--- a/src/key_types.rs	Sun Oct 01 20:37:42 2017 +0200
+++ b/src/key_types.rs	Sun Oct 01 20:38:07 2017 +0200
@@ -149,7 +149,7 @@
 }
 
 /// Parse a key in InternalKey format.
-pub fn parse_internal_key<'a>(ikey: InternalKey<'a>) -> (ValueType, u64, UserKey<'a>) {
+pub fn parse_internal_key<'a>(ikey: InternalKey<'a>) -> (ValueType, SequenceNumber, UserKey<'a>) {
     if ikey.is_empty() {
         return (ValueType::TypeDeletion, 0, &ikey[0..0]);
     }
@@ -158,6 +158,13 @@
     return (typ, seq, &ikey[0..ikey.len() - 8]);
 }
 
+/// truncate_to_userkey performs an in-place conversion from InternalKey to UserKey format.
+pub fn truncate_to_userkey(ikey: &mut Vec<u8>) {
+    let len = ikey.len();
+    assert!(len > 8);
+    ikey.truncate(len-8);
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;