Trait Store

Source

pub trait Store: Send + Sync {
    // Required method
    fn save(&self, json: &str) -> Result<()>;

    // Provided method
    fn lock(&self) -> Result<Option<Locked>> { ... }
}

Expand description

Where a Purse saves its Holder after every change.

The JSON holds the secret key of every note, and notes are bearer: whoever reads it can spend them. Keep it somewhere private, encrypted at rest.

Required Methods§

Source

fn save(&self, json: &str) -> Result<()>

Replaces what was saved with json. Returns only once the data would survive a crash: the purse hands out keys and transfers only after this succeeds.

Provided Methods§

Source

fn lock(&self) -> Result<Option<Locked>>

Locks the store against other processes and reads what is saved in it, for a store more than one process writes. A purse calls it before every change: it makes the change to what was read here, saves, and only then drops the lock, so it never saves over a change another process made since it last looked.

The default returns None, for a store only one purse writes: the purse’s own holder is then always current.