> On 14 Jan 2017, at 12:27, Lee Duhem <lee.du...@gmail.com> wrote:
>
Hi!
another flight, another time to look at it. :)
>> if (free < (to - from))
>> {
>> - memcpy (_gst_cur_bytecodes->ptr, from, free);
>> - _gst_cur_bytecodes->ptr += free;
>> - from += free;
>> realloc_bytecodes (_gst_cur_bytecodes,
>> BYTECODE_CHUNK_SIZE + (to - from));
>> }
> The original logic is that if available space in _gst_cur_bytecodes is
> less than (to - from),
> it will copy part of contents from `from' to _gst_cur_bytecodes, then
> allocate more space
> through realloc_bytecodes(), and copy the rest from `from'. However,
> the reallocation of
> _gst_cur_bytecodes may need to copy the content of it to the new location.
>
> And the new code will resize the capacity of _gst_cur_bytecodes first,
> then copy all the contents
> from `from' to it. In this case, we may save one memcpy call, and
> some extra copying in
> realloc_bytecodes().
Let's do the math now and compare it. My focus is on the from += free
and my suspicion is that we now allocate more memory than before.
free == 10
from == 0
to == 20
to-fr== 20
Before:
free < to-from => true
memcpy of 10 bytes
from + free = 10
realloc CHUNK + 10 =
After:
free < to-from => true
realloc CHUNK + 20
So I agree that the same data is written, ptr will be correct too but
maybe a tiny bit more memory? What do you think?
holger
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