Clever Geek Handbook

Tanda nano JavaScript dan rem prematur

Halo, nama saya Dmitry Karlovsky dan sebelumnya ... Saya mengukur pipet saya setiap hari , tetapi penggaris umum tidak memiliki cukup akurasi untuk mengukur ukuran sekecil itu.







Jadi saya memutuskan bahwa itu cukup untuk menanggungnya! ... dan memarahi saya dengan divisi nanometer, dukungan untuk pengukuran yang sejuk dan panas, pengujian, berbagi, dan kebebasan lainnya. Jadi saya mengundang Anda untuk bergabung dengan Olimpiade khusus ini untuk mengukur kecepatan kode JS Anda.







Pertama, mari kita lihat kasus ini:













Kasus keturunan



Di sini kami memiliki 3 opsi:







  • monomorphic adalah ketika jenis argumen yang sama diteruskan ke fungsi yang sama setiap saat. JIT membuat kode yang dioptimalkan, di awalnya hanya ada pemeriksaan bahwa jenis yang diteruskan sama.
  • — , ( 4 Chrome 88, 7 Firefox 85). JIT .
  • — . JIT .


JIT , . , . , . , , , , .







( ), ( ), .







. , 10 , :







class Base {

    p0 = 0
    p1 = 1
    p2 = 2
    p3 = 3
    p4 = 4
    p5 = 5
    p6 = 6
    p7 = 7
    p8 = 8
    p9 = 9

    get s() {
        return (
            + this.p0
            + this.p1
            + this.p2
            + this.p3
            + this.p4
            + this.p5
            + this.p6
            + this.p7
            + this.p8
            + this.p9
        )
    }

}


:







const Derived = [
    class extends Base { n0 = 0 },
    class extends Base { n1 = 1 },
    class extends Base { n2 = 2 },
    class extends Base { n3 = 3 },
    class extends Base { n4 = 4 },
]


3 :







const mono = Array.from( {length}, ()=> new Derived[0] )
const poly = Array.from( {length}, (_,i)=> new Derived[i%4] )
const mega = Array.from( {length}, (_,i)=> new Derived[i%5] )


, — JIT , , . - , 2 . , .







— . , , , , JIT .







— . JIT . , .







, , , . .









. , :







class A {
    p0 = 0
    p1 = 0
    p2 = 0
    p3 = 0
    p4 = 0
    p5 = 0
    p6 = 0
    p7 = 0
    p8 = 0
    p9 = 0
}

class B {
    constructor() {
        this.p0 = 0
        this.p1 = 0
        this.p2 = 0
        this.p3 = 0
        this.p4 = 0
        this.p5 = 0
        this.p6 = 0
        this.p7 = 0
        this.p8 = 0
        this.p9 = 0
    }
}

function C() {
    this.p0 = 0
    this.p1 = 0
    this.p2 = 0
    this.p3 = 0
    this.p4 = 0
    this.p5 = 0
    this.p6 = 0
    this.p7 = 0
    this.p8 = 0
    this.p9 = 0
}


Chrome 88 :













V8 , , 10 . Firefox 85 :













, , V8 , Firefox , - .









, . , $mol : , , . 3 ..







:







class Dictionary_base {
    constructor( dict ) {
        Object.assign( this , dict )
    }
}


:







class Initializer_base {
    constructor( init ) {
        if( init ) init( this )
    }
}


, .







Chrome 88 :













, . Firefox 85 :













. Chrome , Firefox , Firefox, . c .









. . , , . . — . , , . :







const chain = {}
const uid = ()=> Math.random().toString(16).slice(2)

for( let i = 0; i < 100; i++ ){
    chain[ uid() ] = i
}


. , :







const solid = JSON.parse( JSON.stringify( chain ) )


, , :







const map = new Map
for( let key in chain ) map.set( key, chain[key] )


Chrome 88 .













, , — . Firefox 85 — :















, , , :







function fib_sync(n) {
    if( n < 2 ) return 1
    return fib_sync( n - 1 ) + fib_sync( n - 2 )
}

function* fib_gen(n) {
    if( n < 2 ) return 1
    return ( yield* fib_gen( n - 1 ) ) + ( yield* fib_gen( n - 2 ) )
}

async function fib_async(n) {
    if( n < 2 ) return 1
    return ( await fib_async( n - 1 ) ) + ( await fib_async( n - 2 ) )
}


Chrome 88 :













, — . , . , , . Firefox 85 .









, . - . , . :









. — ISO8601:













, API , dayjs, API, , . dateFns, Date, - , , . .







, — ISO8601:













, JSJoda . dateFns



, Date, .







, , ISO8601 , . :













JSJoda . , $mol_time . .







Firefox 85 JSJoda :













, , , Firefox , JSJoda . , , . , , , .









:

















. , , , . . — , , , .







, .







. {#}



.







, , , , . :







const list = Array.from(
    { length: {#} },
    (_,i)=> new Date( `2015-07-20T07:48:28.${ i % 1000 }Z` ),
})




. :







  • , .
  • , .


{#}



, , . , - :







res = list[{#}].toString()




. :







  • , , .
  • , . , .


:







function measure() {

    // common setup code

    // case setup code

    let accum_$qwerty
    const case_$qwerty = iter_$qwerty => {
        // measured code where {#} replaced by iter_$qwerty
        accum_$qwerty = iter_$qwerty
    }
    let time_$qwerty = -performance.now()

    case_$qwerty(0);
    case_$qwerty(1);
    case_$qwerty(2);

    // ...

    time_$qwerty += performance.now()
    // teardown code
    return time_$qwerty
)


:







function measure() {

    // common setup code

    // case setup code

    let accum_$qwerty
    const case_$qwerty = iter_$qwerty => {
        accum_$qwerty = iter_$qwerty
    }
    let time_$qwerty = -performance.now()

    case_$qwerty(0);
    // measured code where {#} replaced by 0
    case_$qwerty(1);
    // measured code where {#} replaced by 1
    case_$qwerty(2);
    // measured code where {#} replaced by 2

    // ...

    time_$qwerty += performance.now()
    // teardown code
    return time_$qwerty
)


, . , , , . 20 . .









- , $mol_import, CDN:







const {
    $mol_time_moment: Moment,
    $mol_time_interval: Interval,
    $mol_time_duration: Duration,
} = $mol_import.script('https://unpkg.com/mol_time_all@1.1.12/web.js')




$mol_assert:







$mol_assert_like( [ 1 ], [ 1 ], [ 2 ] ) // Not like [1] --- [2]




perf.js.hyoo.ru — , . , . — .







bench.hyoo.ru — , , . : bench.hyoo.ru: JS .







- JS , , , , , .







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