Source Code for Module rospy.service

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