Click here to Skip to main content
11,412,182 members (65,134 online)
Click here to Skip to main content

Pure C# MiniLZO port

, 22 Dec 2006
Rate this:
Please Sign up or sign in to vote.
Fast stream compression using a ported minilzo for .NET.

Introduction

I was recently in a position where I needed to find a fast streamable compression solution.  The great source by Markus Oberhumer provided the answer. After using the C code for a while, I realized C#/.NET lacked a similar library, short of one I found which was commercial.

As a result, I decided to attempt a minimalistic port of MiniLZO compression and decompression into pure C#. At this point, the code uses unsafe/fixed blocks to best mimic the original minilzo implementation. A pure managed solution may be soon to follow (at the cost of speed).

The code has not been unit tested 100%, but all initial tests have been successful. If anyone finds any bugs, please report them so I may fix it. I also have not done any profiling of the speed yet, if anyone feels upto the task of comparing it against the C implementation.

Use of the code is relatively simple, here is a quick example.

Compression

byte[] original = File.ReadAllBytes("...");
byte[] destination;
MiniLZO.Compress(original, out destination);

Decompression

byte[] destination = ...; /* Resulting buffer from above */
byte[] original = new byte[x];
MiniLZO.Decompress(destination, original);

Note that with compression, the destination buffer will be assigned and trimmed to the correct size. With decompression, the "original" buffer must be preallocated with the correct original size. Also note that my implementation removed all use of goto from the original source, and replaces certain uses with OverflowExceptions.

License

This article has no explicit license attached to it but may contain usage terms in the article text or the download files themselves. If in doubt please contact the author via the discussion board below.

A list of licenses authors might use can be found here

Share

About the Author

Astaelan
Web Developer
Canada Canada
Short and simple, I'm a self contracted programmer, my strongest programming skills are in C/C++ and C#/.NET. I have a nack for porting C algorithms to C#.

Comments and Discussions

 
GeneralRe: Another such library... Pinmemberomaurice23-Dec-06 5:32 
GeneralRe: Another such library... PinmemberAstaelan23-Dec-06 5:46 
GeneralRe: Another such library... PinmemberWorldNomad23-Dec-06 4:32 
GeneralRe: Another such library... Pinmemberomaurice23-Dec-06 5:00 
Generalwhy not adding the original size to the header of the buffer PinmemberUnruled Boy5-Nov-06 16:19 
GeneralRe: why not adding the original size to the header of the buffer PinmemberAstaelan6-Nov-06 18:01 
GeneralRe: why not adding the original size to the header of the buffer PinmemberSimmoTech6-Nov-06 21:44 
GeneralRe: why not adding the original size to the header of the buffer PinmemberAstaelan6-Nov-06 22:12 
Using a prepend is probably the easiest way, otherwise you'd have to run some rather archaic processing over the data. So a prepend is the most effective way in terms of transmitting the data.

In my next update, I am considering the possibility of adding the code to also pass an "out" buffer, such that it can be calculated and assigned, but this may not always be the desired use.

M3_MAX_LEN and M1_MAX_OFFSET aren't used based on implementation, they are just leftover if not used, from copying all the like-constants that are used.

I considered the idea of simply allowing to pass a MemoryStream, but again it is specific to implementation so your approach may work. You may also just change the arguments and pass your memory stream, and take care of the GetBuffer/GetLength calls inside the desired function.

Generally speaking it was built to best mimic the original C code while simplifying the interface as much as possible. I'm thinking however, passing offset/length for the byte[]'s may have been better.

In anycase, thanks for your feedback, glad to hear it's getting used Smile | :)
GeneralImpressive, but... Pinmemberwoudwijk4-Nov-06 2:11 
GeneralRe: Impressive, but... PinmemberAstaelan4-Nov-06 11:29 
GeneralAgreement PinmemberBehind The Scene22-Dec-06 13:44 

General General    News News    Suggestion Suggestion    Question Question    Bug Bug    Answer Answer    Joke Joke    Rant Rant    Admin Admin   

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.

| Advertise | Privacy | Terms of Use | Mobile
Web03 | 2.8.150414.5 | Last Updated 22 Dec 2006
Article Copyright 2006 by Astaelan
Everything else Copyright © CodeProject, 1999-2015
Layout: fixed | fluid