From cc0ac982c4dd407213500db8b44fbd501b9ce5ce Mon Sep 17 00:00:00 2001
From: Jeremy Soller <jackpot51@gmail.com>
Date: Fri, 10 Mar 2023 08:37:54 -0700
Subject: [PATCH] Implement __fpurge
---
src/header/stdio/mod.rs | 37 ++++++++++++++++++++++++++++++++++---
1 file changed, 34 insertions(+), 3 deletions(-)
diff --git a/src/header/stdio/mod.rs b/src/header/stdio/mod.rs
index e4d3eb1b9..cd9887dd8 100644
--- a/src/header/stdio/mod.rs
+++ b/src/header/stdio/mod.rs
@@ -85,10 +85,20 @@ impl<W: core_io::Write> Pending for LineWriter<W> {
}
}
-pub trait Writer: Write + Pending {}
+pub trait Writer: Write + Pending {
+ fn purge(&mut self);
+}
-impl<W: core_io::Write> Writer for BufWriter<W> {}
-impl<W: core_io::Write> Writer for LineWriter<W> {}
+impl<W: core_io::Write> Writer for BufWriter<W> {
+ fn purge(&mut self) {
+ self.buf.clear();
+ }
+}
+impl<W: core_io::Write> Writer for LineWriter<W> {
+ fn purge(&mut self) {
+ self.inner.buf.clear();
+ }
+}
/// This struct gets exposed to the C API.
pub struct FILE {
@@ -216,6 +226,16 @@ impl FILE {
x => Err(x),
}
}
+
+ pub fn purge(&mut self) {
+ // Purge read buffer
+ self.read_pos = 0;
+ self.read_size = 0;
+ // Purge unget
+ self.unget.clear();
+ // Purge write buffer
+ self.writer.purge();
+ }
}
pub struct LockGuard<'a>(&'a mut FILE);
@@ -473,6 +493,17 @@ pub unsafe extern "C" fn fopen(filename: *const c_char, mode: *const c_char) ->
}
}
+/// Clear the buffers of a stream
+/// Ensure the file is unlocked before calling this function, as it will attempt to lock the file
+/// itself.
+#[no_mangle]
+pub unsafe extern "C" fn __fpurge(stream: *mut FILE) {
+ if ! stream.is_null() {
+ let mut stream = (*stream).lock();
+ stream.purge();
+ }
+}
+
/// Insert a character into the stream
#[no_mangle]
pub unsafe extern "C" fn fputc(c: c_int, stream: *mut FILE) -> c_int {
--
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