From 51f817a60f02af649da468de5cde047b3199c519 Mon Sep 17 00:00:00 2001
From: Christopher Jeffrey <chjjeffrey@gmail.com>
Date: Sat, 27 Aug 2016 12:37:42 -0700
Subject: [PATCH] chaindb: refactor scanning.

---
 lib/chain/chain.js   |  2 +-
 lib/chain/chaindb.js | 61 +++++++++++++++++++++-----------------------
 2 files changed, 30 insertions(+), 33 deletions(-)

diff --git a/lib/chain/chain.js b/lib/chain/chain.js
index b5cf09c6..37e51fcd 100644
--- a/lib/chain/chain.js
+++ b/lib/chain/chain.js
@@ -66,7 +66,7 @@ function Chain(options) {
 
   this.network = bcoin.network.get(options.network);
   this.logger = options.logger || bcoin.defaultLogger;
-  this.db = new bcoin.chaindb(this, options);
+  this.db = new bcoin.chaindb(this);
   this.total = 0;
   this.currentBlock = null;
   this.orphanLimit = options.orphanLimit || (20 << 20);
diff --git a/lib/chain/chaindb.js b/lib/chain/chaindb.js
index 05e06bcc..444a50c3 100644
--- a/lib/chain/chaindb.js
+++ b/lib/chain/chaindb.js
@@ -150,19 +150,16 @@ if (utils.isBrowser)
  * @emits ChainDB#error
  */
 
-function ChainDB(chain, options) {
+function ChainDB(chain) {
   if (!(this instanceof ChainDB))
-    return new ChainDB(chain, options);
-
-  if (!options)
-    options = {};
+    return new ChainDB(chain);
 
   AsyncObject.call(this);
 
-  this.options = options;
   this.chain = chain;
+  this.options = chain.options;
   this.logger = chain.logger;
-  this.network = this.chain.network;
+  this.network = chain.network;
 
   this.db = bcoin.ldb({
     location: this.options.location,
@@ -174,8 +171,8 @@ function ChainDB(chain, options) {
     bufferKeys: !utils.isBrowser
   });
 
-  this.keepBlocks = options.keepBlocks || 288;
-  this.prune = !!options.prune;
+  this.keepBlocks = this.options.keepBlocks || 288;
+  this.prune = !!this.options.prune;
   this.state = new ChainState();
   this.pending = null;
   this.current = null;
@@ -1255,7 +1252,10 @@ ChainDB.prototype.getCoins = function getCoins(hash, callback) {
 ChainDB.prototype.scan = function scan(start, filter, iter, callback) {
   var self = this;
   var total = 0;
-  var i, j, hashes, address, tx, txs;
+  var i, j, hashes, hash, tx, txs;
+
+  if (this.options.spv)
+    return callback(new Error('Cannot scan in spv mode.'));
 
   if (start == null)
     start = this.network.genesis.hash;
@@ -1268,34 +1268,31 @@ ChainDB.prototype.scan = function scan(start, filter, iter, callback) {
   if (Array.isArray(filter))
     filter = utils.toMap(filter);
 
-  (function next(err, hash) {
+  this.getEntry(start, function(err, entry) {
     if (err)
       return callback(err);
 
-    if (hash == null) {
-      self.logger.info('Finished scanning %d blocks.', total);
-      return callback();
-    }
-
-    total++;
-
-    self.getEntry(hash, function(err, entry) {
+    (function next(err, entry) {
       if (err)
-        return next(err);
+        return callback(err);
 
-      if (!entry)
-        return next();
+      if (!entry) {
+        self.logger.info('Finished scanning %d blocks.', total);
+        return callback();
+      }
 
-      self.getFullBlock(hash, function(err, block) {
+      total++;
+
+      self.getFullBlock(entry.hash, function(err, block) {
         if (err)
           return next(err);
 
         if (!block)
-          return next();
+          return next(new Error('Block not found.'));
 
-        self.logger.info('Scanning block %s (%d).',
-          utils.revHex(entry.hash),
-          block.height);
+        self.logger.info(
+          'Scanning block %s (%d).',
+          entry.rhash, block.height);
 
         txs = [];
 
@@ -1304,8 +1301,8 @@ ChainDB.prototype.scan = function scan(start, filter, iter, callback) {
           hashes = tx.getHashes('hex');
 
           for (j = 0; j < hashes.length; j++) {
-            address = hashes[j];
-            if (filter[address]) {
+            hash = hashes[j];
+            if (filter[hash]) {
               txs.push(tx);
               break;
             }
@@ -1315,11 +1312,11 @@ ChainDB.prototype.scan = function scan(start, filter, iter, callback) {
         iter(entry, txs, function(err) {
           if (err)
             return next(err);
-          self.getNextHash(entry.hash, next);
+          entry.getNext(next);
         });
       });
-    });
-  })(null, start);
+    })(null, entry);
+  });
 };
 
 /**