From bbeba7f014b383568e999650f0d954a33955ce73 Mon Sep 17 00:00:00 2001
From: Oliver Rockstedt <info@sourcebox.de>
Date: Wed, 22 May 2024 14:54:09 +0200
Subject: [PATCH] embassy-sync: Add clear function to all channels

---
 embassy-sync/CHANGELOG.md             |  6 +++---
 embassy-sync/src/channel.rs           |  9 +++++++++
 embassy-sync/src/priority_channel.rs  |  9 +++++++++
 embassy-sync/src/pubsub/mod.rs        | 16 ++++++++++++++++
 embassy-sync/src/pubsub/publisher.rs  | 10 ++++++++++
 embassy-sync/src/pubsub/subscriber.rs |  5 +++++
 6 files changed, 52 insertions(+), 3 deletions(-)

diff --git a/embassy-sync/CHANGELOG.md b/embassy-sync/CHANGELOG.md
index bb919b28a..e5c453ce2 100644
--- a/embassy-sync/CHANGELOG.md
+++ b/embassy-sync/CHANGELOG.md
@@ -7,9 +7,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## Unreleased
 
-- Add `capacity`, `free_capacity`, `len`, `is_empty` and `is_full` functions to `Channel`.
-- Add `capacity`, `free_capacity`, `len`, `is_empty` and `is_full` functions to `PriorityChannel`.
-- Add `capacity`, `free_capacity`, `len`, `is_empty` and `is_full` functions to `PubSubChannel`.
+- Add `capacity`, `free_capacity`, `clear`, `len`, `is_empty` and `is_full` functions to `Channel`.
+- Add `capacity`, `free_capacity`, `clear`, `len`, `is_empty` and `is_full` functions to `PriorityChannel`.
+- Add `capacity`, `free_capacity`, `clear`, `len`, `is_empty` and `is_full` functions to `PubSubChannel`.
 - Made `PubSubBehavior` sealed
   - If you called `.publish_immediate(...)` on the queue directly before, then now call `.immediate_publisher().publish_immediate(...)`
 
diff --git a/embassy-sync/src/channel.rs b/embassy-sync/src/channel.rs
index b124a885f..55ac5fb66 100644
--- a/embassy-sync/src/channel.rs
+++ b/embassy-sync/src/channel.rs
@@ -477,6 +477,10 @@ impl<T, const N: usize> ChannelState<T, N> {
         }
     }
 
+    fn clear(&mut self) {
+        self.queue.clear();
+    }
+
     fn len(&self) -> usize {
         self.queue.len()
     }
@@ -632,6 +636,11 @@ where
         N - self.len()
     }
 
+    /// Clears all elements in the channel.
+    pub fn clear(&self) {
+        self.lock(|c| c.clear());
+    }
+
     /// Returns the number of elements currently in the channel.
     pub fn len(&self) -> usize {
         self.lock(|c| c.len())
diff --git a/embassy-sync/src/priority_channel.rs b/embassy-sync/src/priority_channel.rs
index 2954d1b76..24c6c5a7f 100644
--- a/embassy-sync/src/priority_channel.rs
+++ b/embassy-sync/src/priority_channel.rs
@@ -315,6 +315,10 @@ where
         }
     }
 
+    fn clear(&mut self) {
+        self.queue.clear();
+    }
+
     fn len(&self) -> usize {
         self.queue.len()
     }
@@ -458,6 +462,11 @@ where
         N - self.len()
     }
 
+    /// Clears all elements in the channel.
+    pub fn clear(&self) {
+        self.lock(|c| c.clear());
+    }
+
     /// Returns the number of elements currently in the channel.
     pub fn len(&self) -> usize {
         self.lock(|c| c.len())
diff --git a/embassy-sync/src/pubsub/mod.rs b/embassy-sync/src/pubsub/mod.rs
index 637336d9d..66c9b0017 100644
--- a/embassy-sync/src/pubsub/mod.rs
+++ b/embassy-sync/src/pubsub/mod.rs
@@ -173,6 +173,11 @@ impl<M: RawMutex, T: Clone, const CAP: usize, const SUBS: usize, const PUBS: usi
         CAP - self.len()
     }
 
+    /// Clears all elements in the channel.
+    pub fn clear(&self) {
+        self.inner.lock(|inner| inner.borrow_mut().clear());
+    }
+
     /// Returns the number of elements currently in the channel.
     pub fn len(&self) -> usize {
         self.inner.lock(|inner| inner.borrow().len())
@@ -270,6 +275,10 @@ impl<M: RawMutex, T: Clone, const CAP: usize, const SUBS: usize, const PUBS: usi
         self.free_capacity()
     }
 
+    fn clear(&self) {
+        self.clear();
+    }
+
     fn len(&self) -> usize {
         self.len()
     }
@@ -407,6 +416,10 @@ impl<T: Clone, const CAP: usize, const SUBS: usize, const PUBS: usize> PubSubSta
         self.publisher_count -= 1;
     }
 
+    fn clear(&mut self) {
+        self.queue.clear();
+    }
+
     fn len(&self) -> usize {
         self.queue.len()
     }
@@ -460,6 +473,9 @@ trait SealedPubSubBehavior<T> {
     /// This is equivalent to `capacity() - len()`
     fn free_capacity(&self) -> usize;
 
+    /// Clears all elements in the channel.
+    fn clear(&self);
+
     /// Returns the number of elements currently in the channel.
     fn len(&self) -> usize;
 
diff --git a/embassy-sync/src/pubsub/publisher.rs b/embassy-sync/src/pubsub/publisher.rs
index 26e2c63b7..e66b3b1db 100644
--- a/embassy-sync/src/pubsub/publisher.rs
+++ b/embassy-sync/src/pubsub/publisher.rs
@@ -55,6 +55,11 @@ impl<'a, PSB: PubSubBehavior<T> + ?Sized, T: Clone> Pub<'a, PSB, T> {
         self.channel.free_capacity()
     }
 
+    /// Clears all elements in the ***channel***.
+    pub fn clear(&self) {
+        self.channel.clear();
+    }
+
     /// Returns the number of elements currently in the ***channel***.
     pub fn len(&self) -> usize {
         self.channel.len()
@@ -155,6 +160,11 @@ impl<'a, PSB: PubSubBehavior<T> + ?Sized, T: Clone> ImmediatePub<'a, PSB, T> {
         self.channel.free_capacity()
     }
 
+    /// Clears all elements in the ***channel***.
+    pub fn clear(&self) {
+        self.channel.clear();
+    }
+
     /// Returns the number of elements currently in the ***channel***.
     pub fn len(&self) -> usize {
         self.channel.len()
diff --git a/embassy-sync/src/pubsub/subscriber.rs b/embassy-sync/src/pubsub/subscriber.rs
index 2e2bd26a9..6ad660cb3 100644
--- a/embassy-sync/src/pubsub/subscriber.rs
+++ b/embassy-sync/src/pubsub/subscriber.rs
@@ -83,6 +83,11 @@ impl<'a, PSB: PubSubBehavior<T> + ?Sized, T: Clone> Sub<'a, PSB, T> {
         self.channel.free_capacity()
     }
 
+    /// Clears all elements in the ***channel***.
+    pub fn clear(&self) {
+        self.channel.clear();
+    }
+
     /// Returns the number of elements currently in the ***channel***.
     /// See [Self::available] for how many messages are available for this subscriber.
     pub fn len(&self) -> usize {