From d2ef6d97418c32ef872d2ef5f8800d6141c98887 Mon Sep 17 00:00:00 2001
From: Thomas Kolb <cfr34k-git@tkolb.de>
Date: Sat, 27 Jul 2024 00:50:04 +0200
Subject: [PATCH] Remove empty packets from the queue after their first
 transmission

---
 impl/src/layer2/layer2_tx.c | 13 +++++++++++++
 impl/src/layer2/layer2_tx.h |  4 ++++
 impl/src/main.c             |  2 ++
 3 files changed, 19 insertions(+)

diff --git a/impl/src/layer2/layer2_tx.c b/impl/src/layer2/layer2_tx.c
index fdff035..1e0bb7f 100644
--- a/impl/src/layer2/layer2_tx.c
+++ b/impl/src/layer2/layer2_tx.c
@@ -160,6 +160,19 @@ void layer2_tx_restart(layer2_tx_t *ctx)
 }
 
 
+void layer2_tx_clean_empty_packet(layer2_tx_t *ctx)
+{
+	const packet_queue_entry_t *entry = packet_queue_get(&ctx->packet_queue, 0);
+	if(entry && entry->header.msg_type == L2_MSG_TYPE_EMPTY) {
+		packet_queue_delete(&ctx->packet_queue, 1);
+
+		if(ctx->next_packet_index > 0) {
+			ctx->next_packet_index--;
+		}
+	}
+}
+
+
 void layer2_tx_handle_ack(layer2_tx_t *ctx, uint8_t acked_seq, bool do_ack)
 {
 	ctx->next_packet_index = 0;
diff --git a/impl/src/layer2/layer2_tx.h b/impl/src/layer2/layer2_tx.h
index 04a256d..6376932 100644
--- a/impl/src/layer2/layer2_tx.h
+++ b/impl/src/layer2/layer2_tx.h
@@ -57,6 +57,10 @@ size_t layer2_tx_encode_next_packet(layer2_tx_t *ctx, uint8_t ack_seq_nr, uint8_
  */
 void layer2_tx_restart(layer2_tx_t *ctx);
 
+/*!\brief Remove the first packet from the queue if it is an empty packet.
+ */
+void layer2_tx_clean_empty_packet(layer2_tx_t *ctx);
+
 /*!\brief Handle acknowledgements.
  * \details
  * Removes all packets before the given sequence number from the queue.
diff --git a/impl/src/main.c b/impl/src/main.c
index 26d4242..a2d31cd 100644
--- a/impl/src/main.c
+++ b/impl/src/main.c
@@ -284,6 +284,8 @@ int main(int argc, char **argv)
 				// generate the ramp-down
 				RESULT_CHECK(layer1_tx_finalize_burst(&tx));
 
+				layer2_tx_clean_empty_packet(&l2tx);
+
 				size_t burst_len = layer1_tx_get_sample_count(&tx);
 				const float complex *whole_burst = layer1_tx_get_sample_data(&tx);