avvio 是fastify 团队开发的一个node 应用异步启动的框架，实现了一些方便的异步处理，同时还可以保证
执行顺序，在实际业务中还是一个比较有用的工具包
参考使用
- app.js
const avvio = require("avvio")()
function a (instance, opts, cb) {
(opts.use || []).forEach(_ => { instance.use(_, { use: opts.subUse || [] }) })
setTimeout(cb, 10)
}
const pointer = a
function b (instance, opts, cb) {
(opts.use || []).forEach(_ => { instance.use(_, { use: opts.subUse || [] }) })
setTimeout(cb, 20)
}
function c (instance, opts, cb) {
(opts.use || []).forEach(_ => { instance.use(_, { use: opts.subUse || [] }) })
setTimeout(cb, 30)
}
avvio
.use(first, { hello: 'world' })
.use(duplicate, { count: 0 })
.use(function a (instance, opts, cb) {
instance.use(pointer, { use: [b], subUse: [c] })
.use(b)
setTimeout(cb, 42)
})
.after(function (err, cb) {
if (err) {
console.log('something bad happened')
console.log(err)
}
console.log('after first and second')
cb()
})
.use(duplicate, { count: 4 })
.use(third)
.ready(function (err) {
if (err) {
throw err
}
console.log('application booted!')
})
avvio.on('preReady', () => {
console.log(avvio.prettyPrint())
})
function first (instance, opts, cb) {
console.log('first loaded', opts)
instance.use(second)
setTimeout(cb, 42)
}
function second (instance, opts, cb) {
console.log('second loaded')
process.nextTick(cb)
}
function third (instance, opts, cb) {
console.log('third loaded')
cb()
}
function duplicate (instance, opts, cb) {
console.log('duplicate loaded', opts.count)
if (opts.count > 0) {
instance.use(duplicate, { count: opts.count - 1 })
}
setTimeout(cb, 20)
}
- 运行效果
first loaded { hello: 'world' }
second loaded
duplicate loaded 0
after first and second
duplicate loaded 4
duplicate loaded 3
duplicate loaded 2
duplicate loaded 1
duplicate loaded 0
third loaded
bound root 309 ms
├─┬ first 49 ms
│ └── second 1 ms
├── duplicate 21 ms
├─┬ a 130 ms
│ ├─┬ a 64 ms
│ │ └─┬ b 53 ms
│ │ └── c 31 ms
│ └── b 22 ms
├── bound _after 1 ms
├─┬ duplicate 106 ms
│ └─┬ duplicate 85 ms
│ └─┬ duplicate 63 ms
│ └─┬ duplicate 42 ms
│ └── duplicate 21 ms
└── third 0 ms
application booted!
说明
avvio 在fastify框架中是一个比较重要的，了解一些avvio的机制可以更好的了解fastify的运行机制
参考资料
https://github.com/fastify/avvio
https://github.com/fastify/fastify/blob/main/package.json
https://github.com/fastify/process-warning