Struct stack_buffer::StackBufReader

pub struct StackBufReader<R, const N: usize> { /* fields omitted */ }

The StackBufReader<N, R> struct adds buffering to any reader.

See BufReader for more details.

Examples

use std::io::prelude::*;
use std::fs::File;
use stack_buffer::StackBufReader;

fn main() -> std::io::Result<()> {
    let f = File::open("log.txt")?;
    let mut reader = StackBufReader::<_, 4096>::new(f);

    let mut line = String::new();
    let len = reader.read_line(&mut line)?;
    println!("First line is {} bytes long", len);
    Ok(())
}

Implementations

impl<R: Read, const N: usize> StackBufReader<R, N>

pub fn new(inner: R) -> StackBufReader<R, N>

Creates a new StackBufReader<R, N>.

Examples

use std::fs::File;
use stack_buffer::StackBufReader;

fn main() -> std::io::Result<()> {
    let f = File::open("log.txt")?;
    let reader = StackBufReader::<_, 4096>::new(f);
    Ok(())
}

impl<R, const N: usize> StackBufReader<R, N>

pub fn get_ref(&self) -> &R

Gets a reference to the underlying reader.

It is inadvisable to directly read from the underlying reader.

Examples

use std::fs::File;
use stack_buffer::StackBufReader;

fn main() -> std::io::Result<()> {
    let f1 = File::open("log.txt")?;
    let reader = StackBufReader::<_, 4096>::new(f1);

    let f2 = reader.get_ref();
    Ok(())
}

pub fn get_mut(&mut self) -> &mut R

Gets a mutable reference to the underlying reader.

It is inadvisable to directly read from the underlying reader.

Examples

use std::fs::File;
use stack_buffer::StackBufReader;

fn main() -> std::io::Result<()> {
    let f1 = File::open("log.txt")?;
    let mut reader = StackBufReader::<_, 4096>::new(f1);

    let f2 = reader.get_mut();
    Ok(())
}

pub fn buffer(&self) -> &[u8]

Returns a reference to the internally buffered data.

Unlike fill_buf, this will not attempt to fill the buffer if it is empty.

Examples

use std::io::BufRead;
use std::fs::File;
use stack_buffer::StackBufReader;

fn main() -> std::io::Result<()> {
    let f = File::open("log.txt")?;
    let mut reader = StackBufReader::<_, 4096>::new(f);
    assert!(reader.buffer().is_empty());

    if reader.fill_buf()?.len() > 0 {
        assert!(!reader.buffer().is_empty());
    }
    Ok(())
}

pub fn capacity(&self) -> usize

Returns the number of bytes the internal buffer can hold at once.

Examples

use std::io::BufRead;
use std::fs::File;
use stack_buffer::StackBufReader;

fn main() -> std::io::Result<()> {
    let f = File::open("log.txt")?;
    let mut reader = StackBufReader::<_, 4096>::new(f);

    let capacity = reader.capacity();
    let buffer = reader.fill_buf()?;
    assert!(buffer.len() <= capacity);
    Ok(())
}

pub fn into_inner(self) -> R

Unwraps this BufReader<R>, returning the underlying reader.

Note that any leftover data in the internal buffer is lost. Therefore, a following read from the underlying reader may lead to data loss.

Examples

use std::fs::File;
use stack_buffer::StackBufReader;

fn main() -> std::io::Result<()> {
    let f1 = File::open("log.txt")?;
    let reader = StackBufReader::<_, 4096>::new(f1);

    let f2 = reader.into_inner();
    Ok(())
}

impl<R: Seek, const N: usize> StackBufReader<R, N>

pub fn seek_relative(&mut self, offset: i64) -> Result<()>

Seeks relative to the current position. If the new position lies within the buffer, the buffer will not be flushed, allowing for more efficient seeks. This method does not return the location of the underlying reader, so the caller must track this information themselves if it is required.

Trait Implementations

impl<R: Read, const N: usize> BufRead for StackBufReader<R, N>

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

Returns the contents of the internal buffer, filling it with more data from the inner reader if it is empty.

fn consume(&mut self, amt: usize)

Tells this buffer that amt bytes have been consumed from the buffer, so they should no longer be returned in calls to read.

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

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

Check if the underlying Read has any data left to be read.

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

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

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

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

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

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

fn lines(self) -> Lines<Self>

Returns an iterator over the lines of this reader.

impl<R, const N: usize> Debug for StackBufReader<R, N> where
    R: Debug, 

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

Formats the value using the given formatter.

impl<R: Read, const N: usize> Read for StackBufReader<R, N>

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>

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>

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

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

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

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

Read the exact number of bytes required to fill buf.

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

🔬 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, buf: &mut ReadBuf<'_>) -> Result<(), Error>

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

Read the exact number of bytes required to fill buf.

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

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

fn bytes(self) -> Bytes<Self>

Transforms this Read instance to an Iterator over its bytes.

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

Creates an adapter which will chain this stream with another.

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

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

impl<R: Seek, const N: usize> Seek for StackBufReader<R, N>

fn seek(&mut self, pos: SeekFrom) -> Result<u64>

Seek to an offset, in bytes, in the underlying reader.

See BufReader::seek for more details.

fn stream_position(&mut self) -> Result<u64>

Returns the current seek position from the start of the stream.

See BufReader::stream_position for more details.

Example

use std::{
    io::{self, BufRead, Seek},
    fs::File,
};
use stack_buffer::StackBufReader;

fn main() -> io::Result<()> {
    let mut f = StackBufReader::<_, 4096>::new(File::open("foo.txt")?);

    let before = f.stream_position()?;
    f.read_line(&mut String::new())?;
    let after = f.stream_position()?;

    println!("The first line was {} bytes long", after - before);
    Ok(())
}

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

Rewind to the beginning of a stream.

fn stream_len(&mut self) -> Result<u64, Error>

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

Returns the length of this stream (in bytes).