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

On 05/16/2017 10:03 AM, Michal Privoznik wrote: > 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. */ Well... If it's publicly accessible... @data and @length should probably be checked for non NULL.