public async Task <AppConfigData> GetAppConfigData()
{
// In general, we should limit the calls to GetConfiguration API call to at least once every 15 seconds
// In AppConstants the TimeToLiveExpiration is set to the initial DateTime of Program.cs execution plus AppConstants.TimeToLiveInSeconds (15 seconds)
// This if condition makes sure that we only call the GetConfiguration API call if we have not exceeded the TTL expiration, or
// if the ClientConfigurationVersion is set in our local cache in AppConstants - ClientConfigurationVersion is returned from the initial call to the GetConfiguration API (see below for more info)
if (DateTime.UtcNow > AppConstants.TimeToLiveExpiration || String.IsNullOrEmpty(AppConstants.ClientConfigurationVersion))
{
Console.WriteLine("CALLED GetConfigurationAPI to get AppConfigData \n");
IAppConfigService appConfigService = new AppConfigService(_clientId);
// get Amazon.AppConfig.Model.GetConfigurationResponse from GetConfiguration API Call
GetConfigurationResponse getConfigurationResponse = await appConfigService.GetConfigurationResponse();
// add ConfigurationVersion to AppConstants to AppConstants to be used in subsequent calls to GetConfugration API to avopid excess charges
// https://docs.aws.amazon.com/appconfig/2019-10-09/APIReference/API_GetConfiguration.html#API_GetConfiguration_RequestSyntax
AppConstants.ClientConfigurationVersion = getConfigurationResponse.ConfigurationVersion;
// The GetConfiguration response includes a Content section (i.e., our getConfigurationResponse.Content) that shows the configuration data.
// The Content section only appears if the system finds new or updated configuration data.
// If the system doesn't find new or updated configuration data, then the Content section is not returned (Null).
// https://docs.aws.amazon.com/appconfig/latest/userguide/appconfig-retrieving-the-configuration.html
string decodedResponseData = getConfigurationResponse.Content.Length > 0 ? MemoryStreamHelper.DecodeMemoryStreamToString(getConfigurationResponse.Content) : String.Empty;
// convert DecodedResponseData to our AppConfigData model which consists of:
// bool boolEnableLimitResults
// int intResultLimit
AppConfigData appConfigData = this.ConvertDecodedResponseToAppConfigData(decodedResponseData);
// add AppConfigData to our cache in AppConstants
AppConstants.AppConfigData = appConfigData;
return(AppConstants.AppConfigData);
}
else
{
Console.WriteLine("DID NOT call GetConfigurationAPI to get data. Return AppConfigData from cached value in AppConstants.AppConfigData instead. \n");
return(AppConstants.AppConfigData);
}
}
