[Libguestfs] [PATCH libnbd 2/3] states: Add handle h->wflags field.

[Richard W.M. Jones]

This field contains optimization flags (ie. MSG_MORE) which are passed
through to the socket layer if it supports them.  The flags are reset
automatically when we move to another state.
---
 generator/states.c | 6 ++++--
 lib/internal.h     | 1 +
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/generator/states.c b/generator/states.c
index e879a83..36cca37 100644
--- a/generator/states.c
+++ b/generator/states.c
@@ -92,7 +92,7 @@ send_from_wbuf (struct nbd_handle *h)
 
   if (h->wlen == 0)
     return 0;                   /* move to next state */
-  r = h->sock->ops->send (h, h->sock, h->wbuf, h->wlen, 0);
+  r = h->sock->ops->send (h, h->sock, h->wbuf, h->wlen, h->wflags);
   if (r == -1) {
     if (errno == EAGAIN || errno == EWOULDBLOCK)
       return 1;                 /* more data */
@@ -101,8 +101,10 @@ send_from_wbuf (struct nbd_handle *h)
   }
   h->wbuf += r;
   h->wlen -= r;
-  if (h->wlen == 0)
+  if (h->wlen == 0) {
+    h->wflags = 0;              /* reset this when moving to next state */
     return 0;                   /* move to next state */
+  }
   else
     return 1;                   /* more data */
 }
diff --git a/lib/internal.h b/lib/internal.h
index 1ffb5b7..e7be05b 100644
--- a/lib/internal.h
+++ b/lib/internal.h
@@ -110,6 +110,7 @@ struct nbd_handle {
   /* As above, but for writing using send_from_wbuf. */
   const void *wbuf;
   size_t wlen;
+  int wflags;
 
   /* Static buffer used for short amounts of data, such as handshake
    * and commands.
-- 
2.21.0