hash test for https://twitter.com/kuvos/status/751685187831001088

obj-hash-test.js

var durations={}
	,os={}
function aSet(){
	return new Promise((res,rej)=>{
		var N = n = 10,
			m = 6
		while(m--) {
			//increase keys
			N *= 10
			n = N
			if(!durations[N]) durations[N]=[]
		
			//construct
			if(!os[N]){
				var o = {}
				while(n--) o[btoa(n)] = Math.random()
				os[N]=o
			}
			var o=os[N]

			// random indices to check
			var checks=" ".repeat(100).split("").map(x=>btoa(~~(Math.random()*N)))
		
			//time checks, being sure to do something unoptimizable w/each val
			var last=0
				,t=Date.now()
				,result=checks.reduce((sum,i)=>sum+o[i],0)
				,dt=Date.now()-t
			durations[N].push(dt)
			console.log(`${N} took ${dt}`)
			o={}
		}
		res()
	})
}

//perform as promises to not thrash ui thread
var repeat=10
	,p=aSet()
while(repeat--) p.then(aSet)

p.then(()=>{
	//analyze
	console.log(durations,
		Object.keys(durations).reduce((set,n)=>{
			return set.concat((durations[n].reduce((sum,v)=>sum+v)/durations[n].length).toFixed(3)+"ms for "+n )
		},[])
		.join("\n")
	)
})

/*

some results:

0.273ms for 100
0.000ms for 1000
0.000ms for 10000
0.182ms for 100000
0.000ms for 1000000
0.000ms for 10000000

*/