private async Task <CustomerRewardsProfile> GetCacheDataAsync(Guid customerId)
{
CustomerRewardsProfile result = null;
try
{
logger.LogInformation($"Retrieving data for {LoyaltyConstants.CUSTOMER_ID}:{customerId} from cache data source.");
result = await cacheDataSource.GetRewardsInfoAsync(customerId).TimeoutAfter(this.cacheDataTimeout);
logger.LogInformation($"Received data from cache data source for {LoyaltyConstants.CUSTOMER_ID}:{customerId}.");
}
catch (Exception e)
{
logger.LogError(e, "Exception encountered while trying to get data from cache.");
}
// If we have a cache miss. Fetch data from live source and backfill cache.
// TODO: ADD A CONFIG FLAG HERE SO WE CAN CONTROLL THE FALLBACK BEHAVIOR, SO THAT THE FALLBACK MECHANISM WILL NOT BRING DOWN OUR VENDOR'S DB.
// Without fallback, return will be null with cache miss.
if (result == null)
{
logger.LogWarning($"Unable to retrieve data for {LoyaltyConstants.CUSTOMER_ID}:{customerId} from cache. Attempt to retrieve data from live data source and backfill cache.");
try
{
logger.LogInformation($"Retrieving data for {LoyaltyConstants.CUSTOMER_ID}:{customerId} from live data source.");
result = await liveDataSource.GetRewardsInfoAsync(customerId).TimeoutAfter(this.liveDataTimeout);
logger.LogInformation($"Received data from live data source for {LoyaltyConstants.CUSTOMER_ID}:{customerId}. Backfilling cache..");
var cacheUpdateResult = await cacheUpdater.UpdateRewardsInfoAsync(result).ConfigureAwait(false);
logger.LogInformation($"Cache data for {LoyaltyConstants.CUSTOMER_ID}:{customerId} is backfilled:{cacheUpdateResult}");
return(result);
}
catch (TimeoutException te)
{
var errorMsg = $"Unable to retrieve data from live data source to backfill cache for {LoyaltyConstants.CUSTOMER_ID}:{customerId}. Timed out after {this.liveDataTimeout.TotalMilliseconds}ms.";
logger.LogError(te, errorMsg);
//TODO: POSSIBILY CREATE A CUSTOM EXCEPTION FOR BETTER TRACKING/HANDLING
throw new TimeoutException(errorMsg, te);
}
catch (Exception e)
{
logger.LogError(e, "Exception encountered while trying to get data from live data source as a fallback mechanism.");
throw;
}
}
return(result);
}
/// <summary>
/// Mapper function to transform vendor's model to our model
/// </summary>
/// <param name="vendorData"></param>
/// <returns></returns>
/// <remarks>In real code, mapper libraries will be used.</remarks>
private CustomerRewardsProfile TransformData(VendorXRewardsData vendorData)
{
var mappedData = new CustomerRewardsProfile()
{
LevelInformation = new RewardsLevel()
{
Level = vendorData.Level,
PointsEarnedYTD = vendorData.PointsEarnedYTD,
PointsEarnedLifetime = vendorData.PointsEarnedLifetime
},
NotesInformation = vendorData.Notes
};
return(mappedData);
}
public Task <bool> UpdateRewardsInfoAsync(CustomerRewardsProfile customerId)
{
//TODO: IMPLEMENT THE REAL CACHE UPDATE LOGIC
return(Task.FromResult(true));
}