Struct AtomicFile 

pub struct AtomicFile { /* private fields */ }

One named file capability. It reads, creates, replaces and removes bytes without exposing a path. Replacement atomically installs a complete version.

Implementations

impl AtomicFile

pub fn read_optional(&self) -> Result<Option<Vec<u8>>, FileError>

Read the complete file. Only a missing file is None; other errors retain their operating-system cause.

pub fn open_reader(&self) -> Result<FileReader, ObservationError>

Open this owned file for checked scans and positioned reads.

pub fn replace(&self, bytes: &[u8]) -> Result<(), FileError>

Write and sync a temporary sibling, replace the target, then sync its directory. The parent must already exist. Concurrent writers each install one complete version; a failed pre-rename write leaves it alone.

Windows uses POSIX replacement on a write-through file handle, which flushes the rename’s metadata on NTFS. This requires FileRenameInfoEx and a filesystem supporting POSIX replacement. Windows 10 before 1607 lacks that API; unsupported systems return the OS error without falling back to a rename that can fail while readers hold old versions open.

pub fn write_recorded(&self, bytes: &[u8]) -> Result<(), FileError>

Write and sync complete bytes at this name, then flush its directory and the drive’s cache, as a batch of this one file, with no temporary sibling. The caller records the name as its own first, so bytes a crash interrupts stay recorded for removal. Anything but a regular file there is refused before a byte is written.

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

Write bytes over this existing file’s bytes from offset, which they must lie within, and hand them to the drive. Readers can see some of the old bytes and some of the new while it writes, and a crash can leave them so: only bytes that check themselves, as a cache’s authenticated chunks do, are written this way.

pub fn set_len(&self, length: u64) -> Result<(), ObservationError>

Give this existing file length bytes, cutting it short or adding zeros at its end, and hand the change to the drive.

pub fn remove(&self) -> Result<(), FileError>

Remove the owned file; an absent file is success. On Unix, sync the directory even on a retry after an earlier directory-sync failure. A missing parent is already absent and needs no durability barrier.

pub fn remove_with_temporaries(&self) -> Result<(), FileError>

Remove the owned file and every temporary sibling a write of it left, as a crash or a failed removal does: each holds a whole version of its bytes. The caller holds what guards this file’s writes, so none of them is a write in flight.

pub fn leave_temporary(&self, bytes: &[u8]) -> PathBuf

Leave a temporary sibling holding bytes, as a crash between writing it and renaming it does, and say where.

Trait Implementations

impl Clone for AtomicFile

fn clone(&self) -> AtomicFile

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for AtomicFile

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

Formats the value using the given formatter.