Struct MemoryLedger 

pub struct MemoryLedger { /* private fields */ }

Shared, cloneable handle to the per-principal peak-memory ledger.

Cloning is an Arc bump; every clone observes the same map, so the kernel hands one clone to each WasmEngine and they all record into the same per-principal high-water marks.

Implementations

impl MemoryLedger

pub fn record_peak(&self, principal: &PrincipalId, bytes: u64)

Raise principal’s recorded peak to bytes if it exceeds the current high-water mark (else no-op).

Lock-free in steady state: once a principal has an entry the common path takes a shard read guard and a Relaxed compare-exchange max. Only the first observation of a never-seen principal takes a shard write guard. Relaxed is correct — a monotonic high-water mark with no ordering dependency on other memory.

pub fn peak(&self, principal: &PrincipalId) -> u64

Read principal’s peak linear-memory high-water mark in bytes, or 0 if it has never grown a Store. A snapshot via a shard read guard + a single Relaxed load, the same ordering the record path uses.

Trait Implementations

impl Clone for MemoryLedger

fn clone(&self) -> MemoryLedger

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Default for MemoryLedger

fn default() -> MemoryLedger

Returns the “default value” for a type.