On 22/09/10 09:50, Richard W.M. Jones wrote:
On Wed, Sep 22, 2010 at 09:36:41AM +0100, Matthew Booth wrote:
On 21/09/10 20:12, Richard W.M. Jones wrote:
This patch is not using hread/hwrite?
No. That will be required for changing formats, but not for a straight copy.
Anyway I'd be interested in whether you can do all you wanted from hread/hwrite/hseek/etc using the proposed upload-offset API that I posted here:
http://www.redhat.com/archives/libguestfs/2010-September/msg00026.html http://www.redhat.com/archives/libguestfs/2010-September/msg00027.html
No, because the API requires passing in a file, which I don't have.
This is not true. You can write from anything that you can get into a file descriptor, by specifying "/dev/fd/NN" as the filename.
However the API does require that the source of the data comes from a separate thread or process, which is not how virt-v2v works at the moment.
I suspect you need to just use pwrite. AFAICT it already does everything you need.
Except read and write from a block device, although that could be fixed with new APIs. Also, as I said before, I think the handle-based API is a good alternative for large data-transfer. I don't think your hexedit experience was a good example. For example, I would expect using hread to be less code than using pread for reading the contents of a file into memory in chunks. Matt -- Matthew Booth, RHCA, RHCSS Red Hat Engineering, Virtualisation Team GPG ID: D33C3490 GPG FPR: 3733 612D 2D05 5458 8A8A 1600 3441 EA19 D33C 3490