RE: [cdt-dev] CDT performance

["Krasilnikov, Oleg" <oleg.krasilnikov@xxxxxxxxx>]

Doug,

I have a question to you regarding PDOM-related changes in
scanner-parser-indexer chain.

I'm interested in CDT performance and memory consumption problems
(mostly in parser), 
so it's interesting how much this part will be modified in nearest
future.

Could you please confirm or deny:

- you know, memory usage is another big problem in CDT - in particular,
  current indexing procedure requires too much memory and crashes
sometimes 
  due to OutOfMemory exception (with Mozilla sources on 1Gb, for
example).
  How PDOM will affect this situation ? From the one hand, since header
files 
  will not be re-parsed with each translation unit, resulting AST tree
can be smaller 
  significantly. (currently it's really huge !) From the other hand,
database server
  (required by PDOM) will consume a lot of memory itself - so, Eclipse
and CDT 
  will have less space...

- parser logic itself will be seriously modified for PDOM ? Currently,
parser 
  itself does not know about includes - it simply receives tokens from
scanner.

- PDOM usage is optional - so some users will use current indexing 
  mechanism, expecially for projects with non-trivial headers contents ?

- although parsing will be used less frequently with PDOM (ideally, once
for 
  each file), it will be inevitable when project is first opened - so,
parser 
  performance is still significant a bit in this case ?

Thanks in advance.

-----------------------------------
With best regards, Oleg Krasilnikov
Software designer, Eclipse team. 
Intel corp.
+7 8312 162 444 ext. 2587 
(Russia, Nizhny Novgorod)
 
-----Original Message-----
From: cdt-dev-bounces@xxxxxxxxxxx [mailto:cdt-dev-bounces@xxxxxxxxxxx]
On Behalf Of Doug Schaefer
Sent: Friday, November 18, 2005 6:10 PM
To: CDT General developers list.
Subject: RE: [cdt-dev] CDT performance

<...>
However from what I've seen and heard, we really need to increase
performance by orders of magnitude and this will require a whole new
indexing strategy. My work on the PDOM for 3.1, which in the end is
really
just a new indexer, is aimed at indexing each file once, somewhat like
ctags
but with a real parser and a symbols database to fill in the gaps. The
accuracy will be a bit less but the performance gains should be very
significant.
<...>

Cheers,
Doug