Initial upload of ExplanationCache, a data structure which is used to optimize...

Initial upload of ExplanationCache, a data structure which is used to optimize similation tree browsing for an explanation.

git-svn-id: https://svn.erp5.org/repos/public/erp5/sandbox/amount_generator@35576 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5/ExplanationCache.py

+# -*- coding: utf-8 -*-
+##############################################################################
+#
+# Copyright (c) 2O10 Nexedi SA and Contributors. All Rights Reserved.
+#                    Jean-Paul Smets-Solanes <jp@nexedi.com>
+#
+# WARNING: This program as such is intended to be used by professional
+# programmers who take the whole responsability of assessing all potential
+# consequences resulting from its eventual inadequacies and bugs
+# End users who are looking for a ready-to-use solution with commercial
+# garantees and support are strongly adviced to contract a Free Software
+# Service Company
+#
+# This program is Free Software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program 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 General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+#
+##############################################################################
+
+import types
+
+from Products.CMFCore.utils import getToolByName
+from Products.ERP5Type.TransactionalVariable import getTransactionalVariable
+
+class ExplanationCache:
+  """ExplanationCache provides a central access to 
+  all parameters and values which are needed to process 
+  an explanation. It is based on the idea that a value is calculated
+  once and once only, as a way to accelerate performance of algorithms
+  related to an explanation.
+
+        'explanation_uid': self._getExplanationUidList(explanation) # XXX-JPS why do we need explanation_uid ? and why a list
+        'simulation_path': simulation_path,
+
+    explanation_uid = self._getExplanationUidList(explanation) # A hint value to reduce the size of the tree
+    simulation_path = '/erp5/p.../%' # A list of path
+
+"""
+  def __init__(self, explanation):
+    """
+    """
+    # Define share properties
+    self.explanation = explanation
+    self.portal_catalog = getToolByName(explanation 'portal_catalog')
+    self.simulation_movement_cache = {} # Simulation Movement Cache
+    self.explanation_uid_cache = []
+    self.explanation_path_pattern_cache = []
+
+  def getDeliveryMovementList(self):
+    """Returns self is explanation is a delivery line
+    of the list of explanation delivery lines if explanation
+    is a delivery
+    """
+    explanation = self.explanation
+    if explanation.isDelivery():
+      # Gather all movements of the delivery
+      delivery_movement_list = explanation.getMovementList()
+    else:
+      # Only consider a single movement - XXX-JPS is this OK when we have lines in lines ?
+      delivery_movement_list = [explanation]
+    return delivery_movement_list
+
+  def getRootExplanationUidList(self):
+    """Return the list of explanation_uid values involved
+    in the context of the explanation. This will be useful later
+    in order to accelerate searches in the catalog.
+    """
+    # Return cache if defined
+    if self.explanation_uid_cache:
+      return self.explanation_uid_cache
+    result = set()
+    # For each delivery movement
+    for movement in self.getDeliveryMovementList():
+      # For each simulation movement
+      for simulation_movement in movement.getDeliveryRelatedValueList():
+        result.add(simulation_movement.getExplanationUid()) # XXX-JPS use new API later
+    # Return result
+    self.explanation_uid_cache = result
+    return result
+
+  def getSimulationPathPatternList(self):
+    """Return the list of root path of simulation tree which are 
+    involved in the context of the explanation. This will be useful later
+    in order to accelerate searches in the catalog.
+    """
+    # Return cache if defined
+    if self.explanation_path_pattern_cache:
+      return self.explanation_path_pattern_cache
+
+    # Helper method to update path_dict with
+    # each key which forms the pay of the simulation_movement
+    path_dict = {}
+    def updatePathDict(simulation_movement):
+      local_path_dict = path_dict
+      container_path = simulation_movement.getParentValue().getPhysicalPath()
+      simulation_movement_id = simulation_movement.getId()
+      insert_movement = True
+      for path_id in container_path:
+        if local_path_dict.get(path_id, None) is None:
+          local_path_dict[path_id] = dict()
+        local_path_dict = local_path_dict[path_id]
+        if type(local_path_dict) is not types.DictType:
+          # A movement was already inserted
+          insert_movement = False
+          break
+      if insert_movement:
+        local_path_dict[simulation_movement_id] = simulation_movement
+
+    # For each delivery movement
+    for movement in self.getDeliveryMovementList():
+      # For each simulation movement
+      for simulation_movement in movement.getDeliveryRelatedValueList():
+        updatePathDict(simulation_movement)
+    
+    # Build result by browsing path_dict and
+    # assembling path '/erp5/portal_simulation/1/34/23/43%'
+    result = []
+    def browsePathDict(prefix, local_path_dict):
+      for key, value in local_path_dict.items():
+        if type(value) is not types.DictType:
+          # We have a real root
+          result.append('%s/%s%' % (prefix, key))
+        else:
+          browsePathDict('%s/%s' % (prefix, key), value) # Recursing with string append is slow XXX-JPS
+
+    browsePathDict('', path_dict)
+    self.explanation_path_pattern_cache = result
+    return result
+
+  def getBusinessPathRelatedSimulationMovementValueList(self, business_path):
+    """Returns the list of simulation movements caused by a business_path
+    in the context the our explanation.
+    """
+    return self.getSimulationMovementList(causality_uid=business_path.getUid())
+    
+  def getSimulationMovementList(self, **kw)
+    """Search Simulation Movements related to our explanation.
+    Cache result so that the second time we saarch for the same
+    list we need not involve the catalog again.
+    """
+    kw_tuple = tuple(kw.items()) # We hope that no sorting is needed
+    if self.simulation_movement_list.get(kw_tuple, None) is None:
+      self.simulation_movement_cache[kw_tuple] = \
+           self.portal_catalog(portal_type="Simulation Movement",
+                               explanation_uid=self.getRootExplanationUidList(),
+                               path=self.getSimulationPathPatternList(), # XXX-JPS Explicit Query is better
+                               **kw)
+    return self.simulation_movement_cache[kw_tuple]
+
+def _getExplanationCache(explanation):
+  # Return cached value if any
+  tv = getTransactionalVariable(explanation)
+  if tv.get('explanation_cache', None) is None:
+    tv['explanation_cache'] =  ExplanationCache(explanation)
+  return tv.get('explanation_cache')