Package logilab :: Package common :: Module pyro_ext
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Source Code for Module logilab.common.pyro_ext

  1  # copyright 2003-2011 LOGILAB S.A. (Paris, FRANCE), all rights reserved. 
  2  # contact http://www.logilab.fr/ -- mailto:contact@logilab.fr 
  3  # 
  4  # This file is part of logilab-common. 
  5  # 
  6  # logilab-common is free software: you can redistribute it and/or modify it under 
  7  # the terms of the GNU Lesser General Public License as published by the Free 
  8  # Software Foundation, either version 2.1 of the License, or (at your option) any 
  9  # later version. 
 10  # 
 11  # logilab-common is distributed in the hope that it will be useful, but WITHOUT 
 12  # ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS 
 13  # FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more 
 14  # details. 
 15  # 
 16  # You should have received a copy of the GNU Lesser General Public License along 
 17  # with logilab-common.  If not, see <http://www.gnu.org/licenses/>. 
 18  """Python Remote Object utilities 
 19   
 20  Main functions available: 
 21   
 22  * `register_object` to expose arbitrary object through pyro using delegation 
 23    approach and register it in the nameserver. 
 24  * `ns_unregister` unregister an object identifier from the nameserver. 
 25  * `ns_get_proxy` get a pyro proxy from a nameserver object identifier. 
 26  """ 
 27   
 28  __docformat__ = "restructuredtext en" 
 29   
 30  import logging 
 31  import tempfile 
 32   
 33  from Pyro import core, naming, errors, util, config 
 34   
 35  _LOGGER = logging.getLogger('pyro') 
 36  _MARKER = object() 
 37   
 38  config.PYRO_STORAGE = tempfile.gettempdir() 
 39   
40 -def ns_group_and_id(idstr, defaultnsgroup=_MARKER):
41 try: 42 nsgroup, nsid = idstr.rsplit('.', 1) 43 except ValueError: 44 if defaultnsgroup is _MARKER: 45 nsgroup = config.PYRO_NS_DEFAULTGROUP 46 else: 47 nsgroup = defaultnsgroup 48 nsid = idstr 49 if nsgroup is not None and not nsgroup.startswith(':'): 50 nsgroup = ':' + nsgroup 51 return nsgroup, nsid
52
53 -def host_and_port(hoststr):
54 if not hoststr: 55 return None, None 56 try: 57 hoststr, port = hoststr.split(':') 58 except ValueError: 59 port = None 60 else: 61 port = int(port) 62 return hoststr, port
63 64 _DAEMONS = {} 65 _PYRO_OBJS = {}
66 -def _get_daemon(daemonhost, start=True):
67 if not daemonhost in _DAEMONS: 68 if not start: 69 raise Exception('no daemon for %s' % daemonhost) 70 if not _DAEMONS: 71 core.initServer(banner=0) 72 host, port = host_and_port(daemonhost) 73 daemon = core.Daemon(host=host, port=port) 74 _DAEMONS[daemonhost] = daemon 75 return _DAEMONS[daemonhost]
76 77
78 -def locate_ns(nshost):
79 """locate and return the pyro name server to the daemon""" 80 core.initClient(banner=False) 81 return naming.NameServerLocator().getNS(*host_and_port(nshost))
82 83
84 -def register_object(object, nsid, defaultnsgroup=_MARKER, 85 daemonhost=None, nshost=None, use_pyrons=True):
86 """expose the object as a pyro object and register it in the name-server 87 88 if use_pyrons is False, then the object is exposed, but no 89 attempt to register it to a pyro nameserver is made. 90 91 return the pyro daemon object 92 """ 93 nsgroup, nsid = ns_group_and_id(nsid, defaultnsgroup) 94 daemon = _get_daemon(daemonhost) 95 if use_pyrons: 96 nsd = locate_ns(nshost) 97 # make sure our namespace group exists 98 try: 99 nsd.createGroup(nsgroup) 100 except errors.NamingError: 101 pass 102 daemon.useNameServer(nsd) 103 # use Delegation approach 104 impl = core.ObjBase() 105 impl.delegateTo(object) 106 qnsid = '%s.%s' % (nsgroup, nsid) 107 uri = daemon.connect(impl, qnsid) 108 _PYRO_OBJS[qnsid] = str(uri) 109 _LOGGER.info('registered %s a pyro object using group %s and id %s', 110 object, nsgroup, nsid) 111 return daemon
112
113 -def get_object_uri(qnsid):
114 return _PYRO_OBJS[qnsid]
115
116 -def ns_unregister(nsid, defaultnsgroup=_MARKER, nshost=None):
117 """unregister the object with the given nsid from the pyro name server""" 118 nsgroup, nsid = ns_group_and_id(nsid, defaultnsgroup) 119 try: 120 nsd = locate_ns(nshost) 121 except errors.PyroError, ex: 122 # name server not responding 123 _LOGGER.error('can\'t locate pyro name server: %s', ex) 124 else: 125 try: 126 nsd.unregister('%s.%s' % (nsgroup, nsid)) 127 _LOGGER.info('%s unregistered from pyro name server', nsid) 128 except errors.NamingError: 129 _LOGGER.warning('%s not registered in pyro name server', nsid)
130 131
132 -def ns_reregister(nsid, defaultnsgroup=_MARKER, nshost=None):
133 """reregister a pyro object into the name server. You only have to specify 134 the name-server id of the object (though you MUST have gone through 135 `register_object` for the given object previously). 136 137 This is especially useful for long running server while the name server may 138 have been restarted, and its records lost. 139 """ 140 nsgroup, nsid = ns_group_and_id(nsid, defaultnsgroup) 141 qnsid = '%s.%s' % (nsgroup, nsid) 142 nsd = locate_ns(nshost) 143 try: 144 nsd.unregister(qnsid) 145 except errors.NamingError: 146 # make sure our namespace group exists 147 try: 148 nsd.createGroup(nsgroup) 149 except errors.NamingError: 150 pass 151 nsd.register(qnsid, _PYRO_OBJS[qnsid])
152
153 -def ns_get_proxy(nsid, defaultnsgroup=_MARKER, nshost=None):
154 """ 155 if nshost is None, the nameserver is found by a broadcast. 156 """ 157 # resolve the Pyro object 158 nsgroup, nsid = ns_group_and_id(nsid, defaultnsgroup) 159 try: 160 nsd = locate_ns(nshost) 161 pyrouri = nsd.resolve('%s.%s' % (nsgroup, nsid)) 162 except errors.ProtocolError, ex: 163 raise errors.PyroError( 164 'Could not connect to the Pyro name server (host: %s)' % nshost) 165 except errors.NamingError: 166 raise errors.PyroError( 167 'Could not get proxy for %s (not registered in Pyro), ' 168 'you may have to restart your server-side application' % nsid) 169 return core.getProxyForURI(pyrouri)
170
171 -def get_proxy(pyro_uri):
172 """get a proxy for the passed pyro uri without using a nameserver 173 """ 174 return core.getProxyForURI(pyro_uri)
175
176 -def set_pyro_log_threshold(level):
177 pyrologger = logging.getLogger('Pyro.%s' % str(id(util.Log))) 178 # remove handlers so only the root handler is used 179 pyrologger.handlers = [] 180 pyrologger.setLevel(level)
181