---

yaml
---
r: 30209
b: refs/heads/incoming
c: 9074d9b
h: refs/heads/master
i:
  30207: a02edb7
v: v3

Author: erickt

[refs]

@@ -6,7 +6,7 @@ refs/heads/try: d324a424d8f84b1eb049b12cf34182bda91b0024
 refs/tags/release-0.1: 1f5c5126e96c79d22cb7862f75304136e204f105
 refs/heads/ndm: f3868061cd7988080c30d6d5bf352a5a5fe2460b
 refs/heads/try2: d0c6ce338884ee21843f4b40bf6bf18d222ce5df
-refs/heads/incoming: 7bb65848a15c2970f1b7a52e870bfc98c9c981a9
+refs/heads/incoming: 9074d9b5813c43cb1d4920dbc9de7dfde032577a
 refs/heads/dist-snap: 2f32a1581f522e524009138b33b1c7049ced668d
 refs/tags/release-0.2: c870d2dffb391e14efb05aa27898f1f6333a9596
 refs/tags/release-0.3: b5f0d0f648d9a6153664837026ba1be43d3e2503

branches/incoming/src/libcore/io.rs

@@ -663,24 +663,21 @@ type MemBuffer = @{buf: DVec<u8>, mut pos: uint};
 
 impl MemBuffer: Writer {
     fn write(v: &[const u8]) {
-        // Fast path.
-        let vlen = vec::len(v);
-        let buf_len = self.buf.len();
-        if self.pos == buf_len {
-            self.buf.push_all(v);
-            self.pos += vlen;
-            return;
-        }
+        do self.buf.swap |buf| {
+            let mut buf <- buf;
+            let v_len = v.len();
+            let buf_len = buf.len();
+
+            let count = uint::max(&buf_len, &(self.pos + v_len));
+            vec::reserve(buf, count);
+            unsafe { vec::unsafe::set_len(buf, count); }
+
+            vec::u8::memcpy(vec::mut_view(buf, self.pos, count), v, v_len);
+
+            self.pos += v_len;
 
-        // FIXME #2004--use memcpy here?
-        let mut pos = self.pos, vpos = 0u;
-        while vpos < vlen && pos < buf_len {
-            self.buf.set_elt(pos, copy v[vpos]);
-            pos += 1u;
-            vpos += 1u;
+            buf
         }
-        self.buf.push_slice(v, vpos, vlen);
-        self.pos += vlen;
     }
     fn seek(offset: int, whence: SeekStyle) {
         let pos = self.pos;