From 17d2f1586b7c21ac393f8fd0d0c755c8d1966918 Mon Sep 17 00:00:00 2001
From: Christopher Jeffrey <chjjeffrey@gmail.com>
Date: Wed, 30 Mar 2016 19:52:32 -0700
Subject: [PATCH] refactor.

---
 lib/bcoin/chain.js | 76 +++++++++++++++++++++++++---------------------
 1 file changed, 42 insertions(+), 34 deletions(-)

diff --git a/lib/bcoin/chain.js b/lib/bcoin/chain.js
index 523e5298..61bcce70 100644
--- a/lib/bcoin/chain.js
+++ b/lib/bcoin/chain.js
@@ -503,7 +503,7 @@ Chain.prototype._verify = function _verify(block, prev, callback) {
     //   lockFlags |= constants.flags.MEDIAN_TIME_PAST;
 
     if (network.type === 'segnet4') {
-      self.getState(prev, null, 'witness', function(err, state) {
+      self.getState(prev, 'witness', function(err, state) {
         if (err)
           return callback(err);
 
@@ -1777,7 +1777,7 @@ Chain.prototype.retarget = function retarget(last, first) {
 };
 
 // https://github.com/bitcoin/bitcoin/pull/7648/files
-Chain.prototype.getState = function getState(prev, block, id, callback) {
+Chain.prototype.getState = function getState(prev, id, callback) {
   var self = this;
   var period = network.minerConfirmationWindow;
   var threshold = network.ruleChangeActivationThreshold;
@@ -1803,7 +1803,7 @@ Chain.prototype.getState = function getState(prev, block, id, callback) {
         assert(ancestor.height === height);
         assert(((ancestor.height + 1) % period) === 0);
       }
-      return self.getState(ancestor, block, id, callback);
+      return self.getState(ancestor, id, callback);
     });
   }
 
@@ -1912,7 +1912,7 @@ Chain.prototype.computeBlockVersion = function computeBlockVersion(prev, callbac
 
   utils.forEachSerial(Object.keys(network.deployments), function(id, next) {
     var deployment = network.deployments[id];
-    self.getState(prev, null, id, function(err, state) {
+    self.getState(prev, id, function(err, state) {
       if (err)
         return next(err);
 
@@ -1931,6 +1931,7 @@ Chain.prototype.computeBlockVersion = function computeBlockVersion(prev, callbac
       return callback(null, constants.versionbits.LAST_OLD_BLOCK_VERSION);
 
     version |= constants.versionbits.TOP_BITS;
+    version >>>= 0;
 
     return callback(null, version);
   });
@@ -1938,34 +1939,17 @@ Chain.prototype.computeBlockVersion = function computeBlockVersion(prev, callbac
 
 Chain.prototype.isSegwitActive = function isSegwitActive(callback) {
   var self = this;
-  var tip = this.tip;
   var unlock;
 
+  if (this.segwitActive != null)
+    return utils.asyncify(callback)(null, this.segwitActive);
+
   if (!network.witness) {
     this.segwitActive = false;
     return utils.asyncify(callback)(null, false);
   }
 
-  if (network.type === 'segnet4') {
-    return this.tip.getPrevious(function(err, prev) {
-      if (err)
-        return callback(err);
-
-      return self.getState(prev, null, 'witness', function(err, state) {
-        if (err)
-          return callback(err);
-        return callback(null, state === constants.thresholdStates.ACTIVE);
-      });
-    });
-  }
-
-  if (this.segwitActive != null)
-    return utils.asyncify(callback)(null, this.segwitActive);
-
-  if (!tip)
-    return utils.asyncify(callback)(null, false);
-
-  if (!(network.segwitHeight !== -1 && tip.height >= network.segwitHeight))
+  if (!this.tip)
     return utils.asyncify(callback)(null, false);
 
   unlock = this._lock(isSegwitActive, [callback]);
@@ -1974,24 +1958,48 @@ Chain.prototype.isSegwitActive = function isSegwitActive(callback) {
 
   callback = utils.wrap(callback, unlock);
 
-  if (tip.ancestors.length) {
-    self.segwitActive = tip.isUpgraded(5);
-    return callback(null, self.segwitActive);
+  if (network.type === 'segnet4') {
+    return this.tip.getPrevious(function(err, prev) {
+      if (err)
+        return callback(err);
+
+      return self.getState(prev, 'witness', function(err, state) {
+        if (err)
+          return callback(err);
+        self.segwitActive = state === constants.thresholdStates.ACTIVE;
+        return callback(null, self.segwitActive);
+      });
+    });
   }
 
-  tip.ensureAncestors(function(err) {
+  assert(network.type === 'segnet3');
+
+  if (!(network.segwitHeight !== -1 && this.tip.height >= network.segwitHeight))
+    return utils.asyncify(callback)(null, false);
+
+  return this.tip.getPrevious(function(err, prev) {
     if (err)
       return callback(err);
 
-    if (!tip.isUpgraded(5)) {
-      tip.free();
+    if (!prev) {
       self.segwitActive = false;
       return callback(null, false);
     }
 
-    tip.free();
-    self.segwitActive = true;
-    return callback(null, true);
+    prev.ensureAncestors(function(err) {
+      if (err)
+        return callback(err);
+
+      if (!prev.isUpgraded(5)) {
+        prev.free();
+        self.segwitActive = false;
+        return callback(null, false);
+      }
+
+      prev.free();
+      self.segwitActive = true;
+      return callback(null, true);
+    });
   });
 };