tx indicies. merkle things.

lib/bcoin/abstractblock.js

@@ -47,6 +47,38 @@ function AbstractBlock(data) {
   this.lowVersion = this.version & 7;
 }
 
+AbstractBlock.prototype.getMerkleBranch = function getMerkleBranch(index) {
+  var tree = utils.buildMerkleTree(this.merkleRoot);
+  var branch = [];
+  var j = 0;
+  for (var size = this.totalTX; size > 1; size = (size + 1) / 2 | 0) {
+    var i = Math.min(index ^ 1, size - 1);
+    branch.push(tree[j + i]);
+    index >>= 1;
+    j += size;
+  }
+  return branch;
+};
+
+AbstractBlock.prototype.hasMerkleItem = function hasMerkleItem(hash, branch, index) {
+  if (index === -1)
+    return false;
+
+  if (typeof hash === 'string')
+    hash = new Buffer(hash, 'hex');
+
+  for (var i = 0; i < branch.length; i++) {
+    var otherside = branch[i];
+    if (index & 1)
+      hash = utils.dsha256(Buffer.concat([otherside, hash]));
+    else
+      hash = utils.dsha256(Buffer.concat([hash, otherside]));
+    index >>= 1;
+  }
+
+  return utils.toHex(hash) === this.merkleRoot;
+};
+
 AbstractBlock.prototype.hash = function hash(enc) {
   if (!this._hash)
     this._hash = utils.dsha256(this.abbr());

lib/bcoin/block.js

@@ -29,11 +29,11 @@ function Block(data) {
 
   this._cbHeight = null;
 
-  this.txs = this.txs.map(function(data) {
+  this.txs = this.txs.map(function(data, i) {
     if (data instanceof bcoin.tx)
       return data;
 
-    return bcoin.tx(data, self);
+    return bcoin.tx(data, self, i);
   });
 
   if (!this._raw)

lib/bcoin/mtx.js

@@ -31,6 +31,7 @@ function MTX(options) {
   this.locktime = 0;
   this.ts = 0;
   this.block = null;
+  this.index = -1;
 
   this._hash = null;
   this._raw = null;

lib/bcoin/tx.js

@@ -15,9 +15,9 @@ var constants = bcoin.protocol.constants;
  * TX
  */
 
-function TX(data, block) {
+function TX(data, block, index) {
   if (!(this instanceof TX))
-    return new TX(data, block);
+    return new TX(data, block, index);
 
   if (!data)
     data = {};
@@ -29,6 +29,7 @@ function TX(data, block) {
   this.locktime = data.locktime || 0;
   this.ts = data.ts || 0;
   this.block = data.block || null;
+  this.index = data.index || -1;
   this._hash = null;
 
   this._raw = data._raw || null;
@@ -53,9 +54,9 @@ function TX(data, block) {
   if (block && this.ts === 0) {
     if (block.type === 'merkleblock') {
       if (block.hasTX(this.hash('hex')))
-        this.setBlock(block);
+        this.setBlock(block, index);
     } else {
-      this.setBlock(block);
+      this.setBlock(block, index);
     }
   }
 
@@ -66,10 +67,11 @@ function TX(data, block) {
     this._size = this._raw.length;
 }
 
-TX.prototype.setBlock = function setBlock(block) {
+TX.prototype.setBlock = function setBlock(block, index) {
   this.ts = block.ts;
   this.block = block.hash('hex');
   this.height = block.height;
+  this.index = index;
 };
 
 TX.prototype.clone = function clone() {