src/dawn/wire/server/ServerInlineMemoryTransferService.cpp

// Copyright 2019 The Dawn & Tint Authors
//
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// modification, are permitted provided that the following conditions are met:
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// 1. Redistributions of source code must retain the above copyright notice, this
//    list of conditions and the following disclaimer.
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// 2. Redistributions in binary form must reproduce the above copyright notice,
//    this list of conditions and the following disclaimer in the documentation
//    and/or other materials provided with the distribution.
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// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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#include <cstring>
#include <memory>

#include "dawn/wire/WireServer.h"
#include "src/dawn/wire/server/Server.h"
#include "src/utils/assert.h"
#include "src/utils/compiler.h"

namespace dawn::wire::server {

class InlineMemoryTransferService : public MemoryTransferService {
  public:
    class MemoryHandleImpl : public MemoryHandle {
      public:
        MemoryHandleImpl() {}
        ~MemoryHandleImpl() override = default;

        size_t GetSerializeDataUpdateSize(size_t offset, size_t size) const override {
            return size;
        }

        void SerializeDataUpdate(std::span<std::byte> serializeData,
                                 size_t offset,
                                 size_t size,
                                 std::span<const std::byte> data) const override {
            DAWN_ASSERT(serializeData.size() == GetSerializeDataUpdateSize(offset, size));
            DAWN_ASSERT(data.size() == size);

            // TODO(https://crbug.com/524406299): Use span::copy_from
            DAWN_UNSAFE_TODO(memcpy(serializeData.data(), data.data(), size));
        }

        bool DeserializeDataUpdate(std::span<const std::byte> deserializeData,
                                   size_t offset,
                                   size_t size,
                                   std::span<std::byte> target) override {
            DAWN_ASSERT(target.size() == size);
            if (size > deserializeData.size()) {
                return false;
            }

            // TODO(https://crbug.com/524406299): Use span::copy_from
            DAWN_UNSAFE_TODO(memcpy(target.data(), deserializeData.data(), size));
            return true;
        }
    };

    InlineMemoryTransferService() {}
    ~InlineMemoryTransferService() override = default;

    std::unique_ptr<MemoryHandle> DeserializeMemoryHandle(
        std::span<const std::byte> creationData) override {
        if (!creationData.empty()) {
            return nullptr;
        }
        return std::make_unique<MemoryHandleImpl>();
    }
};

std::unique_ptr<MemoryTransferService> CreateInlineMemoryTransferService() {
    return std::make_unique<InlineMemoryTransferService>();
}

}  // namespace dawn::wire::server