CObArray SetSize()

Brian C. Wadell -- bcwadell@guidedwave.com
Tuesday, May 21, 1996

Win 3.1, MFC 1.52c

I am using a CObArray to store CTests which are a bunch of strings.  I do a 
        CTest *firstOne = new CTest;
then fill in the strings and then Add to a CObArray derived CTestArray.

Originally I wanted to use CArray but this isn't in 1.52.  CObArray seems to
be close so I am using it instead by wrapping it with my own class.

GetSize() seems to go away for a long time.  And most puzzling, Add()
doesn't seem to change the value returned by GetSize().  

Originally I didn't call SetSize() because I am adding five objects during
and intialization and the potential overhead seemed likely to be small.  I
tried the function SetSize(initialSize, growBy) before I do any Adds and now
it appears to be adding the first object at the initialSize location
(observing the value of the document members using Locals).  The next Add()
grows the CTestArray/CObArray by growBy which makes sense.

Why is it adding at the initialSize location?  Shouldn't it add until
initialSize objects are in the array and then enlarge by growBy and keep
adding until intialSize + growBy and then enlarge by growBy again?  Why is
it slow?

Any ideas are welcome.  Thank you.

Brian C. Wadell
Guided Wave Solutions
Hardware & Software Consulting
test, high frequency, transmission lines, simulation
E-mail: bcwadell@guidedwave.com
WWW: http://www.tiac.net/users/bcwadell
Voice/Fax: (617)-942-WAVE

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Brian C. Wadell -- bcwadell@guidedwave.com
Tuesday, May 28, 1996

I found the problem.  When I inherited a new class I made the array a
member.  I was not referring to the member when I accessed the array so
essentially I had a wild pointer which made the CObArray functions appear
slow.  The pointers all looked good when I was debugging but that was
because I was looking at the right pointer and not the (wrong) one I was using!

Brian C. Wadell
Guided Wave Solutions
Hardware & Software Consulting
test, high frequency, transmission lines, simulation
E-mail: bcwadell@guidedwave.com
WWW: http://www.tiac.net/users/bcwadell
Voice/Fax: (617)-942-WAVE

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