Provide XML-RPC proxy abstraction for Python plugins

The proxy module provides an abstraction to facilitate writing ikiwiki

plugins in Python.

Signed-off-by: martin f. krafft <madduck@madduck.net>
(cherry picked from commit f347e83d82f26cdc59de17b754a78db58a933ea6)
master
martin f. krafft 2008-03-15 13:52:27 +01:00 committed by Joey Hess
parent 91142c86ad
commit bd4769fac4
2 changed files with 176 additions and 0 deletions

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plugins/.gitignore vendored 100644
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proxy.pyc

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plugins/proxy.py 100755
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#!/usr/bin/python
# -*- coding: utf-8 -*-
#
# xmlrpc — helper for Python-based external (xml-rpc) ikiwiki plugins
#
# Copyright © martin f. krafft <madduck@madduck.net>
# Released under the terms of the GNU GPL version 2
#
__name__ = 'xmlrpc'
__description__ = 'xml-rpc-based ikiwiki plugin to process RST files'
__version__ = '0.1'
__author__ = 'martin f. krafft <madduck@madduck.net>'
__copyright__ = 'Copyright © ' + __author__
__licence__ = 'GPLv2'
LOOP_DELAY = 0.1
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)
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, allow_none=False, encoding=None):
self._dispatcher = _IkiWikiExtPluginXMLRPCDispatcher(allow_none, encoding)
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(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, **kwargs):
xml = xmlrpclib.dumps(sum(kwargs.iteritems(), ()), cmd)
self._debug_fn('sending xml to ikiwiki to call 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
return None
data = xmlrpclib.loads(xml)[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...')
ret = _IkiWikiExtPluginXMLRPCHandler._read(in_fd)
if ret is None:
# ikiwiki is going down
self._debug_fn('ikiwiki is going down, and so are we...')
return
self._debug_fn('received procedure call from ikiwiki: [%s]' % ret)
ret = self._dispatcher._marshaled_dispatch(ret)
self._debug_fn('sending procedure response to ikiwiki: [%s]' % ret)
_IkiWikiExtPluginXMLRPCHandler._write(out_fd, ret)
return ret
class IkiWikiProcedureProxy(object):
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()
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 register_hook(self, type, function):
self._hooks.append((type, function.__name__))
self._xmlrpc_handler.register_function(function)
def _importme(self):
self._debug_fn('importing...')
for type, function in self._hooks:
self._debug_fn('hooking %s into %s chain...' % (function, type))
self._xmlrpc_handler.send_rpc('hook', self._in_fd, self._out_fd,
id=self._id, type=type, call=function)
return 0
def run(self):
try:
while True:
ret = self._xmlrpc_handler.handle_rpc(self._in_fd, self._out_fd)
if ret is None:
return
time.sleep(LOOP_DELAY)
except Exception, e:
self._debug_fn('uncaught exception: %s' % e)
sys.exit(posix.EX_SOFTWARE)