From e10afb7358825aa9ae05762782a00e818e1b36ae Mon Sep 17 00:00:00 2001
From: Jeff Garzik <jgarzik@bitpay.com>
Date: Fri, 16 Aug 2013 00:56:29 -0400
Subject: [PATCH] util: add varInt encoding helper

---
 util/util.js | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/util/util.js b/util/util.js
index 9e8fe54..076951f 100644
--- a/util/util.js
+++ b/util/util.js
@@ -299,6 +299,30 @@ var getVarIntSize = exports.getVarIntSize = function getVarIntSize(i) {
   }
 };
 
+var varIntBuf = exports.varIntBuf = function varIntBuf(n) {
+  var buf = undefined;
+  if (n < 253) {
+    buf = new Buffer(1);
+    buf.writeUInt8(n, 0);
+  } else if (n < 0x10000) {
+    buf = new Buffer(1 + 2);
+    buf.writeUInt8(253, 0);
+    buf.writeUInt16LE(n, 1);
+  } else if (n < 0x100000000) {
+    buf = new Buffer(1 + 4);
+    buf.writeUInt8(254, 0);
+    buf.writeUInt32LE(n, 1);
+  } else {
+    throw new Error("quadword not supported");
+  }
+
+  return buf;
+};
+
+var varStrBuf = exports.varStrBuf = function varStrBuf(s) {
+  return Buffer.concat(varIntBuf(s.length), s);
+};
+
 // Initializations
 exports.NULL_HASH = new Buffer(32).fill(0);
 exports.EMPTY_BUFFER = new Buffer(0);