Struct flate2::read::GzDecoder

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

A decoder for a single member of a gzip file.

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

To handle gzip files that may have multiple members, see MultiGzDecoder or read more in the introduction.

Examples

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

// Uncompresses a Gz 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 gz = GzDecoder::new(&bytes[..]);
   let mut s = String::new();
   gz.read_to_string(&mut s)?;
   Ok(s)
}

Implementations

impl<R: Read> GzDecoder<R>

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

Creates a new decoder from the given reader, immediately parsing the gzip header.

impl<R> GzDecoder<R>

pub fn header(&self) -> Option<&GzHeader>

Returns the header associated with this stream, if it was valid.

pub fn get_ref(&self) -> &R

Acquires a reference to the underlying reader.

Note that the decoder may have read past the end of the gzip data. To prevent this use bufread::GzDecoder instead.

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 continues to be used.

Note that the decoder may have read past the end of the gzip data. To prevent this use bufread::GzDecoder instead.

pub fn into_inner(self) -> R

Consumes this decoder, returning the underlying reader.

Note that the decoder may have read past the end of the gzip data. Subsequent reads will skip those bytes. To prevent this use bufread::GzDecoder instead.

Trait Implementations

impl<R: Debug> Debug for GzDecoder<R>

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

Formats the value using the given formatter.

impl<R: Read> Read for GzDecoder<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>

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 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)

Read 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<R: Read + Write> Write for GzDecoder<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 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.