From 2189d79c47017a6d1c802e7366ef0961bc1dbd76 Mon Sep 17 00:00:00 2001
From: Christopher Jeffrey <chjjeffrey@gmail.com>
Date: Mon, 9 May 2016 09:34:43 -0700
Subject: [PATCH] optimization for checkFinal.

---
 lib/bcoin/chain.js | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/lib/bcoin/chain.js b/lib/bcoin/chain.js
index 1b16b395..fd5d3fa9 100644
--- a/lib/bcoin/chain.js
+++ b/lib/bcoin/chain.js
@@ -2384,6 +2384,10 @@ Chain.prototype.checkFinal = function checkFinal(prev, tx, flags, callback) {
     return callback(null, tx.isFinal(height, ts));
   }
 
+  // We can skip MTP if the locktime is height.
+  if (tx.locktime < constants.LOCKTIME_THRESHOLD)
+    return utils.asyncify(check)(null, -1);
+
   if (flags & constants.flags.MEDIAN_TIME_PAST)
     return prev.getMedianTimeAsync(check);