Merge pull request #1279 from braydonf/readuint64lebn

Improved performance of block parsing

benchmark/serialization.js

@@ -14,6 +14,65 @@ console.log('Benchmarking Block/Transaction Serialization');
 console.log('---------------------------------------');
 
 async.series([
+  function(next) {
+
+    var buffers = [];
+    var hashBuffers = [];
+    console.log('Generating Random Test Data...');
+    for (var i = 0; i < 100; i++) {
+
+      // uint64le
+      var br = new bitcore.encoding.BufferWriter();
+      var num = Math.round(Math.random() * 10000000000000);
+      br.writeUInt64LEBN(new bitcore.crypto.BN(num));
+      buffers.push(br.toBuffer());
+
+      // hashes
+      var data = bitcore.crypto.Hash.sha256sha256(new Buffer(32));
+      hashBuffers.push(data);
+    }
+
+    var c = 0;
+    var bn;
+
+    function readUInt64LEBN() {
+      if (c >= buffers.length) {
+        c = 0;
+      }
+      var buf = buffers[c];
+      var br = new bitcore.encoding.BufferReader(buf);
+      bn = br.readUInt64LEBN();
+      c++;
+    }
+
+    var reversed;
+
+    function readReverse() {
+      if (c >= hashBuffers.length) {
+        c = 0;
+      }
+      var buf = hashBuffers[c];
+      var br = new bitcore.encoding.BufferReader(buf);
+      reversed = br.readReverse();
+      c++;
+    }
+
+    console.log('Starting benchmark...');
+
+    var suite = new benchmark.Suite();
+    suite.add('bufferReader.readUInt64LEBN()', readUInt64LEBN, {maxTime: maxTime});
+    suite.add('bufferReader.readReverse()', readReverse, {maxTime: maxTime});
+    suite
+      .on('cycle', function(event) {
+        console.log(String(event.target));
+      })
+      .on('complete', function() {
+        console.log('Done');
+        console.log('----------------------------------------------------------------------');
+        next();
+      })
+      .run();
+  },
   function(next) {
 
     var block1;

lib/encoding/bufferreader.js

@@ -91,11 +91,22 @@ BufferReader.prototype.readUInt64BEBN = function() {
 };
 
 BufferReader.prototype.readUInt64LEBN = function() {
-  var buf = this.buf.slice(this.pos, this.pos + 8);
-  var reversebuf = BufferReader({
-    buf: buf
-  }).readReverse();
-  var bn = BN.fromBuffer(reversebuf);
+  var second = this.buf.readUInt32LE(this.pos);
+  var first = this.buf.readUInt32LE(this.pos + 4);
+  var combined = (first * 0x100000000) + second;
+  // Instantiating an instance of BN with a number is faster than with an
+  // array or string. However, the maximum safe number for a double precision
+  // floating point is 2 ^ 52 - 1 (0x1fffffffffffff), thus we can safely use
+  // non-floating point numbers less than this amount (52 bits). And in the case
+  // that the number is larger, we can instatiate an instance of BN by passing
+  // an array from the buffer (slower) and specifying the endianness.
+  var bn;
+  if (combined <= 0x1fffffffffffff) {
+    bn = new BN(combined);
+  } else {
+    var data = Array.prototype.slice.call(this.buf, this.pos, this.pos + 8);
+    bn = new BN(data, 10, 'le');
+  }
   this.pos = this.pos + 8;
   return bn;
 };

lib/util/buffer.js

@@ -152,7 +152,6 @@ module.exports = {
    * @return {Buffer}
    */
   reverse: function reverse(param) {
-    $.checkArgumentType(param, 'Buffer', 'param');
     var ret = new buffer.Buffer(param.length);
     for (var i = 0; i < param.length; i++) {
       ret[i] = param[param.length - i - 1];

test/encoding/bufferreader.js

@@ -190,6 +190,13 @@ describe('BufferReader', function() {
       br.readUInt64LEBN().toNumber().should.equal(1);
     });
 
+    it('should return 10BTC', function() {
+      var tenbtc = 10 * 1e8;
+      var tenbtcBuffer = new Buffer('00ca9a3b00000000', 'hex');
+      var br = new BufferReader(tenbtcBuffer);
+      br.readUInt64LEBN().toNumber().should.equal(tenbtc);
+    });
+
     it('should return 2^30', function() {
       var buf = new Buffer(8);
       buf.fill(0);
@@ -198,6 +205,35 @@ describe('BufferReader', function() {
       br.readUInt64LEBN().toNumber().should.equal(Math.pow(2, 30));
     });
 
+    it('should return 2^32 + 1', function() {
+      var num = Math.pow(2, 32) + 1;
+      var numBuffer = new Buffer('0100000001000000', 'hex');
+      var br = new BufferReader(numBuffer);
+      br.readUInt64LEBN().toNumber().should.equal(num);
+    });
+
+    it('should return max number of satoshis', function() {
+      var maxSatoshis = 21000000 * 1e8;
+      var maxSatoshisBuffer = new Buffer('0040075af0750700', 'hex');
+      var br = new BufferReader(maxSatoshisBuffer);
+      br.readUInt64LEBN().toNumber().should.equal(maxSatoshis);
+    });
+
+    it('should return 2^53 - 1', function() {
+      var maxSafe = Math.pow(2, 53) - 1;
+      var maxSafeBuffer = new Buffer('ffffffffffff1f00', 'hex');
+      var br = new BufferReader(maxSafeBuffer);
+      br.readUInt64LEBN().toNumber().should.equal(maxSafe);
+    });
+
+    it('should return 2^53', function() {
+      var bn = new BN('20000000000000', 16);
+      var bnBuffer = new Buffer('0000000000002000', 'hex');
+      var br = new BufferReader(bnBuffer);
+      var readbn = br.readUInt64LEBN();
+      readbn.cmp(bn).should.equal(0);
+    });
+
     it('should return 0', function() {
       var buf = new Buffer(8);
       buf.fill(0);

test/util/buffer.js

@@ -152,10 +152,5 @@ describe('buffer utils', function() {
       original[1].should.equal(reversed[1]);
       original[2].should.equal(reversed[0]);
     });
-    it('checks the argument type', function() {
-      expect(function() {
-        BufferUtil.reverse('invalid');
-      }).to.throw(errors.InvalidArgumentType);
-    });
   });
 });