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)
}

Implementations

impl<R: BufRead> 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.

pub fn read_vectored(
    &mut self,
    bufs: &mut [IoSliceMut<'_>]
) -> Result<usize, Error>

Like read, except that it reads into a slice of buffers.

pub 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.

pub 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.

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

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

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

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

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

Read the exact number of bytes required to fill buf.

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

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

pub fn bytes(self) -> Bytes<Self>

Transforms this Read instance to an Iterator over its bytes.

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

Creates an adaptor which will chain this stream with another.

pub 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.

pub fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> Result<usize, Error>

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

pub fn is_write_vectored(&self) -> bool

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

Determines if this Writer has an efficient write_vectored implementation.

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

Attempts to write an entire buffer into this writer.

pub fn write_all_vectored(
    &mut self,
    bufs: &mut [IoSlice<'_>]
) -> Result<(), Error>

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

Attempts to write multiple buffers into this writer.

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

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

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

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