Dart: Moves |native| methods to patch files.

sky/engine/bindings/builtin.cc

Index: sky/engine/bindings/builtin.cc
diff --git a/sky/engine/bindings/builtin.cc b/sky/engine/bindings/builtin.cc
index d57ea814eb31a2999c8c1c040eb616564af699c2..8cb25fc8f9d3b9425120e58426dbe1825a438e04 100644
--- a/sky/engine/bindings/builtin.cc
+++ b/sky/engine/bindings/builtin.cc
@@ -16,46 +16,129 @@
 namespace blink {
 namespace {
 
+const char* mojo_core_patch_resource_names_[] = {
+    "/core/buffer_patch.dart",
+    "/core/data_pipe_patch.dart",
+    "/core/handle_patch.dart",
+    "/core/handle_watcher_patch.dart",
+    "/core/message_pipe_patch.dart",
+    NULL,
+};
+
 struct LibraryDescriptor {
   const char* url;
   bool has_natives;
   Dart_NativeEntrySymbol native_symbol;
   Dart_NativeEntryResolver native_resolver;
+  const char* patch_url;
+  const char** patch_resources;
 };
 
 const LibraryDescriptor kBuiltinLibraries[] = {
-    /* { url_, has_natives_, native_symbol_, native_resolver_ } */
-    {"dart:sky_builtin", true, BuiltinNatives::NativeSymbol, BuiltinNatives::NativeLookup},
-    {"dart:sky", true, skySnapshotSymbolizer, skySnapshotResolver},
-    {"mojo:bindings", false, nullptr, nullptr},
-    {"mojo:core", true, MojoNativeSymbol, MojoNativeLookup},
+    /* { url, has_natives, native_symbol, native_resolver,
+         patch_url, patch_paths } */
+    {"dart:sky_builtin",
+     true,
+     BuiltinNatives::NativeSymbol,
+     BuiltinNatives::NativeLookup,
+     nullptr,
+     nullptr},
+    {"dart:sky",
+     true,
+     skySnapshotSymbolizer,
+     skySnapshotResolver,
+     nullptr,
+     nullptr},
+    {"mojo:bindings", false, nullptr, nullptr, nullptr, nullptr},
+    {"mojo:core",
+     true,
+     MojoNativeSymbol,
+     MojoNativeLookup,
+     "mojo:core-patch",
+     mojo_core_patch_resource_names_},
 };
 
 }  // namespace
 
-void Builtin::SetNativeResolver(BuiltinLibraryId id) {
+struct ResourcesEntry {
+  const char* path_;
+  const char* resource_;
+  int length_;
+};
+
+extern ResourcesEntry __dart_embedder_patch_resources_[];
+
+// Returns -1 if resource could not be found.
+int Builtin::FindResource(const char* path, const uint8_t** resource) {
+  ResourcesEntry* table = &__dart_embedder_patch_resources_[0];
+  for (int i = 0; table[i].path_ != NULL; i++) {
+    const ResourcesEntry& entry = table[i];
+    if (strcmp(path, entry.path_) == 0) {
+      *resource = reinterpret_cast<const uint8_t*>(entry.resource_);
+      DCHECK(entry.length_ > 0);
+      return entry.length_;
+    }
+  }
+  *resource = NULL;
+  return -1;
+}
+
+Dart_Handle Builtin::GetStringResource(const char* resource_name) {
+  const uint8_t* resource_string;
+  int resource_length = FindResource(resource_name, &resource_string);
+  if (resource_length > 0) {
+    return Dart_NewStringFromUTF8(resource_string, resource_length);
+  }
+  return Dart_Null();
+}
+
+// Patch all the specified patch files in the array 'patch_resources' into the
+// library specified in 'library'.
+void Builtin::LoadPatchFiles(Dart_Handle library,
+                             const char* patch_uri,
+                             const char** patch_resources) {
+  for (intptr_t j = 0; patch_resources[j] != NULL; j++) {
+    Dart_Handle patch_src = GetStringResource(patch_resources[j]);
+    if (Dart_IsNull(patch_src)) {
+      LOG(ERROR) << "Could not load resource " << patch_resources[j];
+      return;
+    }
+    // Prepend the patch library URI to form a unique script URI for the patch.
+    intptr_t len = snprintf(NULL, 0, "%s%s", patch_uri, patch_resources[j]);
+    char* patch_filename = reinterpret_cast<char*>(malloc(len + 1));
+    snprintf(patch_filename, len + 1, "%s%s", patch_uri, patch_resources[j]);
+    Dart_Handle patch_file_uri = Dart_NewStringFromCString(patch_filename);
+    DART_CHECK_VALID(patch_file_uri);
+    free(patch_filename);
+    DART_CHECK_VALID(Dart_LibraryLoadPatch(library, patch_file_uri, patch_src));
+  }
+}
+
+Dart_Handle Builtin::GetLibrary(BuiltinLibraryId id) {
   static_assert(arraysize(kBuiltinLibraries) == kInvalidLibrary,
       "Unexpected number of builtin libraries");
   DCHECK_GE(id, kBuiltinLibrary);
   DCHECK_LT(id, kInvalidLibrary);
+  Dart_Handle library = DartBuiltin::LookupLibrary(kBuiltinLibraries[id].url);
+  DART_CHECK_VALID(library);
+  return library;
+}
+
+void Builtin::PrepareLibrary(BuiltinLibraryId id) {
+  Dart_Handle library = GetLibrary(id);
+  DCHECK(!Dart_IsError(library));
   if (kBuiltinLibraries[id].has_natives) {
-    Dart_Handle library = DartBuiltin::LookupLibrary(kBuiltinLibraries[id].url);
     // Setup the native resolver for built in library functions.
     DART_CHECK_VALID(
         Dart_SetNativeResolver(library,
                                kBuiltinLibraries[id].native_resolver,
                                kBuiltinLibraries[id].native_symbol));
   }
-}
-
-Dart_Handle Builtin::LoadAndCheckLibrary(BuiltinLibraryId id) {
-  static_assert(arraysize(kBuiltinLibraries) == kInvalidLibrary,
-      "Unexpected number of builtin libraries");
-  DCHECK_GE(id, kBuiltinLibrary);
-  DCHECK_LT(id, kInvalidLibrary);
-  Dart_Handle library = DartBuiltin::LookupLibrary(kBuiltinLibraries[id].url);
-  DART_CHECK_VALID(library);
-  return library;
+  if (kBuiltinLibraries[id].patch_url != nullptr) {
+    DCHECK(kBuiltinLibraries[id].patch_resources != nullptr);
+    LoadPatchFiles(library, kBuiltinLibraries[id].patch_url,
+                   kBuiltinLibraries[id].patch_resources);
+  }
 }
 
 }  // namespace blink