1 files changed, 95 insertions, 0 deletions
diff --git a/dom/webgpu/Buffer.h b/dom/webgpu/Buffer.h
new file mode 100644
index 0000000000..2f809a4768
--- /dev/null
+++ b/dom/webgpu/Buffer.h
@@ -0,0 +1,95 @@
+/* -*- 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/. */
+
+#ifndef GPU_BUFFER_H_
+#define GPU_BUFFER_H_
+
+#include "js/RootingAPI.h"
+#include "mozilla/dom/Nullable.h"
+#include "mozilla/webgpu/WebGPUTypes.h"
+#include "nsTArray.h"
+#include "ObjectModel.h"
+#include "mozilla/ipc/RawShmem.h"
+#include <memory>
+
+namespace mozilla {
+class ErrorResult;
+
+namespace dom {
+struct GPUBufferDescriptor;
+template <typename T>
+class Optional;
+enum class GPUBufferMapState : uint8_t;
+}  // namespace dom
+
+namespace webgpu {
+
+class Device;
+
+struct MappedInfo {
+  // True if mapping is requested for writing.
+  bool mWritable = false;
+  // Populated by `GetMappedRange`.
+  nsTArray<JS::Heap<JSObject*>> mArrayBuffers;
+  BufferAddress mOffset;
+  BufferAddress mSize;
+  MappedInfo() = default;
+  MappedInfo(const MappedInfo&) = delete;
+};
+
+class Buffer final : public ObjectBase, public ChildOf<Device> {
+ public:
+  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_NATIVE_CLASS(Buffer)
+  NS_INLINE_DECL_CYCLE_COLLECTING_NATIVE_REFCOUNTING(Buffer)
+  GPU_DECL_JS_WRAP(Buffer)
+
+  static already_AddRefed<Buffer> Create(Device* aDevice, RawId aDeviceId,
+                                         const dom::GPUBufferDescriptor& aDesc,
+                                         ErrorResult& aRv);
+
+  already_AddRefed<dom::Promise> MapAsync(uint32_t aMode, uint64_t aOffset,
+                                          const dom::Optional<uint64_t>& aSize,
+                                          ErrorResult& aRv);
+  void GetMappedRange(JSContext* aCx, uint64_t aOffset,
+                      const dom::Optional<uint64_t>& aSize,
+                      JS::Rooted<JSObject*>* aObject, ErrorResult& aRv);
+  void Unmap(JSContext* aCx, ErrorResult& aRv);
+  void Destroy(JSContext* aCx, ErrorResult& aRv);
+
+  const RawId mId;
+
+  uint64_t Size() const { return mSize; }
+  uint32_t Usage() const { return mUsage; }
+  dom::GPUBufferMapState MapState() const;
+
+ private:
+  Buffer(Device* const aParent, RawId aId, BufferAddress aSize, uint32_t aUsage,
+         ipc::WritableSharedMemoryMapping&& aShmem);
+  virtual ~Buffer();
+  Device& GetDevice() { return *mParent; }
+  void Drop();
+  void UnmapArrayBuffers(JSContext* aCx, ErrorResult& aRv);
+  void RejectMapRequest(dom::Promise* aPromise, nsACString& message);
+  void AbortMapRequest();
+  void SetMapped(BufferAddress aOffset, BufferAddress aSize, bool aWritable);
+
+  // Note: we can't map a buffer with the size that don't fit into `size_t`
+  // (which may be smaller than `BufferAddress`), but general not all buffers
+  // are mapped.
+  const BufferAddress mSize;
+  const uint32_t mUsage;
+  nsString mLabel;
+  // Information about the currently active mapping.
+  Maybe<MappedInfo> mMapped;
+  RefPtr<dom::Promise> mMapRequest;
+  // mShmem does not point to a shared memory segment if the buffer is not
+  // mappable.
+  std::shared_ptr<ipc::WritableSharedMemoryMapping> mShmem;
+};
+
+}  // namespace webgpu
+}  // namespace mozilla
+
+#endif  // GPU_BUFFER_H_