/// <summary>
/// Gets the sequence for a given table.
/// </summary>
/// <param name="tableName"></param>
/// <returns></returns>
public SequenceIdStore GetSequenceIdStore(string tableName)
{
var schema = SchemaTableProxy.Get(tableName.GetValidPartitionKey(), tableName.GetValidRowKey());
if (schema == null || schema.Entity == null)
{
return(null);
}
var sequence = SequenceTableProxy.Get(tableName.GetValidPartitionKey(), tableName.GetValidRowKey()) ??
CreateSequenceFromSchema(tableName);
return(new SequenceIdStore
{
FinalCachedId = sequence.Entity.Properties[PropertyFinalCachedId].StringValue,
Schema = schema.Entity
});
}
private TableEntityProxy <DynamicTableEntity> CreateSequenceFromSchema(string tableName)
{
var schema = SchemaTableProxy.Get(tableName.GetValidPartitionKey(), tableName.GetValidRowKey());
if (schema == null)
{
throw new ArgumentException(String.Format("Sequence '{0}' is not defined. Cannot get the latest reserved key value.", tableName));
}
var sequence = new TableEntityProxy <DynamicTableEntity>(new DynamicTableEntity(schema.PartitionKey, schema.RowKey, "",
new Dictionary <string, EntityProperty>()));
sequence.Entity.Properties.Add(PropertyFinalCachedId, new EntityProperty(schema.Entity.SeedValue));
SequenceTableProxy.Insert(sequence.Entity);
//Insert would throw if another thread created after SequenceTableProxy.Get was called above. Only one thread can create the sequence.
// - a lock would not help, since the other thread may be in another role (web or worker) instance
return(sequence);
}
