Veggerby.Azure

Azure Storage abstractions, based on K. Scott Allen ideas and extended to support Tables, Queues and Blobs.

All methods are async only!

Table Storage

Entity

The Table Storage entity is declared as a normal TableEntity, e.g.

public class FooEntity : TableEntity 
{
	public string Bar { get; set; }
	public int Baz { get; set; }
}

Table Storage

Define your Table Storage:

public class FooEntityStorage : TableStorage<FooEntity>
{
	public FooEntityStorage(string tableName = null, string connectionString = null, StorageInitializeManager storageInitializeManager = null)
        : base(tableName, connectionString, storageInitializeManager)
    {
    }
}

Interfaces

Interface'ify the storage for Dependency Injection:

public interface IFooEntityStorage : ITableStorage<FooEntity>
{
}

public class FooEntityStorage : TableStorage<FooEntity>, IFooEntotyStorage
{
	...
}

Querying

Remember! Querying in Azure Table Storage where not including PartitionKey (and possibly RowKey) has a huge performance impact. For optimal performance queries should include in descending order of performance impact (see MSDN:

1. PartitionKey (exact) + RowKey (exact)
2. PartitionKey (exact) + RowKey (partial) + properties
3. PartitionKey (partial) + RowKey (partial) + properties
4. Everything else

Querying is done by subclassing StorageQuery

public class ListFooEntityByBarStorageQuery: StorageQuery<FooEntity>
{
	public ListFooEntityByBarStorageQuery(string bar)
	{
		Query = Query.Where(
			TableQuery.GenerateFilterCondition("Bar", QueryComparisons.Equal, bar));
	}
}

Extend the FooEntityStorage class with the List (async) method.

public class FooEntityStorage : TableStorage<FooEntity>
{
	...

	public async Task<IEnumerable<FooEntity>> ListAsync(string bar)
	{
		return await new ListFooEntityByBarStorageQuery(bar).ExecuteOnAsync(Table);
	}
}

Standard Queries

The following queries are implemented by default:

• ListPartitionStorageQuery - list entities in a single partition (see TableStorage.ListAsync())
• ListRowsStorageQuery - list entities by row key (significant performance impact, see TableStorage.ListByRowKeyAsync())
• MultipleEntityStorageQuery - get multiple entities by PartitionKey and RowKey (using TableEntityKey class, see TableStorage.GetAsync() overload)
• MultiplePartitionStorageQuery - list entities in multiple partitions (performance impact)
• MultipleRowKeysStorageQuery - list entities with multiple RowKeys (significant performance impact)
• DateRangeStorageQuery - list entities with having a specific property within a date/time range

By default the MultiplePartitionStorageQuery, MultipleRowKeysStorageQuery and DateRangeStorageQuery queries are not exposed on the TableStorage class because of the significant performance impact (although this also applies to ListRowsStorageQuery).