static Task ScheduleDeleteAsync(CachedGstEntity lastResult, int dayInterval)
{
var nDaysLater = DateTimeOffset.UtcNow.ToOffset(TimeSpan.FromHours(8)).AddDays(dayInterval);
var atThreeAm = nDaysLater.AddHours(3 - nDaysLater.Hour);
var timeDiffFromNow = atThreeAm - DateTime.Now;
return(DeletionQueue.AddMessageAsync(
new CloudQueueMessage(lastResult.PartitionKey + ":" + lastResult.RowKey),
null, timeDiffFromNow, null, null));
}
public async Task <IList <IGstLookupResult> > LookupGstDataAsync(GstLookupInputType inputType, string input, bool validateInput = false)
{
if (validateInput)
{
GstInputValidator.ValidateInput(inputType, input);
}
// Retrieve all entities of the given Partition Key.
var partitionKey = CachedGstEntity.GetPartitionKey(inputType, input);
var resultsQuery = Table.CreateQuery <CachedGstEntity>().Where(e => e.PartitionKey == partitionKey);
var cachedResults = new List <IGstLookupResult>();
TableContinuationToken continuationToken = null;
do
{
var segment = await resultsQuery.AsTableQuery().ExecuteSegmentedAsync(continuationToken);
cachedResults.AddRange(segment.Results);
continuationToken = segment.ContinuationToken;
} while (continuationToken != null);
// Return if there is any entity in the cache.
if (cachedResults.Count > 0)
{
return(cachedResults);
}
// Lookup Customs' server and cache the results.
IList <IGstLookupResult> lookupResults;
try {
lookupResults = await _dataSource.LookupGstDataAsync(inputType, input);
} catch (CustomsGstException ex) {
if (ex.KnownErrorCode == KnownCustomsGstErrorCode.Over100Results)
{
#pragma warning disable 4014
InsertAsync(CachedGstEntity.CreateForError(
inputType, input, KnownCustomsGstErrorCode.Over100Results));
}
#pragma warning restore 4014
throw;
}
if (lookupResults.Count == 0)
{
#pragma warning disable 4014
InsertAndScheduleDeleteAsync(CachedGstEntity.CreateForError(
inputType, input, KnownCustomsGstErrorCode.NoResult), 6);
return(lookupResults);
#pragma warning restore 4014
}
if (lookupResults[0].IsLiveData)
{
CachedGstEntity lastCachedResult = null;
var batchOp = new TableBatchOperation();
for (var i = 0; i < lookupResults.Count; i++)
{
lastCachedResult = CachedGstEntity.CreateForResult(inputType, input, lookupResults[i], i);
batchOp.InsertOrReplace(lastCachedResult);
}
#pragma warning disable 4014
Table.ExecuteBatchAsync(batchOp);
#pragma warning restore 4014
if (inputType == GstLookupInputType.BusinessName)
{
Debug.Assert(lastCachedResult != null, "cacheResult shouldn't be null here");
#pragma warning disable 4014
ScheduleDeleteAsync(lastCachedResult, 6);
#pragma warning restore 4014
}
}
return(lookupResults);
}
static Task InsertAndScheduleDeleteAsync(CachedGstEntity result, int dayInterval)
{
return(Task.WhenAll(InsertAsync(result), ScheduleDeleteAsync(result, dayInterval)));
}
static Task InsertAsync(CachedGstEntity result)
{
return(Table.ExecuteAsync(TableOperation.InsertOrReplace(result)));
}
public static HttpResponseMessage WithCacheTimestamp(this HttpResponseMessage responseMsg, CachedGstEntity cachedResult)
{
responseMsg.Headers.Add("X-CacheDate", cachedResult.Timestamp.DateTime.ToUniversalTime().ToString("R"));
return(responseMsg);
}