codekingpro/portable-devtools

1const EE = require('node:events')
2const fs = require('node:fs')
3const { log, time } = require('proc-log')
4
5const INITIAL_TIMER = 'npm'
6
7class Timers extends EE {
8  #file
9  #timing
10
11  #unfinished = new Map()
12  #finished = {}
13
14  constructor () {
15    super()
16    this.on()
17    time.start(INITIAL_TIMER)
18    this.started = this.#unfinished.get(INITIAL_TIMER)
19  }
20
21  on () {
22    process.on('time', this.#timeHandler)
23  }
24
25  off () {
26    process.off('time', this.#timeHandler)
27  }
28
29  load ({ path, timing } = {}) {
30    this.#timing = timing
31    this.#file = `${path}timing.json`
32  }
33
34  finish (metadata) {
35    time.end(INITIAL_TIMER)
36
37    for (const [name, timer] of this.#unfinished) {
38      log.silly('unfinished npm timer', name, timer)
39    }
40
41    if (!this.#timing) {
42      // Not in timing mode, nothing else to do here
43      return
44    }
45
46    try {
47      this.#writeFile(metadata)
48      log.info('timing', `Timing info written to: ${this.#file}`)
49    } catch (e) {
50      log.warn('timing', `could not write timing file: ${e}`)
51    }
52  }
53
54  #writeFile (metadata) {
55    const globalStart = this.started
56    const globalEnd = this.#finished[INITIAL_TIMER]
57    const content = {
58      metadata,
59      timers: this.#finished,
60      // add any unfinished timers with their relative start/end
61      unfinishedTimers: [...this.#unfinished.entries()].reduce((acc, [name, start]) => {
62        acc[name] = [start - globalStart, globalEnd - globalStart]
63        return acc
64      }, {}),
65    }
66    fs.writeFileSync(this.#file, JSON.stringify(content) + '\n')
67  }
68
69  #timeHandler = (level, name) => {
70    const now = Date.now()
71    switch (level) {
72      case time.KEYS.start:
73        this.#unfinished.set(name, now)
74        break
75      case time.KEYS.end: {
76        if (this.#unfinished.has(name)) {
77          const ms = now - this.#unfinished.get(name)
78          this.#finished[name] = ms
79          this.#unfinished.delete(name)
80          log.timing(name, `Completed in ${ms}ms`)
81        } else {
82          log.silly('timing', `Tried to end timer that doesn't exist: ${name}`)
83        }
84      }
85    }
86  }
87}
88
89module.exports = Timers
90