proxmox-async: imported pbs-tools/src/tokio/tokio_writer_adapter.rs

Signed-off-by: Dietmar Maurer <dietmar@proxmox.com>

proxmox-async/debian/changelog

@@ -1,5 +1,7 @@
 rust-proxmox-async (0.1.0) stable; urgency=medium
 
+  * imported pbs-tools/src/tokio/tokio_writer_adapter.rs
+
   * imported pbs-tools/src/stream.rs
 
   * imported pbs-tools/src/broadcast_future.rs

proxmox-async/src/lib.rs

@@ -2,3 +2,4 @@ pub mod blocking;
 pub mod broadcast_future;
 pub mod runtime;
 pub mod stream;
+pub mod tokio_writer_adapter;

proxmox-async/src/tokio_writer_adapter.rs

@@ -0,0 +1,26 @@
+use std::io::Write;
+
+use tokio::task::block_in_place;
+
+/// Wrapper around a writer which implements Write
+///
+/// wraps each write with a 'block_in_place' so that
+/// any (blocking) writer can be safely used in async context in a
+/// tokio runtime
+pub struct TokioWriterAdapter<W: Write>(W);
+
+impl<W: Write> TokioWriterAdapter<W> {
+    pub fn new(writer: W) -> Self {
+        Self(writer)
+    }
+}
+
+impl<W: Write> Write for TokioWriterAdapter<W> {
+    fn write(&mut self, buf: &[u8]) -> Result<usize, std::io::Error> {
+        block_in_place(|| self.0.write(buf))
+    }
+
+    fn flush(&mut self) -> Result<(), std::io::Error> {
+        block_in_place(|| self.0.flush())
+    }
+}