[PATCH v2 2/3] rpc: Introduce virNetClientStreamInData()
The aim of this function is to look at a virNetClientStream and
tell whether the incoming packet (if there's one) contains data
(type VIR_NET_STREAM) or a hole (type VIR_NET_STREAM_HOLE) and
how big the section is. This function will be called from the
remote driver in one of future commits.
Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com>
---
diff to v1:
- initialize ret to -1
- lock stream even for checking allowSkip
- return 1 only if message was really popped from the queue
- If there's no incoming message, return the size of yet unprocessed
hole. This size should always be zero though, because at EOF there's
a hole of size 0. I have not met this case and I probably never
will, but I figured it's better to be safe than sorry.
src/libvirt_remote.syms | 1 +
src/rpc/virnetclientstream.c | 64 ++++++++++++++++++++++++++++++++++++
src/rpc/virnetclientstream.h | 4 +++
3 files changed, 69 insertions(+)
diff --git a/src/libvirt_remote.syms b/src/libvirt_remote.syms
index 942e1013a6..07d22e368b 100644
--- a/src/libvirt_remote.syms
+++ b/src/libvirt_remote.syms
@@ -66,6 +66,7 @@ virNetClientStreamEOF;
virNetClientStreamEventAddCallback;
virNetClientStreamEventRemoveCallback;
virNetClientStreamEventUpdateCallback;
+virNetClientStreamInData;
virNetClientStreamMatches;
virNetClientStreamNew;
virNetClientStreamQueuePacket;
diff --git a/src/rpc/virnetclientstream.c b/src/rpc/virnetclientstream.c
index 1ba6167a1d..eb4dc6854d 100644
--- a/src/rpc/virnetclientstream.c
+++ b/src/rpc/virnetclientstream.c
@@ -801,3 +801,67 @@ bool virNetClientStreamEOF(virNetClientStream *st)
{
return st->incomingEOF;
}
+
+
+int virNetClientStreamInData(virNetClientStream *st,
+ int *inData,
+ long long *length)
+{
+ int ret = -1;
+ bool msgPopped = false;
+ virNetMessage *msg = NULL;
+
+ virObjectLock(st);
+
+ if (!st->allowSkip) {
+ virReportError(VIR_ERR_OPERATION_INVALID, "%s",
+ _("Holes are not supported with this stream"));
+ goto cleanup;
+ }
+
+ if (virNetClientStreamCheckState(st) < 0)
+ goto cleanup;
+
+ msg = st->rx;
+
+ if (!msg) {
+ /* No incoming message. This means that the stream is at its end. In
+ * this case, virStreamInData() should set both inData and length to
+ * zero and return success. If there is a trailing hole though (there
+ * shouldn't be), signal that to the caller. */
+ *inData = 0;
+ *length = st->holeLength;
+ st->holeLength = 0;
+ } else if (msg->header.type == VIR_NET_STREAM) {
+ *inData = 1;
+ *length = msg->bufferLength - msg->bufferOffset;
+ } else if (msg->header.type == VIR_NET_STREAM_HOLE) {
+ *inData = 0;
+
+ if (st->holeLength == 0) {
+ if (virNetClientStreamHandleHole(NULL, st) < 0)
+ goto cleanup;
+
+ /* virNetClientStreamHandleHole() called above did pop the message from
+ * the queue (and freed it). Instead of trying to push it back let's
+ * just signal to the caller what we did. */
+ msgPopped = true;
+ }
+
+ *length = st->holeLength;
+ st->holeLength = 0;
+ } else {
+ virReportError(VIR_ERR_INTERNAL_ERROR,
+ _("Invalid message prog=%d type=%d serial=%u proc=%d"),
+ msg->header.prog,
+ msg->header.type,
+ msg->header.serial,
+ msg->header.proc);
+ goto cleanup;
+ }
+
+ ret = msgPopped ? 1 : 0;
+ cleanup:
+ virObjectUnlock(st);
+ return ret;
+}
diff --git a/src/rpc/virnetclientstream.h b/src/rpc/virnetclientstream.h
index e16d6e4a9a..7428843f9b 100644
--- a/src/rpc/virnetclientstream.h
+++ b/src/rpc/virnetclientstream.h
@@ -90,3 +90,7 @@ int virNetClientStreamEventRemoveCallback(virNetClientStream *st);
bool virNetClientStreamEOF(virNetClientStream *st)
ATTRIBUTE_NONNULL(1);
+
+int virNetClientStreamInData(virNetClientStream *st,
+ int *inData,
+ long long *length);
--
2.32.0