Struct flate2::read::DeflateDecoder

pub struct DeflateDecoder<R> { /* private fields */ }

A DEFLATE decoder, or decompressor.

This structure implements a Read interface. When read from, it reads compressed data from the underlying Read and provides the uncompressed data.

After reading a single member of the DEFLATE data this reader will return Ok(0) even if there are more bytes available in the underlying reader. DeflateDecoder may have read additional bytes past the end of the DEFLATE data. If you need the following bytes, wrap the Reader in a std::io::BufReader and use bufread::DeflateDecoder instead.

Examples

use std::io::prelude::*;
use std::io;
use flate2::read::DeflateDecoder;

// Uncompresses a Deflate Encoded vector of bytes and returns a string or error
// Here &[u8] implements Read
fn decode_reader(bytes: Vec<u8>) -> io::Result<String> {
   let mut deflater = DeflateDecoder::new(&bytes[..]);
   let mut s = String::new();
   deflater.read_to_string(&mut s)?;
   Ok(s)
}

Implementations

impl<R: Read> DeflateDecoder<R>

pub fn new(r: R) -> DeflateDecoder<R>

Creates a new decoder which will decompress data read from the given stream.

pub fn new_with_buf(r: R, buf: Vec<u8>) -> DeflateDecoder<R>

Same as new, but the intermediate buffer for data is specified.

Note that the capacity of the intermediate buffer is never increased, and it is recommended for it to be large.

impl<R> DeflateDecoder<R>

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

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

This will reset the internal state of this decoder and replace the input stream with the one provided, returning the previous input stream. Future data read from this decoder will be the decompressed version of r’s data.

Note that there may be currently buffered data when this function is called, and in that case the buffered data is discarded.

pub fn get_ref(&self) -> &R

Acquires a reference to the underlying stream

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 decoder is continued to be used.

pub fn into_inner(self) -> R

Consumes this decoder, returning the underlying reader.

Note that there may be buffered bytes which are not re-acquired as part of this transition. It’s recommended to only call this function after EOF has been reached.

pub fn total_in(&self) -> u64

Returns the number of bytes that the decompressor has consumed.

Note that this will likely be smaller than what the decompressor actually read from the underlying stream due to buffering.

pub fn total_out(&self) -> u64

Returns the number of bytes that the decompressor has produced.

Trait Implementations

impl<R: Debug> Debug for DeflateDecoder<R>

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

Formats the value using the given formatter.

impl<R: Read> Read for DeflateDecoder<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.

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.

impl<W: Read + Write> Write for DeflateDecoder<W>

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

Writes a buffer into this writer, returning how many bytes were written.

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

Flushes 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 is_write_vectored(&self) -> bool

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

Determines if this Writer has an efficient write_vectored implementation.

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

Attempts to write an entire buffer into this writer.

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.

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

where Self: Sized,

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