Merged r[280]:[358] from source:/sandbox/follower/b-singlefile/ (Enable building of Single File Library version of OpenLayers library).
git-svn-id: http://svn.openlayers.org/trunk/openlayers@359 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf
This commit is contained in:
follower
@@ -0,0 +1,260 @@
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#
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# According to <http://www.vrplumber.com/programming/> this file
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# is licensed under a BSD-style license. We only use the section
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# originally by Tim Peters.
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#
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# TODO: The use of this code needs to be okayed by someone.
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#
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class RecursionError( OverflowError, ValueError ):
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'''Unable to calculate result because of recursive structure'''
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def sort(nodes, routes, noRecursion=1):
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'''Passed a list of node IDs and a list of source,dest ID routes
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attempt to create a list of stages where each sub list
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is one stage in a process.
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'''
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children, parents = _buildChildrenLists(routes)
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# first stage is those nodes
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# having no incoming routes...
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stage = []
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stages = [stage]
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taken = []
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for node in nodes:
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if (not parents.get(node)):
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stage.append (node)
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if nodes and not stage:
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# there is no element which does not depend on
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# some other element!!!
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stage.append( nodes[0])
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taken.extend( stage )
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nodes = filter ( lambda x, l=stage: x not in l, nodes )
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while nodes:
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previousStageChildren = []
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nodelen = len(nodes)
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# second stage are those nodes
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# which are direct children of the first stage
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for node in stage:
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for child in children.get (node, []):
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if child not in previousStageChildren and child not in taken:
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previousStageChildren.append(child)
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elif child in taken and noRecursion:
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raise RecursionError( (child, node) )
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# unless they are children of other direct children...
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# TODO, actually do that...
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stage = previousStageChildren
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removes = []
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for current in stage:
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currentParents = parents.get( current, [] )
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for parent in currentParents:
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if parent in stage and parent != current:
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# might wind up removing current...
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if not current in parents.get(parent, []):
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# is not mutually dependent...
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removes.append( current )
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for remove in removes:
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while remove in stage:
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stage.remove( remove )
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stages.append( stage)
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taken.extend( stage )
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nodes = filter ( lambda x, l=stage: x not in l, nodes )
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if nodelen == len(nodes):
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if noRecursion:
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raise RecursionError( nodes )
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else:
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stages.append( nodes[:] )
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nodes = []
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return stages
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def _buildChildrenLists (routes):
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childrenTable = {}
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parentTable = {}
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for sourceID,destinationID in routes:
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currentChildren = childrenTable.get( sourceID, [])
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currentParents = parentTable.get( destinationID, [])
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if not destinationID in currentChildren:
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currentChildren.append ( destinationID)
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if not sourceID in currentParents:
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currentParents.append ( sourceID)
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childrenTable[sourceID] = currentChildren
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parentTable[destinationID] = currentParents
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return childrenTable, parentTable
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def toposort (nodes, routes, noRecursion=1):
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'''Topological sort from Tim Peters, fairly efficient
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in comparison (it seems).'''
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#first calculate the recursion depth
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dependencies = {}
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inversedependencies = {}
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if not nodes:
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return []
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if not routes:
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return [nodes]
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for node in nodes:
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dependencies[ node ] = (0, node)
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inversedependencies[ node ] = []
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for depended, depends in routes:
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# is it a null rule
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try:
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newdependencylevel, object = dependencies.get ( depends, (0, depends))
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except TypeError:
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print depends
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raise
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dependencies[ depends ] = (newdependencylevel + 1, depends)
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# "dependency (existence) of depended-on"
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newdependencylevel,object = dependencies.get ( depended, (0, depended) )
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dependencies[ depended ] = (newdependencylevel, depended)
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# Inverse dependency set up
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dependencieslist = inversedependencies.get ( depended, [])
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dependencieslist.append (depends)
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inversedependencies[depended] = dependencieslist
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### Now we do the actual sorting
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# The first task is to create the sortable
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# list of dependency-levels
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sortinglist = dependencies.values()
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sortinglist.sort ()
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output = []
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while sortinglist:
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deletelist = []
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generation = []
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output.append( generation)
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while sortinglist and sortinglist[0][0] == 0:
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number, object = sortinglist[0]
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generation.append ( object )
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deletelist.append( object )
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for inverse in inversedependencies.get(object, () ):
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try:
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oldcount, inverse = dependencies [ inverse]
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if oldcount > 0:
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# will be dealt with on later pass
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dependencies [ inverse] = (oldcount-1, inverse)
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else:
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# will be dealt with on this pass,
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# so needs not to be in the sorting list next time
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deletelist.append( inverse )
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# just in case a loop comes through
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inversedependencies[object] = []
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except KeyError:
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# dealing with a recursion-breaking run...
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pass
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del sortinglist [0]
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# if no elements could be deleted, then
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# there is something which depends upon itself
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if not deletelist:
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if noRecursion:
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raise RecursionError( sortinglist )
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else:
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# hack so that something gets deleted...
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## import pdb
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## pdb.set_trace()
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dependencies[sortinglist[0][1]] = (0,sortinglist[0][1])
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# delete the items that were dealt with
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for item in deletelist:
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try:
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del dependencies [ item ]
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except KeyError:
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pass
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# need to recreate the sortinglist
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sortinglist = dependencies.values()
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if not generation:
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output.remove( generation )
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sortinglist.sort ()
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return output
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if __name__ == "__main__":
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nodes = ['a', 'b', 'c', 'd', 'e', 'f']
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route = [('a', 'b'), ('b', 'c'), ('b', 'd'), ('e','f')]
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for x in toposort( nodes, route):
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for a in x:
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print a
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raise SystemExit
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import pprint, traceback
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nodes= [ 0,1,2,3,4,5 ]
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testingValues = [
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[ (0,1),(1,2),(2,3),(3,4),(4,5)],
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[ (0,1),(0,2),(1,2),(3,4),(4,5)],
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[
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(0,1),
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(0,2),
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(0,2),
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(2,4),
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(2,5),
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(3,2),
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(0,3)],
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[
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(0,1), # 3-element cycle test, no orphan nodes
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(1,2),
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(2,0),
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(2,4),
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(2,5),
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(3,2),
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(0,3)],
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[
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(0,1),
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(1,1),
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(1,1),
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(1,4),
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(1,5),
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(1,2),
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(3,1),
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(2,1),
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(2,0)],
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[
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(0,1),
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(1,0),
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(0,2),
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(0,3),
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],
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[
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(0,1),
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(1,0),
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(0,2),
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(3,1),
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],
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]
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print 'sort, no recursion allowed'
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for index in range(len(testingValues)):
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## print ' %s -- %s'%( index, testingValues[index])
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try:
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print ' ', sort( nodes, testingValues[index] )
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except:
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print 'exception raised'
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print 'toposort, no recursion allowed'
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for index in range(len(testingValues)):
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## print ' %s -- %s'%( index, testingValues[index])
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try:
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print ' ', toposort( nodes, testingValues[index] )
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except:
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print 'exception raised'
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print 'sort, recursion allowed'
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for index in range(len(testingValues)):
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## print ' %s -- %s'%( index, testingValues[index])
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try:
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print ' ', sort( nodes, testingValues[index],0 )
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except:
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print 'exception raised'
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print 'toposort, recursion allowed'
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for index in range(len(testingValues)):
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## print ' %s -- %s'%( index, testingValues[index])
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try:
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print ' ', toposort( nodes, testingValues[index],0 )
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except:
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print 'exception raised'
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