Struct flate2::write::ZlibDecoder

pub struct ZlibDecoder<W: Write> { /* fields omitted */ }

A ZLIB decoder, or decompressor.

This structure implements a Write and will emit a stream of decompressed data when fed a stream of compressed data.

Examples

use std::io::prelude::*;
use std::io;
use flate2::write::ZlibDecoder;

// Uncompresses a Zlib Encoded vector of bytes and returns a string or error
// Here Vec<u8> implements Write

fn decode_reader(bytes: Vec<u8>) -> io::Result<String> {
   let mut writer = Vec::new();
   let mut z = ZlibDecoder::new(writer);
   z.write_all(&bytes[..])?;
   writer = z.finish()?;
   let return_string = String::from_utf8(writer).expect("String parsing error");
   Ok(return_string)
}

Implementations

impl<W: Write> ZlibDecoder<W>

pub fn new(w: W) -> ZlibDecoder<W>

Creates a new decoder which will write uncompressed data to the stream.

When this decoder is dropped or unwrapped the final pieces of data will be flushed.

pub fn get_ref(&self) -> &W

Acquires a reference to the underlying writer.

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

Acquires a mutable reference to the underlying writer.

Note that mutating the output/input state of the stream may corrupt this object, so care must be taken when using this method.

pub fn reset(&mut self, w: W) -> Result<W>

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

This will reset the internal state of this decoder and replace the output stream with the one provided, returning the previous output stream. Future data written to this decoder will be decompressed into the output stream w.

Errors

This function will perform I/O to complete this stream, and any I/O errors which occur will be returned from this function.

pub fn try_finish(&mut self) -> Result<()>

Attempt to finish this output stream, writing out final chunks of data.

Note that this function can only be used once data has finished being written to the output stream. After this function is called then further calls to write may result in a panic.

Panics

Attempts to write data to this stream may result in a panic after this function is called.

Errors

This function will perform I/O to complete this stream, and any I/O errors which occur will be returned from this function.

pub fn finish(self) -> Result<W>

Consumes this encoder, flushing the output stream.

This will flush the underlying data stream and then return the contained writer if the flush succeeded.

Note that this function may not be suitable to call in a situation where the underlying stream is an asynchronous I/O stream. To finish a stream the try_finish (or shutdown) method should be used instead. To re-acquire ownership of a stream it is safe to call this method after try_finish or shutdown has returned Ok.

Errors

This function will perform I/O to complete this stream, and any I/O errors which occur will be returned from this function.

pub fn total_in(&self) -> u64

Returns the number of bytes that the decompressor has consumed for decompression.

Note that this will likely be smaller than the number of bytes successfully written to this stream due to internal buffering.

pub fn total_out(&self) -> u64

Returns the number of bytes that the decompressor has written to its output stream.

Trait Implementations

impl<W: Debug + Write> Debug for ZlibDecoder<W>

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

Formats the value using the given formatter.

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

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.

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<W: Write> Write for ZlibDecoder<W>

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.