Struct AtomicWriter 

pub struct AtomicWriter { /* private fields */ }

Atomic-write fixture: open a temp file, hand the caller a writer, then either fsync + rename it onto dest or unlink it on error.

The pattern in commit:

1. Caller writes payload via Self::write_all.
2. Caller invokes Self::commit.
3. We flush + sync_all + close, then rename(2) onto the destination.
4. On error in step 3, the UnlinkOnDrop guard removes the temp file.

The cross-FS pre-flight check runs in Self::open; subsequent commit cannot fail with EXDEV because we’ve already validated.

Implementations

impl AtomicWriter

pub fn open(dest: &Path) -> Result<Self, SnapshotError>

Open the temp file for writing.

Pre-flight: validate that the temp dir and destination dir live on the same filesystem (cross-FS rename cannot be atomic).

Errors

SnapshotError::AtomicCommitCrossFs for the cross-FS case; SnapshotError::Io for an open / mkdir / stat failure.

pub fn temp_path(&self) -> &Path

The temp-file path (visible during writing, before commit).

pub fn dest_path(&self) -> &Path

The destination path the commit will produce.

pub fn file_mut(&mut self) -> &mut File

Borrow the underlying file for direct writes (used by the streaming envelope

• memory file paths).

pub fn commit(self) -> Result<(), SnapshotError>

fsync the temp file, drop the writer, and rename(2) it onto the destination.

Errors

SnapshotError::AtomicCommitFailed for the rename failure (temp file is unlinked); SnapshotError::Io for an fsync failure (temp file is also unlinked).

Trait Implementations

impl Debug for AtomicWriter

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

Formats the value using the given formatter.

impl Write for AtomicWriter

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

Writes a buffer into this writer, returning how many bytes were written.

fn flush(&mut self) -> Result<()>

Flushes this output stream, ensuring that all intermediately buffered contents reach their destination.

fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> Result<usize, Error>

Like write, except that it writes from a slice of buffers.

fn is_write_vectored(&self) -> bool

🔬This is a nightly-only experimental API. (can_vector)

Determines if this Writer has an efficient write_vectored implementation.

fn write_all(&mut self, buf: &[u8]) -> Result<(), Error>

Attempts to write an entire buffer into this writer.

fn write_all_vectored(&mut self, bufs: &mut [IoSlice<'_>]) -> Result<(), Error>

🔬This is a nightly-only experimental API. (write_all_vectored)

Attempts to write multiple buffers into this writer.

fn write_fmt(&mut self, args: Arguments<'_>) -> Result<(), Error>

Writes a formatted string into this writer, returning any error encountered.

fn by_ref(&mut self) -> &mut Self

where Self: Sized,

Creates a “by reference” adapter for this instance of Write.