unpkg/server/StatsServer.js

79 lines
1.6 KiB
JavaScript

const redis = require('redis')
const invariant = require('invariant')
const RedisURL = process.env.REDIS_URL
invariant(
RedisURL,
'Missing the $REDIS_URL environment variable'
)
const db = redis.createClient(RedisURL)
const sumValues = (array) =>
array.reduce((memo, n) => memo + (parseInt(n, 10) || 0), 0)
const getKeyValues = (keys) =>
new Promise((resolve, reject) => {
db.mget(keys, (error, values) => {
if (error) {
reject(error)
} else {
resolve(values)
}
})
})
const sumKeys = (keys) =>
getKeyValues(keys).then(sumValues)
const createScoresMap = (array) => {
const map = {}
for (let i = 0; i < array.length; i += 2)
map[array[i]] = parseInt(array[i + 1], 10)
return map
}
const getTopScores = (key, n = 10) =>
new Promise((resolve, reject) => {
db.zrevrange(key, 0, n, 'withscores', (error, value) => {
if (error) {
reject(error)
} else {
resolve(createScoresMap(value))
}
})
})
const sumTopScores = (keys, n) =>
Promise.all(keys.map(key => getTopScores(key, n))).then(values => {
return values.reduce((memo, map) => {
Object.keys(map).forEach(key => {
memo[key] = (memo[key] || 0) + map[key]
})
return memo
}, {})
})
const createDayKey = (date) =>
`${date.getUTCFullYear()}-${date.getUTCMonth()}-${date.getUTCDate()}`
const createHourKey = (date) =>
`${createDayKey(date)}-${date.getUTCHours()}`
const createMinuteKey = (date) =>
`${createDayKey(date)}-${date.getUTCMinutes()}`
module.exports = {
getKeyValues,
sumKeys,
getTopScores,
sumTopScores,
createDayKey,
createHourKey,
createMinuteKey
}