Struct File 

pub struct File { /* private fields */ }

An open file. All I/O is positioned (pread/pwrite); there is no shared cursor, so an Arc<File> is safe to use from many tasks at once.

Implementations

impl File

pub async fn read_at(&self, offset: u64, len: u32) -> Result<Bytes, ZeroFsError>

Read up to len bytes at offset; a shorter result means EOF. Returns bytes::Bytes: a read served by one round trip comes back with no copy.

pub async fn write_at( &self, offset: u64, data: &[u8], ) -> Result<(), ZeroFsError>

Write all of data at offset (any size, chunked internally); errors on a short write.

pub async fn metadata(&self) -> Result<Metadata, ZeroFsError>

Current metadata of this open file (fstat).

pub async fn set_len(&self, size: u64) -> Result<(), ZeroFsError>

Truncate or extend to size bytes.

pub async fn set_attr(&self, attrs: SetAttrs) -> Result<Metadata, ZeroFsError>

Apply metadata changes through this handle.

pub async fn sync_all(&self) -> Result<(), ZeroFsError>

Flush data and metadata to durable (S3-backed) storage.

pub async fn sync_data(&self) -> Result<(), ZeroFsError>

Flush file data only.

pub async fn close(&self)

Mark the handle closed (later calls return Closed). The fid is clunked and its number recycled when the handle is dropped (for scope-bound use, right after this call). Always succeeds; idempotent; never blocks.

pub fn cursor(self: &Arc<File>) -> FileCursor

An independent AsyncRead + AsyncWrite + AsyncSeek cursor over this file, starting at offset 0. Multiple cursors over one File are safe: each carries its own position and the underlying I/O is positioned. Rust-only sugar (tokio-io feature); never crosses FFI.

Trait Implementations

impl Debug for File

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

Formats the value using the given formatter.