rospy.msproxy

1 # Software License Agreement (BSD License) 2 # 3 # Copyright (c) 2008, Willow Garage, Inc. 4 # All rights reserved. 5 # 6 # Redistribution and use in source and binary forms, with or without 7 # modification, are permitted provided that the following conditions 8 # are met: 9 # 10 # * Redistributions of source code must retain the above copyright 11 # notice, this list of conditions and the following disclaimer. 12 # * Redistributions in binary form must reproduce the above 13 # copyright notice, this list of conditions and the following 14 # disclaimer in the documentation and/or other materials provided 15 # with the distribution. 16 # * Neither the name of Willow Garage, Inc. nor the names of its 17 # contributors may be used to endorse or promote products derived 18 # from this software without specific prior written permission. 19 # 20 # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 21 # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22 # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 23 # FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 24 # COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 25 # INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 26 # BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 27 # LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 28 # CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 30 # ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 31 # POSSIBILITY OF SUCH DAMAGE. 32 # 33 # Revision $Id$ 34 """ 35 Master/Slave XML-RPC Wrappers. 36 37 The L{MasterProxy} simplifies usage of master/slave 38 APIs by automatically inserting the caller ID and also adding python 39 dictionary accessors on the parameter server. 40 """ 41 42 from threading import Lock 43 44 import rospy.core 45 import rospy.exceptions 46 import rospy.names 47 48 import rospy.impl.paramserver 49 import rospy.impl.masterslave 50 51 _master_arg_remap = { 52 'deleteParam': [0], # remap key 53 'setParam': [0], # remap key 54 'getParam': [0], # remap key 55 'searchParam': [0], # remap key 56 'subscribeParam': [0], # remap key 57 'unsubscribeParam': [0], # remap key 58 'hasParam': [0], # remap key 59 'registerService': [0], # remap service 60 'lookupService': [0], # remap service 61 'unregisterService': [0], # remap service 62 'registerSubscriber': [0], # remap topic 63 'unregisterSubscriber': [0], # remap topic 64 'registerPublisher': [0], # remap topic 65 'unregisterPublisher': [0], # remap topic 66 'lookupNode': [0], # remap node 67 'getPublishedTopics': [0], # remap subgraph 68 } 69

70 -class MasterProxy(object):

71 """ 72 Convenience wrapper for ROS master API and XML-RPC 73 implementation. The Master API methods can be invoked on this 74 object and will be forwarded appropriately. Names in arguments 75 will be remapped according to current node settings. Provides 76 dictionary-like access to parameter server, e.g.:: 77 78 master[key] = value 79 80 All methods are thread-safe. 81 """ 82

83 - def __init__(self, uri):

84 """ 85 Constructor for wrapping a remote master instance. 86 @param uri: XML-RPC URI of master 87 @type uri: str 88 """ 89 self.target = rospy.core.xmlrpcapi(uri)

90

91 - def __getattr__(self, key): #forward api calls to target

92 if key in _master_arg_remap: 93 remappings = _master_arg_remap[key] 94 else: 95 remappings = rospy.impl.masterslave.ROSHandler.remappings(key) 96 def wrappedF(*args, **kwds): 97 args = [rospy.names.get_caller_id(),]+list(args) 98 #print "Remap indicies", remappings 99 for i in remappings: 100 i = i + 1 #callerId does not count 101 #print "Remap %s => %s"%(args[i], rospy.names.resolve_name(args[i])) 102 args[i] = rospy.names.resolve_name(args[i]) 103 f = getattr(self.target, key) 104 return f(*args, **kwds)

105 return wrappedF 106

107 - def __getitem__(self, key):

108 """ 109 Fetch item from parameter server and subscribe to future updates so that 110 values can be cached. 111 @param key: parameter key 112 @type key: str 113 @raise KeyError: if key is not set 114 """ 115 #NOTE: remapping occurs here! 116 resolved_key = rospy.names.resolve_name(key) 117 try: 118 return rospy.impl.paramserver.get_param_server_cache().get(resolved_key) 119 except KeyError: 120 pass 121 code, msg, value = self.target.getParam(rospy.names.get_caller_id(), resolved_key) 122 if code != 1: #unwrap value with Python semantics 123 raise KeyError(key) 124 return value

125

126 - def __setitem__(self, key, val):

127 """ 128 Set parameter value on Parameter Server 129 @param key: parameter key 130 @type key: str 131 @param val: parameter value 132 @type val: XMLRPC legal value 133 """ 134 resolved_key = rospy.names.resolve_name(key) 135 136 self.target.setParam(rospy.names.get_caller_id(), resolved_key, val) 137 try: 138 rospy.impl.paramserver.get_param_server_cache().update(resolved_key, val) 139 except KeyError: 140 pass

141

142 - def search_param(self, key):

143 """ 144 Search for a parameter matching key on the parameter server 145 @return: found key or None if search did not succeed 146 @rtype: str 147 @raise ROSException: if parameter server reports an error 148 """ 149 # #1810 searchParam has to use unresolved form of mappings 150 mappings = rospy.names.get_mappings() 151 if key in mappings: 152 key = mappings[key] 153 code, msg, val = self.target.searchParam(rospy.names.get_caller_id(), key) 154 if code == 1: 155 return val 156 elif code == -1: 157 return None 158 else: 159 raise rospy.exceptions.ROSException("cannot search for parameter: %s"%msg)

160

161 - def get_param_cached(self, key):

162 resolved_key = rospy.names.resolve_name(key) 163 try: 164 # check for value in the parameter server cache 165 return rospy.impl.paramserver.get_param_server_cache().get(resolved_key) 166 except KeyError: 167 # first access, make call to parameter server 168 code, msg, value = self.target.subscribeParam(rospy.names.get_caller_id(), rospy.core.get_node_uri(), resolved_key) 169 if code != 1: #unwrap value with Python semantics 170 raise KeyError(key) 171 # set the value in the cache so that it's marked as subscribed 172 rospy.impl.paramserver.get_param_server_cache().set(resolved_key, value) 173 if isinstance(value, dict) and not value: 174 raise KeyError(key) 175 return value

176

177 - def __delitem__(self, key):

178 """ 179 Delete parameter key from the parameter server. 180 @raise KeyError: if key is not set 181 @raise ROSException: if parameter server reports an error 182 """ 183 resolved_key = rospy.names.resolve_name(key) 184 code, msg, _ = self.target.deleteParam(rospy.names.get_caller_id(), resolved_key) 185 if code == -1: 186 raise KeyError(key) 187 elif code != 1: 188 raise rospy.exceptions.ROSException("cannot delete parameter: %s"%msg)

189

190 - def __contains__(self, key):

191 """ 192 Check if parameter is set on Parameter Server 193 @param key: parameter key 194 @type key: str 195 @raise ROSException: if parameter server reports an error 196 """ 197 code, msg, value = self.target.hasParam(rospy.names.get_caller_id(), rospy.names.resolve_name(key)) 198 if code != 1: 199 raise rospy.exceptions.ROSException("cannot check parameter on server: %s"%msg) 200 return value

201

202 - def __iter__(self):

203 """ 204 @raise ROSException: if parameter server reports an error 205 """ 206 code, msg, value = self.target.getParamNames(rospy.names.get_caller_id()) 207 if code == 1: 208 return value.__iter__() 209 else: 210 raise rospy.exceptions.ROSException("cannot retrieve parameter names: %s"%msg)

211

Source Code for Module rospy.msproxy