impl Into<Vec<u8>> for EasyBuf (cf. tokio-rs#120)

src/io/frame.rs

@@ -1,5 +1,6 @@
 use std::fmt;
 use std::io;
+use std::mem;
 use std::ops::{Deref, DerefMut};
 use std::sync::Arc;
 
@@ -209,6 +210,12 @@ impl fmt::Debug for EasyBuf {
     }
 }
 
+impl Into<Vec<u8>> for EasyBuf {
+    fn into(mut self) -> Vec<u8> {
+        mem::replace(self.get_mut().buf, vec![])
+    }
+}
+
 /// Encoding and decoding of frames via buffers.
 ///
 /// This trait is used when constructing an instance of `Framed`. It provides
@@ -464,4 +471,49 @@ mod tests {
         assert_eq!(*buf.get_mut(), [3, 4, 5, 6, 7, 8]);
         mem::drop(clone); // prevent unused warning
     }
+
+    #[test]
+    fn easybuf_into_vec_simple() {
+        let vec: Vec<u8> = (0u8..10u8).collect();
+        let reference = vec.clone();
+        let buf: EasyBuf = vec.into();
+        let original_pointer = buf.buf.as_ref().as_ptr();
+        let result: Vec<u8> = buf.into();
+        assert_eq!(result, reference);
+        let new_pointer = result.as_ptr();
+        assert_eq!(original_pointer, new_pointer, "Into<Vec<u8>> should be reuse the exclusive Vec");
+    }
+
+    #[test]
+    fn easybuf_into_vec_sliced() {
+        let vec: Vec<u8> = (0u8..10u8).collect();
+        let mut buf: EasyBuf = vec.into();
+        let original_pointer = buf.buf.as_ref().as_ptr();
+        buf.split_off(9);
+        buf.drain_to(3);
+        let result: Vec<u8> = buf.into();
+        let reference: Vec<u8> = (3u8..9u8).collect();
+        assert_eq!(result, reference);
+        let new_pointer = result.as_ptr();
+        assert_eq!(original_pointer, new_pointer, "Into<Vec<u8>> should be reuse the exclusive Vec");
+    }
+
+    #[test]
+    fn easybuf_into_vec_sliced_allocating() {
+        let vec: Vec<u8> = (0u8..10u8).collect();
+        let mut buf: EasyBuf = vec.into();
+        let original_pointer = buf.buf.as_ref().as_ptr();
+        // Create a clone to create second reference to this EasyBuf and force allocation
+        let original = buf.clone();
+        buf.split_off(9);
+        buf.drain_to(3);
+        let result: Vec<u8> = buf.into();
+        let reference: Vec<u8> = (3u8..9u8).collect();
+        assert_eq!(result, reference);
+        let original_reference: EasyBuf =(0u8..10u8).collect::<Vec<u8>>().into();
+        assert_eq!(original.as_ref(), original_reference.as_ref());
+        let new_pointer = result.as_ptr();
+        assert_ne!(original_pointer, new_pointer, "A new vec should be allocated");
+    }
+
 }