model: added policy class + policy-oriented API fixes

+ Added policy class
+ Adapted NormalDIF class to use new policy class
+ NormalDIF constructor argument policy has changed format
  (parameters dict is now mandatory, added empty dicts where it was not passed)
+ Added Node.policies field (type: dict[DIF -> Policy])

1 files changed, 76 insertions, 11 deletions

diff --git a/rumba/model.py b/rumba/model.py
index 9187fcb..442933c 100644
--- a/rumba/model.py
+++ b/rumba/model.py
@@ -112,25 +112,30 @@ class ShimEthDIF(DIF):
 
 # Normal DIF
 #
-# @policies [dict] Policies of the normal DIF
+# @policies [dict] Policies of the normal DIF. Format:
+#       dict( componentName: str --> comp_policy:
+#               dict( policy_name: str --> parameters:
+#                       dict( name: str --> value: str )))
 #
 class NormalDIF(DIF):
     def __init__(self, name, members=None, policies=None):
         DIF.__init__(self, name, members)
         if policies is None:
-            policies = dict()
-        self.policies = policies
+            self.policy = Policy(self)
+        self.policy = Policy(self, policies=policies)
 
-    def add_policy(self, comp, pol):
-        self.policies[comp] = pol
+    def add_policy(self, comp, pol, **params):
+        self.policy.add_policy(comp, pol, **params)
 
-    def del_policy(self, comp):
-        del self.policies[comp]
+    def del_policy(self, comp=None, policy_name=None):
+        self.policy.del_policy(comp, policy_name)
 
     def show(self):
         s = DIF.__repr__(self)
-        for comp, pol in self.policies.items():
-            s += "\n       Component %s has policy %s" % (comp, pol)
+        for comp, pol_dict in self.policy.get_policies().items():
+            for pol, params in pol_dict.items():
+                s += "\n       Component %s has policy %s with params %s" \
+                     % (comp, pol, params)
         return s
 
 
@@ -149,10 +154,11 @@ class SSHConfig:
 # @dif_registrations: Which DIF is registered in which DIF
 # @registrations: Registrations of names in DIFs
 # @bindings: Binding of names on the processing system
+# @policies: dict of dif -> policy dict to apply for that dif in this node
 #
 class Node:
     def __init__(self, name, difs=None, dif_registrations=None,
-                 registrations=None, bindings=None):
+                 registrations=None, bindings=None, policies=None):
         self.name = name
         if difs is None:
             difs = list()
@@ -170,6 +176,13 @@ class Node:
         self.bindings = bindings
         self.ssh_config = SSHConfig(name)
         self.ipcps = []
+        if policies is None:
+            policies = dict()
+            self.policies = dict()
+        for dif in self.difs:
+            if hasattr(dif, 'policy'):
+                self.policies[dif] = \
+                    Policy(dif, self, policies.get(dif.name, {}))
 
         self._validate()
 
@@ -195,7 +208,7 @@ class Node:
             for dif in self.registrations[appl]:
                 self._undeclared_dif(dif)
 
-    def __repr__(self):
+    def __repr__(self):  # TODO add policies in repr?
         s = "Node " + self.name + ":\n"
 
         s += "  DIFs: [ "
@@ -240,11 +253,18 @@ class Node:
     def add_dif(self, dif):
         self.difs.append(dif)
         dif.add_member(self)
+        if hasattr(dif, 'policy'):
+            self.policies[dif] = Policy(dif, self)
         self._validate()
 
     def del_dif(self, dif):
         self.difs.remove(dif)
         dif.del_member(self)
+        try:
+            del self.policies[dif]
+        except KeyError:
+            # It was not in there, so nothing to do
+            pass
         self._validate()
 
     def add_dif_registration(self, upper, lower):
@@ -271,6 +291,12 @@ class Node:
         del self.bindings[name]
         self._validate()
 
+    def add_policy(self, dif, component_name, policy_name, **parameters):
+        self.policies[dif].add_policy(component_name, policy_name, **parameters)
+
+    def del_policy(self, dif, component_name=None, policy_name=None):
+        self.policies[dif].del_policy(component_name, policy_name)
+
 
 # Base class representing an IPC Process to be created in the experiment
 #
@@ -319,6 +345,45 @@ class ShimUDPIPCP(IPCP):
         # TODO: add IP and port
 
 
+# Class representing DIF and Node policies
+class Policy(object):
+    def __init__(self, dif, node=None, policies=None):
+        self.dif = dif  # type: NormalDIF
+        self.node = node
+        if policies is None:
+            self._dict = dict()
+        else:
+            self._dict = policies
+
+    def add_policy(self, component_name, policy_name, **parameters):
+        self._dict.setdefault(component_name, dict())[policy_name] = parameters
+
+    def get_policies(self, component_name=None, policy_name=None):
+        if self.node is not None:
+            policy = self._superimpose(self.dif.policy)
+        else:
+            policy = self
+        if component_name is None:
+            return policy._dict
+        elif policy_name is None:
+            return policy._dict[component_name]
+        else:
+            return policy._dict[component_name][policy_name]
+
+    def del_policy(self, component_name=None, policy_name=None):
+        if component_name is None:
+            self._dict = dict()
+        elif policy_name is None:
+            del self._dict[component_name]
+        else:
+            del self._dict[component_name][policy_name]
+
+    def _superimpose(self, other):
+        base = dict(other._dict)
+        base.update(self._dict)
+        return Policy(base)
+
+
 # Base class for ARCFIRE experiments
 #
 # @name [string] Name of the experiment