Struct neon::types::buffer::Region

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pub struct Region<'cx, T: Binary> { /* private fields */ }

Expand description

Represents a typed region of an ArrayBuffer.

A Region can be created via the Handle<JsArrayBuffer>::region() or JsTypedArray::region() methods.

A region is not checked for validity until it is converted to a typed array via to_typed_array() or JsTypedArray::from_region().

Example

// Allocate a 16-byte ArrayBuffer and a uint32 array of length 2 (i.e., 8 bytes)
// starting at byte offset 4 of the buffer:
//
//       0       4       8       12      16
//      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// buf: | | | | | | | | | | | | | | | | |
//      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
//               ^       ^
//               |       |
//              +-------+-------+
//         arr: |       |       |
//              +-------+-------+
//               0       1       2
let buf = cx.array_buffer(16)?;
let arr = JsUint32Array::from_region(&mut cx, &buf.region(4, 2))?;

Implementations

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impl<'cx, T: Binary> Region<'cx, T>

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pub fn buffer(&self) -> Handle<'cx, JsArrayBuffer>

Returns the handle to the region’s buffer.

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pub fn offset(&self) -> usize

Returns the starting byte offset of the region.

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pub fn len(&self) -> usize

Returns the number of elements of type T in the region.

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pub fn size(&self) -> usize

Returns the size of the region in bytes, which is equal to (self.len() * size_of::<T>()).

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pub fn to_typed_array<'c, C>(&self, cx: &mut C) -> JsResult<'c, JsTypedArray<T>>where
C: Context<'c>,

Constructs a typed array for this buffer region.

The resulting typed array has self.len() elements and a size of self.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.