Struct PersistentProducerNonce 

pub struct PersistentProducerNonce { /* private fields */ }

Persistent u64 nonce loaded from (or created at) a stable path.

Callers construct via Self::load_or_create and read the value via Self::nonce. The struct itself is cheap to clone — the nonce is a u64 and the path is a PathBuf retained for debugging / logging.

Implementations

impl PersistentProducerNonce

pub fn load_or_create(path: impl AsRef<Path>) -> Result<Self>

Load (or create) the persistent nonce at path.

On first call: samples a fresh u64 from getrandom, writes it to path atomically (write to <path>.tmp, fsync, rename to path), and returns the value.

On subsequent calls (post-restart, same path): reads the existing 8-byte file and returns its little-endian u64.

Errors:

• io::ErrorKind::NotFound if the parent directory doesn’t exist. We don’t auto-create the parent — that’s a configuration decision the caller should make explicitly.
• io::ErrorKind::InvalidData if the file exists but has length other than 8 bytes (corrupt or someone else’s file at this path).
• Other io::Error from filesystem operations.

pub fn nonce(&self) -> u64

The loaded (or freshly created) nonce.

Trait Implementations

impl Clone for PersistentProducerNonce

fn clone(&self) -> PersistentProducerNonce

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for PersistentProducerNonce

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

Formats the value using the given formatter.