From 440933c27daf871f43bf2773f3185823659c4071 Mon Sep 17 00:00:00 2001
From: Christopher Jeffrey <chjjeffrey@gmail.com>
Date: Fri, 1 Jan 2016 19:58:35 -0800
Subject: [PATCH] move pow target methods.

---
 lib/bcoin/fullchain.js | 126 ++++++++++++++++++++---------------------
 1 file changed, 63 insertions(+), 63 deletions(-)

diff --git a/lib/bcoin/fullchain.js b/lib/bcoin/fullchain.js
index 4b28211d..bdf066d1 100644
--- a/lib/bcoin/fullchain.js
+++ b/lib/bcoin/fullchain.js
@@ -431,6 +431,69 @@ Chain.prototype.height = function height() {
   return this.getTip().height;
 };
 
+Chain.prototype.target = function target(last) {
+  var proofOfWorkLimit = utils.toCompact(network.powLimit);
+  var adjustmentInterval = network.powTargetTimespan / network.powTargetSpacing;
+  var newBlockTs, heightFirst, first;
+
+  adjustmentInterval |= 0;
+
+  if (!last)
+    last = this.getTip();
+
+  // Do not retarget
+  if ((last.height + 1) % adjustmentInterval) {
+    if (network.powAllowMinDifficultyBlocks) {
+      // Special behavior for testnet:
+      newBlockTs = Date.now() / 1000 | 0;
+      if (newBlockTs > last.ts + network.powTargetSpacing * 2)
+        return proofOfWorkLimit;
+
+      while (last.prev
+        && last.height % adjustmentInterval !== 0
+        && last.bits !== proofOfWorkLimit) {
+        last = last.prev;
+      }
+
+      return last.bits;
+    }
+    return last.bits;
+  }
+
+  // Back 2 weeks
+  heightFirst = last.height - (adjustmentInterval - 1);
+  first = this.byHeight(heightFirst);
+
+  if (!first)
+    return 0;
+
+  return this.retarget(last, first.ts);
+};
+
+Chain.prototype.retarget = function retarget(last, firstTs) {
+  var powTargetTimespan = new bn(network.powTargetTimespan);
+  var actualTimespan, powLimit, target;
+
+  if (network.powNoRetargeting)
+    return last.bits;
+
+  actualTimespan = new bn(last.ts).subn(firstTs);
+  if (actualTimespan.cmp(powTargetTimespan.divn(4)) < 0)
+    actualTimespan = powTargetTimespan.divn(4);
+
+  if (actualTimespan.cmp(powTargetTimespan.muln(4)) > 0)
+    actualTimespan = powTargetTimespan.muln(4);
+
+  powLimit = network.powLimit;
+  target = utils.fromCompact(last.bits);
+  target.imul(actualTimespan);
+  target = target.div(powTargetTimespan);
+  if (target.cmp(powLimit) > 0)
+    target = powLimit.clone();
+
+  return utils.toCompact(target);
+};
+
 Chain.prototype._save = function(hash, obj) {
   var self = this;
 
@@ -520,69 +583,6 @@ ChainBlock.prototype.getChainwork = function() {
   return (this.prev ? this.prev.chainwork : new bn(0)).add(this.proof);
 };
 
-Chain.prototype.target = function target(last) {
-  var proofOfWorkLimit = utils.toCompact(network.powLimit);
-  var adjustmentInterval = network.powTargetTimespan / network.powTargetSpacing;
-  var newBlockTs, heightFirst, first;
-
-  adjustmentInterval |= 0;
-
-  if (!last)
-    last = this.getTip();
-
-  // Do not retarget
-  if ((last.height + 1) % adjustmentInterval) {
-    if (network.powAllowMinDifficultyBlocks) {
-      // Special behavior for testnet:
-      newBlockTs = Date.now() / 1000 | 0;
-      if (newBlockTs > last.ts + network.powTargetSpacing * 2)
-        return proofOfWorkLimit;
-
-      while (last.prev
-        && last.height % adjustmentInterval !== 0
-        && last.bits !== proofOfWorkLimit) {
-        last = last.prev;
-      }
-
-      return last.bits;
-    }
-    return last.bits;
-  }
-
-  // Back 2 weeks
-  heightFirst = last.height - (adjustmentInterval - 1);
-  first = this.byHeight(heightFirst);
-
-  if (!first)
-    return 0;
-
-  return this.retarget(last, first.ts);
-};
-
-Chain.prototype.retarget = function retarget(last, firstTs) {
-  var powTargetTimespan = new bn(network.powTargetTimespan);
-  var actualTimespan, powLimit, target;
-
-  if (network.powNoRetargeting)
-    return last.bits;
-
-  actualTimespan = new bn(last.ts).subn(firstTs);
-  if (actualTimespan.cmp(powTargetTimespan.divn(4)) < 0)
-    actualTimespan = powTargetTimespan.divn(4);
-
-  if (actualTimespan.cmp(powTargetTimespan.muln(4)) > 0)
-    actualTimespan = powTargetTimespan.muln(4);
-
-  powLimit = network.powLimit;
-  target = utils.fromCompact(last.bits);
-  target.imul(actualTimespan);
-  target = target.div(powTargetTimespan);
-  if (target.cmp(powLimit) > 0)
-    target = powLimit.clone();
-
-  return utils.toCompact(target);
-};
-
 ChainBlock.prototype.toJSON = function() {
   // return [
   //   this.hash,