From a4084d82521770282870726536cb8cc1cb84956b Mon Sep 17 00:00:00 2001
From: Christopher Jeffrey <chjjeffrey@gmail.com>
Date: Fri, 1 Jan 2016 18:32:15 -0800
Subject: [PATCH] more chain methods.

---
 lib/bcoin/chain.js     | 63 ++++++++++++++++++++++++++++++------------
 lib/bcoin/fullchain.js | 26 +++++++++++------
 lib/bcoin/tx.js        |  4 +--
 3 files changed, 64 insertions(+), 29 deletions(-)

diff --git a/lib/bcoin/chain.js b/lib/bcoin/chain.js
index ce1758f8..391e1b96 100644
--- a/lib/bcoin/chain.js
+++ b/lib/bcoin/chain.js
@@ -154,7 +154,7 @@ Chain.prototype._addIndex = function _addIndex(hash, ts, height) {
     return new Error('Already added.');
 
   var pos = utils.binaryInsert(this.index.ts, ts, compareTs, true);
-  var checkpoint, obj;
+  var checkpoint;
 
   // Avoid duplicates
   if (this.index.hashes[pos] === hash
@@ -178,14 +178,9 @@ Chain.prototype._addIndex = function _addIndex(hash, ts, height) {
   this.index.heights.splice(pos, 0, height);
   this.index.bloom.add(hash, 'hex');
 
-  if (!this.storage)
-    return;
-
-  obj = { ts: ts, height: height };
-
-  this.storage.put(this.prefix + hash, obj, function(err) {
-    if (err)
-      self.emit('error', err);
+  this._save(hash, {
+    ts: ts,
+    height: height
   });
 };
 
@@ -256,13 +251,7 @@ Chain.prototype._killFork = function _killFork(probe) {
   this.index.heights.splice(index, 1);
 
   // Delete both blocks, let's see what others will choose
-  if (!this.storage)
-    return true;
-
-  this.storage.del(this.prefix + hash, function(err) {
-    if (err)
-      self.emit('error', err);
-  });
+  this._delete(hash);
 
   return true;
 };
@@ -404,7 +393,7 @@ Chain.prototype.byHeight = function byHeight(height) {
   var index = this.index.heights.indexOf(height);
 
   if (index === -1)
-    return -1;
+    return null;
 
   return {
     index: index,
@@ -414,6 +403,16 @@ Chain.prototype.byHeight = function byHeight(height) {
   };
 };
 
+Chain.prototype.getTip = function() {
+  var index = this.index.hashes.length - 1;
+  return {
+    index: index,
+    hash: this.index.hashes[index],
+    ts: this.index.ts[index],
+    height: this.index.heights[index]
+  };
+};
+
 Chain.prototype.byHash = function byHash(hash) {
   if (this.loading)
     return null;
@@ -426,7 +425,7 @@ Chain.prototype.byHash = function byHash(hash) {
   var index = this.index.hashes.indexOf(hash);
 
   if (index === -1)
-    return -1;
+    return null;
 
   return {
     index: index,
@@ -603,6 +602,34 @@ Chain.prototype.size = function size() {
   return this.index.hashes.length;
 };
 
+Chain.prototype.height = function height() {
+  return this.getTip().height;
+};
+
+Chain.prototype._save = function(hash, obj) {
+  var self = this;
+
+  if (!this.storage)
+    return;
+
+  this.storage.put(this.prefix + hash, obj, function(err) {
+    if (err)
+      self.emit('error', err);
+  });
+};
+
+Chain.prototype._delete = function(hash) {
+  var self = this;
+
+  if (!this.storage)
+    return;
+
+  this.storage.del(this.prefix + hash, function(err) {
+    if (err)
+      self.emit('error', err);
+  });
+};
+
 Chain.prototype.toJSON = function toJSON() {
   var keep = 1000;
 
diff --git a/lib/bcoin/fullchain.js b/lib/bcoin/fullchain.js
index 3c0b360e..dcd7ad52 100644
--- a/lib/bcoin/fullchain.js
+++ b/lib/bcoin/fullchain.js
@@ -159,11 +159,8 @@ Chain.prototype.resetHeight = function resetHeight(height) {
 
   this.index.lastTs = this.index.entries[this.index.entries.length - 1].ts;
 
-  if (!this.storage)
-    return;
-
   forked.forEach(function(entry) {
-    self._del(entry);
+    self._delete(entry);
   });
 };
 
@@ -279,7 +276,7 @@ Chain.prototype.byHeight = function byHeight(height) {
   if (this.loading)
     return null;
 
-  return this.index.entries[height];
+  return this.index.entries[height] || null;
 };
 
 Chain.prototype.byHash = function byHash(hash) {
@@ -294,6 +291,13 @@ Chain.prototype.byHash = function byHash(hash) {
   return this.byHeight(this.index.heights[hash]);
 };
 
+Chain.prototype.getTip = function getTip() {
+  if (this.loading)
+    return null;
+
+  return this.index.entries[this.index.entries.length - 1];
+};
+
 Chain.prototype.hasBlock = function hasBlock(hash) {
   if (this.loading)
     return false;
@@ -435,25 +439,29 @@ Chain.prototype.size = function size() {
   return this.index.entries.length;
 };
 
-Chain.prototype._save = function(entry) {
+Chain.prototype.height = function height() {
+  return this.getTip().height;
+};
+
+Chain.prototype._save = function(hash, obj) {
   var self = this;
 
   if (!this.storage)
     return;
 
-  this.storage.put(this.prefix + entry.hash, entry.toJSON(), function(err) {
+  this.storage.put(this.prefix + hash, obj.toJSON(), function(err) {
     if (err)
       self.emit('error', err);
   });
 };
 
-Chain.prototype._del = function(entry) {
+Chain.prototype._delete = function(hash) {
   var self = this;
 
   if (!this.storage)
     return;
 
-  this.storage.del(this.prefix + entry.hash, function(err) {
+  this.storage.del(this.prefix + hash, function(err) {
     if (err)
       self.emit('error', err);
   });
diff --git a/lib/bcoin/tx.js b/lib/bcoin/tx.js
index b304506a..062bdec3 100644
--- a/lib/bcoin/tx.js
+++ b/lib/bcoin/tx.js
@@ -852,10 +852,10 @@ TX.prototype.getConfirmations = function getConfirmations(chain) {
   if (!chain)
     return 0;
 
-  top = chain.getHeight(chain.index.hashes[chain.index.hashes.length - 1]);
+  top = chain.height();
   height = this.getHeight(chain);
 
-  if (top === -1 || height === -1)
+  if (height === -1)
     return 0;
 
   return top - height + 1;