public static async T.Task <int> GetNextId(this CloudUtilities u, string category, string usage, CancellationToken token)
{
var idsTable = u.GetIdsTable();
while (true)
{
try
{
int currentId = 1;
var entity = await idsTable.RetrieveJsonTableEntityAsync(category, usage, token);
TableResult result;
if (entity == null)
{
entity = new JsonTableEntity()
{
PartitionKey = category, RowKey = usage,
};
entity.PutObject(currentId);
result = await idsTable.InsertAsync(entity, token);
}
else
{
currentId = entity.GetObject <int>() + 1;
entity.PutObject(currentId);
result = await idsTable.ReplaceAsync(entity, token);
}
// concurrency failure or conflict
if (result.IsConflict())
{
continue;
}
return(currentId);
}
catch (StorageException ex)
{
// concurrency failure or conflict
if (ex.IsConflict())
{
continue;
}
throw;
}
}
}
