Struct flate2::bufread::DeflateEncoder

pub struct DeflateEncoder<R> { /* fields omitted */ }

A DEFLATE encoder, or compressor.

This structure implements a BufRead interface and will read uncompressed data from an underlying stream and emit a stream of compressed data.

Examples

use std::io::prelude::*;
use std::io;
use flate2::Compression;
use flate2::bufread::DeflateEncoder;
use std::fs::File;
use std::io::BufReader;

// Opens sample file, compresses the contents and returns a Vector
fn open_hello_world() -> io::Result<Vec<u8>> {
   let f = File::open("examples/hello_world.txt")?;
   let b = BufReader::new(f);
   let mut deflater = DeflateEncoder::new(b, Compression::fast());
   let mut buffer = Vec::new();
   deflater.read_to_end(&mut buffer)?;
   Ok(buffer)
}

Methods

impl<R: BufRead> DeflateEncoder<R>

Important traits for DeflateEncoder<R>

impl<R: BufRead> Read for DeflateEncoder<R>impl<W: BufRead + Write> Write for DeflateEncoder<W>

pub fn new(r: R, level: Compression) -> DeflateEncoder<R>

Creates a new encoder which will read uncompressed data from the given stream and emit the compressed stream.

impl<R> DeflateEncoder<R>

pub fn reset(&mut self, r: R) -> R

Resets the state of this encoder entirely, swapping out the input stream for another.

This function will reset the internal state of this encoder and replace the input stream with the one provided, returning the previous input stream. Future data read from this encoder will be the compressed version of r's data.

Important traits for &'a mut R

impl<'a, R> Read for &'a mut R where
    R: Read + ?Sized, impl<'a, W> Write for &'a mut W where
    W: Write + ?Sized, impl<'a, I> Iterator for &'a mut I where
    I: Iterator + ?Sized,  type Item = <I as Iterator>::Item;

pub fn get_ref(&self) -> &R

Acquires a reference to the underlying reader

Important traits for &'a mut R

impl<'a, R> Read for &'a mut R where
    R: Read + ?Sized, impl<'a, W> Write for &'a mut W where
    W: Write + ?Sized, impl<'a, I> Iterator for &'a mut I where
    I: Iterator + ?Sized,  type Item = <I as Iterator>::Item;

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

Acquires a mutable reference to the underlying stream

Note that mutation of the stream may result in surprising results if this encoder is continued to be used.

pub fn into_inner(self) -> R

Consumes this encoder, returning the underlying reader.

pub fn total_in(&self) -> u64

Returns the number of bytes that have been read into this compressor.

Note that not all bytes read from the underlying object may be accounted for, there may still be some active buffering.

pub fn total_out(&self) -> u64

Returns the number of bytes that the compressor has produced.

Note that not all bytes may have been read yet, some may still be buffered.

Trait Implementations

impl<R: Debug> Debug for DeflateEncoder<R>

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

Formats the value using the given formatter.

impl<R: BufRead> Read for DeflateEncoder<R>

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.

unsafe fn initializer(&self) -> Initializer

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

Determines if this Reader can work with buffers of uninitialized memory.

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

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

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

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

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

Read the exact number of bytes required to fill buf.

Important traits for &'a mut R

impl<'a, R> Read for &'a mut R where
    R: Read + ?Sized, impl<'a, W> Write for &'a mut W where
    W: Write + ?Sized, impl<'a, I> Iterator for &'a mut I where
    I: Iterator + ?Sized,  type Item = <I as Iterator>::Item;

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

Creates a "by reference" adaptor for this instance of Read.

Important traits for Bytes<R>

impl<R> Iterator for Bytes<R> where
    R: Read,  type Item = Result<u8, Error>;

fn bytes(self) -> Bytes<Self>

Transforms this Read instance to an [Iterator] over its bytes.

Important traits for Chars<R>

impl<R> Iterator for Chars<R> where
    R: Read,  type Item = Result<char, CharsError>;

fn chars(self) -> Chars<Self>

Deprecated since 1.27.0

: Use str::from_utf8 instead: https://doc.rust-lang.org/nightly/std/str/struct.Utf8Error.html#examples

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

the semantics of a partial read/write of where errors happen is currently unclear and may change

Transforms this Read instance to an [Iterator] over [char]s.

Important traits for Chain<T, U>

impl<T, U> Read for Chain<T, U> where
    T: Read,
    U: Read, 

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

Creates an adaptor which will chain this stream with another.

Important traits for Take<T>

impl<T> Read for Take<T> where
    T: Read, 

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

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

impl<W: BufRead + Write> Write for DeflateEncoder<W>

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

Write a buffer into this object, returning how many bytes were written.

fn flush(&mut self) -> Result<()>

Flush this output stream, ensuring that all intermediately buffered contents reach their destination.

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

Attempts to write an entire buffer into this write.

fn write_fmt(&mut self, fmt: Arguments) -> Result<(), Error>

Writes a formatted string into this writer, returning any error encountered.

Important traits for &'a mut R

impl<'a, R> Read for &'a mut R where
    R: Read + ?Sized, impl<'a, W> Write for &'a mut W where
    W: Write + ?Sized, impl<'a, I> Iterator for &'a mut I where
    I: Iterator + ?Sized,  type Item = <I as Iterator>::Item;

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

Creates a "by reference" adaptor for this instance of Write.