Struct ControlledStepper 

pub struct ControlledStepper<'a, D, S> { /* private fields */ }

Drive a controlled decoder with crate::SliceCursor, crate::ReadAtCursor or an async cursor, returning mandatory boundaries to the adapter.

Use this when a transcode adapter must prepare conversion, metadata and encode together while the decoder is suspended. Ordinary callers can instead use crate::PolicyDecoder to resolve each boundary automatically.

Repeated cursor calls at a suspension return the same boundary without native progress or reads. Only a matching Self::resume can continue. A native or sink failure, cancellation or unwind drops the native session, so retaining this adapter does not retain its managed buffers after failure.

Implementations

impl<'a, D: ControlledIncrementalDecode, S: DecodeRowSink> ControlledStepper<'a, D, S>

pub fn new(decoder: D, sink: &'a mut S) -> Self

Bind a decoder to its destination; construction performs no decoding.

pub fn sink(&self) -> &S

Inspect the adapter’s destination without releasing the native session.

pub fn sink_mut(&mut self) -> &mut S

Configure a destination while the native session is suspended, for example by installing the selected conversion and encoder together. This does not resume the decoder or approve an interpretation.

pub fn info(&self) -> Option<&ImageInfo>

Facts currently available from the held native session.

pub fn output_descriptor(&self) -> Option<PixelDescriptor>

Proposed output layout and interpretation, if known.

pub fn resume( &mut self, boundary: BoundaryId, action: BoundaryAction, pulse: Option<&dyn Pulse>, ) -> Result<(), StepError<D::Error>>

Apply a decision to the exact held boundary. This resumes the protocol; the cursor’s next call performs subsequent native work. None adds no per-call control and preserves native retained controls.

Trait Implementations

impl<D: ControlledIncrementalDecode, S: DecodeRowSink> ByteStepper for ControlledStepper<'_, D, S>

type Output = ControlledEvent

What a productive step yields: an image decode event, a demuxed packet.

type Error = StepError<<D as IncrementalDecode>::Error>

The stage’s error.

fn step( &mut self, input: Input<'_>, pulse: Option<&dyn Pulse>, ) -> Result<Stepped<Self::Output>, Self::Error>

Take a prefix of input and report what happened. None adds no per-call control; any control retained by the stage remains active.

fn requested(&self) -> &[InputRequest]

What the stage needs next, after a Step::Need. Never empty then.