API Examples

server.js

async function syncDbWithBlockchains() {
  const instances = Object.keys(cometInstanceData);

  for (let i = 0; i < instances.length; i++) {
    const instance = instances[i];

    if (!db[instance]) {
      db[instance] = {
        block: 0,
        ts: 0,
        borrowers: [],
        assets: {},
        numCollaterals: 0,
      };
    }

    const timestamp = Date.now();
    const { debounceMs } = cometInstanceData[instance];

    // Polled too recently, debounce to limit frivolous JSON RPC calls
    if (db[instance].ts + debounceMs > timestamp) {
      return;
    }
    db[instance].ts = timestamp;

    const provider = new ethers.providers.JsonRpcProvider(cometInstanceData[instance].rpc);
    const comet = new ethers.Contract(cometInstanceData[instance].proxy, cometAbi, provider);
    const numCollaterals = await comet.callStatic.numAssets();

    // Update the in-memory DB first then save it to disk

    if (numCollaterals !== db[instance].numCollaterals) {
      db[instance].assets = await pullAssetDataFromChain(instance, db[instance].assets);
    }

    db[instance].numCollaterals = numCollaterals;

    await pullPriceDataFromChain(instance, db[instance].assets);
    await pullBorrowerDataFromChain(instance, db[instance].block);
    calculateAccountHealths(instance);
  }
}