Hi Jevgeni

Thank you for your reply , much appreciated.
However I am not sure what you mean.
I am happy to be corrected if I am wrong.

From my code you can see.
I only Create and Populate the Userspace for the #FIRST record.

/* On First pass get the API data */
memmove(Funct,p_iFunc, strlen(p_iFunc));
if (!memcmp(Funct, "#FIRST", 6)) {

On the #NEXT calls I just get the pointer to the Userspace.

if (!memcmp(Funct, "#NEXT", 5)) {
/*! call RetrievePointerToUserSpace - Retrieve Pointer to User Space */
errorCode.BytesProvided = 0;
RetrievePointerToUserSpace("RTVFDUSPC QTEMP ",

Also I Delete the User space when there are no more fields to get.

Odata->EndDta = 0;
/* End ofthe Fields */
if ((EndFlds EQ 1) && (FldIdx EQ p_QDFFRINF->WDFFFLD -1) ) {
Odata->EndDta = 1;
*GotIt = 1;
DeleteUserSpace("RTVFDUSPC QTEMP ",

So I believe I am doing the code correctly exactly how you describe it
should be done.


•Subject: Re: C program for QDFRTVFD API
•From: Jevgeni Astanovski <jevgeniast@xxxxxxxxx>
•Date: Thu, 18 Sep 2014 10:16:46 +0300
After careful examining of your DISPINFOC1 program I should say that
probably you misunderstood the idea of using user space.
Currently your program is not simply inefficient, but it is
"dangerously" inefficient in case you apply it to display files having
really big number of fields.
So after the first call (give me first) you fill the user space by a
number of FieldData_t structures (for all fields). And put the 2
integers in the beginning appropriately. Then you send out the first
structure and increment the pointer to the first unsent structure.
When you get "give me next" call, you do not call QDFRTVFD any more!
You rather get the user space and send away the first unsent structure
and increment the pointer. If the pointer to the next reached the end,
you inform the caller about that with the last structure.
This is one of the possible solutions using user space.

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