Struct FenceToken 

pub struct FenceToken {
    pub epoch: u64,
    pub revision: u64,
}

Opaque local-replica fencing token.

Combines a per-replica epoch (regenerated when the handle is rebuilt — i.e. on daemon restart) with the local revision (the TaskList version counter, which advances on every effective local snapshot change, including remote merges). The token is opaque over the wire: clients must echo it verbatim and MUST NOT interpret or construct it.

ABA safety: because the epoch changes across restart, a token captured before a restart can never match a post-restart token even if the revision counter later reaches the same value. This closes the restart-ABA window without persisting task state.

This is a LOCAL fence only (per-replica): two replicas at the same (epoch, revision) can both accept. It is not a distributed CAS.

Fields

epoch: u64

Per-replica epoch; regenerated on restart.

revision: u64

Local revision = TaskList version counter.

Implementations

impl FenceToken

pub fn to_wire(&self) -> String

Opaque wire encoding: "epoch:revision". Clients echo this verbatim.

pub fn from_wire(s: &str) -> Result<Self, &'static str>

Parse an opaque wire token.

Returns Ok(token) for a well-formed "epoch:revision" string, or Err(&'static str) if the token is malformed (missing colon, non-numeric, or integer overflow). Callers MUST distinguish absent (fence_token: None → unconditional advisory commit) from present but malformed (Err → reject with 400/409 without mutation). Collapsing the two into None would let a corrupt/legacy/attacker token silently downgrade a fenced request to an unfenced one.

Errors

Returns Err if the string is not exactly two colon-separated u64 fields.

Trait Implementations

impl Clone for FenceToken

fn clone(&self) -> FenceToken

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for FenceToken

impl Debug for FenceToken

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

Formats the value using the given formatter.

impl Eq for FenceToken

impl PartialEq for FenceToken

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for FenceToken