[][src]Crate flate2

A DEFLATE-based stream compression/decompression library

This library is meant to supplement/replace the flate library that was previously part of the standard rust distribution providing a streaming encoder/decoder rather than purely an in-memory encoder/decoder.

Like with flate, flate2 is based on miniz.c


This crate consists mainly of three modules, read, write, and bufread. Each module contains a number of types used to encode and decode various streams of data.

All types in the write module work on instances of Write, whereas all types in the read module work on instances of Read and bufread works with BufRead. If you are decoding directly from a &[u8], use the bufread types.

use flate2::write::GzEncoder;
use flate2::Compression;
use std::io;
use std::io::prelude::*;

let mut encoder = GzEncoder::new(Vec::new(), Compression::default());

Other various types are provided at the top-level of the crate for management and dealing with encoders/decoders. Also note that types which operate over a specific trait often implement the mirroring trait as well. For example a flate2::read::DeflateDecoder<T> also implements the Write trait if T: Write. That is, the "dual trait" is forwarded directly to the underlying object if available.

Async I/O

This crate optionally can support async I/O streams with the Tokio stack via the tokio feature of this crate:

flate2 = { version = "0.2", features = ["tokio"] }

All methods are internally capable of working with streams that may return ErrorKind::WouldBlock when they're not ready to perform the particular operation.

Note that care needs to be taken when using these objects, however. The Tokio runtime, in particular, requires that data is fully flushed before dropping streams. For compatibility with blocking streams all streams are flushed/written when they are dropped, and this is not always a suitable time to perform I/O. If I/O streams are flushed before drop, however, then these operations will be a noop.



Types which operate over BufRead streams, both encoders and decoders for various formats.


Types which operate over Read streams, both encoders and decoders for various formats.


Types which operate over Write streams, both encoders and decoders for various formats.



Raw in-memory compression stream for blocks of data.


Error returned when a compression object is used incorrectly or otherwise generates an error.


When compressing data, the compression level can be specified by a value in this enum.


The CRC calculated by a CrcReader.


A wrapper around a Read that calculates the CRC.


A wrapper around a Write that calculates the CRC.


Raw in-memory decompression stream for blocks of data.


Error returned when a decompression object finds that the input stream of bytes was not a valid input stream of bytes.


A builder structure to create a new gzip Encoder.


A structure representing the header of a gzip stream.



Values which indicate the form of flushing to be used when compressing in-memory data.


Values which indicate the form of flushing to be used when decompressing in-memory data.


Possible status results of compressing some data or successfully decompressing a block of data.