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 opaque descriptor travels to each worker that gains the split and is written once at planning. The portable complete stored-value budget is 384 KiB, which every built-in store accepts. Under the current encoding, descriptors up to 294,720 raw bytes reserve padded-base64 expansion and the maximum spec record envelope.

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), and the balance objective.

This is load, not sort order. A planner that populates it as a ranking key rather than a cost skews 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 a large object it cannot cut into ranges a split to itself) still balances correctly. A planner that leaves every weight at the default degrades to count-balancing, which is correct when splits 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) -> Self

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

Formats the value using the given formatter.

impl Eq for SplitSpec

impl PartialEq for SplitSpec

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for SplitSpec