Struct FileStore 

pub struct FileStore { /* private fields */ }

A file-backed WalStore: the default storage for Wal::open.

All reads and writes are positioned (pread/pwrite on Unix, seek_read/ seek_write on Windows), so concurrent appenders writing to disjoint offsets never contend on a shared file cursor, and a recovery read never disturbs an append. sync issues the platform’s true durability barrier: fdatasync on Linux, FlushFileBuffers on Windows, and fcntl(F_FULLFSYNC) on macOS — the last because macOS’s fsync does not flush the drive’s write cache.

Implementations

impl FileStore

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

Open the file at path, creating it if it does not exist.

The store does not interpret the file’s contents — it does not look for a torn tail or validate records. That is Wal::open’s job, which scans on open and truncates any incomplete trailing record.

Errors

Returns WalError::Io if the file cannot be opened (for example a missing parent directory or insufficient permissions).

pub fn path(&self) -> &Path

The path this store was opened from.

Trait Implementations

impl Debug for FileStore

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

Formats the value using the given formatter.

impl WalStore for FileStore

fn write_at(&self, offset: u64, bytes: &[u8]) -> Result<()>

Write bytes at byte offset, growing the store and zero-filling any gap if offset is beyond the current end.

fn read_at(&self, offset: u64, buf: &mut [u8]) -> Result<usize>

Read into buf starting at byte offset, returning the number of bytes read.

fn truncate(&self, len: u64) -> Result<()>

Discard every byte at or after len, shrinking the store to exactly len bytes.

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

Flush every preceding write_at to stable storage.

fn len(&self) -> Result<u64>

The current size of the store in bytes.

fn is_empty(&self) -> Result<bool>

Whether the store holds no bytes.

fn head(&self) -> Result<u64>

The lowest offset that still holds data.

fn truncate_before(&self, _offset: u64) -> Result<u64>

Discard storage entirely below offset, if the backend can, returning the new head.