From 5b449f4e1e43bc59109da5a37edf5ec911d3df8e Mon Sep 17 00:00:00 2001
From: Matthias Schiffer <mschiffer@universe-factory.net>
Date: Mon, 13 Apr 2020 02:13:58 +0200
Subject: IO, error handling

---
 safe_libc/src/stdio.rs | 102 ++++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 83 insertions(+), 19 deletions(-)

(limited to 'safe_libc/src/stdio.rs')

diff --git a/safe_libc/src/stdio.rs b/safe_libc/src/stdio.rs
index 271f023..2d19725 100644
--- a/safe_libc/src/stdio.rs
+++ b/safe_libc/src/stdio.rs
@@ -1,47 +1,111 @@
-use crate as libc;
-use crate::string;
+use crate::{self as libc, errno, string};
 
 use core::fmt;
+use core::ops::{Deref, DerefMut};
 
-pub struct OStream {
-	file: *mut libc::FILE
+pub struct Error {
+	pub errno: errno::Errno,
 }
 
+pub type Result<T> = core::result::Result<T, Error>;
+
+#[inline]
+fn check_io(ok: bool) -> Result<()> {
+	if ok {
+		Ok(())
+	} else {
+		Err(Error {
+			errno: errno::errno(),
+		})
+	}
+}
+
+pub struct BasicOStream(*mut libc::FILE);
+
+unsafe impl Sync for BasicOStream {}
+unsafe impl Send for BasicOStream {}
+
+pub type Stdout = BasicOStream;
+pub type Stderr = BasicOStream;
+
 #[inline]
-pub unsafe fn stdout() -> OStream {
-	OStream { file: libc::stdout }
+pub fn stdout() -> Stdout {
+	BasicOStream(unsafe { libc::stdout })
 }
 
 #[inline]
-pub unsafe fn stderr() -> OStream {
-	OStream { file: libc::stderr }
+pub fn stderr() -> Stderr {
+	BasicOStream(unsafe { libc::stderr })
 }
 
-impl OStream {
+impl BasicOStream {
 	#[inline]
-	pub fn write(&mut self, b: &[u8]) {
-		unsafe {
+	pub fn flush(&mut self) -> Result<()> {
+		check_io(unsafe {
+			libc::fflush(self.0)
+		} == 0)
+	}
+
+	#[inline]
+	pub fn write(&mut self, b: &[u8]) -> Result<()> {
+		check_io(unsafe {
 			libc::fwrite(
 				b.as_ptr().cast(),
 				1,
 				b.len(),
-				self.file,
-			);
+				self.0,
+			)
+		} == b.len())
+	}
+
+	#[inline]
+	pub fn puts(&mut self, s: &string::CStr) -> Result<()> {
+		check_io(unsafe {
+			libc::fputs(s.as_ptr(), self.0)
+		} != libc::EOF)
+	}
+}
+
+impl fmt::Write for BasicOStream {
+	#[inline]
+	fn write_str(&mut self, s: &str) -> fmt::Result {
+		if self.write(s.as_bytes()).is_err() {
+			return Err(fmt::Error);
 		}
+		Ok(())
+	}
+}
+
+pub struct OStream(BasicOStream);
+
+impl OStream {
+	#[inline]
+	pub unsafe fn from_raw(file: *mut libc::FILE) -> OStream {
+		OStream(BasicOStream(file))
 	}
+}
 
+impl Drop for OStream {
 	#[inline]
-	pub fn puts(&mut self, s: &string::CStr) {
+	fn drop(&mut self) {
 		unsafe {
-			libc::fputs(s.as_ptr(), self.file);
+			libc::fclose((self.0).0);
 		}
 	}
 }
 
-impl fmt::Write for OStream {
+impl Deref for OStream {
+	type Target = BasicOStream;
+
 	#[inline]
-	fn write_str(&mut self, s: &str) -> fmt::Result {
-		self.write(s.as_bytes());
-		Ok(())
+	fn deref(&self) -> &BasicOStream {
+		&self.0
+	}
+}
+
+impl DerefMut for OStream {
+	#[inline]
+	fn deref_mut(&mut self) -> &mut BasicOStream {
+		&mut self.0
 	}
 }
-- 
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