aboutsummaryrefslogtreecommitdiff
path: root/plugins/proxy.py
blob: 04472a326fd0c5bdb7381f521788f8e48d389891 (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
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
#!/usr/bin/python
# -*- coding: utf-8 -*-
#
# proxy.py — helper for Python-based external (xml-rpc) ikiwiki plugins
#
# Copyright © 2008      martin f. krafft <madduck@madduck.net>
#             2008-2011 Joey Hess <joey@kitenet.net>
#             2012      W. Trevor King <wking@tremily.us>
#
#  Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
# .
# THIS SOFTWARE IS PROVIDED BY IKIWIKI AND CONTRIBUTORS ``AS IS''
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
# TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
# PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION
# OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
# USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
# OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
# SUCH DAMAGE.
#
__name__ = 'proxy.py'
__description__ = 'helper for Python-based external (xml-rpc) ikiwiki plugins'
__version__ = '0.2'
__author__ = 'martin f. krafft <madduck@madduck.net>'
__copyright__ = 'Copyright © ' + __author__
__licence__ = 'BSD-2-clause'

import sys
import time
import xmlrpclib
import xml.parsers.expat
from SimpleXMLRPCServer import SimpleXMLRPCDispatcher

class _IkiWikiExtPluginXMLRPCDispatcher(SimpleXMLRPCDispatcher):

    def __init__(self, allow_none=False, encoding=None):
        try:
            SimpleXMLRPCDispatcher.__init__(self, allow_none, encoding)
        except TypeError:
            # see http://bugs.debian.org/470645
            # python2.4 and before only took one argument
            SimpleXMLRPCDispatcher.__init__(self)

    def dispatch(self, method, params):
        return self._dispatch(method, params)

class XMLStreamParser(object):

    def __init__(self):
        self._parser = xml.parsers.expat.ParserCreate()
        self._parser.StartElementHandler = self._push_tag
        self._parser.EndElementHandler = self._pop_tag
        self._parser.XmlDeclHandler = self._check_pipelining
        self._reset()

    def _reset(self):
        self._stack = list()
        self._acc = r''
        self._first_tag_received = False

    def _push_tag(self, tag, attrs):
        self._stack.append(tag)
        self._first_tag_received = True

    def _pop_tag(self, tag):
        top = self._stack.pop()
        if top != tag:
            raise ParseError, 'expected %s closing tag, got %s' % (top, tag)

    def _request_complete(self):
        return self._first_tag_received and len(self._stack) == 0

    def _check_pipelining(self, *args):
        if self._first_tag_received:
            raise PipeliningDetected, 'need a new line between XML documents'

    def parse(self, data):
        self._parser.Parse(data, False)
        self._acc += data
        if self._request_complete():
            ret = self._acc
            self._reset()
            return ret

    class ParseError(Exception):
        pass

    class PipeliningDetected(Exception):
        pass

class _IkiWikiExtPluginXMLRPCHandler(object):

    def __init__(self, debug_fn):
        self._dispatcher = _IkiWikiExtPluginXMLRPCDispatcher()
        self.register_function = self._dispatcher.register_function
        self._debug_fn = debug_fn

    def register_function(self, function, name=None):
        # will be overwritten by __init__
        pass

    @staticmethod
    def _write(out_fd, data):
        out_fd.write(str(data))
        out_fd.flush()

    @staticmethod
    def _read(in_fd):
        ret = None
        parser = XMLStreamParser()
        while True:
            line = in_fd.readline()
            if len(line) == 0:
                # ikiwiki exited, EOF received
                return None

            ret = parser.parse(line)
            # unless this returns non-None, we need to loop again
            if ret is not None:
                return ret

    def send_rpc(self, cmd, in_fd, out_fd, *args, **kwargs):
        xml = xmlrpclib.dumps(sum(kwargs.iteritems(), args), cmd)
        self._debug_fn("calling ikiwiki procedure `%s': [%s]" % (cmd, xml))
        _IkiWikiExtPluginXMLRPCHandler._write(out_fd, xml)

        self._debug_fn('reading response from ikiwiki...')

        xml = _IkiWikiExtPluginXMLRPCHandler._read(in_fd)
        self._debug_fn('read response to procedure %s from ikiwiki: [%s]' % (cmd, xml))
        if xml is None:
            # ikiwiki is going down
            self._debug_fn('ikiwiki is going down, and so are we...')
            raise _IkiWikiExtPluginXMLRPCHandler._GoingDown

        data = xmlrpclib.loads(xml)[0][0]
        self._debug_fn('parsed data from response to procedure %s: [%s]' % (cmd, data))
        return data

    def handle_rpc(self, in_fd, out_fd):
        self._debug_fn('waiting for procedure calls from ikiwiki...')
        xml = _IkiWikiExtPluginXMLRPCHandler._read(in_fd)
        if xml is None:
            # ikiwiki is going down
            self._debug_fn('ikiwiki is going down, and so are we...')
            raise _IkiWikiExtPluginXMLRPCHandler._GoingDown

        self._debug_fn('received procedure call from ikiwiki: [%s]' % xml)
        params, method = xmlrpclib.loads(xml)
        ret = self._dispatcher.dispatch(method, params)
        xml = xmlrpclib.dumps((ret,), methodresponse=True)
        self._debug_fn('sending procedure response to ikiwiki: [%s]' % xml)
        _IkiWikiExtPluginXMLRPCHandler._write(out_fd, xml)
        return ret

    class _GoingDown:
        pass

class IkiWikiProcedureProxy(object):

    # how to communicate None to ikiwiki
    _IKIWIKI_NIL_SENTINEL = {'null':''}

    # sleep during each iteration
    _LOOP_DELAY = 0.1

    def __init__(self, id, in_fd=sys.stdin, out_fd=sys.stdout, debug_fn=None):
        self._id = id
        self._in_fd = in_fd
        self._out_fd = out_fd
        self._hooks = list()
        self._functions = list()
        self._imported = False
        if debug_fn is not None:
            self._debug_fn = debug_fn
        else:
            self._debug_fn = lambda s: None
        self._xmlrpc_handler = _IkiWikiExtPluginXMLRPCHandler(self._debug_fn)
        self._xmlrpc_handler.register_function(self._importme, name='import')

    def rpc(self, cmd, *args, **kwargs):
        def subst_none(seq):
            for i in seq:
                if i is None:
                    yield IkiWikiProcedureProxy._IKIWIKI_NIL_SENTINEL
                else:
                    yield i

        args = list(subst_none(args))
        kwargs = dict(zip(kwargs.keys(), list(subst_none(kwargs.itervalues()))))
        ret = self._xmlrpc_handler.send_rpc(cmd, self._in_fd, self._out_fd,
                                            *args, **kwargs)
        if ret == IkiWikiProcedureProxy._IKIWIKI_NIL_SENTINEL:
            ret = None
        return ret

    def hook(self, type, function, name=None, id=None, last=False):
        if self._imported:
            raise IkiWikiProcedureProxy.AlreadyImported

        if name is None:
            name = function.__name__

        if id is None:
            id = self._id

        def hook_proxy(*args):
#            curpage = args[0]
#            kwargs = dict([args[i:i+2] for i in xrange(1, len(args), 2)])
            ret = function(self, *args)
            self._debug_fn("%s hook `%s' returned: [%s]" % (type, name, ret))
            if ret == IkiWikiProcedureProxy._IKIWIKI_NIL_SENTINEL:
                raise IkiWikiProcedureProxy.InvalidReturnValue, \
                        'hook functions are not allowed to return %s' \
                        % IkiWikiProcedureProxy._IKIWIKI_NIL_SENTINEL
            if ret is None:
                ret = IkiWikiProcedureProxy._IKIWIKI_NIL_SENTINEL
            return ret

        self._hooks.append((id, type, name, last))
        self._xmlrpc_handler.register_function(hook_proxy, name=name)

    def inject(self, rname, function, name=None, memoize=True):
        if self._imported:
            raise IkiWikiProcedureProxy.AlreadyImported

        if name is None:
            name = function.__name__

        self._functions.append((rname, name, memoize))
        self._xmlrpc_handler.register_function(function, name=name)

    def getargv(self):
        return self.rpc('getargv')

    def setargv(self, argv):
        return self.rpc('setargv', argv)

    def getvar(self, hash, key):
        return self.rpc('getvar', hash, key)

    def setvar(self, hash, key, value):
        return self.rpc('setvar', hash, key, value)

    def getstate(self, page, id, key):
        return self.rpc('getstate', page, id, key)

    def setstate(self, page, id, key, value):
        return self.rpc('setstate', page, id, key, value)

    def pagespec_match(self, spec):
        return self.rpc('pagespec_match', spec)

    def error(self, msg):
        try:
            self.rpc('error', msg)
        except IOError, e:
            if e.errno != 32:
                raise
        import posix
        sys.exit(posix.EX_SOFTWARE)

    def run(self):
        try:
            while True:
                ret = self._xmlrpc_handler.handle_rpc(self._in_fd, self._out_fd)
                time.sleep(IkiWikiProcedureProxy._LOOP_DELAY)
        except _IkiWikiExtPluginXMLRPCHandler._GoingDown:
            return

        except Exception, e:
            import traceback
            self.error('uncaught exception: %s\n%s' \
                       % (e, traceback.format_exc(sys.exc_info()[2])))
            return

    def _importme(self):
        self._debug_fn('importing...')
        for id, type, function, last in self._hooks:
            self._debug_fn('hooking %s/%s into %s chain...' % (id, function, type))
            self.rpc('hook', id=id, type=type, call=function, last=last)
        for rname, function, memoize in self._functions:
            self._debug_fn('injecting %s as %s...' % (function, rname))
            self.rpc('inject', name=rname, call=function, memoize=memoize)
        self._imported = True
        return IkiWikiProcedureProxy._IKIWIKI_NIL_SENTINEL

    class InvalidReturnValue(Exception):
        pass

    class AlreadyImported(Exception):
        pass