On 04/28/2016 04:04 AM, Michal Privoznik wrote:
The former is a public API and registers a callback that will be called whenever the other side of a stream calls virStreamSkip. The latter is a wrapper that actually calls the callback. It is not made public as it is intended to be used purely internally.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com> ---
+/** + * virStreamSkipFunc: + * @stream: stream + * @offset: size of hole in bytes
Again, naming this 'length' makes more sense (you're not skipping TO a particular offset, but OVER a given length).
+++ b/src/libvirt-stream.c @@ -286,6 +286,76 @@ virStreamRecv(virStreamPtr stream,
/** + * virStreamRegisterSkip: + * @stream: stream + * @skipCb: callback function + * @opaque: optional application provided data + * + * This function registers callback that will be called whenever
s/callback/a callback/
+ * the other side of the @stream is willing to skip a hole in the + * stream. + * + * Returns 0 on success, + * -1 otherwise. + */ +int +virStreamRegisterSkip(virStreamPtr stream, + virStreamSkipFunc skipCb, + void *opaque) +{ + VIR_DEBUG("stream=%p, skipCb=%p opaque=%p", stream, skipCb, opaque); + + virResetLastError(); + + virCheckStreamReturn(stream, -1); + virCheckNonNullArgReturn(skipCb, -1); + + if (stream->skipCb) { + virReportError(VIR_ERR_OPERATION_INVALID, "%s", + _("A skip callback is already registered")); + return -1;
I guess that means we allow passing skipCb=NULL to deregister a callback; does it need to be specifically documented? Are there scenarios where you WANT to deregister before closing something else, to make sure that a stale callback is not called during a race scenario?
+int +virStreamSkipCallback(virStreamPtr stream, + unsigned long long offset) +{ + VIR_DEBUG("stream=%p, offset=%llu", stream, offset); + + virCheckStreamReturn(stream, -1); + + if (stream->skipCb) { + int ret; + ret = (stream->skipCb)(stream, offset, stream->skipCbOpaque);
I might have omitted the () around stream->skipCb, but I don't know if we have a consistent style, and yours makes it obvious that we know we are dereferencing a function pointer.
+++ b/src/libvirt_public.syms @@ -735,6 +735,7 @@ LIBVIRT_1.3.3 { LIBVIRT_1.3.5 { global: virStreamSkip; + virStreamRegisterSkip;
Worth keeping sorted? -- Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org