From da7bb83b128343ea76f4f76503a0823296f2a09d Mon Sep 17 00:00:00 2001
From: Yannick Poirier <yannick.poirier@ses.com>
Date: Mon, 9 Sep 2024 13:46:21 +0200
Subject: [PATCH] Option to enable / disable the reception of objects only once

---
 src/receiver/receiver.rs | 16 +++++++++++-
 tests/flute.rs           | 54 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 69 insertions(+), 1 deletion(-)

diff --git a/src/receiver/receiver.rs b/src/receiver/receiver.rs
index 83d6fa0..e29d8ea 100644
--- a/src/receiver/receiver.rs
+++ b/src/receiver/receiver.rs
@@ -32,6 +32,9 @@ pub struct Config {
     pub object_max_cache_size: Option<usize>,
     /// Enable MD5 check of the received objects. Default `true`
     pub enable_md5_check: bool,
+    /// When set to `true`, the receiver will only reconstruct each object once.
+    /// If the same object is transferred again, it will be automatically discarded.
+    pub object_receive_once: bool,
 }
 
 impl Default for Config {
@@ -42,6 +45,7 @@ impl Default for Config {
             object_timeout: Some(Duration::from_secs(10)),
             object_max_cache_size: None,
             enable_md5_check: true,
+            object_receive_once: true
         }
     }
 }
@@ -295,7 +299,7 @@ impl Receiver {
             .map(|f| f.fdt_instance_id)
             .unwrap();
 
-        if self.is_fdt_received(fdt_instance_id) {
+        if self.config.object_receive_once && self.is_fdt_received(fdt_instance_id) {
             return Ok(());
         }
 
@@ -475,7 +479,17 @@ impl Receiver {
 
     fn push_obj(&mut self, pkt: &alc::AlcPkt, now: SystemTime) -> Result<()> {
         if self.objects_completed.contains_key(&pkt.lct.toi) {
+            if self.config.object_receive_once {
                 return Ok(());
+            }
+
+            let payload_id = alc::get_fec_inline_payload_id(pkt)?;
+            log::warn!("Object already received tsi={} toi={}", payload_id.sbn, payload_id.esi);
+            if payload_id.sbn == 0 && payload_id.esi == 0 {
+                self.objects_completed.remove(&pkt.lct.toi);
+            } else {
+                return Ok(());
+            }
         }
         if self.objects_error.contains(&pkt.lct.toi) {
 
diff --git a/tests/flute.rs b/tests/flute.rs
index 930e3a5..ced0d50 100644
--- a/tests/flute.rs
+++ b/tests/flute.rs
@@ -644,4 +644,58 @@ mod tests {
         let toi_result = sender.add_object(0, obj).unwrap();
         assert!(toi_value == toi_result);
     }
+
+    #[test]
+    pub fn test_receiver_disable_received_once() {
+        crate::tests::init();
+
+        let max_transfert_count = 5usize;
+        let oti: sender::Oti = Default::default();
+        let content_type = "application/octet-stream";
+
+        let (mut obj, _) = create_object(100000, content_type, sender::Cenc::Null, true, None);
+        obj.max_transfer_count = max_transfert_count as u32;
+        let output = Rc::new(receiver::writer::ObjectWriterBufferBuilder::new());
+        let mut receiver_config = receiver::Config::default();
+        receiver_config.object_receive_once = false;
+        let mut receiver =
+            receiver::MultiReceiver::new(output.clone(), Some(receiver_config), false);
+
+        let mut sender = create_sender(vec![obj], &oti, sender::Cenc::Null, None);
+
+        let endpoint = UDPEndpoint::new(None, "224.0.0.1".to_owned(), 5000);
+
+        loop {
+            let now_sender = std::time::SystemTime::now();
+            let data = sender.read(now_sender);
+            if data.is_none() {
+                break;
+            }
+
+            // Simulate reception 60s later -> FDT should be expired
+            let now_receiver = std::time::SystemTime::now() + std::time::Duration::from_secs(60);
+            receiver
+                .push(&endpoint, data.as_ref().unwrap(), now_receiver)
+                .unwrap();
+            receiver.cleanup(now_receiver);
+        }
+
+        let nb_complete_objects = output
+            .as_ref()
+            .objects
+            .borrow()
+            .iter()
+            .filter(|&obj| obj.borrow().complete)
+            .count();
+
+        let nb_error_objects = output
+            .as_ref()
+            .objects
+            .borrow()
+            .iter()
+            .filter(|&obj| obj.borrow().error)
+            .count();
+        assert!(nb_complete_objects == max_transfert_count);
+        assert!(nb_error_objects == 0);
+    }
 }