On 05/16/2017 10:03 AM, Michal Privoznik wrote: > This is just a wrapper over new functions that have been just > introduced: virStreamRecvFlags(), virStreamRecvHole(). It's very > similar to virStreamRecvAll() except it handles sparse streams > well. > > Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; > --- > include/libvirt/libvirt-stream.h | 33 ++++++++++- > src/libvirt-stream.c | 123 +++++++++++++++++++++++++++++++++++++++ > src/libvirt_public.syms | 1 + > 3 files changed, 154 insertions(+), 3 deletions(-) > [...] > diff --git a/src/libvirt-stream.c b/src/libvirt-stream.c > index bedb6159a..6bf4c4f29 100644 > --- a/src/libvirt-stream.c > +++ b/src/libvirt-stream.c > @@ -668,6 +668,129 @@ virStreamRecvAll(virStreamPtr stream, > } > > > +/** > + * virStreamSparseRecvAll: > + * @stream: pointer to the stream object > + * @handler: sink callback for writing data to application > + * @holeHandler: stream hole callback for skipping holes > + * @opaque: application defined data > + * > + * Receive the entire data stream, sending the data to the > + * requested data sink @handler and calling the skip @holeHandler > + * to generate holes for sparse stream targets. This is simply a > + * convenient alternative to virStreamRecvFlags, for apps that do > + * blocking-I/O. > + * > + * An example using this with a hypothetical file download > + * API looks like: > + * > + * int mysink(virStreamPtr st, const char *buf, int nbytes, void *opaque) { > + * int *fd = opaque; > + * > + * return write(*fd, buf, nbytes); > + * } > + * > + * int myskip(virStreamPtr st, long long offset, void *opaque) { > + * int *fd = opaque; > + * I think this is where perhaps the example of lseek in "off_t" chunks of "long long offset" would be applicable... Perhaps why I ended up in the off_t rathole before. > + * return lseek(*fd, offset, SEEK_CUR) == (off_t) -1 ? -1 : 0; > + * } > + * > + * virStreamPtr st = virStreamNew(conn, 0); > + * int fd = open("demo.iso", O_WRONLY); > + * > + * virConnectDownloadSparseFile(conn, st); ^^ This API doesn't exist... Of course neither did virConnectDownloadFile from whence you copied the example. Maybe both should be 'adjusted'. Reviewed-by: John Ferlan <jferlan(a)redhat.com&gt; John > + * if (virStreamSparseRecvAll(st, mysink, myskip, &fd) < 0) { > + * ...report an error ... > + * goto done; > + * } > + * if (virStreamFinish(st) < 0) > + * ...report an error... > + * virStreamFree(st); > + * close(fd); > + * > + * Note that @opaque data is shared between both @handler and > + * @holeHandler callbacks. > + * > + * Returns 0 if all the data was successfully received. The caller > + * should invoke virStreamFinish(st) to flush the stream upon > + * success and then virStreamFree(st). > + * > + * Returns -1 upon any error, with virStreamAbort() already > + * having been called, so the caller need only call virStreamFree(). > + */ [...]