@jmparsons/ccxt
Version:
A JavaScript / Python / PHP cryptocurrency trading library with support for 100+ exchanges
72 lines (54 loc) • 2.37 kB
JavaScript
;
/* ------------------------------------------------------------------------ */
const now = Date.now // TODO: figure out how to utilize performance.now () properly – it's not as easy as it does not return a unix timestamp...
/* ------------------------------------------------------------------------ */
const setTimeout_original = setTimeout
const setTimeout_safe = (done, ms, setTimeout = setTimeout_original /* overrideable for mocking purposes */, targetTime = now () + ms) => {
/* The built-in setTimeout function can fire its callback earlier than specified, so we
need to ensure that it does not happen: sleep recursively until `targetTime` is reached... */
let clearInnerTimeout = () => {}
let active = true
let id = setTimeout (() => {
active = true
const rest = targetTime - now ()
if (rest > 0) {
clearInnerTimeout = setTimeout_safe (done, rest, setTimeout, targetTime) // try sleep more
} else {
done ()
}
}, ms)
return function clear () {
if (active) {
active = false // dunno if IDs are unique on various platforms, so it's better to rely on this flag to exclude the possible cancellation of the wrong timer (if called after completion)
clearTimeout (id)
}
clearInnerTimeout ()
}
}
/* ------------------------------------------------------------------------ */
class TimedOut extends Error {
constructor () {
const message = 'timed out'
super (message)
this.constructor = TimedOut
this.__proto__ = TimedOut.prototype
this.message = message
}
}
/* ------------------------------------------------------------------------ */
module.exports =
{ now
, setTimeout_safe
, sleep: ms => new Promise (resolve => setTimeout_safe (resolve, ms))
, TimedOut
, timeout: async (ms, promise) => {
let clear = () => {}
const expires = new Promise (resolve => (clear = setTimeout_safe (resolve, ms)))
try {
return await Promise.race ([promise, expires.then (() => { throw new TimedOut () })])
} finally {
clear () // fixes https://github.com/ccxt/ccxt/issues/749
}
}
}
/* ------------------------------------------------------------------------ */