Struct FileReader

pub struct FileReader { /* private fields */ }

A simple buffered and bounded file reader. The implementation is much simpler than FileSource.

FileReader treats file as a fixed depot of bytes. Attempt to read beyond the end will result in a NotEnoughBytes error.

Implementations

impl FileReader

pub async fn new(file_id: FileId) -> Result<Self, FileErr>

pub async fn seek(&mut self, to: SeqPos) -> Result<u64, FileErr>

Seek the file stream to a different position. SeqNo is regarded as byte offset. Returns the file offset after sought.

pub fn offset(&self) -> u64

pub fn file_size(&self) -> u64

pub async fn resize(&mut self) -> Result<u64, FileErr>

Trait Implementations

impl ByteSource for FileReader

fn request_bytes(&mut self, size: usize) -> Self::Future<'_>

Read N bytes from file. If there is not enough bytes, it will return NotEnoughBytes error.

If there are enough bytes in the buffer, it yields immediately.

type Future<'a> = Pin<Box<dyn Future<Output = Result<Bytes, FileErr>> + Send + 'a>>