Refactor remote procedure calls in the proxy

Add an rpc() method to the proxy to allow users to call remote
procedures, and route the proxy's own import registration via this
function.

Also, implement convenience functions for the RPC calls exported in the
IkiWiki::XML::RPC namespace.

Signed-off-by: martin f. krafft <madduck@madduck.net>

plugins/proxy.py

@@ -107,8 +107,8 @@ class _IkiWikiExtPluginXMLRPCHandler(object):
             if ret is not None:
                 return ret
 
-    def send_rpc(self, cmd, in_fd, out_fd, **kwargs):
-        xml = xmlrpclib.dumps(sum(kwargs.iteritems(), ()), cmd)
+    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)
 
@@ -120,7 +120,7 @@ class _IkiWikiExtPluginXMLRPCHandler(object):
             # ikiwiki is going down
             return None
 
-        data = xmlrpclib.loads(xml)[0]
+        data = xmlrpclib.loads(xml)[0][0]
         self._debug_fn('parsed data from response to procedure %s: [%s]' % (cmd, data))
         return data
 
@@ -153,6 +153,8 @@ class IkiWikiProcedureProxy(object):
         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:
@@ -160,10 +162,28 @@ class IkiWikiProcedureProxy(object):
         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, last=False):
+        if self._imported:
+            raise IkiWikiProcedureProxy.AlreadyImported
+
         if name is None:
             name = function.__name__
-        self._hooks.append((type, name, last))
 
         def hook_proxy(*args):
 #            curpage = args[0]
@@ -178,16 +198,49 @@ class IkiWikiProcedureProxy(object):
                 ret = IkiWikiProcedureProxy._IKIWIKI_NIL_SENTINEL
             return ret
 
+        self._hooks.append((type, name, last))
         self._xmlrpc_handler.register_function(hook_proxy, name=name)
 
-    def _importme(self):
-        self._debug_fn('importing...')
-        for type, function, last 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,
-                                          last=last)
-        return IkiWikiProcedureProxy._IKIWIKI_NIL_SENTINEL
+    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:
@@ -197,11 +250,25 @@ class IkiWikiProcedureProxy(object):
                     return
                 time.sleep(IkiWikiProcedureProxy._LOOP_DELAY)
         except Exception, e:
-            print >>sys.stderr, 'uncaught exception: %s' % e
             import traceback
-            print >>sys.stderr, traceback.format_exc(sys.exc_info()[2])
+            self.error('uncaught exception: %s\n%s' \
+                       % (e, traceback.format_exc(sys.exc_info()[2])))
             import posix
             sys.exit(posix.EX_SOFTWARE)
 
+    def _importme(self):
+        self._debug_fn('importing...')
+        for type, function, last in self._hooks:
+            self._debug_fn('hooking %s into %s chain...' % (function, type))
+            self.rpc('hook', id=self._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