Struct FileBackend 

pub struct FileBackend { /* private fields */ }

A byte source backed by a file. Reads run as positioned reads on a blocking thread pool so the async runtime is never stalled by disk I/O; the length is captured once at open (the file is treated as immutable while the backend lives).

Implementations

impl FileBackend

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

Opens path and records its current length.

Trait Implementations

impl Backend for FileBackend

fn len(&self) -> BoxFuture<'_, Result<u64>>

Total length of the underlying byte source.

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

Reads up to buf.len() bytes at offset into buf, returning the number of bytes read. Implementations may only return a short count at end of input; anywhere else they must fill the buffer.