From 84b53a049d49a6112c61e3fcff22ad30fcee114b Mon Sep 17 00:00:00 2001
From: Christopher Jeffrey <chjjeffrey@gmail.com>
Date: Sun, 18 May 2014 10:37:00 -0500
Subject: [PATCH] util: perhaps a more clever way of U64 writes using bn.js.

Signed-off-by: Fedor Indutny <fedor@indutny.com>
---
 lib/bcoin/utils.js | 42 ++++++++++--------------------------------
 1 file changed, 10 insertions(+), 32 deletions(-)

diff --git a/lib/bcoin/utils.js b/lib/bcoin/utils.js
index 9cf9c168..ba505641 100644
--- a/lib/bcoin/utils.js
+++ b/lib/bcoin/utils.js
@@ -180,23 +180,12 @@ utils.writeU64 = function writeU64(dst, num, off) {
   if (!off)
     off = 0;
 
-  var num = new bn(num);
+  num = new bn(num).maskn(64).toArray();
+  while (num.length < 8) num.unshift(0);
 
-  var left = num.shrn(32).toArray();
-  while (left.length < 4) left.unshift(0);
-
-  var right = num.maskn(32).toArray();
-  while (right.length < 4) right.unshift(0);
-
-  dst[off] = right[3];
-  dst[off + 1] = right[2];
-  dst[off + 2] = right[1];
-  dst[off + 3] = right[0];
-
-  dst[off + 4] = left[3];
-  dst[off + 5] = left[2];
-  dst[off + 6] = left[1];
-  dst[off + 7] = left[0];
+  num.reverse().forEach(function(ch) {
+    dst[off++] = ch;
+  });
 
   return 8;
 };
@@ -223,23 +212,12 @@ utils.writeU64BE = function writeU64BE(dst, num, off) {
   if (!off)
     off = 0;
 
-  var num = new bn(num);
+  num = new bn(num).maskn(64).toArray();
+  while (num.length < 8) num.unshift(0);
 
-  var left = num.shrn(32).toArray();
-  while (left.length < 4) left.unshift(0);
-
-  var right = num.maskn(32).toArray();
-  while (right.length < 4) right.unshift(0);
-
-  dst[off] = left[0];
-  dst[off + 1] = left[1];
-  dst[off + 2] = left[2];
-  dst[off + 3] = left[3];
-
-  dst[off + 4] = right[0];
-  dst[off + 5] = right[1];
-  dst[off + 6] = right[2];
-  dst[off + 7] = right[3];
+  num.forEach(function(ch) {
+    dst[off++] = ch;
+  });
 
   return 8;
 };