On 2013-09-18 22:01, Sage Weil wrote:
The read-into-existing-buffer is only wired up properly for the C
interface. For the C++ it isn't generally necessary: we allocate and read
the data off the network,a nd pass the reference directly back to the user
without making another copy. The 2010 thread is about similarly avoiding
such a copy for the C API. We didn't contemplate the situation where you
specifically want the bytes to go to a particular address via C++. If
that's what you need, the C++ API needs to be extended, or you can just
use the C call for that case.
sage
Hey Sage,
my particular use case is a pager that uses Rados as a backend. Striping
of pages works identical to the striping mechanism of Ceph. Reads and
writes of multiple pages may be combined into one aio_ call with one
bufferlist. Pages are allocated by the pager.
AFAICT, the C call provides reading into a contiguous buffer, whereas I
would like to read into a bufferlist. What would need to be done to add
support for this in rados?
Thanks,
Rutger
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