Struct ProgressRead 

pub struct ProgressRead<R> { /* private fields */ }

An AsyncRead wrapper that tracks bytes read via a watch channel.

The reader itself is intentionally minimal: it only increments a counter and publishes it through a non-blocking tokio::sync::watch channel on each successful read. This keeps the hot I/O path free from any reporter logic.

Backpressure is handled by the watch channel itself: if the progress renderer is slow, intermediate byte counts are coalesced — the sender never blocks waiting for the receiver to catch up.

Use ProgressRead::new to construct the reader and its companion driver future. The driver must run concurrently with the read (e.g. via tokio::join!) to actually emit ProgressEvent::Progress events.

Place this wrapper before any decompressor so that the fetched counter reflects compressed bytes-over-the-wire, matching the total from the preceding ProgressEvent::Started event.

Implementations

impl<R> ProgressRead<R>

pub fn new( inner: R, reporter: Arc<dyn ProgressReporter>, id: ComponentId, total: Option<u64>, ) -> (ProgressRead<R>, impl Future<Output = ()>)

Wrap inner and return (reader, driver).

The driver is a future that translates raw byte counts into ProgressEvent::Progress events via reporter. It completes when the reader is dropped (i.e. the channel closes). Run it concurrently:

let (reader, driver) = ProgressRead::new(blob, reporter, id, total);
let decompressor = decompress_async(reader, media_type)?;
let (import_result, ()) = tokio::join!(import_tar_async(repo, decompressor), driver);

total should match the value passed to the preceding Started event so the renderer can compute a meaningful percentage.

Trait Implementations

impl<R> AsyncRead for ProgressRead<R>

where R: AsyncRead + Unpin,

fn poll_read( self: Pin<&mut ProgressRead<R>>, cx: &mut Context<'_>, buf: &mut ReadBuf<'_>, ) -> Poll<Result<(), Error>>

Attempts to read from the AsyncRead into buf.

impl<R> Debug for ProgressRead<R>

where R: Debug,

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

Formats the value using the given formatter.