1 files changed, 33 insertions, 49 deletions

diff --git a/python/google/protobuf/symbol_database.py b/python/google/protobuf/symbol_database.py
index 87760f26..aa466abd 100644
--- a/python/google/protobuf/symbol_database.py
+++ b/python/google/protobuf/symbol_database.py
@@ -30,11 +30,9 @@
 
 """A database of Python protocol buffer generated symbols.
 
-SymbolDatabase makes it easy to create new instances of a registered type, given
-only the type's protocol buffer symbol name. Once all symbols are registered,
-they can be accessed using either the MessageFactory interface which
-SymbolDatabase exposes, or the DescriptorPool interface of the underlying
-pool.
+SymbolDatabase is the MessageFactory for messages generated at compile time,
+and makes it easy to create new instances of a registered type, given only the
+type's protocol buffer symbol name.
 
 Example usage:
 
@@ -61,27 +59,17 @@ Example usage:
 
 
 from google.protobuf import descriptor_pool
+from google.protobuf import message_factory
 
 
-class SymbolDatabase(object):
-  """A database of Python generated symbols.
-
-  SymbolDatabase also models message_factory.MessageFactory.
-
-  The symbol database can be used to keep a global registry of all protocol
-  buffer types used within a program.
-  """
-
-  def __init__(self, pool=None):
-    """Constructor."""
-
-    self._symbols = {}
-    self._symbols_by_file = {}
-    self.pool = pool or descriptor_pool.Default()
+class SymbolDatabase(message_factory.MessageFactory):
+  """A database of Python generated symbols."""
 
   def RegisterMessage(self, message):
     """Registers the given message type in the local database.
 
+    Calls to GetSymbol() and GetMessages() will return messages registered here.
+
     Args:
       message: a message.Message, to be registered.
 
@@ -90,10 +78,7 @@ class SymbolDatabase(object):
     """
 
     desc = message.DESCRIPTOR
-    self._symbols[desc.full_name] = message
-    if desc.file.name not in self._symbols_by_file:
-      self._symbols_by_file[desc.file.name] = {}
-    self._symbols_by_file[desc.file.name][desc.full_name] = message
+    self._classes[desc.full_name] = message
     self.pool.AddDescriptor(desc)
     return message
 
@@ -136,47 +121,46 @@ class SymbolDatabase(object):
       KeyError: if the symbol could not be found.
     """
 
-    return self._symbols[symbol]
-
-  def GetPrototype(self, descriptor):
-    """Builds a proto2 message class based on the passed in descriptor.
-
-    Passing a descriptor with a fully qualified name matching a previous
-    invocation will cause the same class to be returned.
-
-    Args:
-      descriptor: The descriptor to build from.
-
-    Returns:
-      A class describing the passed in descriptor.
-    """
-
-    return self.GetSymbol(descriptor.full_name)
+    return self._classes[symbol]
 
   def GetMessages(self, files):
-    """Gets all the messages from a specified file.
-
-    This will find and resolve dependencies, failing if they are not registered
-    in the symbol database.
+    # TODO(amauryfa): Fix the differences with MessageFactory.
+    """Gets all registered messages from a specified file.
 
+    Only messages already created and registered will be returned; (this is the
+    case for imported _pb2 modules)
+    But unlike MessageFactory, this version also returns nested messages.
 
     Args:
       files: The file names to extract messages from.
 
     Returns:
-      A dictionary mapping proto names to the message classes. This will include
-      any dependent messages as well as any messages defined in the same file as
-      a specified message.
+      A dictionary mapping proto names to the message classes.
 
     Raises:
       KeyError: if a file could not be found.
     """
 
+    def _GetAllMessageNames(desc):
+      """Walk a message Descriptor and recursively yields all message names."""
+      yield desc.full_name
+      for msg_desc in desc.nested_types:
+        for full_name in _GetAllMessageNames(msg_desc):
+          yield full_name
+
     result = {}
-    for f in files:
-      result.update(self._symbols_by_file[f])
+    for file_name in files:
+      file_desc = self.pool.FindFileByName(file_name)
+      for msg_desc in file_desc.message_types_by_name.values():
+        for full_name in _GetAllMessageNames(msg_desc):
+          try:
+            result[full_name] = self._classes[full_name]
+          except KeyError:
+            # This descriptor has no registered class, skip it.
+            pass
     return result
 
+
 _DEFAULT = SymbolDatabase(pool=descriptor_pool.Default())