the ability to connect to the messaging and to the database are both provided by seiscomp3.Client.Application; the EventListener only has to enable messaging and database usage in the __init__ routine. The real action takes place in the doSomethingWithEvent routine, which is called by both updateObject and addObject, depending on whether the event object received is a newly added or just and updated event.
Various Python example scripts that retrieve inventory information from the database.
Illustrate the usefulness of simple Python scripts to retrieve inventory information.
The scripts in this chapter all deal with inventory access. All need to be invoked with the -d command line option to specify the SeisComP3 database to read the information from.
E.g.
python configured-streams.py -d localhost
Print a list of all streams configured on a SC3 system.
#!/usr/bin/env python
import sys, traceback, seiscomp3.Client
class ListStreamsApp(seiscomp3.Client.Application):
def __init__(self, argc, argv):
seiscomp3.Client.Application.__init__(self, argc, argv)
self.setMessagingEnabled(False)
self.setDatabaseEnabled(True, True)
self.setLoggingToStdErr(True)
self.setDaemonEnabled(False)
# self.setLoadInventoryEnabled(True)
def validateParameters(self):
try:
if seiscomp3.Client.Application.validateParameters(self) == False:
return False
return True
except:
info = traceback.format_exception(*sys.exc_info())
for i in info: sys.stderr.write(i)
sys.exit(-1)
def run(self):
try:
dbr = seiscomp3.DataModel.DatabaseReader(self.database())
now = seiscomp3.Core.Time.GMT()
inv = seiscomp3.DataModel.Inventory()
dbr.loadNetworks(inv)
result = []
for inet in xrange(inv.networkCount()):
network = inv.network(inet)
dbr.load(network);
for ista in xrange(network.stationCount()):
station = network.station(ista)
try:
start = station.start()
except:
continue
try:
end = station.end()
if not start <= now <= end:
continue
except:
pass
for iloc in xrange(station.sensorLocationCount()):
location = station.sensorLocation(iloc)
for istr in range(location.streamCount()):
stream = location.stream(istr)
result.append( (network.code(), station.code(), location.code(), stream.code()) )
for net, sta, loc, cha in result:
print "%-2s %-5s %-2s %-3s" % (net, sta, loc, cha)
return True
except:
info = traceback.format_exception(*sys.exc_info())
for i in info: sys.stderr.write(i)
sys.exit(-1)
def main():
app = ListStreamsApp(len(sys.argv), sys.argv)
return app()
if __name__ == "__main__":
sys.exit(main())
Print the station coordinated of all stations configured on a SC3 system.
#!/usr/bin/env python
import sys, seiscomp3.Client, seiscomp3.DataModel
class InvApp(seiscomp3.Client.Application):
def __init__(self, argc, argv):
seiscomp3.Client.Application.__init__(self, argc, argv)
self.setMessagingEnabled(False)
self.setDatabaseEnabled(True, True)
self.setLoggingToStdErr(True)
def validateParameters(self):
try:
if seiscomp3.Client.Application.validateParameters(self) == False:
return False
return True
except:
info = traceback.format_exception(*sys.exc_info())
for i in info: sys.stderr.write(i)
sys.exit(-1)
def run(self):
now = seiscomp3.Core.Time.GMT()
try:
lines = []
dbr = seiscomp3.DataModel.DatabaseReader(self.database())
inv = seiscomp3.DataModel.Inventory()
dbr.loadNetworks(inv)
nnet = inv.networkCount()
for inet in xrange(nnet):
net = inv.network(inet)
dbr.load(net);
nsta = net.stationCount()
for ista in xrange(nsta):
sta = net.station(ista)
line = "%-2s %-5s %9.4f %9.4f %6.1f" % ( net.code(), sta.code(), sta.latitude(), sta.longitude(), sta.elevation() )
try:
start = sta.start()
except:
continue
try:
end = sta.end()
if not start <= now <= end:
continue
except:
pass
lines.append(line)
lines.sort()
for line in lines:
print line
return True
except:
info = traceback.format_exception(*sys.exc_info())
for i in info: sys.stderr.write(i)
sys.exit(-1)
def main():
app = InvApp(len(sys.argv), sys.argv)
return app()
if __name__ == "__main__":
sys.exit(main())
Print channel gains for all streams configured on a SC3 system.
#!/usr/bin/env python
import traceback, sys, seiscomp3.Client, seiscomp3.DataModel
class InvApp(seiscomp3.Client.Application):
def __init__(self, argc, argv):
seiscomp3.Client.Application.__init__(self, argc, argv)
self.setMessagingEnabled(False)
self.setDatabaseEnabled(True, True)
self.setLoggingToStdErr(True)
def validateParameters(self):
try:
if seiscomp3.Client.Application.validateParameters(self) == False:
return False
return True
except:
info = traceback.format_exception(*sys.exc_info())
for i in info: sys.stderr.write(i)
sys.exit(-1)
def run(self):
now = seiscomp3.Core.Time.GMT()
try:
lines = []
dbq = seiscomp3.DataModel.DatabaseQuery(self.database())
inv = seiscomp3.DataModel.Inventory()
dbq.loadNetworks(inv)
nnet = inv.networkCount()
for inet in xrange(nnet):
network = inv.network(inet)
sys.stderr.write("\rworking on network %2s" % network.code())
dbq.load(network);
nsta = network.stationCount()
for ista in xrange(nsta):
station = network.station(ista)
try:
start = station.start()
except:
continue
try:
end = station.end()
if not start <= now <= end:
continue
except:
pass
# now we know that this is an operational station
for iloc in xrange(station.sensorLocationCount()):
location = station.sensorLocation(iloc)
for istr in range(location.streamCount()):
stream = location.stream(istr)
line = "%-2s %-5s %-2s %-3s %g" % (network.code(), station.code(), location.code(), stream.code(), stream.gain())
lines.append(line)
lines.sort()
for line in lines:
print line
return True
except:
info = traceback.format_exception(*sys.exc_info())
for i in info: sys.stderr.write(i)
sys.exit(-1)
def main():
app = InvApp(len(sys.argv), sys.argv)
return app()
if __name__ == "__main__":
sys.exit(main())
Example client that connects to a record stream service and dumps the content to stdout.
Illustrate the basic record stream concepts.
#!/usr/bin/env python
import seiscomp3.Client, sys
class App(seiscomp3.Client.StreamApplication):
def __init__(self, argc, argv):
seiscomp3.Client.StreamApplication.__init__(self, argc, argv)
# Do not connect to messaging and do not use database at all
self.setMessagingEnabled(False)
self.setDatabaseEnabled(False, False)
def init(self):
if seiscomp3.Client.StreamApplication.init(self) == False:
return False
# For testing purposes we subscribe to the last 5 minutes of data.
# To use real-time data, do not define an end time and configure
# a real-time capable backend such as Seedlink.
# First, query now
now = seiscomp3.Core.Time.GMT()
# Substract 5 minutes for the start time
start = now - seiscomp3.Core.TimeSpan(300,0)
# Set the start time in our record stream
self.recordStream().setStartTime(start)
# And the end time
self.recordStream().setEndTime(now)
# Now add some streams to fetch
self.recordStream().addStream("GE", "MORC", "", "BHZ")
self.recordStream().addStream("GE", "MORC", "", "BHN")
return True
# handleRecord is called when a new record is being read from the
# record stream
def handleRecord(self, rec):
# Print the streamID which is a join of NSLC separated with '.'
print rec.streamID()
# Print the records start time in ISO format
print " %s" % rec.startTime().iso()
# Print the sampling frequency
print " %fHz" % rec.samplingFrequency()
# If data is available
if rec.data():
# Print the number of samples
print " %d samples" % rec.data().size()
# Try to extract a float array. If the samples are of other
# data types, use rec.dataType() to query the type and use
# the appropriate array classes.
data = seiscomp3.Core.FloatArray.Cast(rec.data())
# Print the samples
if data:
print " data: %s" % str([data.get(i) for i in xrange(data.size())])
else:
print " no data"
def main():
app = App(len(sys.argv), sys.argv)
return app()
if __name__ == "__main__":
sys.exit(main())
The -I command line option can be used to configure the record stream backend when running the test application.
python testrec.py -I slink://localhost:18000
or to ask Arclink for data
python testrec.py -I arclink://localhost:18001