Class DataView

napi.h:1511–1586

/// The DataView provides a low-level interface for reading/writing multiple
/// number types in an ArrayBuffer irrespective of the platform's endianness.
class DataView : public Object {
 public:
  static DataView New(napi_env env, Napi::ArrayBuffer arrayBuffer);
  static DataView New(napi_env env,
                      Napi::ArrayBuffer arrayBuffer,
                      size_t byteOffset);
  static DataView New(napi_env env,
                      Napi::ArrayBuffer arrayBuffer,
                      size_t byteOffset,
                      size_t byteLength);

#ifdef NODE_API_EXPERIMENTAL_HAS_SHAREDARRAYBUFFER
  static DataView New(napi_env env, Napi::SharedArrayBuffer arrayBuffer);
  static DataView New(napi_env env,
                      Napi::SharedArrayBuffer arrayBuffer,
                      size_t byteOffset);
  static DataView New(napi_env env,
                      Napi::SharedArrayBuffer arrayBuffer,
                      size_t byteOffset,
                      size_t byteLength);
#endif

  static void CheckCast(napi_env env, napi_value value);

  DataView();  ///< Creates a new _empty_ DataView instance.
  DataView(napi_env env,
           napi_value value);  ///< Wraps a Node-API value primitive.

  // Gets the backing `ArrayBuffer`.
  //
  // If this `DataView` is not backed by an `ArrayBuffer`, this method will
  // terminate the process with a fatal error when using
  // `NODE_ADDON_API_ENABLE_TYPE_CHECK_ON_AS` or exhibit undefined behavior
  // otherwise. Use `Buffer()` instead to get the backing buffer without
  // assuming its type.
  Napi::ArrayBuffer ArrayBuffer() const;

  // Gets the backing buffer (an `ArrayBuffer` or `SharedArrayBuffer`).
  //
  // Use `IsArrayBuffer()` or `IsSharedArrayBuffer()` to check the type of the
  // backing buffer prior to casting with `As<T>()`.
  Napi::Value Buffer() const;
  size_t ByteOffset()
      const;  ///< Gets the offset into the buffer where the array starts.
  size_t ByteLength() const;  ///< Gets the length of the array in bytes.

  void* Data() const;

  float GetFloat32(size_t byteOffset) const;
  double GetFloat64(size_t byteOffset) const;
  int8_t GetInt8(size_t byteOffset) const;
  int16_t GetInt16(size_t byteOffset) const;
  int32_t GetInt32(size_t byteOffset) const;
  uint8_t GetUint8(size_t byteOffset) const;
  uint16_t GetUint16(size_t byteOffset) const;
  uint32_t GetUint32(size_t byteOffset) const;

  void SetFloat32(size_t byteOffset, float value) const;