Add support for querying network timestamps

[ganeti-local] / lib / serializer.py

diff --git a/lib/serializer.py b/lib/serializer.py
index 090ae00..f008155 100644 (file)
--- a/lib/serializer.py
+++ b/lib/serializer.py
@@ -29,82 +29,32 @@ backend (currently json).
 # C0103: Invalid name, since pylint doesn't see that Dump points to a
 # function and not a constant
 
-_OLD_SIMPLEJSON = False
-
-try:
-  import json
-except ImportError:
-  # The "json" module was only added in Python 2.6. Earlier versions must use
-  # the separate "simplejson" module.
-  import simplejson as json
-  _OLD_SIMPLEJSON = True
-
 import re
-import logging
+
+# Python 2.6 and above contain a JSON module based on simplejson. Unfortunately
+# the standard library version is significantly slower than the external
+# module. While it should be better from at least Python 3.2 on (see Python
+# issue 7451), for now Ganeti needs to work well with older Python versions
+# too.
+import simplejson
 
 from ganeti import errors
 from ganeti import utils
 
 
-_JSON_INDENT = 2
-
 _RE_EOLSP = re.compile("[ \t]+$", re.MULTILINE)
 
 
-class _CustomJsonEncoder(json.JSONEncoder):
-  if __debug__ and not _OLD_SIMPLEJSON:
-    try:
-      _orig_fn = json.JSONEncoder._iterencode_dict
-    except AttributeError:
-      raise Exception("Can't override JSONEncoder's '_iterencode_dict'")
-    else:
-      def _iterencode_dict(self, data, *args, **kwargs):
-        for key in data.keys():
-          if not (key is None or isinstance(key, (basestring, bool))):
-            raise ValueError("Key '%s' is of disallowed type '%s'" %
-                             (key, type(key)))
-
-        return self._orig_fn(data, *args, **kwargs)
-
-
-def _GetJsonDumpers(_encoder_class=_CustomJsonEncoder):
-  """Returns two JSON functions to serialize data.
-
-  @rtype: (callable, callable)
-  @return: The function to generate a compact form of JSON and another one to
-           generate a more readable, indented form of JSON (if supported)
-
-  """
-  plain_encoder = _encoder_class(sort_keys=True)
-
-  # Check whether the simplejson module supports indentation
-  try:
-    indent_encoder = _encoder_class(indent=_JSON_INDENT, sort_keys=True)
-  except TypeError:
-    # Indentation not supported
-    indent_encoder = plain_encoder
-
-  return (plain_encoder.encode, indent_encoder.encode)
-
-
-(_DumpJson, _DumpJsonIndent) = _GetJsonDumpers()
-
-
-def DumpJson(data, indent=True):
+def DumpJson(data):
   """Serialize a given object.
 
   @param data: the data to serialize
-  @param indent: whether to indent output (depends on simplejson version)
-
   @return: the string representation of data
 
   """
-  if indent:
-    fn = _DumpJsonIndent
-  else:
-    fn = _DumpJson
+  encoded = simplejson.dumps(data)
 
-  txt = _RE_EOLSP.sub("", fn(data))
+  txt = _RE_EOLSP.sub("", encoded)
   if not txt.endswith("\n"):
     txt += "\n"
 
@@ -119,7 +69,7 @@ def LoadJson(txt):
   @return: the original data
 
   """
-  return json.loads(txt)
+  return simplejson.loads(txt)
 
 
 def DumpSignedJson(data, key, salt=None, key_selector=None):
@@ -132,7 +82,7 @@ def DumpSignedJson(data, key, salt=None, key_selector=None):
   @return: the string representation of data signed by the hmac key
 
   """
-  txt = DumpJson(data, indent=False)
+  txt = DumpJson(data)
   if salt is None:
     salt = ""
   signed_dict = {
@@ -147,7 +97,7 @@ def DumpSignedJson(data, key, salt=None, key_selector=None):
 
   signed_dict["hmac"] = utils.Sha1Hmac(key, txt, salt=salt + key_selector)
 
-  return DumpJson(signed_dict, indent=False)
+  return DumpJson(signed_dict)
 
 
 def LoadSignedJson(txt, key):
@@ -190,6 +140,28 @@ def LoadSignedJson(txt, key):
   return LoadJson(msg), salt
 
 
+def LoadAndVerifyJson(raw, verify_fn):
+  """Parses and verifies JSON data.
+
+  @type raw: string
+  @param raw: Input data in JSON format
+  @type verify_fn: callable
+  @param verify_fn: Verification function, usually from L{ht}
+  @return: De-serialized data
+
+  """
+  try:
+    data = LoadJson(raw)
+  except Exception, err:
+    raise errors.ParseError("Can't parse input data: %s" % err)
+
+  if not verify_fn(data):
+    raise errors.ParseError("Data does not match expected format: %s" %
+                            verify_fn)
+
+  return data
+
+
 Dump = DumpJson
 Load = LoadJson
 DumpSigned = DumpSignedJson