[libvirt] [PATCH v3 24/31] virNetClientStream: Wire up VIR_NET_STREAM_HOLE

[Michal Privoznik]

Whenever server sends a client stream packet (either regular with
actual data or stream skip one) it is queued on @st->rx. So the
list is a mixture of both types of stream packets. So now that we
have all the helpers needed we can wire their processing up. But
since virNetClientStreamRecvPacket doesn't support
VIR_STREAM_RECV_STOP_AT_HOLE flag yet, let's turn all received
skips into zeroes repeating requested times.

Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
---
 src/rpc/virnetclientstream.c | 45 ++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 43 insertions(+), 2 deletions(-)

diff --git a/src/rpc/virnetclientstream.c b/src/rpc/virnetclientstream.c
index bf3922cb5..75ec3f57f 100644
--- a/src/rpc/virnetclientstream.c
+++ b/src/rpc/virnetclientstream.c
@@ -295,6 +295,8 @@ int virNetClientStreamQueuePacket(virNetClientStreamPtr st,
 
     virObjectLock(st);
 
+    /* Don't distinguish VIR_NET_STREAM and VIR_NET_STREAM_SKIP
+     * here just yet. We want in order processing! */
     virNetMessageQueuePush(&st->rx, tmp_msg);
 
     virNetClientStreamEventTimerUpdate(st);
@@ -390,7 +392,7 @@ virNetClientStreamSetHole(virNetClientStreamPtr st,
  * Returns: 0 on success,
  *          -1 otherwise.
  */
-static int ATTRIBUTE_UNUSED
+static int
 virNetClientStreamHandleHole(virNetClientPtr client,
                              virNetClientStreamPtr st)
 {
@@ -468,6 +470,8 @@ int virNetClientStreamRecvPacket(virNetClientStreamPtr st,
     virCheckFlags(0, -1);
 
     virObjectLock(st);
+
+ reread:
     if (!st->rx && !st->incomingEOF) {
         virNetMessagePtr msg;
         int ret;
@@ -499,8 +503,45 @@ int virNetClientStreamRecvPacket(virNetClientStreamPtr st,
     }
 
     VIR_DEBUG("After IO rx=%p", st->rx);
+
+    if (st->rx &&
+        st->rx->header.type == VIR_NET_STREAM_HOLE &&
+        st->holeLength == 0) {
+        /* Handle skip sent to us by server. */
+
+        if (virNetClientStreamHandleHole(client, st) < 0)
+            goto cleanup;
+    }
+
+    if (!st->rx && !st->incomingEOF && !st->holeLength) {
+        if (nonblock) {
+            VIR_DEBUG("Non-blocking mode and no data available");
+            rv = -2;
+            goto cleanup;
+        }
+
+        /* We have consumed all packets from incoming queue but those
+         * were only skip packets, no data. Read the stream again. */
+        goto reread;
+    }
+
     want = nbytes;
-    while (want && st->rx) {
+
+    if (st->holeLength) {
+        /* Pretend holeLength zeroes was read from stream. */
+        size_t len = want;
+
+        if (len > st->holeLength)
+            len = st->holeLength;
+
+        memset(data, 0, len);
+        st->holeLength -= len;
+        want -= len;
+    }
+
+    while (want &&
+           st->rx &&
+           st->rx->header.type == VIR_NET_STREAM) {
         virNetMessagePtr msg = st->rx;
         size_t len = want;
 
-- 
2.13.0