ofctl: Enable to get all datapath objects

Also, updates the API document of ryu.app.ofctl.api.

Signed-off-by: IWASE Yusuke <iwase.yusuke0@gmail.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>

ryu/app/ofctl/api.py

@@ -16,22 +16,37 @@
 
 # client for ryu.app.ofctl.service
 
-import numbers
-
 from ryu.base import app_manager
 from . import event
 
 
-def get_datapath(app, dpid):
+def get_datapath(app, dpid=None):
     """
     Get datapath object by dpid.
 
     :param app: Client RyuApp instance
-    :param dpid: Datapath-id (in integer)
+    :param dpid: Datapath ID (int type) or None to get all datapath objects
 
-    Returns None on error.
+    Returns a object of datapath, a list of datapath objects when no dpid
+    given or None when error.
+
+    Raises an exception if any of the given values is invalid.
+
+    Example::
+
+        # ...(snip)...
+        import ryu.app.ofctl.api as ofctl_api
+
+
+        class MyApp(app_manager.RyuApp):
+
+            def _my_handler(self, ev):
+                # Get all datapath objects
+                result = ofctl_api.get_datapath(self)
+
+                # Get the datapath object which has the given dpid
+                result = ofctl_api.get_datapath(self, dpid=1)
     """
-    assert isinstance(dpid, numbers.Integral)
     return app.send_request(event.GetDatapathRequest(dpid=dpid))()
 
 
@@ -55,10 +70,17 @@ def send_msg(app, msg, reply_cls=None, reply_multi=False):
 
     Example::
 
-        import ryu.app.ofctl.api as api
+        # ...(snip)...
+        import ryu.app.ofctl.api as ofctl_api
 
+
+        class MyApp(app_manager.RyuApp):
+
+            def _my_handler(self, ev):
+                # ...(snip)...
         msg = parser.OFPPortDescStatsRequest(datapath=datapath)
-        result = api.send_msg(self, msg,
+                result = ofctl_api.send_msg(
+                    self, msg,
                                     reply_cls=parser.OFPPortDescStatsReply,
                                     reply_multi=True)
     """

ryu/app/ofctl/event.py

@@ -33,8 +33,8 @@ class _ReplyBase(event.EventReplyBase):
 # get datapath
 
 class GetDatapathRequest(_RequestBase):
-    def __init__(self, dpid):
-        assert isinstance(dpid, numbers.Integral)
+    def __init__(self, dpid=None):
+        assert dpid is None or isinstance(dpid, numbers.Integral)
         super(GetDatapathRequest, self).__init__()
         self.dpid = dpid
 

ryu/app/ofctl/service.py

@@ -99,15 +99,13 @@ class OfctlService(app_manager.RyuApp):
 
     @set_ev_cls(event.GetDatapathRequest, MAIN_DISPATCHER)
     def _handle_get_datapath(self, req):
-        id = req.dpid
-        assert isinstance(id, numbers.Integral)
-        try:
-            datapath = self._switches[id].datapath
-        except KeyError:
-            datapath = None
-        self.logger.debug('dpid %s -> datapath %s', id, datapath)
-        rep = event.Reply(result=datapath)
-        self.reply_to_request(req, rep)
+        result = None
+        if req.dpid is None:
+            result = [v.datapath for v in self._switches.values()]
+        else:
+            if req.dpid in self._switches:
+                result = self._switches[req.dpid].datapath
+        self.reply_to_request(req, event.Reply(result=result))
 
     @set_ev_cls(event.SendMsgRequest, MAIN_DISPATCHER)
     def _handle_send_msg(self, req):