ikiwiki/plugins/proxy.py

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#!/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'
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__version__ = '0.2'
__author__ = 'martin f. krafft <madduck@madduck.net>'
__copyright__ = 'Copyright © ' + __author__
__licence__ = 'BSD-2-clause'
import sys
import time
import xml.parsers.expat
try: # Python 3
import xmlrpc.client as _xmlrpc_client
except ImportError: # Python 2
import xmlrpclib as _xmlrpc_client
try: # Python 3
import xmlrpc.server as _xmlrpc_server
except ImportError: # Python 2
import SimpleXMLRPCServer as _xmlrpc_server
class ParseError (Exception):
pass
class PipeliningDetected (Exception):
pass
class GoingDown (Exception):
pass
class InvalidReturnValue (Exception):
pass
class AlreadyImported (Exception):
pass
class _IkiWikiExtPluginXMLRPCDispatcher(_xmlrpc_server.SimpleXMLRPCDispatcher):
def __init__(self, allow_none=False, encoding=None):
try:
_xmlrpc_server.SimpleXMLRPCDispatcher.__init__(
self, allow_none, encoding)
except TypeError:
# see http://bugs.debian.org/470645
# python2.4 and before only took one argument
_xmlrpc_server.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(
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'expected {0} closing tag, got {1}'.format(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 _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 = _xmlrpc_client.dumps(sum(kwargs.items(), args), cmd)
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self._debug_fn(
"calling ikiwiki procedure `{0}': [{1}]".format(cmd, xml))
_IkiWikiExtPluginXMLRPCHandler._write(out_fd, xml)
self._debug_fn('reading response from ikiwiki...')
xml = _IkiWikiExtPluginXMLRPCHandler._read(in_fd)
self._debug_fn(
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'read response to procedure {0} from ikiwiki: [{1}]'.format(
cmd, xml))
if xml is None:
# ikiwiki is going down
self._debug_fn('ikiwiki is going down, and so are we...')
raise GoingDown()
data = _xmlrpc_client.loads(xml)[0][0]
self._debug_fn(
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'parsed data from response to procedure {0}: [{1}]'.format(
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 GoingDown()
self._debug_fn(
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'received procedure call from ikiwiki: [{0}]'.format(xml))
params, method = _xmlrpc_client.loads(xml)
ret = self._dispatcher.dispatch(method, params)
xml = _xmlrpc_client.dumps((ret,), methodresponse=True)
self._debug_fn(
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'sending procedure response to ikiwiki: [{0}]'.format(xml))
_IkiWikiExtPluginXMLRPCHandler._write(out_fd, xml)
return ret
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.values()))))
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 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(
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"{0} hook `{1}' returned: [{2}]".format(type, name, ret))
if ret == IkiWikiProcedureProxy._IKIWIKI_NIL_SENTINEL:
raise InvalidReturnValue(
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'hook functions are not allowed to return {0}'.format(
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 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 as 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 GoingDown:
return
except Exception as e:
import traceback
tb = traceback.format_exc()
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self.error('uncaught exception: {0}\n{1}'.format(e, tb))
return
def _importme(self):
self._debug_fn('importing...')
for id, type, function, last in self._hooks:
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self._debug_fn('hooking {0}/{1} into {2} chain...'.format(
id, function, type))
self.rpc('hook', id=id, type=type, call=function, last=last)
for rname, function, memoize in self._functions:
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self._debug_fn('injecting {0} as {1}...'.format(function, rname))
self.rpc('inject', name=rname, call=function, memoize=memoize)
self._imported = True
return IkiWikiProcedureProxy._IKIWIKI_NIL_SENTINEL