Re: [sleuthkit-developers] Re: IO Subsystem patch for fstools

[Brian C. <ca...@sl...>]

On Feb 23, 2004, at 3:03 AM, Paul Bakker wrote:
>> I quickly looked the changes over.  Is there a need to pass
>> FS_INFO to
>> the read functions?  I didn't see you using them and it would be nice
>> if we could avoid doing that (so that we don't have to restrict
>> ourselves to file system code).
>
> Well I do see advantages.... I already wanted to ask this...
>
> The problem with the current code is that it is not possible to
> "read_random" an image efficiently because it cannot check the current
> offset in the image.. This results in unnecessary seeks.. And seeks are
> very expensive if they come in millions....

We can easily fix that though with some data in an IMG_INFO struct, 
which is a more appropriate location than the FS_INFO structure.  For 
the code that uses split or RAID images, we will need multiple copies 
of the current offset data.

Actually, I'm not even sure why fs_read_random doesn't use the 
fs->read_pos value before it does the seek.

brian