Add tcp capacity impls

embassy-net/src/tcp.rs

@@ -93,6 +93,11 @@ impl<'a> TcpReader<'a> {
     {
         self.io.read_with(f).await
     }
+
+    /// Return the maximum number of bytes inside the transmit buffer.
+    pub fn recv_capacity(&self) -> usize {
+        self.io.recv_capacity()
+    }
 }
 
 impl<'a> TcpWriter<'a> {
@@ -122,6 +127,11 @@ impl<'a> TcpWriter<'a> {
     {
         self.io.write_with(f).await
     }
+
+    /// Return the maximum number of bytes inside the transmit buffer.
+    pub fn send_capacity(&self) -> usize {
+        self.io.send_capacity()
+    }
 }
 
 impl<'a> TcpSocket<'a> {
@@ -143,6 +153,16 @@ impl<'a> TcpSocket<'a> {
         }
     }
 
+    /// Return the maximum number of bytes inside the recv buffer.
+    pub fn recv_capacity(&self) -> usize {
+        self.io.recv_capacity()
+    }
+
+    /// Return the maximum number of bytes inside the transmit buffer.
+    pub fn send_capacity(&self) -> usize {
+        self.io.send_capacity()
+    }
+
     /// Call `f` with the largest contiguous slice of octets in the transmit buffer,
     /// and enqueue the amount of elements returned by `f`.
     ///
@@ -478,6 +498,14 @@ impl<'d> TcpIo<'d> {
         })
         .await
     }
+
+    fn recv_capacity(&self) -> usize {
+        self.with(|s, _| s.recv_capacity())
+    }
+
+    fn send_capacity(&self) -> usize {
+        self.with(|s, _| s.send_capacity())
+    }
 }
 
 #[cfg(feature = "nightly")]