lavamoat-core/src/makeInitStatsHook.js

LavaMoat kernel and utils

module.exports = { makeInitStatsHook }

function makeInitStatsHook({ onStatsReady }) {
  let statModuleStack = []
  return reportStatsHook

  function reportStatsHook(event, moduleId) {
    if (event === 'start') {
      // record start
      const startTime = Date.now()
      // console.log(`loaded module ${moduleId}`)
      const statRecord = {
        name: moduleId,
        value: null,
        children: [],
        startTime: startTime,
        endTime: null,
      }
      // add as child to current
      if (statModuleStack.length > 0) {
        const currentStat = statModuleStack[statModuleStack.length - 1]
        currentStat.children.push(statRecord)
      }
      // set as current
      statModuleStack.push(statRecord)
    } else if (event === 'end') {
      const endTime = Date.now()
      const currentStat = statModuleStack[statModuleStack.length - 1]
      // sanity check, should only get an end for the current top of stack
      if (currentStat.name !== moduleId) {
        console.error(
          `stats hook misaligned "${
            currentStat.name
          }", "${moduleId}" ${statModuleStack.map((e) => e.name).join()}`
        )
      }
      currentStat.endTime = endTime
      const startTime = currentStat.startTime
      const duration = endTime - startTime
      currentStat.value = duration
      // console.log(`loaded module ${moduleId} in ${duration}ms`)
      // check if totally done
      if (statModuleStack.length === 1) {
        currentStat.version = 1
        onStatsReady(currentStat)
      }
      statModuleStack.pop()
    }
  }
}