Struct Scheduler 

pub struct Scheduler { /* private fields */ }

Implementations

impl Scheduler

pub fn from_ranges(ranges: &[RangeRecord]) -> Self

Build from persisted ranges. Completed ranges stay completed; anything else becomes pending from its durable prefix — including ranges left in downloading by a process that died (PRD §12 step 4).

pub fn acquire(&self) -> Option<(Lease, Option<Split>)>

Claim work: a pending range if one exists, otherwise steal the tail of the slowest active range. None means “nothing to do right now”.

pub fn complete(&self, idx: u64)

Mark a lease finished. Idempotent.

pub fn release(&self, idx: u64)

Release a lease without completing it. The range keeps its durable prefix and goes back in the queue, so one worker’s failure costs only that range (PRD Invariant 6).

pub fn fail(&self, idx: u64)

Give up on a range permanently. The download as a whole fails, but we keep every other range’s progress.

pub fn set_end(&self, idx: u64, end: u64)

When a range’s real length turns out to differ from the plan — an open-ended sequential transfer that just ended — record the true end.

pub fn is_finished(&self) -> bool

pub fn has_failure(&self) -> bool

pub fn is_drained(&self) -> bool

True when no work is available and none will become available — every range is either complete or failed.

pub async fn wait_for_change(&self, timeout: Duration)

pub fn notify(&self)

pub fn snapshot(&self) -> Vec<RangeRecord>

Current view of every range, for the committer and for progress.

pub fn counts(&self) -> (usize, usize)

pub fn written_bytes(&self) -> u64

Sum of every range’s written prefix — the engine’s view of “downloaded”.