Commit Graph

2 Commits

Author SHA1 Message Date
Ben Walker
c802adc776 util: Add spdk_ioviter for iterating iovecs
spdk_ioviter_next will walk through two iovecs and yield pointers
to common length segments. For example, given a source iovec (siov) with
4 1KiB elements and a destination iovec (diov) with 1 4KiB element, the
following will happen:

first spdk_ioviter_next:

src = siov[0].iov_base
dst = diov[0].iov_base
len = 1KiB

second spdk_ioviter_next:

src = siov[1].iov_base
dst = diov[0].iov_base + 1KiB
len = 1KiB

third spdk_ioviter_next:

src = siov[2].iov_base
dst = diov[0].iov_base + 2KiB
len = 1KiB

fourth spdk_ioviter_next:

src = siov[3].iov_base
dst = diov[0].iov_base + 3KiB
len = 1KiB

fifth spdk_ioviter_next:

len = 0

This is a useful utility for performing operations where both the source
and destination are scattered memory. As an example and a test vehicle,
spdk_iovcpy has been updated to use this internally.

Change-Id: I7e35e76d38e78d07ea1caf6282d0dfc02182aa83
Signed-off-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/10284
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Community-CI: Mellanox Build Bot
Reviewed-by: Changpeng Liu <changpeng.liu@intel.com>
Reviewed-by: Konrad Sztyber <konrad.sztyber@intel.com>
Reviewed-by: Paul Luse <paul.e.luse@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
2022-06-30 13:32:29 -04:00
Ben Walker
e475586b2a util: Add spdk_iovcpy, an iovec to iovec copy function.
Like memcpy, but works on two iovecs.

Change-Id: Ia1cf462a95690286f0c19325fc10937b9ba6baf3
Signed-off-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/473976
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
2019-11-20 09:35:32 +00:00