Enum Home 

enum Home {
    Arena(ArenaSlot),
    Heap {
        ptr: *mut u8,
        layout: Layout,
    },
    Demoting {
        arena: ArenaSlot,
        file_slot: FileSlot,
    },
    File {
        store: Arc<FileStore>,
        slot: FileSlot,
    },
}

Available on Unix and crate feature pool only.

Where an extent’s bytes live.

Variants

Arena(ArenaSlot)

A slot in the pool’s extent arena.

Heap

Global-allocator fallback for an exhausted class. Never paged out: MADV_PAGEOUT over allocator-owned pages leaves swap-entry PTEs on freed ranges for the allocator to recycle into unrelated allocations, which is the failure the arena exists to avoid.

Fields

ptr: *mut u8

layout: Layout

Demoting

File mode, transient: the arena slot still holds the bytes, which are immutable and readable while a demoter writes them to file_slot without the chunk lock. The demoter owns the extent and the transition out of this home: a free of the chunk leaves the extent in place for the demoter’s commit to drop, which also keeps the file slot from being reused mid-write.

Fields

arena: ArenaSlot

file_slot: FileSlot

File

File mode: the bytes live only in slot of store. Terminal until the extent is dropped, so a reader that keeps the extent alive (by borrowing its chunk’s handle) may use the location without the chunk lock.

Fields

store: Arc<FileStore>

slot: FileSlot

Implementations

impl Home

fn ptr(&self) -> Option<*mut u8>

The in-memory copy of the stored bytes, None for a file home.

Trait Implementations

impl Debug for Home

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

Formats the value using the given formatter.