Add a "ctrl" mechanism to bufferevents for property access.

OpenSSL uses something like this to implement get/set access for
properties on its BIOs, so that it doesn't need to add a pair of
get/set functions to the vtable struct for every new abstract property
it provides an accessor for.

Doing this lets us make bufferevent_setfd abstract, and implement an
abstract bufferevent_getfd.

svn:r1284

1 files changed, 38 insertions, 0 deletions

diff --git a/bufferevent.c b/bufferevent.c
index 2d614dae..06386844 100644
--- a/bufferevent.c
+++ b/bufferevent.c
@@ -531,3 +531,41 @@ bufferevent_enable_locking(struct bufferevent *bufev, void *lock)
 #endif
 }
 
+int
+bufferevent_setfd(struct bufferevent *bev, evutil_socket_t fd)
+{
+	union bufferevent_ctrl_data d;
+	int res = -1;
+	d.fd = fd;
+	BEV_LOCK(bev);
+	if (bev->be_ops->ctrl)
+		res = bev->be_ops->ctrl(bev, BEV_CTRL_SET_FD, &d);
+	BEV_UNLOCK(bev);
+	return res;
+}
+
+evutil_socket_t
+bufferevent_getfd(struct bufferevent *bev)
+{
+	union bufferevent_ctrl_data d;
+	int res = -1;
+	d.fd = -1;
+	BEV_LOCK(bev);
+	if (bev->be_ops->ctrl)
+		res = bev->be_ops->ctrl(bev, BEV_CTRL_GET_FD, &d);
+	BEV_UNLOCK(bev);
+	return (res<0) ? -1 : d.fd;
+}
+
+struct bufferevent *
+bufferevent_get_underlying(struct bufferevent *bev)
+{
+	union bufferevent_ctrl_data d;
+	int res = -1;
+	d.ptr = NULL;
+	BEV_LOCK(bev);
+	if (bev->be_ops->ctrl)
+		res = bev->be_ops->ctrl(bev, BEV_CTRL_GET_UNDERLYING, &d);
+	BEV_UNLOCK(bev);
+	return (res<0) ? NULL : d.ptr;
+}