// SPDX-License-Identifier: Apache-2.0

// SPDX-FileCopyrightText: 2019-2024 Second State INC

//===-- wasmedge/runtime/instance/data.h - Data Instance definition -------===//

//

// Part of the WasmEdge Project.

//

//===----------------------------------------------------------------------===//

///

/// \file

/// This file contains the data instance definition in store manager.

///

//===----------------------------------------------------------------------===//

#pragma once

#include "common/span.h"

#include "common/types.h"

#include <vector>

namespace WasmEdge {

namespace Runtime {

namespace Instance {

class DataInstance {

public:

  DataInstance() = delete;

  DataInstance(const uint32_t Offset, Span<const Byte> Init) noexcept

      : Off(Offset), Data(Init.begin(), Init.end()) {}

  /// Get offset in data instance.

  uint32_t getOffset() const noexcept { return Off; }

  /// Get data in data instance.

  Span<const Byte> getData() const noexcept { return Data; }

  /// Load bytes to value.

  ValVariant loadValue(uint32_t Offset, uint32_t N) const noexcept {

    assuming(N <= 16);

    // Check the data boundary.

    if (unlikely(static_cast<uint64_t>(Offset) + static_cast<uint64_t>(N) >

                 Data.size())) {

      return 0;

    }

    // Load the data to the value.

    uint128_t Value;

    std::memcpy(&Value, &Data[Offset], N);

    return Value;

  }

  /// Clear data in data instance.

  void clear() { Data.clear(); }

private:

  /// \name Data of data instance.

  /// @{

  const uint32_t Off;

  std::vector<Byte> Data;

  /// @}

};

} // namespace Instance

} // namespace Runtime

} // namespace WasmEdge