Re: [libvirt] [PATCH v3 10/31] Introduce virStreamInData

This is just an internal API, that calls corresponding function in stream driver. This function will set @data=1 if the underlying file is in data section, or @data=0 if it is in a hole. At any rate, @length is set to number of bytes remaining in the section the file currently is. Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; --- src/driver-stream.h | 6 ++++++ src/libvirt-stream.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ src/libvirt_internal.h | 4 ++++ src/libvirt_private.syms | 1 + 4 files changed, 59 insertions(+)

diff --git a/src/libvirt-stream.c b/src/libvirt-stream.c index 4cbe5eee1..30c305035 100644 --- a/src/libvirt-stream.c +++ b/src/libvirt-stream.c @@ -481,6 +481,54 @@ virStreamRecvHole(virStreamPtr stream, } +/** + * virStreamInData: + * @stream: stream + * @data: are we in data or hole + * @length: length to next section + * + * This function checks the underlying stream (typically a file) + * to learn whether the current stream position lies within a + * data section or a hole. Upon return @data is set to a nonzero + * value if former is the case, or to zero if @stream is in a + * hole. Moreover, @length is updated to tell caller how many + * bytes can be read from @stream until current section changes + * (from data to a hole or vice versa). + * + * NB: there's an implicit hole at EOF. In this situation this + * function should set @data = false, @length = 0 and return 0. + * + * To sum it up: + * + * data section: @data = true, @length > 0 + * hole: @data = false, @length > 0 + * EOF: @data = false, @length = 0 + * + * Returns 0 on success, + * -1 otherwise + */ +int +virStreamInData(virStreamPtr stream, + int *data, + long long *length) +{ + VIR_DEBUG("stream=%p, data=%p, length=%p", stream, data, length); + + /* No checks of arguments or error resetting. This is an + * internal function that just happen to live next to some + * public functions of ours. */