JavaScript bindings for Mojo message validation

mojo/public/tools/bindings/generators/mojom_js_generator.py

 # Copyright 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Generates JavaScript source files from a mojom.Module."""
 
 import mojom.generate.generator as generator
 import mojom.generate.module as mojom
 import mojom.generate.pack as pack
 from mojom.generate.template_expander import UseJinja
@@ skipping 28 matching lines @@
 def JavaScriptDefaultValue(field):
   if field.default:
     if mojom.IsStructKind(field.kind):
       assert field.default == "default"
       return "new %s()" % JavascriptType(field.kind)
     return ExpressionToText(field.default)
   if field.kind in mojom.PRIMITIVES:
     return _kind_to_javascript_default_value[field.kind]
   if mojom.IsStructKind(field.kind):
     return "null"
   if mojom.IsArrayKind(field.kind):

[yzshen1, 2014/08/14 18:02:22]

I think this should also be IsAnyArrayKind right?

[hansmuller, 2014/08/14 23:51:46]

Yes. I've changed it.

     return "null"
   if mojom.IsInterfaceKind(field.kind) or \
      mojom.IsInterfaceRequestKind(field.kind):
     return _kind_to_javascript_default_value[mojom.MSGPIPE]
   if mojom.IsEnumKind(field.kind):
     return "0"
 
 
 def JavaScriptPayloadSize(packed):
   packed_fields = packed.packed_fields
@@ skipping 30 matching lines @@
   mojom.STRING:                "codec.String",
   mojom.NULLABLE_STRING:       "codec.String",
 }
 
 
 def CodecType(kind):
   if kind in mojom.PRIMITIVES:
     return _kind_to_codec_type[kind]
   if mojom.IsStructKind(kind):
     return "new codec.PointerTo(%s)" % CodecType(kind.name)
-  if mojom.IsArrayKind(kind) and mojom.IsBoolKind(kind.kind):
-    return "new codec.ArrayOf(new codec.ArrayOf(codec.PackedBool))"
-  if mojom.IsArrayKind(kind):
+  if mojom.IsAnyArrayKind(kind) and mojom.IsBoolKind(kind.kind):
+    return "new codec.ArrayOf(codec.PackedBool)"
+  if mojom.IsAnyArrayKind(kind):
     return "new codec.ArrayOf(%s)" % CodecType(kind.kind)
   if mojom.IsInterfaceKind(kind) or mojom.IsInterfaceRequestKind(kind):
     return CodecType(mojom.MSGPIPE)
   if mojom.IsEnumKind(kind):
     return _kind_to_codec_type[mojom.INT32]
   return kind
 
 
 def JavaScriptDecodeSnippet(kind):
   if kind in mojom.PRIMITIVES:
     return "decodeStruct(%s)" % CodecType(kind)
   if mojom.IsStructKind(kind):
     return "decodeStructPointer(%s)" % CodecType(kind.name)
-  if mojom.IsArrayKind(kind) and mojom.IsBoolKind(kind.kind):
-    return "decodeArrayPointer(new codec.ArrayOf(codec.PackedBool))"
-  if mojom.IsArrayKind(kind):
+  if mojom.IsAnyArrayKind(kind) and mojom.IsBoolKind(kind.kind):
+    return "decodeArrayPointer(codec.PackedBool)"
+  if mojom.IsAnyArrayKind(kind):
     return "decodeArrayPointer(%s)" % CodecType(kind.kind)
   if mojom.IsInterfaceKind(kind) or mojom.IsInterfaceRequestKind(kind):
     return JavaScriptDecodeSnippet(mojom.MSGPIPE)
   if mojom.IsEnumKind(kind):
     return JavaScriptDecodeSnippet(mojom.INT32)
 
 
 def JavaScriptEncodeSnippet(kind):
   if kind in mojom.PRIMITIVES:
     return "encodeStruct(%s, " % CodecType(kind)
   if mojom.IsStructKind(kind):
     return "encodeStructPointer(%s, " % CodecType(kind.name)
-  if mojom.IsArrayKind(kind) and mojom.IsBoolKind(kind.kind):
-    return "encodeArrayPointer(new codec.ArrayOf(codec.PackedBool), ";
+  if mojom.IsAnyArrayKind(kind) and mojom.IsBoolKind(kind.kind):
+    return "encodeArrayPointer(codec.PackedBool, ";
   if mojom.IsAnyArrayKind(kind):
     return "encodeArrayPointer(%s, " % CodecType(kind.kind)
   if mojom.IsInterfaceKind(kind) or mojom.IsInterfaceRequestKind(kind):
     return JavaScriptEncodeSnippet(mojom.MSGPIPE)
   if mojom.IsEnumKind(kind):
     return JavaScriptEncodeSnippet(mojom.INT32)
 
 
+def JavaScriptFieldOffset(packed_field):
+  return "offset + codec.kStructHeaderSize + %s" % packed_field.offset
+
+def JavaScriptValidateArrayParams(pf):
+  elementKind = pf.field.kind.kind
+  elementSize = pack.PackedField.GetSizeForKind(elementKind)
+  elementCount = generator.ExpectedArraySize(pf.field.kind)
+  elementType = "codec.PackedBool" if mojom.IsBoolKind(elementKind) \
+      else CodecType(elementKind)
+  return "%s, %s, %s, %s" % \
+    (JavaScriptFieldOffset(pf), elementSize, elementCount, elementType)
+
+def JavaScriptValidateStructParams(pf):
+  return "%s, %s" % (JavaScriptFieldOffset(pf), pf.field.kind.name)
+
+
 def TranslateConstants(token):
   if isinstance(token, (mojom.EnumValue, mojom.NamedValue)):
     # Both variable and enum constants are constructed like:
     # NamespaceUid.Struct[.Enum].CONSTANT_NAME
     name = []
     if token.imported_from:
       name.append(token.imported_from["unique_name"])
     if token.parent_kind:
       name.append(token.parent_kind.name)
     if isinstance(token, mojom.EnumValue):
       name.append(token.enum_name)
     name.append(token.name)
     return ".".join(name)
   return token
 
 
 def ExpressionToText(value):
   return TranslateConstants(value)
 
 
 def JavascriptType(kind):
   if kind.imported_from:
     return kind.imported_from["unique_name"] + "." + kind.name
   return kind.name
 
 
+def HasCallbacks(interface):

[yzshen1, 2014/08/14 18:02:22]

Shall we move this method into generator.py so that both mojom_cpp_generator and
mojom_js_generate can use it?

[hansmuller, 2014/08/14 23:51:46]

Yes. I moved it into module.py, since the Interface class is defined there. The
C++ bindings generator now uses it as well.

+  for method in interface.methods:
+    if method.response_parameters != None:
+      return True
+  return False
+
+def IsArrayPointerField(field):

[yzshen1, 2014/08/14 18:02:22]

[optional] If you want, you could consider directly export mojom.IsXXXKind() in
js_filters. The consequence is that you need to do field.kind|is_any_array_kind,
for example. But you don't need to define these one-line functions.

[hansmuller, 2014/08/14 23:51:46]

That's a reasonable suggestion however if you don't mind I will leave  this
particular detail alone for the moment. I liked the fact that the both the test,
like is_struct_pointer_field, and the corresponding method parameter generate,
like validate_struct_params, both just applied to the field object.

[yzshen1, 2014/08/15 16:26:36]

Acknowledged.

+  return mojom.IsAnyArrayKind(field.kind)
+
+def IsStringPointerField(field):
+  return mojom.IsStringKind(field.kind)
+
+def IsStructPointerField(field):
+  return mojom.IsStructKind(field.kind)
+
+def IsHandleField(field):
+  return mojom.IsAnyHandleKind(field.kind)
+
+
 class Generator(generator.Generator):
 
   js_filters = {
     "default_value": JavaScriptDefaultValue,
     "payload_size": JavaScriptPayloadSize,
     "decode_snippet": JavaScriptDecodeSnippet,
     "encode_snippet": JavaScriptEncodeSnippet,
     "expression_to_text": ExpressionToText,
+    "field_offset": JavaScriptFieldOffset,
+    "has_callbacks": HasCallbacks,
+    "is_array_pointer_field": IsArrayPointerField,
+    "is_struct_pointer_field": IsStructPointerField,
+    "is_string_pointer_field": IsStringPointerField,
+    "is_handle_field": IsHandleField,
     "js_type": JavascriptType,
     "stylize_method": generator.StudlyCapsToCamel,
+    "validate_array_params": JavaScriptValidateArrayParams,
+    "validate_struct_params": JavaScriptValidateStructParams,
   }
 
   @UseJinja("js_templates/module.js.tmpl", filters=js_filters)
   def GenerateJsModule(self):
     return {
       "namespace": self.module.namespace,
       "imports": self.GetImports(),
       "kinds": self.module.kinds,
       "enums": self.module.enums,
       "module": self.module,
       "structs": self.GetStructs() + self.GetStructsFromMethods(),
       "interfaces": self.module.interfaces,
     }
 
   def GenerateFiles(self, args):
     self.Write(self.GenerateJsModule(), "%s.js" % self.module.name)
 
   def GetImports(self):
     # Since each import is assigned a variable in JS, they need to have unique
     # names.
     counter = 1
     for each in self.module.imports:
       each["unique_name"] = "import" + str(counter)
       counter += 1
     return self.module.imports