public async Task <LittleUrlAzure> CheckDupe(string longUrl)
{
LittleUrlAzure itemRet = null;
try
{
// Construct the query operation
TableQuery <LittleUrlAzure> query = new TableQuery <LittleUrlAzure>()
.Where(TableQuery.GenerateFilterCondition("LongUrl", QueryComparisons.Equal, longUrl));
// Collect the urls in the list
TableContinuationToken token = null;
TableQuerySegment <LittleUrlAzure> resultSegment =
await _littleUrlTable.ExecuteQuerySegmentedAsync <LittleUrlAzure>(query, token);
itemRet = resultSegment.Results.FirstOrDefault <LittleUrlAzure>();
// If this URL is deleted; undelete and return
if (itemRet.IsDeleted)
{
itemRet = await ToggleDelete(itemRet.ShortUrl, false);
}
}
catch (Exception ex)
{
Debug.WriteLine("CheckDupe() | Exception caught:" + ex.Message);
itemRet = null;
}
return(itemRet);
}
// Retention/Undelete
public async Task <LittleUrlAzure> ToggleDelete(string shortUrl, bool bDeleteThis)
{
// Move url to 'True' or 'False' partitions based on current state
if (!string.IsNullOrEmpty(shortUrl))
{
// Setup Table op from appropriate partition
TableOperation retrieveOp = TableOperation.Retrieve <LittleUrlAzure>((bDeleteThis).ToString(), shortUrl);
TableResult result = await _littleUrlTable.ExecuteAsync(retrieveOp);
LittleUrlAzure item = (LittleUrlAzure)result.Result;
if (item != null)
{
// Found
// Now delete it from this partition and recreate in the other
TableOperation deleteOp = TableOperation.Delete(item);
await _littleUrlTable.ExecuteAsync(deleteOp);
// If we are deleting this entity
if (bDeleteThis)
{
// Set deleted time
item.DeletedTime = DateTime.UtcNow;
// Set retention limit (midnight 90 days from now)
DateTime purgeDate = DateTime.UtcNow.AddDays(_retentionDays);
item.PurgeDate = new DateTime(purgeDate.Year, purgeDate.Month, purgeDate.Day,
23, 59, 59, 999, DateTimeKind.Utc);
}
else
{
// We are undeleting; reset retention dates
item.DeletedTime = DateTime.MinValue;
item.PurgeDate = DateTime.MinValue;
}
// Insert into the other partition
item.PartitionKey = (!bDeleteThis).ToString();
TableOperation insertOp = TableOperation.Insert(item);
await _littleUrlTable.ExecuteAsync(insertOp);
// Return
return(item);
}
}
return(null);
}
public async Task <TableResult> GetUrl(string sKey, bool bIsUrlDeleted = false)
{
// Call purge operation whenever a Get is called
// The op runs only once a day
if (_lastPurgeDate.AddDays(1) < DateTime.UtcNow)
{
PurgeUrls();
}
if (!string.IsNullOrEmpty(sKey))
{
// Setup Table op to retrieve from the appropriate partition
string partitionKey = (!bIsUrlDeleted).ToString();
TableOperation retrieveOp = TableOperation.Retrieve <LittleUrlAzure>(partitionKey, sKey);
bool bExists = await _littleUrlTable.ExistsAsync();
if (bExists)
{
TableResult result = await _littleUrlTable.ExecuteAsync(retrieveOp);
// If found, update last accessed time
LittleUrlAzure item = (LittleUrlAzure)result.Result;
if (item != null)
{
item.LastAccessedTime = DateTime.UtcNow;
TableOperation updateOp = TableOperation.InsertOrReplace(item);
await _littleUrlTable.ExecuteAsync(updateOp);
}
// Perform retention management once a day
if (_lastRetentionDate.AddDays(1) < DateTime.UtcNow)
{
RemoveStaleUrls();
}
return(result);
}
}
return(null);
}
public async Task <TableResult> InsertUrl(int urlId, string urlToInsert)
{
TableResult result = null;
try
{
string sKey = GetNewKey();
LittleUrlAzure littleUrl = new LittleUrlAzure(_partitionKey, sKey, urlId, urlToInsert);
// Create the insert op (use upsert to prevent key duplication)
TableOperation insertOp = TableOperation.InsertOrMerge(littleUrl);
// Execute
result = await _littleUrlTable.ExecuteAsync(insertOp);
}
catch (Exception ex)
{
Debug.WriteLine("InsertUrl() | Exception caught:" + ex.Message);
result = null;
}
return(result);
}