Enum PagedColumn 

pub enum PagedColumn<C: Columnar> {
    Resident(Column<C>, ResidentTicket),
    Paged {
        handle: Handle,
        meta: Meta,
    },
    Compressed {
        inner: CompressedInner,
        meta: Meta,
    },
}

A column whose body may be resident, paged out, or paged out and compressed.

Each variant corresponds to one of the PageDecision outcomes.

All variants are Send. The Resident variant’s drop credit goes back to the policy via PageEvent::ResidentReleased; concrete policies that ship with this crate (notably policy::TieredPolicy) credit a single process-wide atomic pool, so dropping a Resident on a different thread than the one that called ColumnPager::page is safe. Custom policies that introduce thread-local accounting must take care to either pin the column to its origin thread (e.g. via a SendColumn wrapper) or carry the origin in PageEvent::ResidentReleased so credit can be routed correctly.

Variants

Resident(Column<C>, ResidentTicket)

Body kept resident. Returned when the policy answered PageDecision::Skip. The accompanying ResidentTicket fires a PageEvent::ResidentReleased when the variant is dropped or consumed by ColumnPager::take, so the policy can reclaim the budget it granted in PagingPolicy::decide.

Paged

Raw ContainerBytes payload stored via pager::Handle. The backend (Swap or File) is baked into the handle.

Fields

handle: Handle

Pager handle owning the raw payload.

meta: Meta

Sizing metadata.

Compressed

Lz4-framed serialized form. The framed bytes themselves may live in memory or in the pager (see CompressedInner).

Fields

inner: CompressedInner

Where the framed bytes live.

meta: Meta

Sizing metadata.