[cvsnt] Re: Performance problems

[Tony Hoyle]

Nitzan Shaked wrote:
> I am not talking about inserting into the beginning. I am talking about
> chaining the tag (into a linked list) at the end of the current file. This
> saves writing a new file and should thus be much faster.

You can't do that...  tags go at the beginning - all the commonly 
accessed data is there.  On many operating systems seeking to the end of 
a file is quite slow, plus it also means the % of the file you need to 
read to get a specific revision is kept to a minimum (for HEAD it may 
only be a the size of the HEAD revision plus about 1k).

I don't understand what you mean be 'sector writes'.  These are files, 
and you cannot make any assumption about the underlying hardware.  cvs 
knows nothing about 'sectors'.  The RCS file could be stored on pigeons 
for all I know or care... it would be a fatal error to start building in 
hardware specific code.

The RCS file has a very strict structure.  cvsnt hasn't changed that.. 
just added new tags (which is allowed by the file format anyway). 
Someone spent a *lot* of time optimising it and I've avoided making too 
many changes so I don't break that.

Tony