Add support for snapshot loading to Sky

sky/engine/core/script/dart_controller.cc

 // Copyright 2015 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.
 
 #include "sky/engine/config.h"
 #include "sky/engine/core/script/dart_controller.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/single_thread_task_runner.h"
 #include "base/trace_event/trace_event.h"
 #include "dart/runtime/bin/embedded_dart_io.h"
 #include "dart/runtime/include/dart_mirrors_api.h"
 #include "gen/sky/platform/RuntimeEnabledFeatures.h"
 #include "sky/engine/bindings/builtin.h"
 #include "sky/engine/bindings/builtin_natives.h"
 #include "sky/engine/bindings/builtin_sky.h"
 #include "sky/engine/core/app/AbstractModule.h"
 #include "sky/engine/core/app/Module.h"
 #include "sky/engine/core/dom/Element.h"
 #include "sky/engine/core/frame/LocalFrame.h"
 #include "sky/engine/core/html/HTMLScriptElement.h"
 #include "sky/engine/core/html/imports/HTMLImport.h"
 #include "sky/engine/core/html/imports/HTMLImportChild.h"
 #include "sky/engine/core/loader/FrameLoaderClient.h"
 #include "sky/engine/core/script/dart_debugger.h"
 #include "sky/engine/core/script/dart_dependency_catcher.h"
 #include "sky/engine/core/script/dart_loader.h"
 #include "sky/engine/core/script/dart_service_isolate.h"
+#include "sky/engine/core/script/dart_snapshot_loader.h"
 #include "sky/engine/core/script/dom_dart_state.h"
 #include "sky/engine/public/platform/Platform.h"
 #include "sky/engine/tonic/dart_api_scope.h"
 #include "sky/engine/tonic/dart_class_library.h"
 #include "sky/engine/tonic/dart_error.h"
 #include "sky/engine/tonic/dart_gc_controller.h"
 #include "sky/engine/tonic/dart_invoke.h"
 #include "sky/engine/tonic/dart_isolate_scope.h"
 #include "sky/engine/tonic/dart_state.h"
 #include "sky/engine/tonic/dart_wrappable.h"
@@ skipping 86 matching lines @@
 }
 
 void DartController::LoadMainLibrary(const KURL& url, mojo::URLResponsePtr response) {
   DartLoader& loader = dart_state()->loader();
   DartDependencyCatcher dependency_catcher(loader);
   loader.LoadLibrary(url, response.Pass());
   loader.WaitForDependencies(dependency_catcher.dependencies(),
                              base::Bind(&DartController::DidLoadMainLibrary, weak_factory_.GetWeakPtr(), url));
 }
 
+void DartController::DidLoadSnapshot() {
+  DCHECK(Dart_CurrentIsolate() == nullptr);
+  snapshot_loader_ = nullptr;
+
+  Dart_Isolate isolate = dart_state()->isolate();
+  DartIsolateScope isolate_scope(isolate);
+  DartApiScope dart_api_scope;
+
+  Dart_Handle library = Dart_RootLibrary();
+  if (LogIfError(library))
+    return;
+  DartInvokeAppField(library, ToDart("main"), 0, nullptr);
+}
+
+void DartController::LoadSnapshot(const KURL& url, mojo::URLResponsePtr response) {
+  snapshot_loader_ = adoptPtr(new DartSnapshotLoader(dart_state()));
+  snapshot_loader_->LoadSnapshot(url, response.Pass(),
+      base::Bind(&DartController::DidLoadSnapshot, weak_factory_.GetWeakPtr()));
+}
+
 void DartController::LoadScriptInModule(
     AbstractModule* module,
     const String& source,
     const TextPosition& position,
     const LoadFinishedCallback& finished_callback) {
   DartIsolateScope isolate_scope(dart_state()->isolate());
   DartApiScope dart_api_scope;
 
   DartDependencyCatcher dependency_catcher(dart_state()->loader());
   Dart_Handle library_handle = CreateLibrary(module, source, position);
@@ skipping 136 matching lines @@
   dart_state->SetIsolate(isolate);
 
   CHECK(!LogIfError(Dart_SetLibraryTagHandler(LibraryTagHandler)));
 
   {
     DartApiScope apiScope;
     Builtin::SetNativeResolver(Builtin::kBuiltinLibrary);
     Builtin::SetNativeResolver(Builtin::kMojoInternalLibrary);
     Builtin::SetNativeResolver(Builtin::kIOLibrary);
 
-    // Ensure the isolate has a root library.
-    Dart_LoadScript(Dart_NewStringFromCString("dart:empty"),
-                    Dart_NewStringFromCString(""), 0, 0);
+    if (!script_uri) {
+      // Ensure the isolate has a root library.

[eseidel, 2015/06/23 06:21:39]

I don't think this is necessary anymore  This was for when we had .sky files. So
I guess we still need it, but not in the SkyView case.

I think if we remove it we have to use a different loading function.

[abarth-chromium, 2015/06/23 14:50:42]

Yeah, I was close to removing it entirely.  I think it's only needed for one of
the oddball isolates.  I can try again to remove it entirely, but for now I'll
add a comment explaining.

[eseidel, 2015/06/23 16:02:03]

My recollection was it was needed because of the way we did library creation (to
allow mutiple libraries in a single .sky file).

+      Dart_LoadScript(Dart_NewStringFromCString("dart:empty"),
+                      Dart_EmptyString(), 0, 0);
+    }
   }
 
   Dart_ExitIsolate();
 
   CHECK(Dart_IsolateMakeRunnable(isolate));
   return isolate;
 }
 
 static void CallHandleMessage(base::WeakPtr<DartState> dart_state) {
   TRACE_EVENT0("sky", "CallHandleMessage");
@@ skipping 22 matching lines @@
       static_cast<DartState*>(dom_dart_state_.get()), &error);
   Dart_SetMessageNotifyCallback(MessageNotifyCallback);
   CHECK(isolate) << error;
   dom_dart_state_->SetIsolate(isolate);
   Dart_SetGcCallbacks(DartGCPrologue, DartGCEpilogue);
   CHECK(!LogIfError(Dart_SetLibraryTagHandler(LibraryTagHandler)));
 
   {
     DartApiScope apiScope;
 
-    // Ensure the isolate has a root library.
-    Dart_LoadScript(Dart_NewStringFromCString("dart:empty"),
-                    Dart_NewStringFromCString(""), 0, 0);
-
     Builtin::SetNativeResolver(Builtin::kBuiltinLibrary);
     Builtin::SetNativeResolver(Builtin::kMojoInternalLibrary);
     Builtin::SetNativeResolver(Builtin::kIOLibrary);
     BuiltinNatives::Init(BuiltinNatives::MainIsolate);
 
     builtin_sky_ = adoptPtr(new BuiltinSky(dart_state()));
     dart_state()->class_library().set_provider(builtin_sky_.get());
 
     if (dart_state()->document())
       builtin_sky_->InstallWindow(dart_state());
@@ skipping 37 matching lines @@
                         nullptr,  // Isolate interrupt callback.
                         UnhandledExceptionCallback, IsolateShutdownCallback,
                         // File IO callbacks.
                         nullptr, nullptr, nullptr, nullptr, nullptr));
   // Wait for load port- ensures handle watcher and service isolates are
   // running.
   Dart_ServiceWaitForLoadPort();
 }
 
 } // namespace blink