Bytes::unsplit (#182)

Add `Bytes::unsplit`, analogous to `BytesMut::unsplit`.

tests/test_bytes.rs

@@ -554,7 +554,141 @@ fn partial_eq_bytesmut() {
 }
 
 #[test]
-fn unsplit_basic() {
+fn bytes_unsplit_basic() {
+    let mut buf = Bytes::with_capacity(64);
+    buf.extend_from_slice(b"aaabbbcccddd");
+
+    let splitted = buf.split_off(6);
+    assert_eq!(b"aaabbb", &buf[..]);
+    assert_eq!(b"cccddd", &splitted[..]);
+
+    buf.unsplit(splitted);
+    assert_eq!(b"aaabbbcccddd", &buf[..]);
+}
+
+#[test]
+fn bytes_unsplit_empty_other() {
+    let mut buf = Bytes::with_capacity(64);
+    buf.extend_from_slice(b"aaabbbcccddd");
+
+    // empty other
+    let other = Bytes::new();
+
+    buf.unsplit(other);
+    assert_eq!(b"aaabbbcccddd", &buf[..]);
+}
+
+#[test]
+fn bytes_unsplit_empty_self() {
+    // empty self
+    let mut buf = Bytes::new();
+
+    let mut other = Bytes::with_capacity(64);
+    other.extend_from_slice(b"aaabbbcccddd");
+
+    buf.unsplit(other);
+    assert_eq!(b"aaabbbcccddd", &buf[..]);
+}
+
+#[test]
+fn bytes_unsplit_inline_arc() {
+    let mut buf = Bytes::with_capacity(8); //inline
+    buf.extend_from_slice(b"aaaabbbb");
+
+    let mut buf2 = Bytes::with_capacity(64);
+    buf2.extend_from_slice(b"ccccddddeeee");
+
+    buf2.split_off(8); //arc
+
+    buf.unsplit(buf2);
+    assert_eq!(b"aaaabbbbccccdddd", &buf[..]);
+}
+
+#[test]
+fn bytes_unsplit_arc_inline() {
+    let mut buf = Bytes::with_capacity(64);
+    buf.extend_from_slice(b"aaaabbbbeeee");
+
+    buf.split_off(8); //arc
+
+    let mut buf2 = Bytes::with_capacity(8); //inline
+    buf2.extend_from_slice(b"ccccdddd");
+
+    buf.unsplit(buf2);
+    assert_eq!(b"aaaabbbbccccdddd", &buf[..]);
+
+}
+
+#[test]
+fn bytes_unsplit_both_inline() {
+    let mut buf = Bytes::with_capacity(16); //inline
+    buf.extend_from_slice(b"aaaabbbbccccdddd");
+
+    let splitted = buf.split_off(8); // both inline
+    assert_eq!(b"aaaabbbb", &buf[..]);
+    assert_eq!(b"ccccdddd", &splitted[..]);
+
+    buf.unsplit(splitted);
+    assert_eq!(b"aaaabbbbccccdddd", &buf[..]);
+}
+
+
+#[test]
+fn bytes_unsplit_arc_different() {
+    let mut buf = Bytes::with_capacity(64);
+    buf.extend_from_slice(b"aaaabbbbeeee");
+
+    buf.split_off(8); //arc
+
+    let mut buf2 = Bytes::with_capacity(64);
+    buf2.extend_from_slice(b"ccccddddeeee");
+
+    buf2.split_off(8); //arc
+
+    buf.unsplit(buf2);
+    assert_eq!(b"aaaabbbbccccdddd", &buf[..]);
+}
+
+#[test]
+fn bytes_unsplit_arc_non_contiguous() {
+    let mut buf = Bytes::with_capacity(64);
+    buf.extend_from_slice(b"aaaabbbbeeeeccccdddd");
+
+    let mut buf2 = buf.split_off(8); //arc
+
+    let buf3 = buf2.split_off(4); //arc
+
+    buf.unsplit(buf3);
+    assert_eq!(b"aaaabbbbccccdddd", &buf[..]);
+}
+
+#[test]
+fn bytes_unsplit_two_split_offs() {
+    let mut buf = Bytes::with_capacity(64);
+    buf.extend_from_slice(b"aaaabbbbccccdddd");
+
+    let mut buf2 = buf.split_off(8); //arc
+    let buf3 = buf2.split_off(4); //arc
+
+    buf2.unsplit(buf3);
+    buf.unsplit(buf2);
+    assert_eq!(b"aaaabbbbccccdddd", &buf[..]);
+}
+
+#[test]
+fn bytes_unsplit_overlapping_references() {
+    let mut buf = Bytes::with_capacity(64);
+    buf.extend_from_slice(b"abcdefghijklmnopqrstuvwxyz");
+    let mut buf0010 = buf.slice(0, 10);
+    let buf1020 = buf.slice(10, 20);
+    let buf0515 = buf.slice(5, 15);
+    buf0010.unsplit(buf1020);
+    assert_eq!(b"abcdefghijklmnopqrst", &buf0010[..]);
+    assert_eq!(b"fghijklmno", &buf0515[..]);
+}
+
+#[test]
+fn bytes_mut_unsplit_basic() {
     let mut buf = BytesMut::with_capacity(64);
     buf.extend_from_slice(b"aaabbbcccddd");
 
@@ -567,7 +701,7 @@ fn unsplit_basic() {
 }
 
 #[test]
-fn unsplit_empty_other() {
+fn bytes_mut_unsplit_empty_other() {
     let mut buf = BytesMut::with_capacity(64);
     buf.extend_from_slice(b"aaabbbcccddd");
 
@@ -579,7 +713,7 @@ fn unsplit_empty_other() {
 }
 
 #[test]
-fn unsplit_empty_self() {
+fn bytes_mut_unsplit_empty_self() {
     // empty self
     let mut buf = BytesMut::new();
 
@@ -591,7 +725,7 @@ fn unsplit_empty_self() {
 }
 
 #[test]
-fn unsplit_inline_arc() {
+fn bytes_mut_unsplit_inline_arc() {
     let mut buf = BytesMut::with_capacity(8); //inline
     buf.extend_from_slice(b"aaaabbbb");
 
@@ -605,7 +739,7 @@ fn unsplit_inline_arc() {
 }
 
 #[test]
-fn unsplit_arc_inline() {
+fn bytes_mut_unsplit_arc_inline() {
     let mut buf = BytesMut::with_capacity(64);
     buf.extend_from_slice(b"aaaabbbbeeee");
 
@@ -620,7 +754,7 @@ fn unsplit_arc_inline() {
 }
 
 #[test]
-fn unsplit_both_inline() {
+fn bytes_mut_unsplit_both_inline() {
     let mut buf = BytesMut::with_capacity(16); //inline
     buf.extend_from_slice(b"aaaabbbbccccdddd");
 
@@ -634,7 +768,7 @@ fn unsplit_both_inline() {
 
 
 #[test]
-fn unsplit_arc_different() {
+fn bytes_mut_unsplit_arc_different() {
     let mut buf = BytesMut::with_capacity(64);
     buf.extend_from_slice(b"aaaabbbbeeee");
 
@@ -650,7 +784,7 @@ fn unsplit_arc_different() {
 }
 
 #[test]
-fn unsplit_arc_non_contiguous() {
+fn bytes_mut_unsplit_arc_non_contiguous() {
     let mut buf = BytesMut::with_capacity(64);
     buf.extend_from_slice(b"aaaabbbbeeeeccccdddd");
 
@@ -663,7 +797,7 @@ fn unsplit_arc_non_contiguous() {
 }
 
 #[test]
-fn unsplit_two_split_offs() {
+fn bytes_mut_unsplit_two_split_offs() {
     let mut buf = BytesMut::with_capacity(64);
     buf.extend_from_slice(b"aaaabbbbccccdddd");