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Diffstat (limited to 'python/altgraph/altgraph/ObjectGraph.py')
| -rw-r--r-- | python/altgraph/altgraph/ObjectGraph.py | 202 |
1 files changed, 202 insertions, 0 deletions
diff --git a/python/altgraph/altgraph/ObjectGraph.py b/python/altgraph/altgraph/ObjectGraph.py new file mode 100644 index 000000000..d07f51b68 --- /dev/null +++ b/python/altgraph/altgraph/ObjectGraph.py @@ -0,0 +1,202 @@ +""" +altgraph.ObjectGraph - Graph of objects with an identifier +========================================================== + +A graph of objects that have a "graphident" attribute. +graphident is the key for the object in the graph +""" + +from altgraph import GraphError +from altgraph.Graph import Graph +from altgraph.GraphUtil import filter_stack + +class ObjectGraph(object): + """ + A graph of objects that have a "graphident" attribute. + graphident is the key for the object in the graph + """ + def __init__(self, graph=None, debug=0): + if graph is None: + graph = Graph() + self.graphident = self + self.graph = graph + self.debug = debug + self.indent = 0 + graph.add_node(self, None) + + def __repr__(self): + return '<%s>' % (type(self).__name__,) + + def flatten(self, condition=None, start=None): + """ + Iterate over the subgraph that is entirely reachable by condition + starting from the given start node or the ObjectGraph root + """ + if start is None: + start = self + start = self.getRawIdent(start) + return self.graph.iterdata(start=start, condition=condition) + + def nodes(self): + for ident in self.graph: + node = self.graph.node_data(ident) + if node is not None: + yield self.graph.node_data(ident) + + + def get_edges(self, node): + start = self.getRawIdent(node) + _, _, outraw, incraw = self.graph.describe_node(start) + def iter_edges(lst, n): + seen = set() + for tpl in (self.graph.describe_edge(e) for e in lst): + ident = tpl[n] + if ident not in seen: + yield self.findNode(ident) + seen.add(ident) + return iter_edges(outraw, 3), iter_edges(incraw, 2) + + def edgeData(self, fromNode, toNode): + start = self.getRawIdent(fromNode) + stop = self.getRawIdent(toNode) + edge = self.graph.edge_by_node(start, stop) + return self.graph.edge_data(edge) + + def updateEdgeData(self, fromNode, toNode, edgeData): + start = self.getRawIdent(fromNode) + stop = self.getRawIdent(toNode) + edge = self.graph.edge_by_node(start, stop) + self.graph.update_edge_data(edge, edgeData) + + def filterStack(self, filters): + """ + Filter the ObjectGraph in-place by removing all edges to nodes that + do not match every filter in the given filter list + + Returns a tuple containing the number of: (nodes_visited, nodes_removed, nodes_orphaned) + """ + visited, removes, orphans = filter_stack(self.graph, self, filters) + + for last_good, tail in orphans: + self.graph.add_edge(last_good, tail, edge_data='orphan') + + for node in removes: + self.graph.hide_node(node) + + return len(visited)-1, len(removes), len(orphans) + + def removeNode(self, node): + """ + Remove the given node from the graph if it exists + """ + ident = self.getIdent(node) + if ident is not None: + self.graph.hide_node(ident) + + def removeReference(self, fromnode, tonode): + """ + Remove all edges from fromnode to tonode + """ + if fromnode is None: + fromnode = self + fromident = self.getIdent(fromnode) + toident = self.getIdent(tonode) + if fromident is not None and toident is not None: + while True: + edge = self.graph.edge_by_node(fromident, toident) + if edge is None: + break + self.graph.hide_edge(edge) + + def getIdent(self, node): + """ + Get the graph identifier for a node + """ + ident = self.getRawIdent(node) + if ident is not None: + return ident + node = self.findNode(node) + if node is None: + return None + return node.graphident + + def getRawIdent(self, node): + """ + Get the identifier for a node object + """ + if node is self: + return node + ident = getattr(node, 'graphident', None) + return ident + + def __contains__(self, node): + return self.findNode(node) is not None + + def findNode(self, node): + """ + Find the node on the graph + """ + ident = self.getRawIdent(node) + if ident is None: + ident = node + try: + return self.graph.node_data(ident) + except KeyError: + return None + + def addNode(self, node): + """ + Add a node to the graph referenced by the root + """ + self.msg(4, "addNode", node) + + try: + self.graph.restore_node(node.graphident) + except GraphError: + self.graph.add_node(node.graphident, node) + + def createReference(self, fromnode, tonode, edge_data=None): + """ + Create a reference from fromnode to tonode + """ + if fromnode is None: + fromnode = self + fromident, toident = self.getIdent(fromnode), self.getIdent(tonode) + if fromident is None or toident is None: + return + self.msg(4, "createReference", fromnode, tonode, edge_data) + self.graph.add_edge(fromident, toident, edge_data=edge_data) + + def createNode(self, cls, name, *args, **kw): + """ + Add a node of type cls to the graph if it does not already exist + by the given name + """ + m = self.findNode(name) + if m is None: + m = cls(name, *args, **kw) + self.addNode(m) + return m + + def msg(self, level, s, *args): + """ + Print a debug message with the given level + """ + if s and level <= self.debug: + print ("%s%s %s" % (" " * self.indent, s, ' '.join(map(repr, args)))) + + def msgin(self, level, s, *args): + """ + Print a debug message and indent + """ + if level <= self.debug: + self.msg(level, s, *args) + self.indent = self.indent + 1 + + def msgout(self, level, s, *args): + """ + Dedent and print a debug message + """ + if level <= self.debug: + self.indent = self.indent - 1 + self.msg(level, s, *args) |