new object ConditionalBuffer added

dream/simulation/ConditionalBuffer.py

+# ===========================================================================
+# Copyright 2013 University of Limerick
+#
+# This file is part of DREAM.
+#
+# DREAM is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# DREAM is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with DREAM.  If not, see <http://www.gnu.org/licenses/>.
+# ===========================================================================
+'''
+Created on 15 Jan 2014
+
+@author: Ioannis
+'''
+'''
+Inherits from QueuePreemptive. Checks the condition of (a) component(s) before in can dispose of them/it
+'''
+
+from QueuePreemptive import QueuePreemptive
+from SimPy.Simulation import now
+
+# ===========================================================================
+# the QueuePreemptive object
+# ===========================================================================
+class ConditionalBuffer(QueuePreemptive):
+    # ===========================================================================
+    # the __init__ function
+    # ===========================================================================
+    def __init__(self, id, name, capacity=1, dummy=False, schedulingRule="CB"):
+        # run the default method, change the schedulingRule to CB 
+        # for description, check activeQSorter function of Queue coreObject 
+        QueuePreemptive.__init__(self, id, name, capacity, dummy, schedulingRule)
+                    
+    # =======================================================================
+    # checks if the Buffer can dispose an entity. 
+    # Returns True only to the potential receiver
+    # If it holds secondary components, checks first if the basicsEnded is
+    # True first. Otherwise, it waits until the basics are ended.
+    # =======================================================================     
+    def haveToDispose(self, callerObject=None):
+        # get active object and its queue
+        activeObject=self.getActiveObject()
+        activeObjectQueue=self.getActiveObjectQueue()
+        thecaller = callerObject
+        
+        # if the type of the component is Secondary then assert that the basics of the same order
+        # are already processed before disposing them to the next object
+        activeEntity = activeObjectQueue[0]
+        if activeEntity.componentType=='Secondary':
+            if not activeEntity.order.basicsEnded:
+                return False
+        
+        #if we have only one possible receiver just check if the Queue holds one or more entities
+        if(len(activeObject.next)==1 or callerObject==None):
+            activeObject.receiver=activeObject.next[0]
+            return len(activeObjectQueue)>0\
+                    and thecaller==activeObject.receiver
+        
+        #give the entity to the possible receiver that is waiting for the most time. 
+        #plant does not do this in every occasion!       
+        maxTimeWaiting=0     
+                                                        # loop through the object in the successor list
+        for object in activeObject.next:
+            if(object.canAccept(activeObject)):                                 # if the object can accept
+                timeWaiting=now()-object.timeLastEntityLeft         # compare the time that it has been waiting 
+                if(timeWaiting>maxTimeWaiting or maxTimeWaiting==0):# with the others'
+                    maxTimeWaiting=timeWaiting
+                    self.receiver=object                           # and update the receiver to the index of this object
+        
+        #return True if the Queue has Entities and the caller is the receiver
+        return len(activeObjectQueue)>0 and (thecaller is self.receiver) 
+        
+    
+    
+    
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