Buffer.writeUInt32() benchmarklet

benchmark.txt

$ time ./node tmp/test-uint32-slow.js 

real    0m8.819s
user    0m8.790s
sys     0m0.030s

$ time ./node tmp/test-uint32-fast.js 

real    0m2.210s
user    0m2.190s
sys     0m0.030s

test-uint32-fast.js

Buffer.prototype.fastWriteUInt32 = function(value, offset, be) {
  if (be) {
    this[offset] = (value >>> 24) & 0xFF;
    this[offset + 1] = (value >>> 16) & 0xFF;
    this[offset + 2] = (value >>> 8) & 0xFF;
    this[offset + 3] = value & 0xFF;
  }
  else {
    this[offset] = value & 0xFF;
    this[offset + 1] = (value >>> 8) & 0xFF;
    this[offset + 2] = (value >>> 16) & 0xFF;
    this[offset + 3] = (value >>> 24) & 0xFF;
  }
};

var b = new Buffer(4);
for (var i = 0; i < 32 * 1024 * 1024; ++i) {
  b.fastWriteUInt32(i, 0, false);
}

test-uint32-slow.js

var b = new Buffer(4);
for (var i = 0; i < 32 * 1024 * 1024; ++i) {
  b.writeUInt32(i, 0, 'little');
}