cybertools.brain: work in progress

git-svn-id: svn://svn.cy55.de/Zope3/src/cybertools/trunk@1272 fd906abe-77d9-0310-91a1-e0d9ade77398

brain/README.txt

@@ -34,13 +34,21 @@ get triggered so that the receiver neurons' states are updated:
   >>> n02.getState()
   <State 1.0>
 
-To allow for concurrent (thread-safe) access to the brain all changes to
-the neurons' states is under the control of a transaction. If we end the
-current transaction all state changes will be forgotton:
+To allow for concurrent access to the brain by different clients
+simultaneously, the changes to the neurons' states may be under the control of
+a session:
 
-  >>> from cybertools.brain.transaction import endTransaction
-  >>> endTransaction()
+  >>> n01.setState(State())
+  >>> n02.setState(State())
+  >>> from cybertools.brain.session import Session
+  >>> session = Session()
+  >>> n01.setState(State(1.0), session)
   >>> n01.getState()
   <State 0.0>
+  >>> n01.getState(session)
+  <State 1.0>
+  >>> n01.notify(session)
   >>> n02.getState()
   <State 0.0>
+  >>> n02.getState(session)
+  <State 1.0>

brain/interfaces.py

@@ -34,7 +34,7 @@ class ISynapsis(Interface):
 
     transition = Attribute("A transition changes the sender neuron's state.")
 
-    def trigger(transaction=None):
+    def trigger(session=None):
         """ Recalculate the receiver neuron's state by executing the
             synapse's transition using the state of the sender neuron.
         """
@@ -45,15 +45,15 @@ class INeuron(Interface):
     senders = Attribute("The sender synapses")
     receivers = Attribute("The receiver synapses")
 
-    def setState(state, transaction=None):
+    def setState(state, session=None):
         """ Set the neuron's state.
         """
 
-    def getState(transaction=None):
+    def getState(session=None):
         """ Return the neuron's state.
         """
 
-    def notify(transaction=None):
+    def notify(session=None):
         """ Notifies the neuron that something has happened. This method
             calls the trigger() method on all downstream (receiver) synapses.
             In addition it may perform side effects like changing
@@ -70,12 +70,13 @@ class IState(Interface):
 
 class ITransition(Interface):
 
-    def execute(transaction=None):
+    def execute(session=None):
         """ Transform the receiver's state to a new state value and return it.
         """
 
 
-class ITransaction(Interface):
-    """ A transaction that keeps track of the neurons' states.
+class ISession(Interface):
+    """ A session keeps all actions for a certain sequence of user interactions
+        together by keeping track of the neurons' current and cumulated states.
     """
 

brain/neuron.py

@@ -25,7 +25,6 @@ $Id$
 from zope.interface import implements
 from cybertools.brain.interfaces import INeuron, ISynapsis
 from cybertools.brain.state import State, Transition
-from cybertools.brain.transaction import getTransaction
 
 
 class Synapsis(object):
@@ -41,10 +40,10 @@ class Synapsis(object):
         receiver.senders.append(self)
         self.transition = Transition(self)
 
-    def trigger(self, transaction=None):
+    def trigger(self, session=None):
         receiver = self.receiver
-        receiver.setState(self.transition.execute(transaction), transaction)
-        receiver.notify(transaction)
+        receiver.setState(self.transition.execute(session), session)
+        receiver.notify(session)
 
 
 class Neuron(object):
@@ -56,18 +55,18 @@ class Neuron(object):
         self.receivers = []
         self.state = State()
 
-    def setState(self, state, transaction=None):
-        transaction = getTransaction(transaction)
-        transaction.setState(self, state)
+    def setState(self, state, session=None):
+        if session is None:
+            self.state = state
+        else:
+            session.setState(self, state)
 
-    def getState(self, transaction=None):
-        if transaction is None:
-            transaction = getTransaction(create=False)
-            if transaction is None:
+    def getState(self, session=None):
+        if session is None:
                 return self.state
-        return transaction.getState(self)
+        return session.getState(self)
 
-    def notify(self, transaction=None):
+    def notify(self, session=None):
         for r in self.receivers:
-            r.trigger(transaction)
+            r.trigger(session)
 

brain/session.py

@@ -23,12 +23,12 @@ $Id$
 """
 
 from zope.interface import implements
-from cybertools.brain.interfaces import ITransaction
+from cybertools.brain.interfaces import ISession
 
 
-class Transaction(object):
+class Session(object):
 
-    implements(ITransaction)
+    implements(ISession)
 
     def __init__(self):
         self.states = {}
@@ -39,25 +39,3 @@ class Transaction(object):
     def getState(self, neuron):
         return self.states.get(neuron, neuron.state)
 
-
-transactions = []
-
-def getTransaction(transaction=None, create=True):
-    if transaction is None:
-        if transactions:
-            transaction = transactions[0]
-        elif create:
-            transaction = Transaction()
-            transactions.append(transaction)
-        else:
-            return None
-    return transaction
-
-def endTransaction(transaction=None):
-    if transaction is None:
-        if transactions:
-            del transactions[0]
-    else:
-        if transaction in transactions:
-            del transactions[transactions.index(transaction)]
-

brain/state.py

@@ -47,9 +47,9 @@ class Transition(object):
         self.synapsis = synapsis
         self.factor = factor
 
-    def execute(self, transaction=None):
-        oldState = self.synapsis.receiver.getState(transaction)
-        senderState = self.synapsis.sender.getState(transaction)
+    def execute(self, session=None):
+        oldState = self.synapsis.receiver.getState(session)
+        senderState = self.synapsis.sender.getState(session)
         return State(oldState.value + senderState.value * self.factor)