Struct InputBuffer 

pub struct InputBuffer<T> { /* private fields */ }

Available on crate feature embedded_runtime only.

An address-stable FIFO queue that backs a [futures::Stream] input parameter of a generated embedded function.

The queue is filled from application code via push and drained by the dataflow graph through an InputStream created with stream. The stream never terminates: while the queue is empty it returns Poll::Pending, and it is woken by the next push.

Implementations

impl<T> InputBuffer<T>

pub const fn new() -> Self

Creates an empty buffer. Does not allocate.

pub fn push(&self, item: T)

Pushes an item onto the queue and wakes the InputStream if it is waiting.

Note that the item is only queued; it is processed the next time the flow runs.

pub fn len(&self) -> usize

Returns the number of items currently queued.

pub fn is_empty(&self) -> bool

Returns true if no items are currently queued.

pub unsafe fn stream(self: Pin<&Self>) -> InputStream<T>

Creates a never-terminating [futures::Stream] that drains this buffer, for passing to a generated embedded function.

Multiple streams over one buffer are allowed (though rarely useful): items are delivered to whichever stream polls first, and only the most recent waker is woken.

Safety

The buffer must outlive the returned stream. (The buffer cannot move while the stream exists, which is guaranteed by self being pinned, and the stream cannot be sent to another thread, as it is !Send.)

Trait Implementations

impl<T> Debug for InputBuffer<T>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<T> Default for InputBuffer<T>

fn default() -> Self

Returns the “default value” for a type.