Re: YAJL Parser... getting a pointer to the data and length of the data?

On Mon, May 23, 2016 at 4:17 PM, John Yeung <gallium.arsenide@xxxxxxxxx>
wrote:

On Mon, May 23, 2016 at 4:52 PM, Bradley Stone <bvstone@xxxxxxxxx> wrote:

If I pass a size into yajl_get_string_buf() then where would the cleanup
happen?

I know that was asked in a rhetorical, I'm-about-to-answer-it-myself
kind of way, but I'll elaborate anyway: I would think that
yajl_get_string_buf() cannot do any cleanup itself, regardless.
Whether the space is allocated by the caller ahead of time or by the
called procedure, the buffer cannot be cleared before the caller has a
chance to read what's in it. So the cleanup must happen outside
yajl_get_string_buf().

I think the choices are: (1) If the caller did %alloc(), then the
caller has to do %dealloc(). (2) If the caller just used an RPG
character variable (and passed a pointer to THAT), then the RPG
"runtime" handles the cleanup. (Anything else like user spaces ought
to be a variation on one of those.)

Good points. Passing in an address to a variable would make it more
readable for most RPGers.

If I call this 100 times (passing in a size and not allocating and
deallocating) and the cleanup doesn't happen until the end that could be

a

LOT of allocated space. And right now the only cleanup I see is
deallocating the main tree using yajl_tree_free(node);

Um... if you're passing the same pointer (let me be clear: passing in
the same memory address) each time, then I would think you're not
allocating more and more space, but reusing the same space (or at most
the space needed by the largest size you've passed in). But yes, if
you get a new address for a new allocation each time, then you
probably could be using more and more memory.

Another good point, John. I didn't think about reusing the same memory.

Does that mean that the procedure would do a realloc() each time on the
pointer for the size passed in if the pointer is not null? Sounds like it
should work.

But there's still the cleanup issue. Would we need to make a new cleanup()
procedure that called yajl_tree_free and clean up any allocated memory as
well?

John Y.
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