How to use the snappy.compress function in snappy

var simple_s=JSON.stringify(simple);
var t2=hrnow();

console.log("simple:",simple_s.length, t2-t1);


var t3=hrnow();
var bulk_s=JSON.stringify(bulk);
var t4=hrnow();
console.log("bulk:", bulk_s.length, t4-t3);


var snappy=require("snappy");

var t5=hrnow();
snappy.compress(simple_s, function(err,compd) {
    var t6=hrnow();
    console.log("snappyed_simple:", compd.length, t6-t5);
});


var t7=hrnow();
snappy.compress(bulk_s, function(err,compd) {
    var t8=hrnow();
    console.log("snappyed_bulk:", compd.length, t8-t7);
});


var t9=hrnow();
var bytes_s=JSON.stringify(bytes);
var t10=hrnow();
console.log("bytes tojson:", bytes_s.length,t10-t9);

});


var t7=hrnow();
snappy.compress(bulk_s, function(err,compd) {
    var t8=hrnow();
    console.log("snappyed_bulk:", compd.length, t8-t7);
});


var t9=hrnow();
var bytes_s=JSON.stringify(bytes);
var t10=hrnow();
console.log("bytes tojson:", bytes_s.length,t10-t9);

snappy.compress(bytes_s, function(err,compd) {
    var t11=hrnow();
    console.log("snappyed_bytes:", compd.length, t11-t10);
});

require("./lzw.js");

var t11=hrnow();
var lzwout=lzw_encode(bytes_s);
var t12=hrnow();
console.log("lzw:", lzwout.length, t12-t11);

var bulk_s=JSON.stringify(bulk);
var t4=hrnow();
console.log("bulk:", bulk_s.length, t4-t3);


var snappy=require("snappy");

var t5=hrnow();
snappy.compress(simple_s, function(err,compd) {
    var t6=hrnow();
    console.log("snappyed_simple:", compd.length, t6-t5);
});


var t7=hrnow();
snappy.compress(bulk_s, function(err,compd) {
    var t8=hrnow();
    console.log("snappyed_bulk:", compd.length, t8-t7);
});


var t9=hrnow();
var bytes_s=JSON.stringify(bytes);
var t10=hrnow();
console.log("bytes tojson:", bytes_s.length,t10-t9);

snappy.compress(bytes_s, function(err,compd) {
    var t11=hrnow();
    console.log("snappyed_bytes:", compd.length, t11-t10);
});

require("./lzw.js");

CompressStream.prototype._transform = function (chunk, enc, callback) {
  var self = this

  snappy.compress(chunk, function (err, compressed) {
    if (err)
      return callback(err)

    if (compressed.length < chunk.length)
      self._compressed(chunk, compressed)
    else
      self._uncompressed(chunk)

    callback()
  })
}

compress(data) {
    return promisify(snappy.compress)(data);
  }