40 lines
1011 B
JavaScript
40 lines
1011 B
JavaScript
|
const Minipass = require('minipass')
|
||
|
|
const _flush = Symbol('_flush')
|
||
|
|
const _flushed = Symbol('_flushed')
|
||
|
|
const _flushing = Symbol('_flushing')
|
||
|
|
class Flush extends Minipass {
|
||
|
|
constructor (opt = {}) {
|
||
|
|
if (typeof opt === 'function')
|
||
|
|
opt = { flush: opt }
|
||
|
|
|
||
|
|
super(opt)
|
||
|
|
|
||
|
|
// or extend this class and provide a 'flush' method in your subclass
|
||
|
|
if (typeof opt.flush !== 'function' && typeof this.flush !== 'function')
|
||
|
|
throw new TypeError('must provide flush function in options')
|
||
|
|
|
||
|
|
this[_flush] = opt.flush || this.flush
|
||
|
|
}
|
||
|
|
|
||
|
|
emit (ev, ...data) {
|
||
|
|
if ((ev !== 'end' && ev !== 'finish') || this[_flushed])
|
||
|
|
return super.emit(ev, ...data)
|
||
|
|
|
||
|
|
if (this[_flushing])
|
||
|
|
return
|
||
|
|
|
||
|
|
this[_flushing] = true
|
||
|
|
|
||
|
|
const afterFlush = er => {
|
||
|
|
this[_flushed] = true
|
||
|
|
er ? super.emit('error', er) : super.emit('end')
|
||
|
|
}
|
||
|
|
|
||
|
|
const ret = this[_flush](afterFlush)
|
||
|
|
if (ret && ret.then)
|
||
|
|
ret.then(() => afterFlush(), er => afterFlush(er))
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
module.exports = Flush
|