Thanks Steve. That is a very good idea. To use the database to hold the
memory chunk. However, one question I have is what about the MemHandle and
char * that is used to hold the record handler (from DmGetRecord) and the
char * (from MemHandleLock)?? Would these be just an address so they won't
overrun the heap? Also, I would need to call SysFormArrayPointerToStrings
(because I am passing the string to a List Object) so I will need a second
handle, would this cause overrun to the heap?
After these two question is solved, I think this is going to be my solution.
Thank you very much!!!
Eric Sun
Developer - RAD systems
Q. Data Inc.
4/28/00 1:09 PM
-----Original Message-----
From: Steve Jackson [SMTP:[EMAIL PROTECTED]]
Sent: Friday, April 28, 2000 11:54 AM
To: Palm Developer Forum
Subject: Re: MemHandle Question
Hi Eric,
Here goes:
- MemHandleNew and MemHandleResize allocate memory in the dynamic
heap.
- The size of the dynamic heap varies depending on the version of
Palm OS.
- If I remember correctly, it is never as small as 4K. On Palm OS
2.0 it is
about 12K. It is significantly larger on Palm OS 3.X.
Notes and Recommendations:
- The way memory is organized in Palm OS, only very small amounts of
working
memory can be used at one time by a program. Working memory includes
the
stack and the dynamic heap.
- With a data size that "large" (9300 bytes), your data should go
into a
Palm OS "database" in order to run on Palm OS 2.0 devices.
- It is probably best to put this data in a Palm OS "database"
regardless of
which platforms you plan to support with your app.
- A database record is just a chunk of memory up to 64K in size. You
use
database APIs to create, write to, manage, and free the "record".
You read
from a database record directly using a pointer. But, you must use a
database API to write to it because the memory is protected from
direct
write.
- This is documented. But, you'll need to read nearly all of the
memory and
data manager to see the whole picture.
Good luck!
-----Steve Jackson
"Eric" <[EMAIL PROTECTED]> wrote in message
news:9870@palm-dev-forum...
>
> Hello all,
> I just need to know, if I call MemHandleNew or MemHandleResize,
where do
> they create the memory chunk for me? Would it be within the 4K
heap we
are
> allocated to use or would be out in memory?
>
> I need to know this because the application I am working on will
generate
a
> selectable report-like List Object. Each entry in the report is 3
rows.
> Therefore, if I have 100 entries, then it will really be 300 lines
and at
> that point, each line I is 31 bytes, for a total of 9300 bytes.
That is
> double the heap??
>
> If that is the case, are there any other way to provide a report
in which
> they can select entries in the report and do some data massaging
> afterwards??
>
> Thanks,
> Eric Sun
> Developer - RAD systems
> Q. Data Inc.
> 4/27/00 5:06 PM
>
>
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