Android Question Fastest File Compare

[Richard Peck]

Hi All

Can anyone tell me the fastest way to condense of 2 files. I've tried the normal file access and I've tried the RandomAccessFile library with 8 byte access but both a really slow. Any know a faster way ?

Thanks

 

[JakeBullet70]

If you are compiling with rapid - debug its going to be slow. try it compiled to release mode to see the real speed.

 

[Richard Peck]

Hi,

I have compiled it as a release but it's still very slow. Is the a faster way to do a file compare then the ways I mentioned ? Is there any other libraries I can try. Any other thought would be helpful.

Thanks

 

[DonManfred]

How did you the compare? are you comparing each single byte? I would try to read 8k or 16k (or more) in a string and then a string-compare of these 8/16kb each...

Maybe post your code (export as zip) and we have a look

 

[Erel]

You shouldn't convert the bytes to a string. It will only make it slower (and not 100% accurate).

The fastest way will be to first check whether the files sizes are the same and then compare the raw bytes with InputStreams.

A library will not make it faster.

 

[Richard Peck]

How did you the compare? are you comparing each single byte? I would try to read 8k or 16k (or more) in a string and then a string-compare of these 8/16kb each...

Maybe post your code (export as zip) and we have a look

Right now I'm doing 8 byte compares. I'm not sure how you would do a 16k compare, can you give a shore example ?

Thanks

 

[DonManfred]

I would do it like this on Windows if i code with delphi. But as Arel states on post before yours it is not a good idea to to a string-compare cause it where not 100% accurate.

 

[warwound]

How about generating an MD5 checksum for each file?
http://www.b4x.com/android/forum/threads/how-to-get-md5-of-a-file.7332/#post-41864

Martin.

 

[DonManfred]

That would be a GOOD alternative ;-)

But i think it could be to slow too if the files are big...

 

[warwound]

If the files are big then i think any solution will be slow...

Martin.

 

[DonManfred]

Richard did not state any informations about the filesizes the files have which he tried