From 9994d24749127681b65ff3feb625a33b056e4515 Mon Sep 17 00:00:00 2001
From: Jakub Horak <jakub.horak@ibawizard.net>
Date: Thu, 8 Jun 2023 07:37:00 +0200
Subject: [PATCH] Add `len` method for `UnboundedSender`

Add `len` method to inspect how many messages are enqueued in the
message queue.
---
 futures-channel/src/mpsc/mod.rs | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/futures-channel/src/mpsc/mod.rs b/futures-channel/src/mpsc/mod.rs
index edbac7aa3..6e88c2626 100644
--- a/futures-channel/src/mpsc/mod.rs
+++ b/futures-channel/src/mpsc/mod.rs
@@ -836,6 +836,15 @@ impl<T> UnboundedSender<T> {
         let ptr = self.0.as_ref().map(|inner| inner.ptr());
         ptr.hash(hasher);
     }
+
+    /// Return the number of messages in the queue or 0 if channel is disconnected.
+    pub fn len(&self) -> usize {
+        if let Some(sender) = &self.0 {
+            decode_state(sender.inner.state.load(SeqCst)).num_messages
+        } else {
+            0
+        }
+    }
 }
 
 impl<T> Clone for Sender<T> {