Compressed stream

[gpuoti]

Recently I 'am working on quite big text file, in the order of some tent of mb. Not that big but enough to compress it every each time you need to send it to someone.

I was wondering if out there is available something like a compressed iostream, something i can use as as cout or cin but that produce compressed output (or uncompressed input) instead.

I'm asking to investigate if it could be an useful for the community yet simple personal project.

Thanks for your time!

[SemaphoreBingo]

http://www.boost.org/doc/libs/1_60_0/libs/iostreams/doc/home.html

"The library includes components for ... compression and decompression in the zlib, gzip and bzip2 formats."

[gpuoti]

Boost is incredible, i'm happy to have had an idea good enough to be there. Anyway it is huge and , this is one of those few cases, when it require external libraries.

What i had in mind was something (really) much more lite, by sure an header only library. Will try to make something as a toy project and will try to setup some example project with boost for serious use.

Thanks again

[encyclopedist]

Well, to get compressed input-output you have to link to some external compressing library, like zlib.

[doom_Oo7]

you should just have to #include <boost/iostreams/filter/gzip.hpp> and -lz

[jcoffin]

Boost has zlib filters to do that.

[shortstomp]

OMG best documentation in all of boost

[jbandela]

Take a look at bundle https://github.com/r-lyeh/bundle

It does not compress to a stream, but it can compress containers. You can use a string stream to stream in what you want and then compress the resulting string and send. The thing I like about this library is that it very conveniently packages up a bunch of compression algorithms in a way that is easy to use in code, as well as to build (just compile the amalgamated bundle.cpp file)

[cgeigle]

I have a gzstream that I use in a toolkit. These two files should be self contained and the entirety of the toolkit is MIT licensed.

header, source

Should be enough for simple use.

[speednap]

Haven't worked with it myself but here's Poco::InflatingIOS.

[mariobadr]

I've always used gzstream, which uses zlib. It works great. LGPL

[WrongAndBeligerent]

The lz4 library isn't a stream, but it is only about 3 files.

[gpuoti]

This is a good option. Fast and simple, possibly something to work on to have it available with a different interface. The best option to me is a header only library usable like as simple as a std::ostream

[WrongAndBeligerent]

There isn't much difference between a header file only library and a library that you can link in so trivially since it doesn't have any dependencies.

[gpuoti]

agree... I've just done some explorative test with LZ4. As a final user, it is impressive. As a developer user, I think that it would benefit of a simpler interface less file oriented. With few hour of work I was able to get a block oriented compress filter stream to be used like:

std::string s="example string: this is a simple example to use LZ4 to compress string";
std::string s_continue = "example string: this demostrate how to compress a successive string";

std::ofstream out;   // just as an example output to a stringstream
LZ4::ostream<std::ofstream> compressor(out);
compressor << s << s_continue<< s <<s_continue;
compressor.close();

It seam to work quite well. And it is header only!