Lazily load extension API schemas

tools/json_schema_compiler/compiler.py

Index: tools/json_schema_compiler/compiler.py
diff --git a/tools/json_schema_compiler/compiler.py b/tools/json_schema_compiler/compiler.py
index cac08eea2cca83b1d364716245b1feb084c749d6..f51bcc0f1735081af43818642072c3f496b36dcf 100755
--- a/tools/json_schema_compiler/compiler.py
+++ b/tools/json_schema_compiler/compiler.py
@@ -48,6 +48,33 @@ def _LoadSchema(schema):
 
   return api_defs
 
+class TypeNamespaceResolver(object):

[not at google - send to devlin, 2013/03/22 22:10:12]

pull into separate file?

[cduvall, 2013/03/22 22:52:29]

Done.

+  '''Resolves a type name into the namespace the type belongs to.
+  '''
+  def __init__(self, api_path):
+    self._api_path = api_path
+
+  def Resolve(self, full_name, default_namespace):
+    name_parts = full_name.rsplit('.', 1)
+    if len(name_parts) == 1:
+      if full_name not in default_namespace.types:
+        return None

[not at google - send to devlin, 2013/03/22 22:10:12]

can this be an assertion?

[cduvall, 2013/03/22 22:52:29]

Still returning None, to be handled in CppTypeGenerator.

+      return default_namespace
+    namespace_name, type_name = name_parts
+    json_name = '%s.json' % namespace_name
+    idl_name = '%s.idl' % namespace_name
+    if os.path.exists(json_name):
+      real_name = json_name
+    elif os.path.exists(idl_name):
+      real_name = idl_name
+    else:
+      return None

[not at google - send to devlin, 2013/03/22 22:10:12]

I think a structure like

real_name = None
for ext in ['json, 'idl']:
  ...
assert(real_name is not None,
       'Cannot find schema for %s' % namespace_name)

or something like that would be a bit nicer.

[cduvall, 2013/03/22 22:52:29]

Done.

+    namespace = Model().AddNamespace(_LoadSchema(real_name)[0],
+                                     os.path.join(self._api_path, real_name))
+    if type_name not in namespace.types:
+      return None

[not at google - send to devlin, 2013/03/22 22:10:12]

can this be an assertion?

[cduvall, 2013/03/22 22:52:29]

Same as above.

+    return namespace
+
 def GenerateSchema(generator,
                    filenames,
                    root,
@@ -68,33 +95,8 @@ def GenerateSchema(generator,
     api_defs.extend(api_def)
 
   api_model = Model()
-
-  # Load type dependencies into the model.
-  #
-  # HACK(kalman): bundle mode doesn't work with dependencies, because not all
-  # schemas work in bundle mode.
-  #
-  # TODO(kalman): load dependencies lazily (get rid of the 'dependencies' list)
-  # and this problem will go away.
-  if generator != 'cpp-bundle':
-    for target_namespace in api_defs:
-      for referenced_schema in target_namespace.get('dependencies', []):
-        split_schema = referenced_schema.split(':', 1)
-        if len(split_schema) > 1:
-          if split_schema[0] != 'api':
-            continue
-          else:
-            referenced_schema = split_schema[1]
-
-        referenced_schema_path = os.path.join(
-            os.path.dirname(schema), '%s.json' % UnixName(referenced_schema))
-        referenced_api_defs = json_schema.Load(referenced_schema_path)
-
-        for namespace in referenced_api_defs:
-          api_model.AddNamespace(
-              namespace,
-              os.path.relpath(referenced_schema_path, root),
-              include_compiler_options=True)
+  type_namespace_resolver = TypeNamespaceResolver(
+      os.path.dirname(os.path.relpath(schema, root)))
 
   # For single-schema compilation make sure that the first (i.e. only) schema
   # is the default one.
@@ -125,6 +127,7 @@ def GenerateSchema(generator,
 
   # Construct the type generator with all the namespaces in this model.
   type_generator = CppTypeGenerator(api_model,
+                                    type_namespace_resolver,
                                     default_namespace=default_namespace)
 
   if generator == 'cpp-bundle':