19233 - factor buffering into separate stream class

Status: VERIFIED FIXED

(Core :: XPCOM, defect, P3)

Description

[Warren Harris]

We should factor the buffering out of nsFileOutputStream and into a separate
filter stream, nsBufferOutputStream. nsBufferOutputStream should take another
stream to flush to when its buffer becomes full:

  NS_NewBufferOutputStream(nsIOutputStream* out, nsIOutputStream* *result);

(Do we need to do a similar thing for input streams?)

Comment 1

[Doug Turner (:dougt)]

setting milestone.

we already have buffering in the file stream.  We should rip that out and use
this method instead.

Comment 2

[Doug Turner (:dougt)]

reassigning to warren.

Comment 3

[Warren Harris]

This needs to get done for beta now since all file i/o is now going through the 
new file streams we did for nsIFile, and that stuff isn't yet buffered. I've got 
some code in my tree for this.

Comment 4

[Phil Peterson]

PDT agrees that buffered I/O is good. PDT+

Comment 5

[Warren Harris]

I just checked in some preliminary code for this. It lives in 
netwerk/base/public/nsIFileStreams.idl right now. Made the file transport use 
it. It should speed up caching, and save-as, but I haven't noticed any 
improvements for reading files (e.g. chrome files). That time is dwarfed by 
lots of other things (0.03% of runtime).

Comment 6

[leger]

So could this be marked as Verified as far as work done.  Or should this be open 
for more work?

Comment 7

[Warren Harris]

Mark it verified.

Comment 8

[leger]

marking Verified per last comments...thanks! :-)