Struct FenceState 

pub struct FenceState {
    pub epoch: u64,
    pub pointer_generation: u64,
}

What the sink’s fence currently stands at — the two comparands tail_frames checks a writer against, and nothing else.

R869: this is the off-fleet copy of a fencing token. It matters because epoch is minted by a raft group, and a raft group can be destroyed — wipe the raft dir, re-form, and the fresh cluster’s first ClaimTenant grants epoch 1 while this sidecar still says 5, so the rebuilt cluster is fenced out of its own sink. Reading the fence back is how a rebuild starts above the number its dead predecessor left here.

Fields

epoch: u64

The fencing epoch of the writer that last advanced the sidecar. 0 means “unfenced” — either nothing has claimed this sink or it predates R732-F2 — and fences nobody.

pointer_generation: u64

The pointer generation of that same writer. 0 means unfenced, exactly as for epoch.

Trait Implementations

impl Clone for FenceState

fn clone(&self) -> FenceState

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for FenceState

impl Debug for FenceState

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

Formats the value using the given formatter.

impl Default for FenceState

fn default() -> FenceState

Returns the “default value” for a type.

impl Eq for FenceState

impl PartialEq for FenceState

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for FenceState