Struct DirStore 

pub struct DirStore { /* private fields */ }

A Store in the directory it was opened on, whose folders are made as files are written. Each change locks the directory’s lock file, so stores open on one directory, in this process or another, take turns; reads take no lock. Cloning opens the same directory.

Implementations

impl DirStore

pub fn open(dir: impl Into<PathBuf>) -> Result<Self, SessionError>

The session in dir, which need not exist yet. Nothing is written.

Errors

SessionError::OldLayout when dir holds a top-level *.jsonl file, as a session saved by an older rig does; it is left as it is. SessionError::Io when dir cannot be listed.

Trait Implementations

impl Clone for DirStore

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Files for DirStore

fn write_file(&self, name: &str, bytes: &[u8]) -> Result<()>

Replaces the file name with bytes, atomically: a reader sees the old content or the new.

fn append_file(&self, name: &str, bytes: &[u8]) -> Result<()>

Adds bytes at the end of the file name, which it creates when there is none.

fn read_file(&self, name: &str) -> Result<Vec<u8>>

The file name; io::ErrorKind::NotFound when there is none.

fn remove_file(&self, name: &str) -> Result<()>

Removes the file name; removing one that is not there succeeds.

fn files(&self) -> Result<Vec<String>>

The names of the files, in no particular order.

impl Store for DirStore

fn replace_log( &self, name: &str, len: u64, bytes: &[u8], ) -> Result<(), LogWriteError>

The new log is written beside, synced and renamed over the old one: the one synced write, as it is rare and replaces history.

fn destroy(&self) -> Result<()>

Each folder is renamed to a trash name inside the directory, so it is gone at once, then removed; a second call removes what a crash left of the first. The lock file stays.

fn logs(&self) -> Result<Vec<String>>

The names of the logs, in no particular order.

fn read_log(&self, name: &str) -> Result<Vec<u8>>

The whole log name; io::ErrorKind::NotFound when there is none.

fn append_log( &self, name: &str, len: u64, bytes: &[u8], ) -> Result<(), LogWriteError>

Appends bytes to the log name if it is len bytes long now (0 when there is none, which it then starts); else LogWriteError::Changed, writing nothing. The check and the append are one step for every writer of the store, other processes included, so of two writers that read the log at the same length one appends and the other is refused. A log that shrank and grew back to exactly len bytes since it was read is not told apart; rig shrinks a log only by setting a torn last line aside, or by rewrite and Self::destroy, which are for a stopped session.