Struct flate2::bufread::GzEncoder

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

A gzip streaming encoder

This structure exposes a BufRead interface that will read uncompressed data from the underlying reader and expose the compressed version as a BufRead interface.

Examples

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

// Opens sample file, compresses the contents and returns a Vector or error
// File wrapped in a BufReader implements BufRead

fn open_hello_world() -> io::Result<Vec<u8>> {
    let f = File::open("examples/hello_world.txt")?;
    let b = BufReader::new(f);
    let mut gz = GzEncoder::new(b, Compression::fast());
    let mut buffer = Vec::new();
    gz.read_to_end(&mut buffer)?;
    Ok(buffer)
}

Methods

impl<R: BufRead> GzEncoder<R>

Important traits for GzEncoder<R>

impl<R: BufRead> Read for GzEncoder<R>impl<R: BufRead + Write> Write for GzEncoder<R>

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

Creates a new encoder which will use the given compression level.

The encoder is not configured specially for the emitted header. For header configuration, see the GzBuilder type.

The data read from the stream r will be compressed and available through the returned reader.

impl<R> GzEncoder<R>

pub fn get_ref(&self) -> &R

Acquires a reference to the underlying reader.

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

Acquires a mutable reference to the underlying reader.

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

pub fn into_inner(self) -> R

Returns the underlying stream, consuming this encoder

Trait Implementations

impl<R: Debug> Debug for GzEncoder<R>

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

Formats the value using the given formatter.

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

fn read(&mut self, into: &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.

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.

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 adaptor which will chain this stream with another.

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

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

impl<R: BufRead + Write> Write for GzEncoder<R>

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

Write a buffer into this writer, 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_vectored(&mut self, bufs: &[IoSlice]) -> Result<usize, Error>

Like write, except that it writes from a slice of buffers.

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

Attempts to write an entire buffer into this writer.

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

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

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

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