From 292e077550b5804cfbae09e5929c4c2fa82716bf Mon Sep 17 00:00:00 2001
From: Christopher Jeffrey <chjjeffrey@gmail.com>
Date: Fri, 20 May 2016 16:21:33 -0700
Subject: [PATCH] optimization for rolling filter.

---
 lib/bcoin/bloom.js | 17 +++++++++++++----
 lib/bcoin/pool.js  |  2 +-
 test/bloom-test.js |  6 +++---
 3 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/lib/bcoin/bloom.js b/lib/bcoin/bloom.js
index fc86c1d5..01e22a5c 100644
--- a/lib/bcoin/bloom.js
+++ b/lib/bcoin/bloom.js
@@ -216,14 +216,17 @@ function RollingFilter(items, rate) {
 
   this.n = Math.max(1, Math.min(Math.round(logRate / Math.log(0.5)), 50));
   this.limit = (items + 1) / 2 | 0;
+
   max = this.limit * 3;
   this.size = -1 * this.n * max / Math.log(1.0 - Math.exp(logRate / this.n));
   this.size = Math.ceil(this.size);
+
   this.items = ((this.size + 63) / 64 | 0) << 1;
-  this.filter = new Buffer(this.items * 8);
+
   this.tweak = (Math.random() * 0x100000000) >>> 0;
 
-  this.reset();
+  this.filter = new Buffer(this.items * 8);
+  this.filter.fill(0);
 }
 
 /**
@@ -242,6 +245,9 @@ RollingFilter.prototype.hash = function hash(val, n) {
  */
 
 RollingFilter.prototype.reset = function reset() {
+  if (this.entries === 0)
+    return;
+
   this.entries = 0;
   this.generation = 1;
   this.filter.fill(0);
@@ -318,6 +324,9 @@ RollingFilter.prototype.add = function add(val, enc) {
 RollingFilter.prototype.test = function test(val, enc) {
   var i, hash, bits, pos, pos1, pos2, bit, oct;
 
+  if (this.entries === 0)
+    return false;
+
   if (typeof val === 'string')
     val = new Buffer(val, enc);
 
@@ -333,8 +342,8 @@ RollingFilter.prototype.test = function test(val, enc) {
     pos1 += oct;
     pos2 += oct;
 
-    bits = (this.filter[pos1] >> bit) & 1;
-    bits |= (this.filter[pos2] >> bit) & 1;
+    bits = (this.filter[pos1] >>> bit) & 1;
+    bits |= (this.filter[pos2] >>> bit) & 1;
 
     if (bits === 0)
       return false;
diff --git a/lib/bcoin/pool.js b/lib/bcoin/pool.js
index 44cc8bd4..f3723e1a 100644
--- a/lib/bcoin/pool.js
+++ b/lib/bcoin/pool.js
@@ -1647,7 +1647,7 @@ Pool.prototype._sendRequests = function _sendRequests(peer) {
       size = 500;
     else if (this.chain.height <= 150000)
       size = 250;
-    else if (this.chain.height <= 170000)
+    else if (this.chain.height <= 250000)
       size = 20;
     else
       size = 10;
diff --git a/test/bloom-test.js b/test/bloom-test.js
index a2bc211e..4691cc55 100644
--- a/test/bloom-test.js
+++ b/test/bloom-test.js
@@ -79,7 +79,7 @@ describe('Bloom', function() {
       var j = i;
       do {
         var str = 'foobar' + j;
-        assert(filter.test(str, 'ascii') === true, str + i);
+        assert(filter.test(str, 'ascii') === true, str);
         assert(filter.test(str + '-', 'ascii') === false, str);
       } while (j--);
     }
@@ -99,7 +99,7 @@ describe('Bloom', function() {
       var j = i;
       do {
         var str = 'foobar' + j;
-        assert(filter.test(str, 'ascii') === true, str + ' GOOD');
+        assert(filter.test(str, 'ascii') === true, str);
         assert(filter.test(str + '-', 'ascii') === false, str);
       } while (j-- > 25);
       assert(filter.test('foobar 24', 'ascii') === false);
@@ -110,7 +110,7 @@ describe('Bloom', function() {
       var j = i;
       do {
         var str = 'foobar' + j;
-        assert(filter.test(str, 'ascii') === true, str + ' GOOD');
+        assert(filter.test(str, 'ascii') === true, str);
         assert(filter.test(str + '-', 'ascii') === false, str);
       } while (j-- > 50);
     }