summaryrefslogtreecommitdiff
path: root/pylint/graph.py
blob: 219d0b3929a121629344db6c00749cf749298ba1 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
# Copyright (c) 2015-2018 Claudiu Popa <pcmanticore@gmail.com>
# Copyright (c) 2015 Florian Bruhin <me@the-compiler.org>
# Copyright (c) 2016 Ashley Whetter <ashley@awhetter.co.uk>
# Copyright (c) 2018 ssolanki <sushobhitsolanki@gmail.com>
# Copyright (c) 2019 Nick Drozd <nicholasdrozd@gmail.com>
# Copyright (c) 2019 Pierre Sassoulas <pierre.sassoulas@gmail.com>
# Copyright (c) 2020 Benjamin Graham <benwilliamgraham@gmail.com>

# Licensed under the GPL: https://www.gnu.org/licenses/old-licenses/gpl-2.0.html
# For details: https://github.com/PyCQA/pylint/blob/master/COPYING

"""Graph manipulation utilities.

(dot generation adapted from pypy/translator/tool/make_dot.py)
"""
import codecs
import os
import subprocess
import sys
import tempfile
from os import path as osp


def target_info_from_filename(filename):
    """Transforms /some/path/foo.png into ('/some/path', 'foo.png', 'png')."""
    basename = osp.basename(filename)
    storedir = osp.dirname(osp.abspath(filename))
    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",
        renderer="dot",
        additional_param=None,
    ):
        if additional_param is None:
            additional_param = {}
        self.graphname = graphname
        self.renderer = renderer
        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)
        for param in additional_param.items():
            self.emit("=".join(param))

    def get_source(self):
        """returns self._source"""
        if self._source is None:
            self.emit("}\n")
            self._source = "\n".join(self.lines)
            del self.lines
        return self._source

    source = property(get_source)

    def generate(self, outputfile=None, mapfile=None):
        """Generates a graph file.

        :param str outputfile: filename and path [defaults to graphname.png]
        :param str mapfile: filename and path

        :rtype: str
        :return: a path to the generated file
        """
        name = self.graphname
        if outputfile is not None:
            _, _, target = target_info_from_filename(outputfile)
            if target != "dot":
                pdot, dot_sourcepath = tempfile.mkstemp(".dot", name)
                os.close(pdot)
            else:
                dot_sourcepath = outputfile
        else:
            target = "png"
            pdot, dot_sourcepath = tempfile.mkstemp(".dot", name)
            ppng, outputfile = tempfile.mkstemp(".png", name)
            os.close(pdot)
            os.close(ppng)
        pdot = codecs.open(dot_sourcepath, "w", encoding="utf8")
        pdot.write(self.source)
        pdot.close()
        if target != "dot":
            use_shell = sys.platform == "win32"
            if mapfile:
                subprocess.call(
                    [
                        self.renderer,
                        "-Tcmapx",
                        "-o",
                        mapfile,
                        "-T",
                        target,
                        dot_sourcepath,
                        "-o",
                        outputfile,
                    ],
                    shell=use_shell,
                )
            else:
                subprocess.call(
                    [self.renderer, "-T", target, dot_sourcepath, "-o", outputfile],
                    shell=use_shell,
                )
            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):
        """emit an edge from <name1> to <name2>.
        edge properties: see https://www.graphviz.org/doc/info/attrs.html
        """
        attrs = ['%s="%s"' % (prop, value) for prop, value in props.items()]
        n_from, n_to = normalize_node_id(name1), normalize_node_id(name2)
        self.emit("%s -> %s [%s];" % (n_from, n_to, ", ".join(sorted(attrs))))

    def emit_node(self, name, **props):
        """emit a node with given properties.
        node properties: see https://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(sorted(attrs))))


def normalize_node_id(nid):
    """Returns a suitable DOT node id for `nid`."""
    return '"%s"' % nid


def get_cycles(graph_dict, vertices=None):
    """given a dictionary 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, [], set(), result, vertice)
    return result


def _get_cycles(graph_dict, path, visited, result, vertice):
    """recursive function doing the real work for get_cycles"""
    if vertice in path:
        cycle = [vertice]
        for node in path[::-1]:
            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 cycle not in result:
            result.append(cycle)
        return
    path.append(vertice)
    try:
        for node in graph_dict[vertice]:
            # don't check already visited nodes again
            if node not in visited:
                _get_cycles(graph_dict, path, visited, result, node)
                visited.add(node)
    except KeyError:
        pass
    path.pop()