RE: API receiver variable limit

Hi Buck -

>I'm writing a boilerplate for QDBRTVFD (Retrieve file description API).
The
>maximum RPG IV string size is 32kb.  The FILD0200 request for a particular
>file is returning 49kb of data.  I've used a multiple occurrence data
>structure and a based pointer to move an internal data structure around
>(which works), but can I rely on the compiler always storing the
occurrences
>one after the other (to form one block of contiguous API populated memory?)

Yes and no.  If alignment is used, it is possible that the start of the
second occurrence might not immediately follow the end of the first
occurrence.  However if that is the case, the space between would never be
assigned to anything else and is available for your data.  So long as you
always base your access from the start of the FIRST occurrence and never
from the start of any other occurrences, you'll be okay.

>Is there a better way? (I hope so!)  Should I use C? (sigh)

Yes to the first question, no to the second.  I think that Jon's suggestion
of using ALLOC is best.  Don't forget to use DEALLOC to release the memory,
otherwise it will be held until the activation group ends; it will NOT be
released when the program ends.  Be sure to read the RPG IV manual about the
ALLOC, REALLOC, and DEALLOC opcodes.  There are things that you need to be
careful about:
1. storage allocated by ALLOC is uninitialized, as is additional storage
allocated by REALLOC.  Don't expect it to blanks or binary zeros or anything
in particular.
2. when you do a REALLOC or DEALLOC, the pointer MUST point to the BEGINNING
of the allocated area.  You might want to keep a separate pointer just for
the ALLOC/REALLOC/DEALLOC operations, and use a different pointer or
pointers for your basing pointer(s) to actually use the data.

Ken
Southern Wine and Spirits of Nevada, Inc.
Opinions expressed are my own and do not necessarily represent the views of
my employer or anyone in their right mind.

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