neon/types_impl/buffer/types.rs
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use std::{marker::PhantomData, slice};
use crate::{
context::{
internal::{ContextInternal, Env},
Context, Cx,
},
handle::{internal::TransparentNoCopyWrapper, Handle},
object::Object,
result::{JsResult, Throw},
sys::{self, raw, typedarray::TypedArrayInfo, TypedArrayType},
types_impl::{
buffer::{
lock::{Ledger, Lock},
private::{self, JsTypedArrayInner},
BorrowError, Ref, RefMut, Region, TypedArray,
},
private::ValueInternal,
Value,
},
};
#[cfg(feature = "doc-comment")]
use doc_comment::doc_comment;
#[cfg(not(feature = "doc-comment"))]
macro_rules! doc_comment {
{$comment:expr, $decl:item} => { $decl };
}
/// The type of Node
/// [`Buffer`](https://nodejs.org/api/buffer.html)
/// objects.
///
/// # Example
///
/// ```
/// # use neon::prelude::*;
/// use neon::types::buffer::TypedArray;
///
/// fn make_sequence(mut cx: FunctionContext) -> JsResult<JsBuffer> {
/// let len = cx.argument::<JsNumber>(0)?.value(&mut cx);
/// let mut buffer = cx.buffer(len as usize)?;
///
/// for (i, elem) in buffer.as_mut_slice(&mut cx).iter_mut().enumerate() {
/// *elem = i as u8;
/// }
///
/// Ok(buffer)
/// }
/// ```
#[derive(Debug)]
#[repr(transparent)]
pub struct JsBuffer(raw::Local);
impl JsBuffer {
/// Constructs a new `Buffer` object, safely zero-filled.
///
/// **See also:** [`Context::buffer`]
pub fn new<'a, C: Context<'a>>(cx: &mut C, len: usize) -> JsResult<'a, Self> {
unsafe {
let result = sys::buffer::new(cx.env().to_raw(), len);
if let Ok(buf) = result {
Ok(Handle::new_internal(Self(buf)))
} else {
Err(Throw::new())
}
}
}
/// Constructs a `JsBuffer` from a slice by copying its contents.
///
/// This method is defined on `JsBuffer` as a convenience and delegates to
/// [`TypedArray::from_slice`][TypedArray::from_slice].
pub fn from_slice<'cx, C>(cx: &mut C, slice: &[u8]) -> JsResult<'cx, Self>
where
C: Context<'cx>,
{
<JsBuffer as TypedArray>::from_slice(cx, slice)
}
/// Constructs a new `Buffer` object with uninitialized memory
pub unsafe fn uninitialized<'a, C: Context<'a>>(cx: &mut C, len: usize) -> JsResult<'a, Self> {
let result = sys::buffer::uninitialized(cx.env().to_raw(), len);
if let Ok((buf, _)) = result {
Ok(Handle::new_internal(Self(buf)))
} else {
Err(Throw::new())
}
}
#[cfg(feature = "external-buffers")]
#[cfg_attr(docsrs, doc(cfg(feature = "external-buffers")))]
/// Construct a new `Buffer` from bytes allocated by Rust.
///
/// # Compatibility Note
///
/// Some Node environments are built using V8's _sandboxed pointers_ functionality, which
/// [disallows the use of external buffers](https://www.electronjs.org/blog/v8-memory-cage).
/// In those environments, calling the underlying
/// [runtime function](https://nodejs.org/api/n-api.html#napi_create_external_buffer)
/// used by this method results in an immediate termination of the Node VM.
///
/// As a result, this API is disabled by default. If you are confident that your code will
/// only be used in environments that disable sandboxed pointers, you can make use of this
/// method by enabling the **`external-buffers`** feature flag.
pub fn external<'a, C, T>(cx: &mut C, data: T) -> Handle<'a, Self>
where
C: Context<'a>,
T: AsMut<[u8]> + Send + 'static,
{
let env = cx.env().to_raw();
let value = unsafe { sys::buffer::new_external(env, data) };
Handle::new_internal(Self(value))
}
}
unsafe impl TransparentNoCopyWrapper for JsBuffer {
type Inner = raw::Local;
fn into_inner(self) -> Self::Inner {
self.0
}
}
impl ValueInternal for JsBuffer {
fn name() -> &'static str {
"Buffer"
}
fn is_typeof<Other: Value>(cx: &mut Cx, other: &Other) -> bool {
unsafe { sys::tag::is_buffer(cx.env().to_raw(), other.to_local()) }
}
fn to_local(&self) -> raw::Local {
self.0
}
unsafe fn from_local(_env: Env, h: raw::Local) -> Self {
Self(h)
}
}
impl Value for JsBuffer {}
impl Object for JsBuffer {}
impl private::Sealed for JsBuffer {}
impl TypedArray for JsBuffer {
type Item = u8;
fn as_slice<'cx, 'a, C>(&self, cx: &'a C) -> &'a [Self::Item]
where
C: Context<'cx>,
{
// # Safety
// Only the `Context` with the *most* narrow scope is accessible because `compute_scoped`
// and `execute_scope` take an exclusive reference to `Context`. A handle is always
// associated with a `Context` and the value will not be garbage collected while that
// `Context` is in scope. This means that the referenced data is valid *at least* as long
// as `Context`, even if the `Handle` is dropped.
unsafe { sys::buffer::as_mut_slice(cx.env().to_raw(), self.to_local()) }
}
fn as_mut_slice<'cx, 'a, C>(&mut self, cx: &'a mut C) -> &'a mut [Self::Item]
where
C: Context<'cx>,
{
// # Safety
// See `as_slice`
unsafe { sys::buffer::as_mut_slice(cx.env().to_raw(), self.to_local()) }
}
fn try_borrow<'cx, 'a, C>(&self, lock: &'a Lock<C>) -> Result<Ref<'a, Self::Item>, BorrowError>
where
C: Context<'cx>,
{
// The borrowed data must be guarded by `Ledger` before returning
Ledger::try_borrow(&lock.ledger, unsafe {
sys::buffer::as_mut_slice(lock.cx.env().to_raw(), self.to_local())
})
}
fn try_borrow_mut<'cx, 'a, C>(
&mut self,
lock: &'a Lock<C>,
) -> Result<RefMut<'a, Self::Item>, BorrowError>
where
C: Context<'cx>,
{
// The borrowed data must be guarded by `Ledger` before returning
Ledger::try_borrow_mut(&lock.ledger, unsafe {
sys::buffer::as_mut_slice(lock.cx.env().to_raw(), self.to_local())
})
}
fn size<'cx, C: Context<'cx>>(&self, cx: &mut C) -> usize {
unsafe { sys::buffer::size(cx.env().to_raw(), self.to_local()) }
}
fn from_slice<'cx, C>(cx: &mut C, slice: &[u8]) -> JsResult<'cx, Self>
where
C: Context<'cx>,
{
let mut buffer = cx.buffer(slice.len())?;
let target = buffer.as_mut_slice(cx);
target.copy_from_slice(slice);
Ok(buffer)
}
}
/// The type of JavaScript
/// [`ArrayBuffer`](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer)
/// objects.
///
/// # Example
///
/// ```
/// # use neon::prelude::*;
/// use neon::types::buffer::TypedArray;
///
/// fn make_sequence(mut cx: FunctionContext) -> JsResult<JsArrayBuffer> {
/// let len = cx.argument::<JsNumber>(0)?.value(&mut cx);
/// let mut buffer = cx.array_buffer(len as usize)?;
///
/// for (i, elem) in buffer.as_mut_slice(&mut cx).iter_mut().enumerate() {
/// *elem = i as u8;
/// }
///
/// Ok(buffer)
/// }
/// ```
#[derive(Debug)]
#[repr(transparent)]
pub struct JsArrayBuffer(raw::Local);
impl JsArrayBuffer {
/// Constructs a new `JsArrayBuffer` object, safely zero-filled.
///
/// **See also:** [`Context::array_buffer`]
pub fn new<'a, C: Context<'a>>(cx: &mut C, len: usize) -> JsResult<'a, Self> {
unsafe {
let result = sys::arraybuffer::new(cx.env().to_raw(), len);
if let Ok(buf) = result {
Ok(Handle::new_internal(Self(buf)))
} else {
Err(Throw::new())
}
}
}
/// Constructs a `JsArrayBuffer` from a slice by copying its contents.
///
/// This method is defined on `JsArrayBuffer` as a convenience and delegates to
/// [`TypedArray::from_slice`][TypedArray::from_slice].
pub fn from_slice<'cx, C>(cx: &mut C, slice: &[u8]) -> JsResult<'cx, Self>
where
C: Context<'cx>,
{
<JsArrayBuffer as TypedArray>::from_slice(cx, slice)
}
#[cfg(feature = "external-buffers")]
#[cfg_attr(docsrs, doc(cfg(feature = "external-buffers")))]
/// Construct a new `JsArrayBuffer` from bytes allocated by Rust.
///
/// # Compatibility Note
///
/// Some Node environments are built using V8's _sandboxed pointers_ functionality, which
/// [disallows the use of external buffers](https://www.electronjs.org/blog/v8-memory-cage).
/// In those environments, calling the underlying
/// [runtime function](https://nodejs.org/api/n-api.html#napi_create_external_arraybuffer)
/// used by this method results in an immediate termination of the Node VM.
///
/// As a result, this API is disabled by default. If you are confident that your code will
/// only be used in environments that disable sandboxed pointers, you can make use of this
/// method by enabling the **`external-buffers`** feature flag.
pub fn external<'a, C, T>(cx: &mut C, data: T) -> Handle<'a, Self>
where
C: Context<'a>,
T: AsMut<[u8]> + Send + 'static,
{
let env = cx.env().to_raw();
let value = unsafe { sys::arraybuffer::new_external(env, data) };
Handle::new_internal(Self(value))
}
/// Returns a region of this buffer.
///
/// See also: [`Handle<JsArrayBuffer>::region()`](Handle::region) for a more
/// ergonomic form of this method.
pub fn region<'cx, T: Binary>(
buffer: &Handle<'cx, JsArrayBuffer>,
offset: usize,
len: usize,
) -> Region<'cx, T> {
buffer.region(offset, len)
}
}
impl<'cx> Handle<'cx, JsArrayBuffer> {
/// Returns a [`Region`] representing a typed
/// region of this buffer, starting at `offset` and containing `len` elements
/// of type `T`.
///
/// The region is **not** checked for validity by this method. Regions are only
/// validated when they are converted to typed arrays.
///
/// # Example
///
/// ```
/// # use neon::prelude::*;
/// # fn f(mut cx: FunctionContext) -> JsResult<JsUndefined> {
/// let buf: Handle<JsArrayBuffer> = cx.argument(0)?;
/// let region = buf.region::<u32>(64, 8);
/// println!("offset={}, len={}, size={}", region.offset(), region.len(), region.size());
/// # Ok(cx.undefined())
/// # }
/// ```
///
/// See the [`Region`] documentation for more information.
pub fn region<T: Binary>(&self, offset: usize, len: usize) -> Region<'cx, T> {
Region {
buffer: *self,
offset,
len,
phantom: PhantomData,
}
}
}
unsafe impl TransparentNoCopyWrapper for JsArrayBuffer {
type Inner = raw::Local;
fn into_inner(self) -> Self::Inner {
self.0
}
}
impl ValueInternal for JsArrayBuffer {
fn name() -> &'static str {
"JsArrayBuffer"
}
fn is_typeof<Other: Value>(cx: &mut Cx, other: &Other) -> bool {
unsafe { sys::tag::is_arraybuffer(cx.env().to_raw(), other.to_local()) }
}
fn to_local(&self) -> raw::Local {
self.0
}
unsafe fn from_local(_env: Env, h: raw::Local) -> Self {
Self(h)
}
}
impl Value for JsArrayBuffer {}
impl Object for JsArrayBuffer {}
impl private::Sealed for JsArrayBuffer {}
impl TypedArray for JsArrayBuffer {
type Item = u8;
fn as_slice<'cx, 'a, C>(&self, cx: &'a C) -> &'a [Self::Item]
where
C: Context<'cx>,
{
unsafe { sys::arraybuffer::as_mut_slice(cx.env().to_raw(), self.to_local()) }
}
fn as_mut_slice<'cx, 'a, C>(&mut self, cx: &'a mut C) -> &'a mut [Self::Item]
where
C: Context<'cx>,
{
unsafe { sys::arraybuffer::as_mut_slice(cx.env().to_raw(), self.to_local()) }
}
fn try_borrow<'cx, 'a, C>(&self, lock: &'a Lock<C>) -> Result<Ref<'a, Self::Item>, BorrowError>
where
C: Context<'cx>,
{
// The borrowed data must be guarded by `Ledger` before returning
Ledger::try_borrow(&lock.ledger, unsafe {
sys::arraybuffer::as_mut_slice(lock.cx.env().to_raw(), self.to_local())
})
}
fn try_borrow_mut<'cx, 'a, C>(
&mut self,
lock: &'a Lock<C>,
) -> Result<RefMut<'a, Self::Item>, BorrowError>
where
C: Context<'cx>,
{
// The borrowed data must be guarded by `Ledger` before returning
Ledger::try_borrow_mut(&lock.ledger, unsafe {
sys::arraybuffer::as_mut_slice(lock.cx.env().to_raw(), self.to_local())
})
}
fn size<'cx, C: Context<'cx>>(&self, cx: &mut C) -> usize {
unsafe { sys::arraybuffer::size(cx.env().to_raw(), self.to_local()) }
}
fn from_slice<'cx, C>(cx: &mut C, slice: &[u8]) -> JsResult<'cx, Self>
where
C: Context<'cx>,
{
let len = slice.len();
let mut buffer = JsArrayBuffer::new(cx, len)?;
let target = buffer.as_mut_slice(cx);
target.copy_from_slice(slice);
Ok(buffer)
}
}
/// A marker trait for all possible element types of binary buffers.
///
/// This trait can only be implemented within the Neon library.
pub trait Binary: private::Sealed + Copy {
/// The internal Node-API enum value for this binary type.
const TYPE_TAG: TypedArrayType;
}
/// The family of JavaScript [typed array][typed-arrays] types.
///
/// ## Typed Arrays
///
/// JavaScript's [typed arrays][typed-arrays] are objects that allow efficiently reading
/// and writing raw binary data in memory. In Neon, the generic type `JsTypedArray<T>`
/// represents a JavaScript typed array with element type `T`. For example, a JavaScript
/// [`Uint32Array`][Uint32Array] represents a compact array of 32-bit unsigned integers,
/// and is represented in Neon as a `JsTypedArray<u32>`.
///
/// Neon also offers a set of convenience shorthands for concrete instances of
/// `JsTypedArray`, named after their corresponding JavaScript type. For example,
/// `JsTypedArray<u32>` can also be referred to as [`JsUint32Array`][JsUint32Array].
///
/// The following table shows the complete set of typed array types, with both their
/// JavaScript and Neon types:
///
/// | Rust Type | Convenience Type | JavaScript Type |
/// | ------------------------------ | -------------------------------------- | ---------------------------------- |
/// | `JsTypedArray<`[`u8`][u8]`>` | [`JsUint8Array`][JsUint8Array] | [`Uint8Array`][Uint8Array] |
/// | `JsTypedArray<`[`i8`][i8]`>` | [`JsInt8Array`][JsInt8Array] | [`Int8Array`][Int8Array] |
/// | `JsTypedArray<`[`u16`][u16]`>` | [`JsUint16Array`][JsUint16Array] | [`Uint16Array`][Uint16Array] |
/// | `JsTypedArray<`[`i16`][i16]`>` | [`JsInt16Array`][JsInt16Array] | [`Int16Array`][Int16Array] |
/// | `JsTypedArray<`[`u32`][u32]`>` | [`JsUint32Array`][JsUint32Array] | [`Uint32Array`][Uint32Array] |
/// | `JsTypedArray<`[`i32`][i32]`>` | [`JsInt32Array`][JsInt32Array] | [`Int32Array`][Int32Array] |
/// | `JsTypedArray<`[`u64`][u64]`>` | [`JsBigUint64Array`][JsBigUint64Array] | [`BigUint64Array`][BigUint64Array] |
/// | `JsTypedArray<`[`i64`][i64]`>` | [`JsBigInt64Array`][JsBigInt64Array] | [`BigInt64Array`][BigInt64Array] |
/// | `JsTypedArray<`[`f32`][f32]`>` | [`JsFloat32Array`][JsFloat32Array] | [`Float32Array`][Float32Array] |
/// | `JsTypedArray<`[`f64`][f64]`>` | [`JsFloat64Array`][JsFloat64Array] | [`Float64Array`][Float64Array] |
///
/// ### Example: Creating an integer array
///
/// This example creates a typed array of unsigned 32-bit integers with a user-specified
/// length:
///
/// ```
/// # use neon::prelude::*;
/// fn create_int_array(mut cx: FunctionContext) -> JsResult<JsTypedArray<u32>> {
/// let len = cx.argument::<JsNumber>(0)?.value(&mut cx) as usize;
/// JsTypedArray::new(&mut cx, len)
/// }
/// ```
///
/// ## Buffers
///
/// Typed arrays are managed with the [`ArrayBuffer`][ArrayBuffer] type, which controls
/// the storage of the underlying data buffer, and several typed views for managing access
/// to the buffer. Neon provides access to the `ArrayBuffer` class with the
/// [`JsArrayBuffer`](crate::types::JsArrayBuffer) type.
///
/// Node also provides a [`Buffer`][Buffer] type, which is built on top of `ArrayBuffer`
/// and provides additional functionality. Neon provides access to the `Buffer` class
/// with the [`JsBuffer`](crate::types::JsBuffer) type.
///
/// Many of Node's I/O APIs work with these types, and they can also be used for
/// compact in-memory data structures, which can be shared efficiently between
/// JavaScript and Rust without copying.
///
/// [u8]: std::primitive::u8
/// [i8]: std::primitive::i8
/// [u16]: std::primitive::u16
/// [i16]: std::primitive::i16
/// [u32]: std::primitive::u32
/// [i32]: std::primitive::i32
/// [u64]: std::primitive::u64
/// [i64]: std::primitive::i64
/// [f32]: std::primitive::f32
/// [f64]: std::primitive::f64
/// [JsUint8Array]: crate::types::JsUint8Array
/// [JsInt8Array]: crate::types::JsInt8Array
/// [JsUint16Array]: crate::types::JsUint16Array
/// [JsInt16Array]: crate::types::JsInt16Array
/// [JsUint32Array]: crate::types::JsUint32Array
/// [JsInt32Array]: crate::types::JsInt32Array
/// [JsBigUint64Array]: crate::types::JsBigUint64Array
/// [JsBigInt64Array]: crate::types::JsBigInt64Array
/// [JsFloat32Array]: crate::types::JsFloat32Array
/// [JsFloat64Array]: crate::types::JsFloat64Array
/// [Uint8Array]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Uint8Array
/// [Int8Array]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Int8Array
/// [Uint16Array]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Uint16Array
/// [Int16Array]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Int16Array
/// [Uint32Array]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Uint32Array
/// [Int32Array]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Int32Array
/// [BigUint64Array]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/BigUint64Array
/// [BigInt64Array]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/BigInt64Array
/// [Float32Array]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Float32Array
/// [Float64Array]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Float64Array
/// [typed-arrays]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Typed_arrays
/// [ArrayBuffer]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer
/// [Buffer]: https://nodejs.org/api/buffer.html
#[derive(Debug)]
#[repr(transparent)]
pub struct JsTypedArray<T: Binary>(JsTypedArrayInner<T>);
impl<T: Binary> private::Sealed for JsTypedArray<T> {}
unsafe impl<T: Binary> TransparentNoCopyWrapper for JsTypedArray<T> {
type Inner = JsTypedArrayInner<T>;
fn into_inner(self) -> Self::Inner {
self.0
}
}
impl<T> TypedArray for JsTypedArray<T>
where
T: Binary,
Self: Value,
{
type Item = T;
fn as_slice<'cx, 'a, C>(&self, cx: &'a C) -> &'a [Self::Item]
where
C: Context<'cx>,
{
unsafe {
let env = cx.env().to_raw();
let value = self.to_local();
let info = sys::typedarray::info(env, value);
slice_from_info(info)
}
}
fn as_mut_slice<'cx, 'a, C>(&mut self, cx: &'a mut C) -> &'a mut [Self::Item]
where
C: Context<'cx>,
{
unsafe {
let env = cx.env().to_raw();
let value = self.to_local();
let info = sys::typedarray::info(env, value);
slice_from_info_mut(info)
}
}
fn try_borrow<'cx, 'b, C>(
&self,
lock: &'b Lock<'b, C>,
) -> Result<Ref<'b, Self::Item>, BorrowError>
where
C: Context<'cx>,
{
unsafe {
let env = lock.cx.env().to_raw();
let value = self.to_local();
let info = sys::typedarray::info(env, value);
// The borrowed data must be guarded by `Ledger` before returning
Ledger::try_borrow(&lock.ledger, slice_from_info(info))
}
}
fn try_borrow_mut<'cx, 'a, C>(
&mut self,
lock: &'a Lock<'a, C>,
) -> Result<RefMut<'a, Self::Item>, BorrowError>
where
C: Context<'cx>,
{
unsafe {
let env = lock.cx.env().to_raw();
let value = self.to_local();
let info = sys::typedarray::info(env, value);
// The borrowed data must be guarded by `Ledger` before returning
Ledger::try_borrow_mut(&lock.ledger, slice_from_info_mut(info))
}
}
fn size<'cx, C: Context<'cx>>(&self, cx: &mut C) -> usize {
self.len(cx) * std::mem::size_of::<Self::Item>()
}
fn from_slice<'cx, C>(cx: &mut C, slice: &[T]) -> JsResult<'cx, Self>
where
C: Context<'cx>,
{
let _elt_size = std::mem::size_of::<T>();
let size = std::mem::size_of_val(slice);
let buffer = cx.array_buffer(size)?;
let mut array = Self::from_buffer(cx, buffer)?;
let target = array.as_mut_slice(cx);
target.copy_from_slice(slice);
Ok(array)
}
}
impl<T: Binary> JsTypedArray<T>
where
JsTypedArray<T>: Value,
{
/// Constructs an instance from a slice by copying its contents.
///
/// This method is defined on `JsTypedArray` as a convenience and delegates to
/// [`TypedArray::from_slice`][TypedArray::from_slice].
pub fn from_slice<'cx, C>(cx: &mut C, slice: &[T]) -> JsResult<'cx, Self>
where
C: Context<'cx>,
{
<JsTypedArray<T> as TypedArray>::from_slice(cx, slice)
}
}
impl<T> JsTypedArray<T>
where
T: Binary,
Self: Value,
{
/// Constructs a typed array that views `buffer`.
///
/// The resulting typed array has `(buffer.size() / size_of::<T>())` elements.
pub fn from_buffer<'cx, 'b: 'cx, C>(
cx: &mut C,
buffer: Handle<'b, JsArrayBuffer>,
) -> JsResult<'cx, Self>
where
C: Context<'cx>,
{
let size = buffer.size(cx);
let elt_size = std::mem::size_of::<T>();
let len = size / elt_size;
if (len * elt_size) != size {
return cx.throw_range_error(format!(
"byte length of typed array should be a multiple of {elt_size}"
));
}
Self::from_region(cx, &buffer.region(0, len))
}
/// Constructs a typed array for the specified buffer region.
///
/// The resulting typed array has `region.len()` elements and a size of
/// `region.size()` bytes.
///
/// Throws an exception if the region is invalid, for example if the starting
/// offset is not properly aligned, or the length goes beyond the end of the
/// buffer.
pub fn from_region<'c, 'r, C>(cx: &mut C, region: &Region<'r, T>) -> JsResult<'c, Self>
where
C: Context<'c>,
{
let &Region {
buffer,
offset,
len,
..
} = region;
let arr = unsafe {
sys::typedarray::new(
cx.env().to_raw(),
T::TYPE_TAG,
buffer.to_local(),
offset,
len,
)
.map_err(|_| Throw::new())?
};
Ok(Handle::new_internal(Self(JsTypedArrayInner {
local: arr,
buffer: buffer.to_local(),
_type: PhantomData,
})))
}
/// Returns information about the backing buffer region for this typed array.
pub fn region<'cx, C>(&self, cx: &mut C) -> Region<'cx, T>
where
C: Context<'cx>,
{
let env = cx.env();
let info = unsafe { sys::typedarray::info(env.to_raw(), self.to_local()) };
Region {
buffer: Handle::new_internal(unsafe { JsArrayBuffer::from_local(cx.env(), info.buf) }),
offset: info.offset,
len: info.length,
phantom: PhantomData,
}
}
/// Constructs a new typed array of length `len`.
///
/// The resulting typed array has a newly allocated storage buffer of
/// size `(len * size_of::<T>())` bytes.
pub fn new<'cx, C>(cx: &mut C, len: usize) -> JsResult<'cx, Self>
where
C: Context<'cx>,
{
let buffer = cx.array_buffer(len * std::mem::size_of::<T>())?;
Self::from_region(cx, &buffer.region(0, len))
}
/// Returns the [`JsArrayBuffer`](JsArrayBuffer) that owns the underlying storage buffer
/// for this typed array.
///
/// Note that the typed array might only reference a region of the buffer; use the
/// [`offset()`](JsTypedArray::offset) and
/// [`size()`](crate::types::buffer::TypedArray::size) methods to
/// determine the region.
pub fn buffer<'cx, C>(&self, cx: &mut C) -> Handle<'cx, JsArrayBuffer>
where
C: Context<'cx>,
{
Handle::new_internal(unsafe { JsArrayBuffer::from_local(cx.env(), self.0.buffer) })
}
/// Returns the offset (in bytes) of the typed array from the start of its
/// [`JsArrayBuffer`](JsArrayBuffer).
pub fn offset<'cx, C>(&self, cx: &mut C) -> usize
where
C: Context<'cx>,
{
let info = unsafe { sys::typedarray::info(cx.env().to_raw(), self.to_local()) };
info.offset
}
/// Returns the length of the typed array, i.e. the number of elements.
///
/// Note that, depending on the element size, this is not necessarily the same as
/// [`size()`](crate::types::buffer::TypedArray::size). In particular:
///
/// ```ignore
/// self.size() == self.len() * size_of::<T>()
/// ```
#[allow(clippy::len_without_is_empty)]
pub fn len<'cx, C>(&self, cx: &mut C) -> usize
where
C: Context<'cx>,
{
let info = unsafe { sys::typedarray::info(cx.env().to_raw(), self.to_local()) };
info.length
}
}
unsafe fn slice_from_info<'a, T>(info: TypedArrayInfo) -> &'a [T] {
if info.length == 0 {
&[]
} else {
slice::from_raw_parts(info.data.cast(), info.length)
}
}
unsafe fn slice_from_info_mut<'a, T>(info: TypedArrayInfo) -> &'a mut [T] {
if info.length == 0 {
&mut []
} else {
slice::from_raw_parts_mut(info.data.cast(), info.length)
}
}
macro_rules! impl_typed_array {
($typ:ident, $etyp:ty, $($pattern:pat_param)|+, $tag:ident, $alias:ident, $two:expr$(,)?) => {
impl private::Sealed for $etyp {}
impl Binary for $etyp {
const TYPE_TAG: TypedArrayType = TypedArrayType::$tag;
}
impl Value for JsTypedArray<$etyp> {}
impl Object for JsTypedArray<$etyp> {}
impl ValueInternal for JsTypedArray<$etyp> {
fn name() -> &'static str {
stringify!($typ)
}
fn is_typeof<Other: Value>(cx: &mut Cx, other: &Other) -> bool {
let env = cx.env().to_raw();
let other = other.to_local();
if unsafe { !sys::tag::is_typedarray(env, other) } {
return false;
}
let info = unsafe { sys::typedarray::info(env, other) };
matches!(info.typ, $($pattern)|+)
}
fn to_local(&self) -> raw::Local {
self.0.local
}
unsafe fn from_local(env: Env, local: raw::Local) -> Self {
// Safety: Recomputing this information ensures that the lifetime of the
// buffer handle matches the lifetime of the typed array handle.
let info = unsafe { sys::typedarray::info(env.to_raw(), local) };
Self(JsTypedArrayInner {
local,
buffer: info.buf,
_type: PhantomData,
})
}
}
doc_comment! {
concat!(
"The type of JavaScript [`",
stringify!($typ),
"`](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/",
stringify!($typ),
") objects.
# Example
```
# use neon::prelude::*;
use neon::types::buffer::TypedArray;
fn double(mut cx: FunctionContext) -> JsResult<JsUndefined> {
let mut array: Handle<",
stringify!($alias),
"> = cx.argument(0)?;
for elem in array.as_mut_slice(&mut cx).iter_mut() {
*elem *= ",
stringify!($two),
";
}
Ok(cx.undefined())
}
```",
),
pub type $alias = JsTypedArray<$etyp>;
}
};
}
impl_typed_array!(Int8Array, i8, TypedArrayType::I8, I8, JsInt8Array, 2);
impl_typed_array!(
Uint8Array,
u8,
TypedArrayType::U8 | TypedArrayType::U8Clamped,
U8,
JsUint8Array,
2,
);
impl_typed_array!(Int16Array, i16, TypedArrayType::I16, I16, JsInt16Array, 2);
impl_typed_array!(Uint16Array, u16, TypedArrayType::U16, U16, JsUint16Array, 2);
impl_typed_array!(Int32Array, i32, TypedArrayType::I32, I32, JsInt32Array, 2);
impl_typed_array!(Uint32Array, u32, TypedArrayType::U32, U32, JsUint32Array, 2);
impl_typed_array!(
Float32Array,
f32,
TypedArrayType::F32,
F32,
JsFloat32Array,
2.0,
);
impl_typed_array!(
Float64Array,
f64,
TypedArrayType::F64,
F64,
JsFloat64Array,
2.0,
);
impl_typed_array!(
BigInt64Array,
i64,
TypedArrayType::I64,
I64,
JsBigInt64Array,
2,
);
impl_typed_array!(
BigUint64Array,
u64,
TypedArrayType::U64,
U64,
JsBigUint64Array,
2,
);