Hi rafaello
once you find the solution can you do a pull request on the UFFI doc?
Your question is important we should improve the documentation.
tx
Stf
Hi,
browsing through ByteArray's and ExternalAddress's code, I'm getting the
impression that copying *portions* of ByteArrays from/to the C heap can
be quite costly.
Copying *to* the C heap sometimes requires first copying the portion of
the ByteArray into a newly instantiated temporary ByteArray, then
copying the latter to the C heap.
Copying *from* the C heap might require explicitly looping over the
single bytes. I say "might" because I still cannot find more direct way,
as using ByteArray>>replaceFrom:to:with:startingAt: doesn't seem to work.
Any suggestion on more effective copy operations?
Thanks
Raffaello
On 22/02/17 15:08, Raffaello Giulietti wrote:
Hi Esteban,
not sure I'm understanding your snippet correctly.
Below is my try. It throws a SubscriptOutOfBounds exception in the last
line. The reason is that the implementation of ByteArray
replaceFrom:to:with:startingAt: does not consider that ea is meant to be
a pointer to a C byte array, not an object whose content is to be copied
directly.
| ea ba |
ea := ExternalAddress gcallocate: 200.
ba := ByteArray new: 100.
ba replaceFrom: 1 to: 50 with: ea startingAt: 51.
Am I missing some point?
On 2017-02-21 17:20, Esteban Lorenzano wrote:
usually, something more or less like this:
sourceByteArrayOrExternalAddress := … some ...
destEnternalAddressOrByteArray
replaceFrom: 1
to: sourceByteArrayOrExternalAddress size
with: sourceByteArrayOrExternalAddress
startingAt: 1
and or course you can play with the starting points and sizes.
cheers,
Esteban
On 21 Feb 2017, at 17:13, Raffaello Giulietti
<raffaello.giulie...@lifeware.ch> wrote:
Hi,
I'm having a hard time finding documentation on how to copy a portion
of a ByteArray to/from another portion of a heap allocated C byte
array with UFFI.
My current reference is
https://ci.inria.fr/pharo-contribution/view/Books/job/PharoBookWorkInProgress/lastSuccessfulBuild/artifact/book-result/UnifiedFFI/UnifiedFFI.pdf
Thanks for directing me at relevant docs or examples and sorry in
advance if I missed some important point in the docs.
RG
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