1 files changed, 125 insertions, 0 deletions
diff --git a/dom/webgpu/Instance.cpp b/dom/webgpu/Instance.cpp
new file mode 100644
index 0000000000..4bf58b7fa8
--- /dev/null
+++ b/dom/webgpu/Instance.cpp
@@ -0,0 +1,125 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "Instance.h"
+
+#include "Adapter.h"
+#include "nsIGlobalObject.h"
+#include "ipc/WebGPUChild.h"
+#include "ipc/WebGPUTypes.h"
+#include "mozilla/webgpu/ffi/wgpu.h"
+#include "mozilla/dom/Promise.h"
+#include "mozilla/gfx/CanvasManagerChild.h"
+#include "mozilla/gfx/gfxVars.h"
+#include "mozilla/StaticPrefs_dom.h"
+
+#include <optional>
+#include <string_view>
+
+namespace mozilla::webgpu {
+
+GPU_IMPL_CYCLE_COLLECTION(Instance, mOwner)
+
+static inline nsDependentCString ToCString(const std::string_view s) {
+  return {s.data(), s.length()};
+}
+
+/* static */ bool Instance::PrefEnabled(JSContext* aCx, JSObject* aObj) {
+  if (!StaticPrefs::dom_webgpu_enabled()) {
+    return false;
+  }
+
+  if (NS_IsMainThread()) {
+    return true;
+  }
+
+  return StaticPrefs::dom_webgpu_workers_enabled();
+}
+
+/*static*/
+already_AddRefed<Instance> Instance::Create(nsIGlobalObject* aOwner) {
+  RefPtr<Instance> result = new Instance(aOwner);
+  return result.forget();
+}
+
+Instance::Instance(nsIGlobalObject* aOwner) : mOwner(aOwner) {}
+
+Instance::~Instance() { Cleanup(); }
+
+void Instance::Cleanup() {}
+
+JSObject* Instance::WrapObject(JSContext* cx,
+                               JS::Handle<JSObject*> givenProto) {
+  return dom::GPU_Binding::Wrap(cx, this, givenProto);
+}
+
+already_AddRefed<dom::Promise> Instance::RequestAdapter(
+    const dom::GPURequestAdapterOptions& aOptions, ErrorResult& aRv) {
+  RefPtr<dom::Promise> promise = dom::Promise::Create(mOwner, aRv);
+  if (NS_WARN_IF(aRv.Failed())) {
+    return nullptr;
+  }
+
+  // -
+  // Check if we should allow the request.
+
+  const auto errStr = [&]() -> std::optional<std::string_view> {
+#ifdef RELEASE_OR_BETA
+    if (true) {
+      return "WebGPU is not yet available in Release or Beta builds.";
+    }
+#endif
+    if (!gfx::gfxVars::AllowWebGPU()) {
+      return "WebGPU is disabled by blocklist.";
+    }
+    if (!StaticPrefs::dom_webgpu_enabled()) {
+      return "WebGPU is disabled by dom.webgpu.enabled:false.";
+    }
+    return {};
+  }();
+  if (errStr) {
+    promise->MaybeRejectWithNotSupportedError(ToCString(*errStr));
+    return promise.forget();
+  }
+
+  // -
+  // Make the request.
+
+  auto* const canvasManager = gfx::CanvasManagerChild::Get();
+  if (!canvasManager) {
+    promise->MaybeRejectWithInvalidStateError(
+        "Failed to create CanavasManagerChild");
+    return promise.forget();
+  }
+
+  RefPtr<WebGPUChild> bridge = canvasManager->GetWebGPUChild();
+  if (!bridge) {
+    promise->MaybeRejectWithInvalidStateError("Failed to create WebGPUChild");
+    return promise.forget();
+  }
+
+  RefPtr<Instance> instance = this;
+
+  bridge->InstanceRequestAdapter(aOptions)->Then(
+      GetCurrentSerialEventTarget(), __func__,
+      [promise, instance, bridge](ipc::ByteBuf aInfoBuf) {
+        auto info = std::make_shared<ffi::WGPUAdapterInformation>();
+        ffi::wgpu_client_adapter_extract_info(ToFFI(&aInfoBuf), info.get());
+        MOZ_ASSERT(info->id != 0);
+        RefPtr<Adapter> adapter = new Adapter(instance, bridge, info);
+        promise->MaybeResolve(adapter);
+      },
+      [promise](const Maybe<ipc::ResponseRejectReason>& aResponseReason) {
+        if (aResponseReason.isSome()) {
+          promise->MaybeRejectWithAbortError("Internal communication error!");
+        } else {
+          promise->MaybeResolve(JS::NullHandleValue);
+        }
+      });
+
+  return promise.forget();
+}
+
+}  // namespace mozilla::webgpu