Struct FooterProgress 

pub struct FooterProgress { /* private fields */ }

How far a dataset’s footer pass has got, for the loading screen to read.

Opening a directory of many files reads a footer from each before a row is shown, and on a few thousand files that is seconds of a screen that says only “Reading schema”. The count is what makes the wait legible: a number that climbs is a wait, and a number that stops is a problem.

Shared with the threads doing the reading, which is why it is atomic and why it is only ever written by them and read by the render.

Implementations

impl FooterProgress

pub fn listing(&self) -> Listing<'_>

Begin a listing. Its count starts from nothing and is shown until the guard drops.

pub fn listed(&self) -> Option<usize>

Objects listed so far while a listing is running, None when none is.

pub fn begin(&self, total: usize)

Begin a pass over total footers. Any earlier pass’s count is forgotten.

pub fn advance(&self)

One more footer read, or failed to read: both are footers no longer waited on.

pub fn done(&self)

Nothing is being waited on any more.

pub fn pass(&self, total: usize) -> Pass<'_>

A pass over total footers that says it has finished however it ends.

A panic between begin and done would otherwise leave the count on screen for as long as that counter is read — and the counter outlives the pass, since the render holds it.

pub fn reading(&self) -> Option<(usize, usize)>

(read, total) while a pass is running, None when none is.

pub fn cancel(&self)

The load was abandoned: any pass on this counter stops issuing reads. Cancelling is one-way; a new load gets a new counter.

pub fn is_cancelled(&self) -> bool

pub fn cancel_flag(&self) -> Arc<AtomicBool>

The flag itself, for read tasks that outlive the borrow.

pub fn counting() -> Self

A counter for an exact count: its passes read COUNT_AT_ONCE footers at once.

pub fn reads_at_once(&self) -> usize

Footers a pass against this counter reads at once.

pub fn set_estimate(&self, estimate: Option<RowEstimate>)

What a sample of the footers says the row count is.

pub fn estimate(&self) -> Option<RowEstimate>

Trait Implementations

impl Debug for FooterProgress

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

Formats the value using the given formatter.

impl Default for FooterProgress

fn default() -> Self

Returns the “default value” for a type.