Struct ReadingStream

pub struct ReadingStream { /* private fields */ }

A stream of sensor readings from a device.

The stream polls the device at a configured interval and sends readings through a channel. It supports graceful shutdown via close.

Implementations

impl ReadingStream

pub fn new(device: Arc<Device>, options: StreamOptions) -> Self

Create a new reading stream from a connected device (takes Arc).

This spawns a background task that polls the device at the configured interval and sends readings to the stream.

If max_consecutive_failures is set, the stream will automatically close after that many consecutive read failures.

pub fn close(self)

Close the stream and stop the background polling task gracefully.

This signals the background task to stop via a cancellation token, allowing it to complete any in-progress operations before exiting. This is preferred over aborting the task, which may leave resources in an inconsistent state.

pub fn cancellation_token(&self) -> CancellationToken

Get a cancellation token that can be used to cancel the stream externally.

This allows multiple places to trigger cancellation of the stream.

pub fn is_active(&self) -> bool

Check if the stream is still active (background task running).

pub fn is_cancelled(&self) -> bool

Check if the stream has been cancelled.

pub fn has_unexpectedly_stopped(&self) -> bool

Check if the stream stopped unexpectedly.

Returns true if the background task has finished but was not explicitly cancelled via close() or by dropping the stream.

This can indicate:

• A panic in the background task
• The stream auto-closed due to reaching max_consecutive_failures
• The receiver was dropped unexpectedly

This can be useful for detecting and handling unexpected stream termination:

if stream.has_unexpectedly_stopped() {
    // Log the event and potentially restart the stream
    log::warn!("Stream stopped unexpectedly - may need restart");
}

Note: To distinguish between auto-close due to failures vs actual panics, you may need additional monitoring of the stream’s error output.

pub fn has_panicked(&self) -> bool

👎Deprecated since 0.2.0: Use has_unexpectedly_stopped() instead for clearer semantics

Check if the background task has panicked.

Deprecated: Use has_unexpectedly_stopped() instead, which has clearer semantics. This method may return true even when the stream stopped due to max_consecutive_failures being reached, not just panics.

Trait Implementations

impl Drop for ReadingStream

fn drop(&mut self)

Executes the destructor for this type.

impl Stream for ReadingStream

type Item = Result<CurrentReading, Error>

Values yielded by the stream.

fn poll_next( self: Pin<&mut Self>, cx: &mut Context<'_>, ) -> Poll<Option<Self::Item>>

Attempt to pull out the next value of this stream, registering the current task for wakeup if the value is not yet available, and returning None if the stream is exhausted.

fn size_hint(&self) -> (usize, Option<usize>)

Returns the bounds on the remaining length of the stream.