From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Tue, 1 Jun 2021 12:58:38 +0000 (+0100)
Subject: utils: Provide CookedStdout, buffered and with die on flush fail
X-Git-Tag: otter-0.7.0~153
X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=commitdiff_plain;h=bd1af9d9ddeb88ac0261e9ea07cf525e1bab8843;p=otter.git

utils: Provide CookedStdout, buffered and with die on flush fail

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
---

diff --git a/src/utils.rs b/src/utils.rs
index 4c239b34..d4533ef3 100644
--- a/src/utils.rs
+++ b/src/utils.rs
@@ -731,6 +731,30 @@ impl<W:Write> Write for SigPipeWriter<W> {
 pub type RawStdout = SigPipeWriter<io::Stdout>;
 impl RawStdout { pub fn new() -> Self { SigPipeWriter(io::stdout()) } }
 
+pub struct CookedStdout(pub BufWriter<SigPipeWriter<io::Stdout>>);
+impl CookedStdout {
+  pub fn new() -> Self { Self(BufWriter::new(RawStdout::new())) }
+  fn handle_err(e: io::Error) -> ! {
+    AE::from(e).context("write stdout").end_process(12);
+  }
+  fn must_flush(&mut self) {
+    self.0.flush().unwrap_or_else(|e| Self::handle_err(e))
+  }
+}
+impl Write for CookedStdout {
+  #[throws(io::Error)]
+  fn write(&mut self, buf: &[u8]) -> usize {
+    let r = self.0.write(buf).unwrap_or_else(|e| Self::handle_err(e));
+    if buf.contains(&b'\n') { self.flush()? }
+    r
+  }
+  #[throws(io::Error)]
+  fn flush(&mut self) { self.must_flush() }
+}
+impl Drop for CookedStdout {
+  fn drop(&mut self) { self.must_flush() }
+}
+
 #[throws(fmt::Error)]
 pub fn fmt_hex(f: &mut Formatter, buf: &[u8]) {
   for v in buf { write!(f, "{:02x}", v)?; }