Batch RPC calls

pancake-reserves.js

  updatePrices() {
    const batch = new web3.eth.BatchRequest()
    this.pairs = []

    const requests = [];

    serializedPairs.forEach(lp => {
      requests.push(new Promise((resolve, reject) => {
        const contract = new web3.eth.Contract(pancakePairAbis, lp.pair.address)
        batch.add(contract.methods.getReserves().call.request((error, reserves) => {
          this.requestCount++
          if (error) return reject(error)
          this.pairs.push(
            this.newPairFromSerializedPairAndReserves(lp, reserves)
          )
          resolve(reserves);
        }))
      }))
    });

    batch.execute()
    return Promise.all(requests);
  }