Subj : sweep
To   : Jonathan De Boyne Pollard
From : Eddy Thilleman
Date : Fri Aug 03 2001 12:40 am

Hello Jonathan,

Tuesday 31 July 2001 08:06, Jonathan de Boyne Pollard wrote to Eddy Thilleman:

ET>> This new version of sweep has the same small delays as the
ET>> previous one, so these delays might be caused by calling the
ET>> command interpreter (CMD.EXE on my system).

JdBP> Possibly, although it's always better to profile the application to
JdBP> determine this.  With a REXX script run within the command interpreter
JdBP> process, there isn't the overhead of invoking an additional instance
JdBP> of the command interpreter when one issues an external command, which
JdBP> may be why your REXX script is faster.

I don't have experience profiling with REXX. I'll look into this when I've
time.

JdBP> You can optimise things slightly, of course.  Here are some
JdBP> suggestions:

JdBP> 1.    Change your calls to DosFind{First,Next} to grab many directory
JdBP> entries in a single call, rather than just a single one (and then have
JdBP> an inner loop that iterates over the buffer entry by entry).

Do I need to change or replace the lines with DosFindFirst() and DosFindNext()
or should I just change the number of entries to find? Problably I need extra
calls to DosFindFirst() and DosFindNext() to iterate over entries in the
buffer? How would I make them work with the entries in the buffer?

JdBP> 2.    Obtain the value of the COMSPEC environment variable just
JdBP> once.

I already do this in all the versions.

JdBP> 3.    Use the API of my 32-bit CMD to invoke commands, rather than
JdBP> spawning an instance of the command interpreter as a child process.
JdBP> Commands would be interpreted by an interpreter for the CMD language
JdBP> running directly in your SWEEP process itself.

I need to study this, I haven't had the time yet (I don't know when I've the
time).

JdBP> If the problem is the process execution overhead for the command
JdBP> interpreter, as you suspect, the third suggestion may result in the
JdBP> largest speed increase.

I'll look into it.


 Greetings   -=Eddy=-

 email: [email protected]
        [email protected]

... Beer Bong? Now that's a sport I can get into!
--- GoldED/2 3.0.1
* Origin: "DOS for dummies?"  Isn't that what Windows is? (1:2320/38.3)

You are viewing proxied material from vert.synchro.net. The copyright of proxied material belongs to its original authors. Any comments or complaints in relation to proxied material should be directed to the original authors of the content concerned. Please see the disclaimer for more details.