Clever Geek Handbook

JavaScript-Nanobenchmarks und vorzeitige Bremsen

Hallo, mein Name ist Dmitry Karlovsky und früher ... Ich habe meine Pipette jeden Tag gemessen , aber die üblichen Lineale hatten nicht genug Genauigkeit, um so kleine Größen zu messen.







Also entschied ich, dass es genug war, um es zu ertragen! ... und schalt meine mit Nanometer-Teilungen, Unterstützung für eine kühle und erhitzte Messung, Tests, Teilen und anderen Freiheiten. Deshalb lade ich Sie ein, an dieser speziellen Olympiade teilzunehmen, um die Geschwindigkeit Ihres JS-Codes zu messen.







Schauen wir uns zunächst diesen Fall an:













Erblicher Fall



Hier haben wir 3 Möglichkeiten:







  • Monomorph ist, wenn jedes Mal dieselben Argumenttypen an dieselbe Funktion übergeben werden. JIT erstellt optimierten Code, zu dessen Beginn nur überprüft wird, ob der übergebene Typ identisch ist.
  • — , ( 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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