Struct SequentialFileReader 

pub struct SequentialFileReader<'a> { /* private fields */ }

Reader for non-seekable files.

Implements read-ahead using io_uring.

Implementations

impl<'a> SequentialFileReader<'a>

pub fn set_path(&mut self, path: impl AsRef<Path>) -> Result<()>

Open file under path, check its metadata to determine read limit and add it to the reader.

See add_owned_file_to_prefetch for more details.

pub fn add_owned_file_to_prefetch( &mut self, file: File, read_limit: FileSize, ) -> Result<()>

Add file to read. Starts reading the file as soon as a buffer is available.

This function uses the direct io settings set in SequentialFileReaderBuilder.

A direct io mode reader is safe to use with non direct io files. However, passing direct io mode files to the reader in non direct io mode might result in an io error due to unaligned read.

It is up to the end user to ensure that they are passing files that conform to the direct io settings of this SequentialFileReader.

The read finishes when EOF is reached or read_limit bytes are read. The read_limit must be less than or equal to the file size when in direct io mode. Multiple files can be added to the reader and they will be read-ahead in FIFO order.

Reader takes ownership of the file and will drop it after it’s done reading and move_to_next_file is called.

pub fn rebind<'b>(self) -> Result<SequentialFileReader<'b>>

Reset to idle state and re-type with a fresh lifetime 'b.

Drains the prefetch queue (cancels in-flight reads) before returning.

Trait Implementations

impl<'a> BufRead for SequentialFileReader<'a>

fn fill_buf(&mut self) -> Result<&[u8]>

Returns the contents of the internal buffer, filling it with more data, via Read methods, if empty.

fn consume(&mut self, amt: usize)

Marks the given amount of additional bytes from the internal buffer as having been read. Subsequent calls to read only return bytes that have not been marked as read.

fn has_data_left(&mut self) -> Result<bool, Error>

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

Checks if there is any data left to be read.

fn read_until(&mut self, byte: u8, buf: &mut Vec<u8>) -> Result<usize, Error>

Reads all bytes into buf until the delimiter byte or EOF is reached.

fn skip_until(&mut self, byte: u8) -> Result<usize, Error>

Skips all bytes until the delimiter byte or EOF is reached.

fn read_line(&mut self, buf: &mut String) -> Result<usize, Error>

Reads all bytes until a newline (the 0xA byte) is reached, and append them to the provided String buffer.

fn split(self, byte: u8) -> Split<Self>

where Self: Sized,

Returns an iterator over the contents of this reader split on the byte byte.

fn lines(self) -> Lines<Self>

where Self: Sized,

Returns an iterator over the lines of this reader.

impl<'a> FileBufRead<'a> for SequentialFileReader<'a>

fn set_file(&mut self, file: &'a File, read_limit: FileSize) -> Result<()>

The SequentialFileReader must be in direct io mode if passing in direct io files. read_limit must be less than the file size if using direct io. See add_owned_file_to_prefetch for more details.

fn add_file_to_prefetch( &mut self, file: &'a File, read_limit: FileSize, ) -> Result<()>

Queue file for read-ahead (prefetch). Files are processed in FIFO order by subsequent set_file calls.

fn get_file_offset(&self) -> FileSize

Returns the current file offset corresponding to the start of the buffer that will be returned by the next call to fill_buf.

fn consume_or_skip(&mut self, amt: usize)

Advance the offset by amt bytes, potentially skipping past the current buffer into the underlying file.

impl<'a> Read for SequentialFileReader<'a>

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

Pull some bytes from this source into the specified buffer, returning how many bytes were read.

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

Reads the exact number of bytes required to fill buf.

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

Like read, except that it reads into a slice of buffers.

fn is_read_vectored(&self) -> bool

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

Determines if this Reader has an efficient read_vectored implementation.

fn read_to_end(&mut self, buf: &mut Vec<u8>) -> Result<usize, Error>

Reads all bytes until EOF in this source, placing them into buf.

fn read_to_string(&mut self, buf: &mut String) -> Result<usize, Error>

Reads all bytes until EOF in this source, appending them to buf.

fn read_buf(&mut self, buf: BorrowedCursor<'_, u8>) -> Result<(), Error>

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

Pull some bytes from this source into the specified buffer.

fn read_buf_exact( &mut self, cursor: BorrowedCursor<'_, u8>, ) -> Result<(), Error>

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

Reads the exact number of bytes required to fill cursor.

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

where Self: Sized,

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

fn bytes(self) -> Bytes<Self>

where Self: Sized,

Transforms this Read instance to an Iterator over its bytes.

fn chain<R>(self, next: R) -> Chain<Self, R>

where R: Read, Self: Sized,

Creates an adapter which will chain this stream with another.

fn take(self, limit: u64) -> Take<Self>

where Self: Sized,

Creates an adapter which will read at most limit bytes from it.

fn read_array<const N: usize>(&mut self) -> Result<[u8; N], Error>

where Self: Sized,

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

Read and return a fixed array of bytes from this source.

fn read_le<T>(&mut self) -> Result<T, Error>

where T: FromEndianBytes, Self: Sized,

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

Read and return a type (e.g. an integer) in little-endian order.

fn read_be<T>(&mut self) -> Result<T, Error>

where T: FromEndianBytes, Self: Sized,

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

Read and return a type (e.g. an integer) in big-endian order.