Adding comm_info_request and comm_info_reply messages

ipykernel/inprocess/client.py

@@ -128,6 +128,16 @@ def kernel_info(self):
         self._dispatch_to_kernel(msg)
         return msg['header']['msg_id']
 
+    def comm_info(self, target_name=None):
+        """Request a dictionary of valid comms and their targets."""
+        if target_name is None:
+            content = {}
+        else:
+            content = dict(target_name=target_name)
+        msg = self.session.msg('comm_info_request', content)
+        self._dispatch_to_kernel(msg)
+        return msg['header']['msg_id']
+
     def input(self, string):
         if self.kernel is None:
             raise RuntimeError('Cannot send input reply. No kernel exists.')

ipykernel/kernelbase.py

@@ -119,7 +119,7 @@ def __init__(self, **kwargs):
         # Build dict of handlers for message types
         msg_types = [ 'execute_request', 'complete_request',
                       'inspect_request', 'history_request',
-                      'kernel_info_request',
+                      'comm_info_request', 'kernel_info_request',
                       'connect_request', 'shutdown_request',
                       'apply_request', 'is_complete_request',
                     ]
@@ -427,7 +427,7 @@ def inspect_request(self, stream, ident, parent):
     def do_inspect(self, code, cursor_pos, detail_level=0):
         """Override in subclasses to allow introspection.
         """
-        return {'status': 'ok', 'data':{}, 'metadata':{}, 'found':False}
+        return {'status': 'ok', 'data': {}, 'metadata': {}, 'found': False}
 
     def history_request(self, stream, ident, parent):
         content = parent['content']
@@ -470,6 +470,24 @@ def kernel_info_request(self, stream, ident, parent):
                                 self.kernel_info, parent, ident)
         self.log.debug("%s", msg)
 
+    def comm_info_request(self, stream, ident, parent):
+        content = parent['content']
+        target_name = content.get('target_name', None)
+
+        # Should this be moved to ipkernel?
+        if hasattr(self, 'comm_manager'):
+            comms = {
+                k: dict(target_name=v.target_name)
+                for (k, v) in self.comm_manager.comms.items()
+                if v.target_name == target_name or target_name is None
+            }
+        else:
+            comms = {}
+        reply_content = dict(comms=comms)
+        msg = self.session.send(stream, 'comm_info_reply',
+                                reply_content, parent, ident)
+        self.log.debug("%s", msg)
+
     def shutdown_request(self, stream, ident, parent):
         content = self.do_shutdown(parent['content']['restart'])
         self.session.send(stream, u'shutdown_reply', content, parent, ident=ident)

ipykernel/tests/test_message_spec.py

@@ -12,6 +12,7 @@
     from Queue import Empty  # Py 2
 
 import nose.tools as nt
+from nose.plugins.skip import SkipTest
 
 from traitlets import (
     HasTraits, TraitError, Bool, Unicode, Dict, Integer, List, Enum,
@@ -163,6 +164,8 @@ def check(self, d):
         Reference.check(self, d)
         LanguageInfo().check(d['language_info'])
 
+class CommInfoReply(Reference):
+    comms = Dict()
 
 class IsCompleteReply(Reference):
     status = Enum((u'complete', u'incomplete', u'invalid', u'unknown'), default_value=u'complete')
@@ -198,6 +201,7 @@ class DisplayData(MimeBundle):
 class ExecuteResult(MimeBundle):
     execution_count = Integer()
 
+
 class HistoryReply(Reference):
     history = List(List())
 
@@ -208,6 +212,7 @@ class HistoryReply(Reference):
     'status' : Status(),
     'complete_reply' : CompleteReply(),
     'kernel_info_reply': KernelInfoReply(),
+    'comm_info_reply': CommInfoReply(),
     'is_complete_reply': IsCompleteReply(),
     'execute_input' : ExecuteInput(),
     'execute_result' : ExecuteResult(),
@@ -419,6 +424,15 @@ def test_kernel_info_request():
     validate_message(reply, 'kernel_info_reply', msg_id)
 
 
+def test_comm_info_request():
+    flush_channels()
+    if not hasattr(KC, 'comm_info'):
+        raise SkipTest()
+    msg_id = KC.comm_info()
+    reply = KC.get_shell_msg(timeout=TIMEOUT)
+    validate_message(reply, 'comm_info_reply', msg_id)
+
+
 def test_single_payload():
     flush_channels()
     msg_id, reply = execute(code="for i in range(3):\n"+