londiste handlers' arg names are checked now

2 files changed, 33 insertions, 0 deletions

diff --git a/python/londiste/handler.py b/python/londiste/handler.py
index 42187158..76c47f8d 100644
--- a/python/londiste/handler.py
+++ b/python/londiste/handler.py
@@ -77,6 +77,36 @@ class BaseHandler:
         self.fq_table_name = skytools.quote_fqident(self.table_name)
         self.fq_dest_table = skytools.quote_fqident(self.dest_table)
         self.args = args
+        self._check_args (args)
+
+    def _parse_args_from_doc (self):
+        doc = self.__doc__ or ""
+        params_descr = []
+        params_found = False
+        for line in doc.splitlines():
+            ln = line.strip()
+            if params_found:
+                if ln == "":
+                    break
+                descr = ln.split (None, 1)
+                name, sep, rest = descr[0].partition('=')
+                if sep:
+                    expr = descr[0].rstrip(":")
+                    text = descr[1].lstrip(":- \t")
+                else:
+                    name, expr, text = params_descr.pop()
+                    text += "\n" + ln
+                params_descr.append ((name, expr, text))
+            elif ln == "Parameters:":
+                params_found = True
+        return params_descr
+
+    def _check_args (self, args):
+        passed_arg_names = args.keys() if args else []
+        self.valid_arg_names = list(zip(*self._parse_args_from_doc())[0])
+        invalid = set(passed_arg_names) - set(self.valid_arg_names)
+        if invalid:
+            raise ValueError ("Invalid handler argument: %s" % list(invalid))
 
     def add(self, trigger_arg_list):
         """Called when table is added.
diff --git a/python/londiste/handlers/multimaster.py b/python/londiste/handlers/multimaster.py
index f28535e8..aa1d4e51 100644
--- a/python/londiste/handlers/multimaster.py
+++ b/python/londiste/handlers/multimaster.py
@@ -30,6 +30,9 @@ class MultimasterHandler(ApplyFuncHandler):
         args = update(args, {'func_name': 'merge_on_time', 'func_conf': conf})
         ApplyFuncHandler.__init__(self, table_name, args, dest_table)
 
+    def _check_args (self, args):
+        pass # any arg can be passed
+
     def add(self, trigger_arg_list):
         """Create SKIP and BEFORE INSERT trigger"""
         trigger_arg_list.append('no_merge')