1 files changed, 37 insertions, 0 deletions
diff --git a/helix-core/src/rope_reader.rs b/helix-core/src/rope_reader.rs
new file mode 100644
index 00000000..20ed7bac
--- /dev/null
+++ b/helix-core/src/rope_reader.rs
@@ -0,0 +1,37 @@
+use std::io;
+
+use ropey::iter::Chunks;
+use ropey::RopeSlice;
+
+pub struct RopeReader<'a> {
+    current_chunk: &'a [u8],
+    chunks: Chunks<'a>,
+}
+
+impl<'a> RopeReader<'a> {
+    pub fn new(rope: RopeSlice<'a>) -> RopeReader<'a> {
+        RopeReader {
+            current_chunk: &[],
+            chunks: rope.chunks(),
+        }
+    }
+}
+
+impl io::Read for RopeReader<'_> {
+    fn read(&mut self, mut buf: &mut [u8]) -> io::Result<usize> {
+        let buf_len = buf.len();
+        loop {
+            let read_bytes = self.current_chunk.read(buf)?;
+            buf = &mut buf[read_bytes..];
+            if buf.is_empty() {
+                return Ok(buf_len);
+            }
+
+            if let Some(next_chunk) = self.chunks.next() {
+                self.current_chunk = next_chunk.as_bytes();
+            } else {
+                return Ok(buf_len - buf.len());
+            }
+        }
+    }
+}