1 files changed, 72 insertions, 0 deletions
diff --git a/third_party/rust/hyper/src/common/buf.rs b/third_party/rust/hyper/src/common/buf.rs
new file mode 100644
index 0000000000..8f71b7bbad
--- /dev/null
+++ b/third_party/rust/hyper/src/common/buf.rs
@@ -0,0 +1,72 @@
+use std::collections::VecDeque;
+use std::io::IoSlice;
+
+use bytes::Buf;
+
+pub(crate) struct BufList<T> {
+    bufs: VecDeque<T>,
+}
+
+impl<T: Buf> BufList<T> {
+    pub(crate) fn new() -> BufList<T> {
+        BufList {
+            bufs: VecDeque::new(),
+        }
+    }
+
+    #[inline]
+    pub(crate) fn push(&mut self, buf: T) {
+        debug_assert!(buf.has_remaining());
+        self.bufs.push_back(buf);
+    }
+
+    #[inline]
+    pub(crate) fn bufs_cnt(&self) -> usize {
+        self.bufs.len()
+    }
+}
+
+impl<T: Buf> Buf for BufList<T> {
+    #[inline]
+    fn remaining(&self) -> usize {
+        self.bufs.iter().map(|buf| buf.remaining()).sum()
+    }
+
+    #[inline]
+    fn bytes(&self) -> &[u8] {
+        self.bufs.front().map(Buf::bytes).unwrap_or_default()
+    }
+
+    #[inline]
+    fn advance(&mut self, mut cnt: usize) {
+        while cnt > 0 {
+            {
+                let front = &mut self.bufs[0];
+                let rem = front.remaining();
+                if rem > cnt {
+                    front.advance(cnt);
+                    return;
+                } else {
+                    front.advance(rem);
+                    cnt -= rem;
+                }
+            }
+            self.bufs.pop_front();
+        }
+    }
+
+    #[inline]
+    fn bytes_vectored<'t>(&'t self, dst: &mut [IoSlice<'t>]) -> usize {
+        if dst.is_empty() {
+            return 0;
+        }
+        let mut vecs = 0;
+        for buf in &self.bufs {
+            vecs += buf.bytes_vectored(&mut dst[vecs..]);
+            if vecs == dst.len() {
+                break;
+            }
+        }
+        vecs
+    }
+}