Add function remove last bcm frame

This commit creates the function remove_last_bcm_frame.
This function removes the last bcm frame of the subscription.

Bug-AGL : SPEC-2779

Change-Id: I5bb6f07a8d677c4aa882549fc1950f00a0b1da04
Signed-off-by: Arthur Guyader <arthur.guyader@iot.bzh>

2 files changed, 12 insertions, 0 deletions

diff --git a/low-can-binding/binding/low-can-subscription.cpp b/low-can-binding/binding/low-can-subscription.cpp
index a1187edd..bec3ad63 100644
--- a/low-can-binding/binding/low-can-subscription.cpp
+++ b/low-can-binding/binding/low-can-subscription.cpp
@@ -353,6 +353,17 @@ void low_can_subscription_t::add_one_bcm_frame(struct canfd_frame& cfd, struct b
 	bcm_msg.msg_head.nframes++;
 }
 
+/// @brief Take an existing bcm_msg struct and add a can_frame.
+/// Currently only 1 uniq can_frame can be added, it's not possible to build
+/// a multiplexed message with several can_frame.
+void low_can_subscription_t::remove_last_bcm_frame(struct bcm_msg& bcm_msg)
+{
+	struct canfd_frame cf;
+	memset(&cf,0,sizeof(cf));
+	bcm_msg.fd_frames[bcm_msg.msg_head.nframes] = cf;
+	bcm_msg.msg_head.nframes--;
+}
+
 #ifdef USE_FEATURE_J1939
 int low_can_subscription_t::create_rx_filter_j1939(low_can_subscription_t &subscription, std::shared_ptr<signal_t> sig)
 {
diff --git a/low-can-binding/binding/low-can-subscription.hpp b/low-can-binding/binding/low-can-subscription.hpp
index d0462ecb..b5d4f7aa 100644
--- a/low-can-binding/binding/low-can-subscription.hpp
+++ b/low-can-binding/binding/low-can-subscription.hpp
@@ -93,6 +93,7 @@ public:
 
 	static struct bcm_msg make_bcm_head(uint32_t opcode, uint32_t can_id = 0, uint32_t flags = 0, const struct timeval& timeout = {0,0}, const struct timeval& frequency_thinning = {0,0});
 	static void add_one_bcm_frame(struct canfd_frame& cfd, struct bcm_msg& bcm_msg);
+	static void remove_last_bcm_frame(struct bcm_msg& bcm_msg);
 
 	static int open_socket(low_can_subscription_t &subscription, const std::string& bus_name = "", socket_type type = socket_type::INVALID);