JavaScript pricefeed cache example

pricefeed_cache_example.ts

const cache: {
  [tokenSymbol: string]: Promise<any>
} = {}

const cacheTimestamps: {
  [tokenSymbol: string]: number
} = {}

class MyClass {
  cacheTimeMs = 5 * 60 * 1000

  async getData (id: string, date: number) {
    const cacheKey = `${id}:${date}`
    if (cache[cacheKey] && cacheTimestamps[cacheKey]) {
      const isRecent = cacheTimestamps[cacheKey] > Date.now() - this.cacheTimeMs
      if (isRecent) {
        return cache[cacheKey]
      }
    }
    const promise = this._getData(tokenSymbol, days)
    cache[cacheKey] = promise
    cacheTimestamps[cacheKey] = Date.now()
    return promise
  }

  async _getData (id: string, date: number) {
    // ...
  }
}