From 31a7a0614ecf2e47db92e7bd475cd2901fd11ecb Mon Sep 17 00:00:00 2001
From: Paul Hauner <paul@paulhauner.com>
Date: Thu, 23 May 2019 23:34:49 +1000
Subject: [PATCH] Remove `bytes` dependency from shuffling

---
 eth2/utils/swap_or_not_shuffle/Cargo.toml          | 1 -
 eth2/utils/swap_or_not_shuffle/src/shuffle_list.rs | 9 ++++-----
 2 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/eth2/utils/swap_or_not_shuffle/Cargo.toml b/eth2/utils/swap_or_not_shuffle/Cargo.toml
index 3a866da92..19d5444fb 100644
--- a/eth2/utils/swap_or_not_shuffle/Cargo.toml
+++ b/eth2/utils/swap_or_not_shuffle/Cargo.toml
@@ -15,6 +15,5 @@ hex = "0.3"
 ethereum-types = "0.5"
 
 [dependencies]
-bytes = "0.4"
 hashing = { path = "../hashing" }
 int_to_bytes = { path = "../int_to_bytes" }
diff --git a/eth2/utils/swap_or_not_shuffle/src/shuffle_list.rs b/eth2/utils/swap_or_not_shuffle/src/shuffle_list.rs
index f60d793f2..96e100def 100644
--- a/eth2/utils/swap_or_not_shuffle/src/shuffle_list.rs
+++ b/eth2/utils/swap_or_not_shuffle/src/shuffle_list.rs
@@ -1,7 +1,5 @@
-use bytes::Buf;
 use hashing::hash;
 use int_to_bytes::int_to_bytes4;
-use std::io::Cursor;
 
 const SEED_SIZE: usize = 32;
 const ROUND_SIZE: usize = 1;
@@ -117,9 +115,10 @@ pub fn shuffle_list(
     Some(input)
 }
 
-fn bytes_to_int64(bytes: &[u8]) -> u64 {
-    let mut cursor = Cursor::new(bytes);
-    cursor.get_u64_le()
+fn bytes_to_int64(slice: &[u8]) -> u64 {
+    let mut bytes = [0; 8];
+    bytes.copy_from_slice(&slice[0..8]);
+    u64::from_le_bytes(bytes)
 }
 
 #[cfg(test)]