--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/rust/lib-hedgewars-engine/src/ipc/queue.rs	Wed Jul 31 23:14:27 2019 +0200
@@ -0,0 +1,115 @@
+use hedgewars_engine_messages::{
+    messages::EngineMessage::*, messages::SyncedEngineMessage::*,
+    messages::UnsyncedEngineMessage::*, messages::*,
+};
+use queues::*;
+
+#[derive(PartialEq)]
+pub enum QueueChatStrategy {
+    NetworkGame,
+    LocalGame,
+}
+
+pub struct MessagesQueue {
+    strategy: QueueChatStrategy,
+    hi_ticks: u32,
+    unordered: Queue<EngineMessage>,
+    ordered: Queue<EngineMessage>,
+}
+
+impl MessagesQueue {
+    pub fn new(strategy: QueueChatStrategy) -> Self {
+        MessagesQueue {
+            strategy,
+            hi_ticks: 0,
+            unordered: queue![],
+            ordered: queue![],
+        }
+    }
+
+    fn is_unordered(&self, message: &EngineMessage) -> bool {
+        match message {
+            Unordered(_) => true,
+            Unsynced(HogSay(_)) | Unsynced(ChatMessage(_)) | Unsynced(TeamMessage(_)) => {
+                self.strategy == QueueChatStrategy::NetworkGame
+            }
+            _ => false,
+        }
+    }
+
+    pub fn push(&mut self, engine_message: EngineMessage) {
+        if self.is_unordered(&engine_message) {
+            self.unordered.add(engine_message).unwrap();
+        } else if let Synced(TimeWrap, timestamp) = engine_message {
+            self.ordered
+                .add(Synced(TimeWrap, timestamp + self.hi_ticks))
+                .unwrap();
+            self.hi_ticks += 65536;
+        } else if let Synced(message, timestamp) = engine_message {
+            self.ordered
+                .add(Synced(message, timestamp + self.hi_ticks))
+                .unwrap();
+        } else {
+            self.ordered.add(engine_message).unwrap();
+        }
+    }
+
+    pub fn pop(&mut self, timestamp: u32) -> Option<EngineMessage> {
+        if let Ok(message) = self.unordered.remove() {
+            Some(message)
+        } else if let Ok(Synced(_, message_timestamp)) = self.ordered.peek() {
+            if message_timestamp == timestamp {
+                self.ordered.remove().ok()
+            } else {
+                None
+            }
+        } else {
+            self.ordered.remove().ok()
+        }
+    }
+
+    pub fn iter(&mut self, timestamp: u32) -> MessagesQueueIterator {
+        MessagesQueueIterator {
+            timestamp,
+            queue: self,
+        }
+    }
+}
+
+pub struct MessagesQueueIterator<'a> {
+    timestamp: u32,
+    queue: &'a mut MessagesQueue,
+}
+
+impl<'a> Iterator for MessagesQueueIterator<'a> {
+    type Item = EngineMessage;
+
+    fn next(&mut self) -> Option<EngineMessage> {
+        self.queue.pop(self.timestamp)
+    }
+}
+
+#[test]
+fn queue_order() {
+    use hedgewars_engine_messages::messages::UnorderedEngineMessage::*;
+
+    let mut queue = MessagesQueue::new(QueueChatStrategy::LocalGame);
+
+    queue.push(Synced(Skip, 1));
+    queue.push(Unsynced(ChatMessage("hi".to_string())));
+    queue.push(Synced(TimeWrap, 65535));
+    queue.push(Unordered(Ping));
+    queue.push(Synced(Skip, 2));
+
+    let zero_tick: Vec<EngineMessage> = queue.iter(0).collect();
+    assert_eq!(zero_tick, vec![Unordered(Ping)]);
+    assert_eq!(queue.pop(1), Some(Synced(Skip, 1)));
+    assert_eq!(queue.pop(1), Some(Unsynced(ChatMessage("hi".to_string()))));
+    assert_eq!(queue.pop(1), None);
+    assert_eq!(queue.pop(2), None);
+    assert_eq!(queue.pop(65535), Some(Synced(TimeWrap, 65535)));
+    assert_eq!(queue.pop(65535), None);
+    assert_eq!(queue.pop(65538), Some(Synced(Skip, 65538)));
+    assert_eq!(queue.pop(65538), None);
+    assert_eq!(queue.pop(65539), None);
+}