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"""some various graph manipuliation utilities
(dot generation adapted from pypy/translator/tool/make_dot.py)
:organization: Logilab
:copyright: 2003-2007 LOGILAB S.A. (Paris, FRANCE), all rights reserved.
:contact: http://www.logilab.fr/ -- mailto:contact@logilab.fr
"""
__docformat__ = "restructuredtext en"
__metaclass__ = type
import os.path as osp
import os
def escape(value):
"""make <value> usable in a dot file"""
lines = [line.replace('"', '\\"') for line in value.split('\n')]
data = '\\l'.join(lines)
return '\\n' + data
def target_info_from_filename(filename):
"""transforms /some/path/foo.png into ('/some/path', 'foo.png', 'png')"""
abspath = osp.abspath(filename)
basename = osp.basename(filename)
storedir = osp.dirname(abspath)
target = filename.split('.')[-1]
return storedir, basename, target
class DotBackend:
"""Dot File backend"""
def __init__(self, graphname, rankdir=None, size=None, ratio=None, charset='utf-8'):
self.graphname = graphname
self.lines = []
self._source = None
self.emit("digraph %s {" % normalize_node_id(graphname))
if rankdir:
self.emit('rankdir=%s' % rankdir)
if ratio:
self.emit('ratio=%s' % ratio)
if size:
self.emit('size="%s"' % size)
if charset:
assert charset.lower() in ('utf-8', 'iso-8859-1', 'latin1'), \
'unsupported charset %s' % charset
self.emit('charset="%s"' % charset)
def get_source(self):
"""returns self._source"""
if self._source is None:
self.emit("}")
self._source = '\n'.join(self.lines)
del self.lines
return self._source
source = property(get_source)
def generate(self, outputfile=None, dotfile=None):
"""generates a graph file
:param target: output format ('png', 'ps', etc.). If None,
the raw dot source will be returned
:return: a path to the generated file
"""
if outputfile is not None:
storedir, basename, target = target_info_from_filename(outputfile)
else:
storedir = '/tmp'
basename = '%s.png' % (self.graphname)
target = 'png'
outputfile = osp.join(storedir, basename)
dotfile = dotfile or ('%s.dot' % self.graphname)
dot_sourcepath = osp.join(storedir, dotfile)
pdot = file(dot_sourcepath, 'w')
if isinstance(self.source, unicode):
pdot.write(self.source.encode('UTF8'))
else:
pdot.write(self.source)
pdot.close()
if target != 'dot':
os.system('dot -T%s %s -o%s' % (target, dot_sourcepath, outputfile))
os.unlink(dot_sourcepath)
return outputfile
def emit(self, line):
"""adds <line> to final output"""
self.lines.append(line)
def emit_edge(self, name1, name2, **props):
"""emits edge from <name1> to <name2>
authorized props: see http://www.graphviz.org/doc/info/attrs.html
"""
attrs = ['%s="%s"' % (prop, value) for prop, value in props.items()]
self.emit('edge [%s];' % ", ".join(attrs))
self.emit('%s -> %s' % (normalize_node_id(name1), normalize_node_id(name2)))
def emit_node(self, name, **props):
"""authorized props: see http://www.graphviz.org/doc/info/attrs.html
"""
attrs = ['%s="%s"' % (prop, value) for prop, value in props.items()]
self.emit('%s [%s];' % (normalize_node_id(name), ", ".join(attrs)))
def normalize_node_id(nid):
"""returns a suitable DOT node id for `nid`"""
return '"%s"' % nid
class GraphGenerator:
def __init__(self, backend):
# the backend is responsible to output the graph is a particular format
self.backend = backend
def generate(self, visitor, propshdlr, outputfile=None):
# the visitor
# the properties handler is used to get nodes and edges properties
# according to the graph and to the backend
self.propshdlr = propshdlr
for nodeid, node in visitor.nodes():
props = propshdlr.node_properties(node)
self.backend.emit_node(nodeid, **props)
for subjnode, objnode, edge in visitor.edges():
props = propshdlr.edge_properties(edge, subjnode, objnode)
self.backend.emit_edge(subjnode, objnode, **props)
return self.backend.generate(outputfile)
def get_cycles(graph_dict, vertices=None):
'''given a dictionnary representing an ordered graph (i.e. key are vertices
and values is a list of destination vertices representing edges), return a
list of detected cycles
'''
if not graph_dict:
return ()
result = []
if vertices is None:
vertices = graph_dict.keys()
for vertice in vertices:
_get_cycles(graph_dict, vertice, [], result)
return result
def _get_cycles(graph_dict, vertice=None, path=None, result=None):
"""recursive function doing the real work for get_cycles"""
if vertice in path:
cycle = [vertice]
for i in range(len(path)-1, 0, -1):
node = path[i]
if node == vertice:
break
cycle.insert(0, node)
# make a canonical representation
start_from = min(cycle)
index = cycle.index(start_from)
cycle = cycle[index:] + cycle[0:index]
# append it to result if not already in
if not cycle in result:
result.append(cycle)
return
path.append(vertice)
try:
for node in graph_dict[vertice]:
_get_cycles(graph_dict, node, path, result)
except KeyError:
pass
path.pop()
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