KeyValueStorage is a project aimed at making storage of data simple, bridging the gap between various NoSql solutions, and strives to provide a common interface that can be shared between all providers. Tools are also available to deal with more complex scenarios such as relational data and encryption.

New: Relational API Simple memory store support Keys of primitive types are now implicitly converted so you can use Guid's or ints for keys without any string operations. The KeyTransformKVStore gives more control over key generation

(http://nuget.org/List/Packages/KeyValueStorage.FSText)

Features

Get/Set complex types by key operations
Sequences
CAS
Key expiry
Retry strategies
One common interface for all abstractions
Tools for working with relational data
Tools for Membership/Role/Profile substitutes
Tools for encryption and decryption of keys on insertion
Locking
Written using TDD and loosely coupled code. Plenty of extension points to customize behaviour.
Available on NuGet!

Possible features to support in the future:

Locking (or some other mechanism for performing atomic operations)
Atomic Collections

Write code like:

KVStore.Initialize(new Func<Interfaces.IStoreProvider>(() => new KeyValueStorage.Redis.RedisStoreProvider(new ServiceStack.Redis.RedisClient())));

using (var context = KVStore.Factory.Get())
{
	var bo = new TestBO_A()
	{
		Id = 1,
		Description = "Description"
	};

	context.Set(key, bo);

	var bo2Check = context.Get<TestBO_A>(key);

	var bo3 = new TestBO_A();
	bo3.Id = context.GetNextSequenceValue(key+"S");
}

New relational API persisting keys in both directions:

	var relatedKeys = context.GetRelatedKeysFor<TestBO_A, TestBO_B>(boAKey).ToList();
	var relatedKeysAssoc1 = context.GetRelatedKeysFor<TestBO_B, TestBO_A>(KeyRel1);
	context.ClearRelationships<TestBO_A, TestBO_B>(boAKey);
	context.RemoveRelationship<TestBO_A, TestBO_B>(boAKey, KeyRel1);
	var relatedObjs = context.GetRelatedFor<TestBO_A, TestBO_B>(boAKey);

Currently fully supported:

Couchbase
Redis
SqlServer
FileSystem
SimpleMemoryStoreProvider (included in base package)

Partly supported:

AzureTable (expiry early proto)
Oracle (all except CAS, Expiry, and sequence ops)
Cassandra (CRUD support)

Implementing a new database provider technology is as simple as implementing the IStoreProvider interface. This can be found in KeyValueStorage.Interfaces.IStoreProvider

There are currently 4 components:

The Factory - Allows generation of store' contexts. This should be your entry point for creating your store objects.
The Provider (IStoreProvider) - Bridges the key(string)/value(string) interface to a database implementation
The Serializer (ITextSerializer) - Provides serialization of a strongly typed object to string. By default we use ServiceStack.Text due to its fantastic performance.
The Store(IKVStore) - Bridges the key(string)/value(T) interface to the provider via a serializer or other intermediary logic. A standard bridge implementation is provided so normally speaking it is not necessary to implement this interface.