Source Code for Module rospy.service

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 33  # Revision $Id: service.py 11753 2010-10-25 06:23:19Z kwc $ 
 34   
 35  """Base-classes and management of ROS services. 
 36  See L{rospy.tcpros_service} for actual implementation.""" 
 37   
 38  from __future__ import with_statement 
 39   
 40  import logging 
 41  import traceback 
 42   
 43  from rospy.core import * 
 44   
 45  from rospy.impl.registration import set_service_manager, Registration, get_registration_listeners 
 46  from rospy.impl.transport import * 
 47   
 48  logger = logging.getLogger('rospy.service') 
 49   
 50  ## alias of roslib.message.ServiceDefinition 
 51  import roslib.message 
 52  ServiceDefinition = roslib.message.ServiceDefinition 
 53   
 54 -class ServiceException(Exception): 
 55      """Exception class for service-related errors""" 
 56      pass 
 57   
 58 -class _Service(object): 
 59      """Internal-use superclass for storing service information""" 
 60 -    def __init__(self, name, service_class): 
 61          self.resolved_name = resolve_name(name) #services remap as well 
 62          self.service_class = service_class 
 63          self.request_class = service_class._request_class 
 64          self.response_class = service_class._response_class 
 65          self.uri = None #initialize attr 
 66   
 67 -class ServiceManager(object): 
 68      """Keeps track of currently registered services in the ROS system""" 
 69       
 70 -    def __init__(self, registration_listeners=None): 
 71          """ 
 72          ctor 
 73          @param registration_listeners: override default registration listener. 
 74          @type  registration_listeners: RegistrationListeners 
 75          """ 
 76          self.map = {} # {name : Service} 
 77          self.lock = threading.RLock() 
 78          if registration_listeners is None: 
 79              self.registration_listeners = get_registration_listeners() 
 80          else: 
 81              self.registration_listeners = registration_listeners        
 82   
 83 -    def get_services(self): 
 84          """ 
 85          @return: List of (service_name, service_uri)  for all registered services. 
 86          @rtype: [(str, str)] 
 87          """ 
 88          with self.lock: 
 89              ret_val = [] 
 90              for name, service in self.map.iteritems(): 
 91                  ret_val.append((name, service.uri)) 
 92              services = self.map.values() 
 93          return ret_val 
 94       
 95 -    def unregister_all(self): 
 96          """ 
 97          Unregister all registered services 
 98          """ 
 99          self.map.clear() 
100       
101 -    def register(self, resolved_service_name, service): 
102          """ 
103          Register service with ServiceManager and ROS master 
104          @param resolved_service_name: name of service (resolved) 
105          @type  resolved_service_name: str 
106          @param service: Service to register 
107          @type  service: L{_Service} 
108          """ 
109          err = None 
110          with self.lock: 
111              if resolved_service_name in self.map: 
112                  err = "service [%s] already registered"%resolved_service_name 
113              else: 
114                  self.map[resolved_service_name] = service 
115                   
116              # NOTE: this call can potentially take a long time under lock and thus needs to be reimplmented 
117              self.registration_listeners.notify_added(resolved_service_name, service.uri, Registration.SRV) 
118   
119          if err: 
120              raise ServiceException(err) 
121           
122 -    def unregister(self, resolved_service_name, service): 
123          """ 
124          Unregister service with L{ServiceManager} and ROS Master 
125          @param resolved_service_name: name of service 
126          @type  resolved_service_name: str 
127          @param service: service implementation 
128          @type  service: L{_Service} 
129          """         
130          with self.lock: 
131              curr = self.map.get(resolved_service_name, None) 
132              if curr == service: 
133                  del self.map[resolved_service_name] 
134                   
135              # NOTE: this call can potentially take a long time under lock 
136              self.registration_listeners.notify_removed(resolved_service_name, service.uri, Registration.SRV)                 
137   
138 -    def get_service(self, resolved_service_name): 
139          """ 
140          @param resolved_service_name: name of service 
141          @type  resolved_service_name: str 
142          @return: service implementation 
143          @rtype: _Service 
144          """ 
145          return self.map.get(resolved_service_name, None) 
146   
147  set_service_manager(ServiceManager()) 
148