Fix WriteFmtFuture not taking into account already written bytes (#964)

rkarp · rkarp · commit 5bc34cb6ba61 · 2021-03-13T23:34:33.000+01:00
diff --git a/src/io/write/write_fmt.rs b/src/io/write/write_fmt.rs
@@ -11,7 +11,7 @@ pub struct WriteFmtFuture<'a, T: Unpin + ?Sized> {
     pub(crate) writer: &'a mut T,
     pub(crate) res: Option<io::Result<Vec<u8>>>,
     pub(crate) buffer: Option<Vec<u8>>,
-    pub(crate) amt: u64,
+    pub(crate) amt: usize,
 }
 
 impl<T: Write + Unpin + ?Sized> Future for WriteFmtFuture<'_, T> {
@@ -37,15 +37,15 @@ impl<T: Write + Unpin + ?Sized> Future for WriteFmtFuture<'_, T> {
 
         // Copy the data from the buffer into the writer until it's done.
         loop {
-            if *amt == buffer.len() as u64 {
+            if *amt == buffer.len() {
                 futures_core::ready!(Pin::new(&mut **writer).poll_flush(cx))?;
                 return Poll::Ready(Ok(()));
             }
-            let i = futures_core::ready!(Pin::new(&mut **writer).poll_write(cx, buffer))?;
+            let i = futures_core::ready!(Pin::new(&mut **writer).poll_write(cx, &buffer[*amt..]))?;
             if i == 0 {
                 return Poll::Ready(Err(io::ErrorKind::WriteZero.into()));
             }
-            *amt += i as u64;
+            *amt += i;
         }
     }
 }

Original file line number	Diff line number	Diff line change
`@@ -11,7 +11,7 @@ pub struct WriteFmtFuture<'a, T: Unpin + ?Sized> {`
`11`	`11`	`pub(crate) writer: &'a mut T,`
`12`	`12`	`pub(crate) res: Option<io::Result<Vec<u8>>>,`
`13`	`13`	`pub(crate) buffer: Option<Vec<u8>>,`
`14`		`- pub(crate) amt: u64,`
	`14`	`+ pub(crate) amt: usize,`
`15`	`15`	`}`
`16`	`16`
`17`	`17`	`impl<T: Write + Unpin + ?Sized> Future for WriteFmtFuture<'_, T> {`
`@@ -37,15 +37,15 @@ impl<T: Write + Unpin + ?Sized> Future for WriteFmtFuture<'_, T> {`
`37`	`37`
`38`	`38`	`// Copy the data from the buffer into the writer until it's done.`
`39`	`39`	`loop {`
`40`		`- if *amt == buffer.len() as u64 {`
	`40`	`+ if *amt == buffer.len() {`
`41`	`41`	`futures_core::ready!(Pin::new(&mut **writer).poll_flush(cx))?;`
`42`	`42`	`return Poll::Ready(Ok(()));`
`43`	`43`	`}`
`44`		`- let i = futures_core::ready!(Pin::new(&mut **writer).poll_write(cx, buffer))?;`
	`44`	`+ let i = futures_core::ready!(Pin::new(&mut *writer).poll_write(cx, &buffer[amt..]))?;`
`45`	`45`	`if i == 0 {`
`46`	`46`	`return Poll::Ready(Err(io::ErrorKind::WriteZero.into()));`
`47`	`47`	`}`
`48`		`- *amt += i as u64;`
	`48`	`+ *amt += i;`
`49`	`49`	`}`
`50`	`50`	`}`
`51`	`51`	`}`