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Buffer

Class Napi::Buffer inherits from class Napi::Uint8Array.

The Napi::Buffer class creates a projection of raw data that can be consumed by script.

Methods

New

Allocates a new Napi::Buffer object with a given length.

static Napi::Buffer<T> Napi::Buffer::New(napi_env env, size_t length);
  • [in] env: The environment in which to create the Napi::Buffer object.
  • [in] length: The number of T elements to allocate.

Returns a new Napi::Buffer object.

New

When NODE_API_NO_EXTERNAL_BUFFERS_ALLOWED is defined, this method is not available. See External Buffer for more information.

Wraps the provided external data into a new Napi::Buffer object.

The Napi::Buffer object does not assume ownership for the data and expects it to be valid for the lifetime of the object. Since the Napi::Buffer is subject to garbage collection this overload is only suitable for data which is static and never needs to be freed. This factory method will not provide the caller with an opportunity to free the data when the Napi::Buffer gets garbage-collected. If you need to free the data retained by the Napi::Buffer object please use other variants of the Napi::Buffer::New factory method that accept Napi::Finalizer, which is a function that will be invoked when the Napi::Buffer object has been destroyed.

static Napi::Buffer<T> Napi::Buffer::New(napi_env env, T* data, size_t length);
  • [in] env: The environment in which to create the Napi::Buffer object.
  • [in] data: The pointer to the external data to expose.
  • [in] length: The number of T elements in the external data.

Returns a new Napi::Buffer object.

New

When NODE_API_NO_EXTERNAL_BUFFERS_ALLOWED is defined, this method is not available. See External Buffer for more information.

Wraps the provided external data into a new Napi::Buffer object.

The Napi::Buffer object does not assume ownership for the data and expects it to be valid for the lifetime of the object. The data can only be freed once the finalizeCallback is invoked to indicate that the Napi::Buffer has been released.

template <typename Finalizer>
static Napi::Buffer<T> Napi::Buffer::New(napi_env env,
                     T* data,
                     size_t length,
                     Finalizer finalizeCallback);
  • [in] env: The environment in which to create the Napi::Buffer object.
  • [in] data: The pointer to the external data to expose.
  • [in] length: The number of T elements in the external data.
  • [in] finalizeCallback: The function to be called when the Napi::Buffer is destroyed. It must implement operator(), accept an Napi::Env, a T* (which is the external data pointer), and return void.

Returns a new Napi::Buffer object.

New

When NODE_API_NO_EXTERNAL_BUFFERS_ALLOWED is defined, this method is not available. See External Buffer for more information.

Wraps the provided external data into a new Napi::Buffer object.

The Napi::Buffer object does not assume ownership for the data and expects it to be valid for the lifetime of the object. The data can only be freed once the finalizeCallback is invoked to indicate that the Napi::Buffer has been released.

template <typename Finalizer, typename Hint>
static Napi::Buffer<T> Napi::Buffer::New(napi_env env,
                     T* data,
                     size_t length,
                     Finalizer finalizeCallback,
                     Hint* finalizeHint);
  • [in] env: The environment in which to create the Napi::Buffer object.
  • [in] data: The pointer to the external data to expose.
  • [in] length: The number of T elements in the external data.
  • [in] finalizeCallback: The function to be called when the Napi::Buffer is destroyed. It must implement operator(), accept an Napi::Env, a T* (which is the external data pointer) and Hint*, and return void.
  • [in] finalizeHint: The hint to be passed as the second parameter of the finalize callback.

Returns a new Napi::Buffer object.

NewOrCopy

Wraps the provided external data into a new Napi::Buffer object. When the external buffer is not supported, allocates a new Napi::Buffer object and copies the provided external data into it.

The Napi::Buffer object does not assume ownership for the data and expects it to be valid for the lifetime of the object. Since the Napi::Buffer is subject to garbage collection this overload is only suitable for data which is static and never needs to be freed.

This factory method will not provide the caller with an opportunity to free the data when the Napi::Buffer gets garbage-collected. If you need to free the data retained by the Napi::Buffer object please use other variants of the Napi::Buffer::New factory method that accept Napi::Finalizer, which is a function that will be invoked when the Napi::Buffer object has been destroyed.

static Napi::Buffer<T> Napi::Buffer::NewOrCopy(napi_env env, T* data, size_t length);
  • [in] env: The environment in which to create the Napi::Buffer object.
  • [in] data: The pointer to the external data to expose.
  • [in] length: The number of T elements in the external data.

Returns a new Napi::Buffer object.

NewOrCopy

Wraps the provided external data into a new Napi::Buffer object. When the external buffer is not supported, allocates a new Napi::Buffer object and copies the provided external data into it and the finalizeCallback is invoked immediately.

The Napi::Buffer object does not assume ownership for the data and expects it to be valid for the lifetime of the object. The data can only be freed once the finalizeCallback is invoked to indicate that the Napi::Buffer has been released.

template <typename Finalizer>
static Napi::Buffer<T> Napi::Buffer::NewOrCopy(napi_env env,
                                               T* data,
                                               size_t length,
                                               Finalizer finalizeCallback);
  • [in] env: The environment in which to create the Napi::Buffer object.
  • [in] data: The pointer to the external data to expose.
  • [in] length: The number of T elements in the external data.
  • [in] finalizeCallback: The function to be called when the Napi::Buffer is destroyed. It must implement operator(), accept an Napi::Env, a T* (which is the external data pointer), and return void.

Returns a new Napi::Buffer object.

NewOrCopy

Wraps the provided external data into a new Napi::Buffer object. When the external buffer is not supported, allocates a new Napi::Buffer object and copies the provided external data into it and the finalizeCallback is invoked immediately.

The Napi::Buffer object does not assume ownership for the data and expects it to be valid for the lifetime of the object. The data can only be freed once the finalizeCallback is invoked to indicate that the Napi::Buffer has been released.

template <typename Finalizer, typename Hint>
static Napi::Buffer<T> Napi::Buffer::NewOrCopy(napi_env env,
                                               T* data,
                                               size_t length,
                                               Finalizer finalizeCallback,
                                               Hint* finalizeHint);
  • [in] env: The environment in which to create the Napi::Buffer object.
  • [in] data: The pointer to the external data to expose.
  • [in] length: The number of T elements in the external data.
  • [in] finalizeCallback: The function to be called when the Napi::Buffer is destroyed. It must implement operator(), accept an Napi::Env, a T* (which is the external data pointer) and Hint*, and return void.
  • [in] finalizeHint: The hint to be passed as the second parameter of the finalize callback.

Returns a new Napi::Buffer object.

Copy

Allocates a new Napi::Buffer object and copies the provided external data into it.

static Napi::Buffer<T> Napi::Buffer::Copy(napi_env env, const T* data, size_t length);
  • [in] env: The environment in which to create the Napi::Buffer object.
  • [in] data: The pointer to the external data to copy.
  • [in] length: The number of T elements in the external data.

Returns a new Napi::Buffer object containing a copy of the data.

Constructor

Initializes an empty instance of the Napi::Buffer class.

Napi::Buffer::Buffer();

Constructor

Initializes the Napi::Buffer object using an existing Uint8Array.

Napi::Buffer::Buffer(napi_env env, napi_value value);
  • [in] env: The environment in which to create the Napi::Buffer object.
  • [in] value: The Uint8Array reference to wrap.

Data

T* Napi::Buffer::Data() const;

Returns a pointer the external data.

Length

size_t Napi::Buffer::Length() const;

Returns the number of T elements in the external data.