[POC] Implement "module responses map" concept

third_party/WebKit/Source/core/workers/WorkletModuleResponsesMapProxy.cpp

Index: third_party/WebKit/Source/core/workers/WorkletModuleResponsesMapProxy.cpp
diff --git a/third_party/WebKit/Source/core/workers/WorkletModuleResponsesMapProxy.cpp b/third_party/WebKit/Source/core/workers/WorkletModuleResponsesMapProxy.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..570850a74ee8d7b0517c56dad1642275fbba5de4
--- /dev/null
+++ b/third_party/WebKit/Source/core/workers/WorkletModuleResponsesMapProxy.cpp
@@ -0,0 +1,109 @@
+// Copyright 2017 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 "core/workers/WorkletModuleResponsesMapProxy.h"
+
+#include "core/loader/modulescript/ModuleScriptCreationParams.h"
+#include "platform/CrossThreadFunctional.h"
+#include "platform/wtf/Functional.h"
+
+namespace blink {
+
+namespace {
+
+// ClientAdapter mediates WorkletModuleResponsesMap on the main thread and
+// WorkletModuileResponsesMap::Client implementation on the worklet context
+// thread. This lives on the main thread.
+class ClientAdapter final : public GarbageCollectedFinalized<ClientAdapter>,
+                            public WorkletModuleResponsesMap::Client {
+  USING_GARBAGE_COLLECTED_MIXIN(ClientAdapter);
+
+ public:
+  ClientAdapter(WorkletModuleResponsesMap::Client* client,
+                RefPtr<WebTaskRunner> inside_settings_task_runner)
+      : client_(client),
+        inside_settings_task_runner_(std::move(inside_settings_task_runner)) {}
+  ~ClientAdapter() override = default;
+
+  void OnRead(const ModuleScriptCreationParams& params) override {
+    DCHECK(IsMainThread());
+    inside_settings_task_runner_->PostTask(
+        BLINK_FROM_HERE,
+        CrossThreadBind(&WorkletModuleResponsesMap::Client::OnRead, client_,
+                        params));
+  }
+  void OnFetchNeeded() override {
+    DCHECK(IsMainThread());
+    inside_settings_task_runner_->PostTask(
+        BLINK_FROM_HERE,
+        CrossThreadBind(&WorkletModuleResponsesMap::Client::OnFetchNeeded,
+                        client_));
+  }
+  void OnFailed() override {
+    DCHECK(IsMainThread());
+    inside_settings_task_runner_->PostTask(
+        BLINK_FROM_HERE,
+        CrossThreadBind(&WorkletModuleResponsesMap::Client::OnFailed, client_));
+  }
+
+  DEFINE_INLINE_VIRTUAL_TRACE() {}
+
+ private:
+  CrossThreadPersistent<WorkletModuleResponsesMap::Client> client_;
+  RefPtr<WebTaskRunner> inside_settings_task_runner_;
+};
+
+}  // namespace
+
+WorkletModuleResponsesMapProxy::WorkletModuleResponsesMapProxy(
+    WorkletModuleResponsesMap* module_responses_map,
+    RefPtr<WebTaskRunner> outside_settings_task_runner,
+    RefPtr<WebTaskRunner> inside_settings_task_runner)
+    : module_responses_map_(module_responses_map),
+      outside_settings_task_runner_(outside_settings_task_runner),
+      inside_settings_task_runner_(inside_settings_task_runner) {
+  DCHECK(module_responses_map_);
+  DCHECK(outside_settings_task_runner_);
+  DCHECK(inside_settings_task_runner_);
+  DCHECK(inside_settings_task_runner_->RunsTasksInCurrentSequence());
+}
+
+void WorkletModuleResponsesMapProxy::ReadEntry(const KURL& url,
+                                               Client* client) {
+  DCHECK(inside_settings_task_runner_->RunsTasksInCurrentSequence());
+  outside_settings_task_runner_->PostTask(
+      BLINK_FROM_HERE,
+      CrossThreadBind(&WorkletModuleResponsesMapProxy::ReadEntryOnMainThread,
+                      WrapCrossThreadPersistent(this), url,
+                      WrapCrossThreadPersistent(client)));
+}
+
+void WorkletModuleResponsesMapProxy::UpdateEntry(
+    const KURL& url,
+    const ModuleScriptCreationParams& params) {
+  DCHECK(inside_settings_task_runner_->RunsTasksInCurrentSequence());
+  outside_settings_task_runner_->PostTask(
+      BLINK_FROM_HERE, CrossThreadBind(&WorkletModuleResponsesMap::UpdateEntry,
+                                       module_responses_map_, url, params));
+}
+
+void WorkletModuleResponsesMapProxy::InvalidateEntry(const KURL& url) {
+  DCHECK(inside_settings_task_runner_->RunsTasksInCurrentSequence());
+  outside_settings_task_runner_->PostTask(
+      BLINK_FROM_HERE,
+      CrossThreadBind(&WorkletModuleResponsesMap::InvalidateEntry,
+                      module_responses_map_, url));
+}
+
+DEFINE_TRACE(WorkletModuleResponsesMapProxy) {}
+
+void WorkletModuleResponsesMapProxy::ReadEntryOnMainThread(const KURL& url,
+                                                           Client* client) {
+  DCHECK(IsMainThread());
+  ClientAdapter* wrapper =
+      new ClientAdapter(client, inside_settings_task_runner_);
+  module_responses_map_->ReadOrCreateEntry(url, wrapper);
+}
+
+}  // namespace blink