Profiler snippet

profiler-snippet.js

(async()=>{let t=1,e=[];const n=new PerformanceObserver(n=>{const r=n.getEntries();for(const n of r)e.push({id:`${t}`,type:n.entryType,name:n.name,start:Math.round(n.startTime),end:Math.round(n.startTime+n.duration),duration:Math.round(n.duration)}),t++});n.observe({type:"longtask",buffered:!0});const r=await performance.profile({categories:["js"],sampleInterval:1,sampleBufferSize:Number.MAX_SAFE_INTEGER});async function o(){n.disconnect();const t=function(t){const n={};for(const r of t.samples){const o=Math.round(r.timestamp);for(const a of e){const{start:e,name:c,type:i,id:u,end:f,duration:d}=a;if(o>=e&&o<=f){n[u]||(n[u]={name:c,type:i,start:e,end:f,duration:d,culprits:[]});const a=s(t,r.stackId);n[u].culprits.push({time:o,stackId:r.stackId,stack:a})}}}return function(t,e){Object.keys(t).forEach(n=>{const{culprits:r,start:o,end:a}=t[n],s=[];let i=o;for(let t=0,n=1;n<r.length+1;t++,n++){let o=r[t],u=r[n];for(;u&&u.stackId===o.stackId;)n++,o=r[++t],u=r[n];const f=n===r.length,d=f?o.time-i+(a-o.time):o.time-i;s.push({totalTime:d,frames:c(e,o.stack)}),i=o.time}t[n].culprits=s})}(n,t),n}(await r.stop());try{const e="https://rum-profiler.now.sh",n=`${e}/flamegraph`,r=await fetch(n,{method:"POST",headers:{"content-type":"application/json"},body:JSON.stringify(t),mode:"cors",redirect:"follow"}),o=`${e}/trace/${await r.text()}`;console.log("%c Open this link in new tab to see the profiler data - "+o,"color: red"),window.open(o,"_blank")}catch(t){console.error("Failed to generate flamegraphs data because of an error",t)}}function a(t,e){return function(t,e){let{name:n,line:r,column:o,resourceId:a}=e;if(!n&&!r&&!o)return"unknown";n||(n="anonymous");if(!r||!o)return`${n} (native code)`;const s=function(t,e){return t.resources[e]}(t,a);return`${n} (${s}:${r}:${o})`}(t,function(t,e){return t.frames[e]}(t,e.frameId))}function s(t,e){return t.stacks[e]}function c(t,e,n=[]){if(!e)return n;const{parentId:r}=e;if(null!=r){return n.unshift(a(t,e)),c(t,s(t,r),n)}return n.unshift(a(t,e)),n}window.addEventListener("load",()=>o())})()