def call_service(service_name, service_args):
"""
Call a service. Mostly extracted from rosservice.
"""
service_class = rosservice.get_service_class_by_name(service_name)
request = service_class._request_class()
try:
now = rospy.get_rostime()
keys = {'now': now, 'auto': std_msgs.msg.Header(stamp=now)}
genpy.message.fill_message_args(request, service_args, keys=keys)
except genpy.MessageException as e:
def argsummary(args):
if type(args) in [tuple, list]:
return '\n'.join(
[' * %s (type %s)' % (a, type(a).__name__) for a in args])
else:
return ' * %s (type %s)' % (args, type(args).__name__)
raise rosservice.ROSServiceException(
"Incompatible arguments to call service:\n%s\n" +
"Provided arguments are:\n%s\n\n" + "Service arguments are: [%s]" %
(e, argsummary(service_args),
genpy.message.get_printable_message_args(request)))
try:
return request, rospy.ServiceProxy(service_name,
service_class)(request)
except rospy.ServiceException as e:
raise rosservice.ROSServiceException(str(e))
except genpy.SerializationError as e:
raise rosservice.ROSServiceException(
"Unable to send request. One of the fields has an incorrect type:\n"
+ " %s\n\nsrv file:\n%s" %
(e, rosmsg.get_srv_text(service_class._type)))
except rospy.ROSSerializationException as e:
raise rosservice.ROSServiceException(
"Unable to send request. One of the fields has an incorrect type:\n"
+ " %s\n\nsrv file:\n%s" %
(e, rosmsg.get_srv_text(service_class._type)))
def get_service_class(self, allow_get_type=False):
'''
Get the service class using the type of the service. NOTE: this
method is from `rosservice` and changed to avoid a probe call to the service.
:param allow_get_type: allow to connect to service and get the type if the type is not valid (in case of other host)
:type allow_get_type: bool
:return: service class
:rtype: ServiceDefinition: service class
:raise: ``ROSServiceException``, if service class cannot be retrieved
'''
if self.__service_class is not None:
return self.__service_class
srv_type = self.type
# request the type if it is empty and allowed
if not srv_type and allow_get_type and self.uri:
dest_addr = dest_port = None
try:
dest_addr, dest_port = rospy.parse_rosrpc_uri(self.uri)
except:
pass
else:
import socket
import cStringIO
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
try:
# connect to service and probe it to get the headers
s.settimeout(0.5)
s.connect((dest_addr, dest_port))
header = {
'probe': '1',
'md5sum': '*',
'callerid': rospy.get_name(),
'service': self.name
}
roslib.network.write_ros_handshake_header(s, header)
srv_type = roslib.network.read_ros_handshake_header(
s, cStringIO.StringIO(), 2048)
srv_type = srv_type['type']
except socket.error:
pass
except:
pass
finally:
if s is not None:
s.close()
import rosservice
if not srv_type:
raise rosservice.ROSServiceException(
"Not valid type of service [%s]." % str(srv_type))
# get the Service class so we can populate the request
service_class = roslib.message.get_service_class(srv_type)
# #1083: roscpp services are currently returning the wrong type
if service_class and self.type.endswith('Request') and \
not hasattr(service_class, "_request_class"):
srv_type = srv_type[:-7]
service_class = roslib.message.get_service_class(srv_type)
if service_class is None:
pkg = roslib.names.resource_name_package(self.type)
raise rosservice.ROSServiceException(
"Unable to load type [%s].\n" % self.type +
"Have you typed 'make' in [%s]?" % pkg)
self.__service_class = service_class
return service_class