modules: cloud: Use pointer instead of message copy

Use a pointer instead of a complete message copy in the
cloud message convenience macro.
This saves memory.

Signed-off-by: Jan Tore Guggedal <jantore.guggedal@nordicsemi.no>

Author: jtguggedal

app/src/main.c

@@ -398,9 +398,9 @@ static void idle_run(void *o)
 	struct main_state *state_object = o;
 
 	if (state_object->chan == &CLOUD_CHAN) {
-		struct cloud_msg msg = MSG_TO_CLOUD_MSG(state_object->msg_buf);
+		const struct cloud_msg *msg = MSG_TO_CLOUD_MSG_PTR(state_object->msg_buf);
 
-		if (msg.type == CLOUD_CONNECTED) {
+		if (msg->type == CLOUD_CONNECTED) {
 			state_object->connected = true;
 			smf_set_state(SMF_CTX(state_object), &states[STATE_TRIGGERING]);
 			return;
@@ -452,17 +452,17 @@ static void triggering_run(void *o)
 	struct main_state *state_object = o;
 
 	if (state_object->chan == &CLOUD_CHAN) {
-		struct cloud_msg msg = MSG_TO_CLOUD_MSG(state_object->msg_buf);
+		const struct cloud_msg *msg = MSG_TO_CLOUD_MSG_PTR(state_object->msg_buf);
 
-		if (msg.type == CLOUD_DISCONNECTED) {
+		if (msg->type == CLOUD_DISCONNECTED) {
 			state_object->connected = false;
 			smf_set_state(SMF_CTX(state_object), &states[STATE_IDLE]);
 			return;
 		}
 
-		if (msg.type == CLOUD_SHADOW_RESPONSE) {
-			err = get_update_interval_from_cbor_response(msg.response.buffer,
-								     msg.response.buffer_data_len,
+		if (msg->type == CLOUD_SHADOW_RESPONSE) {
+			err = get_update_interval_from_cbor_response(msg->response.buffer,
+								     msg->response.buffer_data_len,
 								     &state_object->interval_sec);
 			if (err) {
 				LOG_ERR("get_update_interval_from_cbor_response, error: %d", err);

app/src/modules/cloud/cloud_module.c

@@ -669,10 +669,10 @@ static void state_connected_ready_run(void *o)
 #endif /* CONFIG_APP_ENVIRONMENTAL */
 
 	if (state_object->chan == &CLOUD_CHAN) {
-		const struct cloud_msg msg = MSG_TO_CLOUD_MSG(state_object->msg_buf);
+		const struct cloud_msg *msg = MSG_TO_CLOUD_MSG_PTR(state_object->msg_buf);
 
-		if (msg.type == CLOUD_PAYLOAD_JSON) {
-			err = nrf_cloud_coap_json_message_send(msg.payload.buffer,
+		if (msg->type == CLOUD_PAYLOAD_JSON) {
+			err = nrf_cloud_coap_json_message_send(msg->payload.buffer,
 							       false, confirmable);
 			if (err == -ENETUNREACH) {
 				LOG_WRN("Network is unreachable, error: %d", err);
@@ -682,7 +682,7 @@ static void state_connected_ready_run(void *o)
 				SEND_FATAL_ERROR();
 				return;
 			}
-		} else if (msg.type == CLOUD_POLL_SHADOW) {
+		} else if (msg->type == CLOUD_POLL_SHADOW) {
 			LOG_DBG("Poll shadow trigger received");
 
 			shadow_get(true);

app/src/modules/cloud/cloud_module.h

@@ -48,7 +48,8 @@ struct cloud_msg {
 	};
 };
 
-#define MSG_TO_CLOUD_MSG(_msg)	(*(const struct cloud_msg *)_msg)
+/* Cast a pointer to a message to a pointer to a cloud message */
+#define MSG_TO_CLOUD_MSG_PTR(_msg)	((const struct cloud_msg *)_msg)
 
 #ifdef __cplusplus
 }