From 015eaa1f2d08097f20dac926044bd4a8058cc582 Mon Sep 17 00:00:00 2001
From: Christopher Jeffrey <chjjeffrey@gmail.com>
Date: Wed, 2 Nov 2016 20:37:31 -0700
Subject: [PATCH] chaindb: better rescan algo.

---
 lib/chain/chaindb.js | 34 ++++++++++++++++++++++++++++------
 1 file changed, 28 insertions(+), 6 deletions(-)

diff --git a/lib/chain/chaindb.js b/lib/chain/chaindb.js
index f20dddd5..51519b1f 100644
--- a/lib/chain/chaindb.js
+++ b/lib/chain/chaindb.js
@@ -21,6 +21,7 @@ var ldb = require('../db/ldb');
 var LRU = require('../utils/lru');
 var Block = require('../primitives/block');
 var Coin = require('../primitives/coin');
+var Outpoint = require('../primitives/outpoint');
 var TX = require('../primitives/tx');
 var Address = require('../primitives/address');
 var ChainEntry = require('./chainentry');
@@ -1096,8 +1097,8 @@ ChainDB.prototype.getTXByAddress = co(function* getTXByAddress(addresses) {
 
 ChainDB.prototype.scan = co(function* scan(start, filter, iter) {
   var total = 0;
-  var i, j, entry, hashes;
-  var hash, tx, txs, block;
+  var i, j, entry, hash, tx, txs, block;
+  var found, input, output, prevout;
 
   if (start == null)
     start = this.network.genesis.hash;
@@ -1116,7 +1117,7 @@ ChainDB.prototype.scan = co(function* scan(start, filter, iter) {
     throw new Error('Cannot rescan an alternate chain.');
 
   while (entry) {
-    block = yield this.getFullBlock(entry.hash);
+    block = yield this.getBlock(entry.hash);
     txs = [];
     total++;
 
@@ -1134,11 +1135,32 @@ ChainDB.prototype.scan = co(function* scan(start, filter, iter) {
 
     for (i = 0; i < block.txs.length; i++) {
       tx = block.txs[i];
-      hashes = tx.getHashes();
+      found = false;
+
+      for (j = 0; j < tx.outputs.length; j++) {
+        output = tx.outputs[j];
+        hash = output.getHash();
+
+        if (!hash)
+          continue;
 
-      for (j = 0; j < hashes.length; j++) {
-        hash = hashes[j];
         if (filter.test(hash)) {
+          prevout = Outpoint.fromTX(tx, j);
+          filter.add(prevout.toRaw());
+          found = true;
+        }
+      }
+
+      if (found) {
+        txs.push(tx);
+        continue;
+      }
+
+      for (j = 0; j < tx.inputs.length; j++) {
+        input = tx.inputs[j];
+        prevout = input.prevout;
+
+        if (filter.test(prevout.toRaw())) {
           txs.push(tx);
           break;
         }