Struct ConcatReader

pub struct ConcatReader<I: IntoIterator> { /* private fields */ }

The ConcatReader struct allows to read from multiple readers in a sequential order.

If the current reader reaches its EOF the ConcatReader will start reading from the next reader in the iterator. If all readers reached EOF the ConcatReader will also be EOF.

Examples

use concat_reader::*;
use std::fs::File;
use std::io;
use std::io::prelude::*;

fn main() -> io::Result<()> {
    let foo = File::open("foo.txt")?;
    let bar = File::open("bar.txt")?;
    let baz = File::open("bar.txt")?;
    let files = [foo, bar, baz];
    let mut c = ConcatReader::new(&files);
    let mut buffer = [0; 10];

    // read up to 10 bytes
    let n = c.read(&mut buffer[..])?;

    println!("The bytes: {:?}", &buffer[..n]);

    //skip to the next file
    c.skip();

    let mut buffer = Vec::new();
    // read all rest files into a single buffer
    c.read_to_end(&mut buffer)?;
    Ok(())
}

Implementations

impl<I> ConcatReader<I>

where I: IntoIterator, I::Item: Read,

pub fn new(iter: I) -> Self

Creates a new ConcatReader from an value which can be converted into an Iterator<Item=Read>.

use std::io::prelude::*;
use concat_reader::{ConcatRead, ConcatReader};
let bytes = vec!["first".as_bytes(), "second".as_bytes()];
let r = ConcatReader::new(bytes);

Trait Implementations

impl<I> ConcatRead for ConcatReader<I>

where I: IntoIterator, I::Item: Read,

type Item = <I as IntoIterator>::Item

fn current(&self) -> Option<&Self::Item>

Returns the current Read item in the internal iterator being read from.

fn skip(&mut self) -> bool

Skips to the next Read item in the internal Iterator.

impl<I> Debug for ConcatReader<I>

where I: IntoIterator, I::Item: Debug, I::IntoIter: Clone,

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

Formats the value using the given formatter.

impl<I> From<I> for ConcatReader<I>

where I: IntoIterator, I::Item: Read,

fn from(iter: I) -> ConcatReader<I>

Converts to this type from the input type.

impl<I> Read for ConcatReader<I>

where I: IntoIterator, I::Item: Read,

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.