The selector API has performance issues in miniapps

[ickg5]

Although the selector API is provided by miniapps, the performance of the selector API of miniapps is not good.

Getting a rect of an element in a browser takes 0ms each time, but getting a rect of an element in a miniapp takes 30ms+ each time.

This is very bad for developers developing component libraries.

I hope miniapps will pay attention to this problem,

[xfq]

Thanks for the report. Could you give some specific code examples and performance data? Also, if it's purely a performance issue of a miniapp implementation (rather than an API design issue), it may not be within the scope of this group's work.

[ickg5]

I don't know how to reply.

[ickg5]

https://github.com/mallfoundry/miniapp-scr-performance

[ickg5]

It takes no more than 3ms to get a rect in any browser

<script>
    function stopWatch() {
        return new Promise(resolve => {
            const start = Date.now();
            document.querySelector(".container").getBoundingClientRect()
            const end = Date.now();
            resolve(end - start)
        })
    }

    function queryCounts() {
        return Promise.all(Array.from(Array(100)).map(stopWatch))
    }

    queryCounts().then(console.log)
</script>

But not less than 30ms in any mini program

function stopWatch() {
  return new Promise(resolve => {
    const start = Date.now();
    wx.createSelectorQuery()
      .select(".container")
      .boundingClientRect()
      .exec(() => {
        const end = Date.now();
        resolve(end - start)
      })
  })
}

function queryCounts() {
  return Promise.all( Array.from(Array(100)).map(stopWatch))
}

Page({
  onLoad() {
    queryCounts().then(console.log)
  },
})

[ickg5]

Browser time:

[0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]

Miniapp time:

[123,132,130,129,129,128,128,127,126,126,126,124,124,125,124,124,124,123,122,122,122,121,121,121,120,120,120,119,119,119,118,118,115,114,113,112,112,111,111,111,111,111,110,110,110,110,110,109,109,109,109,108,108,103,101,101,100,100,101,101,100,100,100,100,99,99,99,98,98,98,98,98,97,97,97,97,97,96,96,96,96,95,95,95,95,95,94,94,94,94,94,93,93,93,91,90,90,90,90,90]