Struct SplitSpec 

#[non_exhaustive]
pub struct SplitSpec {
    pub id: SplitId,
    pub descriptor: Vec<u8>,
    pub weight: u64,
}

One unit of leasable work, as the planner enumerated it.

The descriptor is carried verbatim to whichever worker gains the split, so workers never re-enumerate the input (one LIST/scan per plan, on the leader). It is opaque to the framework and to backends; keep it small — backends enforce a size cap (the NATS backend: a fixed 512 KiB per stored value). Descriptors are written once at planning and never rewritten by commits, so their size never taxes the commit path.

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.

id: SplitId

Deterministic identity, stable across replans of unchanged work.

descriptor: Vec<u8>

Source-defined payload: everything a worker needs to process the split (an object-store source: member keys with etags and sizes; a database source: an id range).

weight: u64

Relative cost hint (bytes, rows) — the balance objective.

This is load, not sort order. Under the work-stealing balancer this field only ordered claims and balance was on split count; a planner that populated it as a ranking key rather than a cost will now skew the leader’s distribution.

The leader distributes summed weight, not split count, so a planner that emits wildly uneven splits (an object-store planner gives any object at or above its packing target a split to itself) still balances correctly. A planner that leaves every weight at the default degrades to count-balancing, which is the right behaviour when splits really are uniform. 0 is treated as 1.

Implementations

impl SplitSpec

pub fn new(id: SplitId, descriptor: Vec<u8>) -> SplitSpec

A split with the default weight of 1.

pub fn with_weight(self, weight: u64) -> SplitSpec

Set the relative cost hint.

Trait Implementations

impl Clone for SplitSpec

fn clone(&self) -> SplitSpec

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for SplitSpec

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

Formats the value using the given formatter.

impl Eq for SplitSpec

impl PartialEq for SplitSpec

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for SplitSpec