rpc: Use definitions directly instead of via generated code

Until now “autotools/build-rpc” would read the definition of all RPCs
and write them to a new file, “lib/_generated_rpc.py” with some
modifications. With this patch the generated code loads the definitions
and, at module load time, gets references to the actual definitions.
Further patches will even remove the calls to the post-processing
functions from the generated code.

Signed-off-by: Michael Hanselmann <hansmi@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>

autotools/build-rpc

@@ -52,6 +52,8 @@ def _WritePreamble(sw):
   sw.Write("")
   sw.Write("\"\"\"")
   sw.Write("")
+  sw.Write("from ganeti import rpc_defs")
+  sw.Write("")
 
 
 def _WrapCode(line):
@@ -112,6 +114,9 @@ def _WriteBaseClass(sw, clsname, calls):
       sw.Write("pass")
       return
 
+    sw.Write("_CALLS = rpc_defs.CALLS[%r]", clsname)
+    sw.Write("")
+
     for (name, kind, timeout, args, postproc, desc) in calls:
       funcargs = ["self"]
 
@@ -127,6 +132,8 @@ def _WriteBaseClass(sw, clsname, calls):
       assert "read_timeout" not in funcargs
       funcargs.append("read_timeout=%s" % timeout)
 
+      funcargs.append("_def=_CALLS[%r]" % name)
+
       funcdef = "def call_%s(%s):" % (name, utils.CommaJoin(funcargs))
       for line in _WrapCode(funcdef):
         sw.Write(line)
@@ -143,18 +150,15 @@ def _WriteBaseClass(sw, clsname, calls):
 
         if postproc:
           buf.write("%s(" % postproc)
-        buf.write("self._Call(")
+        buf.write("self._Call(_def, ")
         if kind == _SINGLE:
           buf.write("[node]")
         else:
           buf.write("node_list")
 
-        buf.write(", \"%s\", read_timeout, [%s], [%s])" %
-                  (name,
-                   # Argument definitions
-                   utils.CommaJoin(map(compat.snd, args)),
-                   # Function arguments
-                   utils.CommaJoin(map(compat.fst, args))))
+        buf.write(", read_timeout, [%s])" %
+                  # Function arguments
+                  utils.CommaJoin(map(compat.fst, args)))
 
         if kind == _SINGLE:
           buf.write("[node]")

lib/rpc.py

@@ -430,13 +430,14 @@ class _RpcClientBase:
     else:
       return encoder_fn(argkind)(value)
 
-  def _Call(self, node_list, procedure, timeout, argdefs, args):
+  def _Call(self, cdef, node_list, timeout, args):
     """Entry point for automatically generated RPC wrappers.
 
     """
-    assert len(args) == len(argdefs), "Wrong number of arguments"
+    (procedure, _, _, argdefs, _, _) = cdef
 
-    body = serializer.DumpJson(map(self._encoder, zip(argdefs, args)),
+    body = serializer.DumpJson(map(self._encoder,
+                                   zip(map(compat.snd, argdefs), args)),
                                indent=False)
 
     return self._proc(node_list, procedure, body, read_timeout=timeout)