Struct Demand 

#[non_exhaustive]
pub struct Demand {
    pub want_bytes: usize,
    pub saturated: bool,
}

A stage’s hint about how much more input it can usefully accept right now.

This is advisory backpressure, not enforcement: a driver may call Stage::feed with more than want_bytes, or while saturated is true, and a well-behaved stage must still handle it correctly (buffering, erroring, or blocking as its own contract dictates) — Demand only lets a cooperative driver avoid doing so needlessly.

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

want_bytes: usize

How many more bytes this stage would like handed to Stage::feed before it is called again. 0 carries no meaning beyond “no particular preference”; it is not a demand for zero bytes.

saturated: bool

true if the stage is currently full and would prefer not to receive more input until it has been polled / has had time to drain.

Implementations

impl Demand

pub const fn new(want_bytes: usize) -> Self

Build a Demand requesting want_bytes more input, not saturated.

pub const fn saturated() -> Self

A Demand indicating the stage currently wants no more input.

Trait Implementations

impl Clone for Demand

fn clone(&self) -> Demand

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for Demand

impl Debug for Demand

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

Formats the value using the given formatter.

impl Default for Demand

fn default() -> Demand

Returns the “default value” for a type.

impl Eq for Demand

impl PartialEq for Demand

fn eq(&self, other: &Demand) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for Demand