Overwrite Cursor's Seek::stream_{len, position} for performance

LukasKalbertodt · LukasKalbertodt · commit c518f2dd7040 · 2019-03-14T13:43:19.000+01:00
diff --git a/src/libstd/io/cursor.rs b/src/libstd/io/cursor.rs
@@ -212,6 +212,14 @@ impl<T> io::Seek for Cursor<T> where T: AsRef<[u8]> {
                            "invalid seek to a negative or overflowing position"))
         }
     }
+
+    fn stream_len(&mut self) -> io::Result<u64> {
+        Ok(self.inner.as_ref().len() as u64)
+    }
+
+    fn stream_position(&mut self) -> io::Result<u64> {
+        Ok(self.pos)
+    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]

Original file line number	Diff line number	Diff line change
`@@ -212,6 +212,14 @@ impl<T> io::Seek for Cursor<T> where T: AsRef<[u8]> {`
`212`	`212`	`"invalid seek to a negative or overflowing position"))`
`213`	`213`	`}`
`214`	`214`	`}`
	`215`	`+`
	`216`	`+ fn stream_len(&mut self) -> io::Result<u64> {`
	`217`	`+ Ok(self.inner.as_ref().len() as u64)`
	`218`	`+ }`
	`219`	`+`
	`220`	`+ fn stream_position(&mut self) -> io::Result<u64> {`
	`221`	`+ Ok(self.pos)`
	`222`	`+ }`
`215`	`223`	`}`
`216`	`224`
`217`	`225`	`#[stable(feature = "rust1", since = "1.0.0")]`