Getters are slow, can we change it?

[qfox]

Why we decide to use getters?

[blond]

Getters are slow

Any proofs?

Why we decide to use getters?

1. These fields can not be overwritten
2. id and type fields can be calculated only when necessary

[qfox]

http://jsperf.com/javascript-performance-of-property-access-comparing-exp/15

[blond]

In NodeJS performance is better.

benchmark:

var Benchmark = require('benchmark');
var BemEntity = require('bem-entity');

var Benchmark = require('benchmark');
var BemEntity = require('./index.js');

var entity = new BemEntity({ block: 'button', mod: 'disabled' });
var suite = new Benchmark.Suite;

// add tests
suite
.add('direct access', function() {
    entity._obj.mod;
})
.add('function call', function() {
    entity.mmm();
})
.add('readonly property', function() {
    entity.mod;
})
// add listeners
.on('cycle', function(event) {
    console.log(String(event.target));
})
.on('complete', function() {
    console.log('Fastest is ' + this.filter('fastest').map('name'));
})
// run async
.run({ 'async': true });

$ node -v
v4.4.2

$ node ./bench.js

direct access x 80,577,480 ops/sec ±4.30% (78 runs sampled)
function call x 86,146,651 ops/sec ±1.41% (79 runs sampled)
readonly property x 73,289,864 ops/sec ±2.08% (81 runs sampled)

$ node -v
v5.10.1

$ node ./bench.js

direct access x 83,861,168 ops/sec ±2.41% (83 runs sampled)
function call x 85,250,727 ops/sec ±1.71% (78 runs sampled)
readonly property x 73,711,415 ops/sec ±1.45% (81 runs sampled)

[blond]

In addition current interface (with gettres) will allow to save memory.

const BemEntity = require('bem-entity');

const entity1 = new BemEntity({ block: 'button' }); // creates new instance
const entity2 = new BemEntity({ block: 'button' }); // returns previously created instance

entity1 === entity2 // true

[blond]

Update benchmark:

var Benchmark = require('benchmark');
var BemEntity = require('./index.js');

var entity = new BemEntity({ block: 'button', mod: 'disabled' });
var suite = new Benchmark.Suite;

suite
.add('direct access', function() {
    var data = entity._obj.mod;

    return f(data);
})
.add('function call', function() {
    var data = entity.mmm();

    return f(data);
})
.add('readonly property', function() {
    var data = entity.mod;

    return f(data);
})
.on('cycle', function(event) {
    console.log(String(event.target));
})
.on('complete', function() {
    console.log('Fastest is ' + this.filter('fastest').map('name'));
})
.run({ 'async': true });

function f(data) {
    return data + 'abc';
}

$ node -v
v4.4.2

$ node ./bench.js

direct access x 79,371,173 ops/sec ±2.36% (75 runs sampled)
function call x 78,999,689 ops/sec ±1.43% (81 runs sampled)
readonly property x 66,832,962 ops/sec ±1.46% (75 runs sampled)

$ node -v
v5.10.1

$ node ./bench.js

direct access x 73,403,549 ops/sec ±3.67% (75 runs sampled)
function call x 71,923,368 ops/sec ±4.15% (73 runs sampled)
readonly property x 66,553,090 ops/sec ±3.17% (77 runs sampled)

[qfox]

Okay. Looks good torr me