Struct SkippingBufReader

pub struct SkippingBufReader<F: Read + Seek> { /* private fields */ }

A buffering reader that transparently skips inaccessible parts of a file.

It functions similarly to io::BufReader in that it fills an internal buffer using larger, infrequent reads but is further capable of handling intermittent permission errors by repeatedly halving the buffer size and attempting another read. Eventually, it will fall back to skipping byte by byte towards the next readable section.

This will occur for many regions in /dev/mem with a brute-force search. Skipping long inaccessible sections is very slow, so that should only be a last resort when no memory map is available.

Implementations

impl<F: Read + Seek> SkippingBufReader<F>

pub fn new(file: F, start_offset: usize, max_offset: Option<usize>) -> Self

pub fn with_buffer_size( buffer_size: usize, file: F, start_offset: usize, max_offset: Option<usize>, ) -> Self

Create a reader with an internal buffer of the given initial size.

Panics

This function panics if it cannot seek to the given start_offset within file.

pub fn position_in_file(&mut self) -> usize

Return the current read position in the file.

Note

This is the position a subsequent call to read() will return bytes from (or refill the buffer if empty). It is distinct from the actual seek position in the file, which reflects the end of the latest read performed to fill the buffer.

Panics

This function panics if the current seek position in the underlying reader cannot be obtained.

Trait Implementations

impl<F: Read + Seek> BufRead for SkippingBufReader<F>

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<F: Read + Seek> Read for SkippingBufReader<F>

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

Reads the exact number of bytes required to fill buf.

fn read_buf(&mut self, buf: BorrowedCursor<'_>) -> 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<'_>) -> 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” adaptor 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.