From 3e2f43e178962c060518483f5f8da353a101f4b6 Mon Sep 17 00:00:00 2001
From: Christopher Jeffrey <chjjeffrey@gmail.com>
Date: Fri, 20 May 2016 17:11:40 -0700
Subject: [PATCH] use bloom filter for addresses in wallet db.

---
 lib/bcoin/txdb.js     | 55 +++++++++++++++++++++++++++++++++++++++++++
 lib/bcoin/walletdb.js | 29 ++++++++++++++++-------
 2 files changed, 75 insertions(+), 9 deletions(-)

diff --git a/lib/bcoin/txdb.js b/lib/bcoin/txdb.js
index 07851982..d8845fb3 100644
--- a/lib/bcoin/txdb.js
+++ b/lib/bcoin/txdb.js
@@ -59,6 +59,9 @@ function TXDB(db, options) {
   this.busy = false;
   this.jobs = [];
   this.locker = new bcoin.locker(this);
+  this.filter = this.options.useFilter
+    ? new bcoin.bloom.rolling(800000, 0.01)
+    : null;
 
   if (this.options.mapAddress)
     this.options.indexAddress = true;
@@ -70,6 +73,43 @@ TXDB.prototype._lock = function _lock(func, args, force) {
   return this.locker.lock(func, args, force);
 };
 
+TXDB.prototype._loadFilter = function loadFilter(callback) {
+  var self = this;
+
+  if (!this.filter)
+    return callback();
+
+  this.db.iterate({
+    gte: 'W',
+    lte: 'W~',
+    transform: function(key) {
+      return key.split('/')[1];
+    }
+  }, function(err, keys) {
+    if (err)
+      return callback(err);
+
+    for (i = 0; i < keys.length; i++)
+      self.filter.add(keys[i], 'hex');
+
+    return callback();
+  });
+};
+
+TXDB.prototype._testFilter = function _testFilter(addresses) {
+  var i;
+
+  if (!this.filter)
+    return true;
+
+  for (i = 0; i < addresses.length; i++) {
+    if (this.filter.test(addresses[i], 'hex'))
+      return true;
+  }
+
+  return false;
+};
+
 /**
  * Map a transactions' addresses to wallet IDs.
  * @param {TX} tx
@@ -86,6 +126,9 @@ TXDB.prototype.getMap = function getMap(tx, callback) {
   output = tx.getOutputHashes();
   addresses = utils.uniq(input.concat(output));
 
+  if (!this._testFilter(addresses))
+    return callback();
+
   function cb(err, table) {
     if (err)
       return callback(err);
@@ -267,6 +310,9 @@ TXDB.prototype.add = function add(tx, callback, force) {
     if (err)
       return callback(err);
 
+    if (!map)
+      return callback(null, false);
+
     if (self.options.mapAddress) {
       if (map.all.length === 0)
         return callback(null, false);
@@ -757,6 +803,9 @@ TXDB.prototype.remove = function remove(hash, callback, force) {
       if (err)
         return callback(err);
 
+      if (!map)
+        return callback(null, false);
+
       if (self.options.mapAddress) {
         if (map.all.length === 0)
           return callback(null, false);
@@ -788,6 +837,9 @@ TXDB.prototype.lazyRemove = function lazyRemove(tx, callback, force) {
     if (err)
       return callback(err);
 
+    if (!map)
+      return callback(null, false);
+
     if (self.options.mapAddress) {
       if (map.all.length === 0)
         return callback(null, false);
@@ -938,6 +990,9 @@ TXDB.prototype.unconfirm = function unconfirm(hash, callback, force) {
       if (err)
         return callback(err);
 
+      if (!map)
+        return callback(null, false);
+
       if (self.options.mapAddress) {
         if (map.all.length === 0)
           return callback(null, false);
diff --git a/lib/bcoin/walletdb.js b/lib/bcoin/walletdb.js
index 08b8a409..84b47d3d 100644
--- a/lib/bcoin/walletdb.js
+++ b/lib/bcoin/walletdb.js
@@ -107,20 +107,26 @@ WalletDB.prototype._init = function _init() {
     writeBufferSize: 4 << 20
   });
 
-  this.db.open(function(err) {
-    if (err)
-      return self.emit('error', err);
-
-    self.emit('open');
-    self.loaded = true;
-  });
-
   this.tx = new bcoin.txdb(this.db, {
     network: this.network,
     indexExtra: true,
     indexAddress: true,
     mapAddress: true,
-    verify: this.options.verify
+    verify: this.options.verify,
+    useFilter: true
+  });
+
+  this.db.open(function(err) {
+    if (err)
+      return self.emit('error', err);
+
+    self.tx._loadFilter(function(err) {
+      if (err)
+        return self.emit('error', err);
+
+      self.emit('open');
+      self.loaded = true;
+    });
   });
 
   this.tx.on('error', function(err) {
@@ -373,9 +379,14 @@ WalletDB.prototype.saveJSON = function saveJSON(id, json, callback) {
 
     if (json) {
       batch = self.db.batch();
+
       Object.keys(json.addressMap).forEach(function(address) {
+        if (self.tx.filter)
+          self.tx.filter.add(address, 'hex');
+
         batch.put('W/' + address + '/' + json.id, DUMMY);
       });
+
       return batch.write(function(err) {
         if (err)
           return callback(err);