On 04/28/2016 04:04 AM, Michal Privoznik wrote:
This API can be used to tell the other side of the stream to skip
some bytes in the stream. This can be used to create a sparse
file on the receiving side of a stream.
It takes just one argument @offset, which says how big the hole
is. Since our streams are not rewindable like regular files, we
don't need @whence argument like seek(2) has.
Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com>
---
include/libvirt/libvirt-stream.h | 3 +++
src/driver-stream.h | 5 +++++
src/libvirt-stream.c | 40 ++++++++++++++++++++++++++++++++++++++++
src/libvirt_public.syms | 5 +++++
4 files changed, 53 insertions(+)
+++ b/src/libvirt-stream.c
@@ -286,6 +286,46 @@ virStreamRecv(virStreamPtr stream,
/**
+ * virStreamSkip:
+ * @stream: pointer to the stream object
+ * @offset: number of bytes to skip
+ *
+ * Skip @offset bytes in the stream. This is useful when there's
+ * no actual data in the stream, just a hole. If that's the case,
+ * this API can be used to skip the hole properly instead of
+ * transmitting zeroes to the other side.
+ *
+ * Returns 0 on success,
+ * -1 error
+ */
+int
+virStreamSkip(virStreamPtr stream,
+ unsigned long long offset)
'offset' is a bit misleading - you're not skipping _to_ the given
offset, so much as _over_ length bytes. I'd name it 'length'.
Otherwise looks okay.
--
Eric Blake eblake redhat com +1-919-301-3266
Libvirt virtualization library
http://libvirt.org