move more tools for the client into subcrates

Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>

pbs-tools/src/sync/mod.rs

@@ -0,0 +1,2 @@
+mod std_channel_writer;
+pub use std_channel_writer::StdChannelWriter;

pbs-tools/src/sync/std_channel_writer.rs

@@ -0,0 +1,28 @@
+use std::io::Write;
+use std::sync::mpsc::SyncSender;
+
+use anyhow::{Error};
+
+/// Wrapper around SyncSender, which implements Write
+///
+/// Each write in translated into a send(Vec<u8>).
+pub struct StdChannelWriter(SyncSender<Result<Vec<u8>, Error>>);
+
+impl StdChannelWriter {
+    pub fn new(sender: SyncSender<Result<Vec<u8>, Error>>) -> Self {
+        Self(sender)
+    }
+}
+
+impl Write for StdChannelWriter {
+    fn write(&mut self, buf: &[u8]) -> Result<usize, std::io::Error> {
+        self.0
+            .send(Ok(buf.to_vec()))
+            .map_err(proxmox::sys::error::io_err_other)
+            .and(Ok(buf.len()))
+    }
+
+    fn flush(&mut self) -> Result<(), std::io::Error> {
+        Ok(())
+    }
+}