Merge pull request #1279 from braydonf/readuint64lebn

Improved performance of block parsing
This commit is contained in:
Patrick Nagurny 2015-07-06 14:24:33 -04:00
commit bbad29a76b
5 changed files with 111 additions and 11 deletions

View File

@ -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;

View File

@ -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;
};

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@ -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];

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@ -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);

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@ -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);
});
});
});