overleaf/services/real-time/app/js/DrainManager.js
2021-07-13 12:04:45 +01:00

59 lines
1.6 KiB
JavaScript

const logger = require('logger-sharelatex')
module.exports = {
startDrainTimeWindow(io, minsToDrain, callback) {
const drainPerMin = io.sockets.clients().length / minsToDrain
// enforce minimum drain rate
this.startDrain(io, Math.max(drainPerMin / 60, 4), callback)
},
startDrain(io, rate, callback) {
// Clear out any old interval
clearInterval(this.interval)
logger.log({ rate }, 'starting drain')
if (rate === 0) {
return
}
let pollingInterval
if (rate < 1) {
// allow lower drain rates
// e.g. rate=0.1 will drain one client every 10 seconds
pollingInterval = 1000 / rate
rate = 1
} else {
pollingInterval = 1000
}
this.interval = setInterval(() => {
const requestedAllClientsToReconnect = this.reconnectNClients(io, rate)
if (requestedAllClientsToReconnect && callback) {
callback()
callback = undefined
}
}, pollingInterval)
},
RECONNECTED_CLIENTS: {},
reconnectNClients(io, N) {
let drainedCount = 0
for (const client of io.sockets.clients()) {
if (!this.RECONNECTED_CLIENTS[client.id]) {
this.RECONNECTED_CLIENTS[client.id] = true
logger.log(
{ client_id: client.id },
'Asking client to reconnect gracefully'
)
client.emit('reconnectGracefully')
drainedCount++
}
const haveDrainedNClients = drainedCount === N
if (haveDrainedNClients) {
break
}
}
if (drainedCount < N) {
logger.log('All clients have been told to reconnectGracefully')
return true
}
return false
},
}