DynaMight

DynaMight is a powerful library wrapper for Amazon's DynamoDB SDK, designed to simplify the usage of complex features. It provides a convenient way to execute atomic operations, implement pagination, and filter results. ​

Features

• Easier operations using builder: DynaMight uses the builder pattern to make it easier to create the configurations for queries and atomic operations.
• More readable code: DynaMight uses a fluent API pattern, which makes the code more readable.
• Effortless pagination and filtering: Performing pagination and filtering in the DynamoDB SDK can be challenging. DynaMight abstracts away this complexity.

Examples

Consider the following classes below:

[DynamoDBTable("Session")]
public class Session
{
    [DynamoDBHashKey]
    public string UserId { get; set; } = default!;
    [DynamoDBRangeKey]
    public string SessionId { get; set; } = default!;
    public SessionStatus Status { get; set; } = default!;
    public int Clicks { get; set; }
}

public enum SessionStatus
{
    Active,
    Inactive
}

To instruct DynaMight on how to handle the SessionStatus enum, you can use the DynaMightCustomConverter attribute, which registers the default converter (enum to int transformation) when the DynaMightCustomConverter.LoadAndRegister() function is called.

[DynaMightCustomConverter]
public enum SessionStatus
{
    Active,
    Inactive
}

Registering DynaMight

var client = new AmazonDynamoDBClient();
var config = new DynamoDBContextConfig();
var dbContext = new DynaMightDbContext(client, config);
services.AddSingleton<IDynamoDBContext>(dbContext);

If you need to provide credentials to create the AmazonDynamoDBClient, please do so as usual.

We recommend calling the LoadAndRegister function during registration, which loads all classes and enums marked with the DynaMightCustomConverter attribute and registers them.

DynaMightCustomConverter.LoadAndRegister();

Retrieving all sessions for a user

public async Task<List<Session>> GetAllSessions(CancellationToken cancellationToken)
{
    var config = QueryBuilder
        .Create()
        .SetKey(nameof(Session.UserId), "userId1");

    return await _dynaMightContext.GetAll<Session>(config, cancellationToken);
}

Retrieving paginated sessions for a user

public async Task<Page<Session>> GetSessionPaginated(int? pageSize, string? pageToken, CancellationToken cancellationToken)
{
    var config = QueryBuilder
        .Create()
        .SetKey(nameof(Session.UserId), "userId1")
        .SetPage(pageSize, pageToken);

    return await _dynaMightContext.GetPage<Session>(config, cancellationToken);
}

The Page<T> class has two properties: string PageToken and IList<T>? Results. The PageToken should be passed back to retrieve the next page.

Retrieving paginated sessions for a user with filtering for inactive sessions

public async Task<List<Session>> GetInactiveSessionsPaginated(int? pageSize, string? pageToken, CancellationToken cancellationToken)
{
    var config = QueryBuilder
        .Create()
        .SetKey(nameof(Session.UserId), "userId1")
        .SetPage(pageSize, pageToken)
        .AddCriteria(new EqualDynamoCriteria<SessionStatus>(nameof(Session.Status), SessionStatus.Inactive));

    return await _dynaMightContext.GetFilteredPage<Session>(config, cancellationToken);
}

Retrieving paginated sessions for a user with filtering for inactive sessions and sessions with 100 clicks or more

public async Task<Page<Session>> GetInactiveSessionsOver100ClicksPaginated(int? pageSize, string? pageToken, CancellationToken cancellationToken)
{
    var config = QueryBuilder
        .Create()
        .SetKey(nameof(Session.UserId), "userId1")
        .SetPage(pageSize, pageToken)
        .AddCriteria(new AndDynamoCriteria(
            new EqualDynamoCriteria<SessionStatus>(nameof(Session.Status), SessionStatus.Inactive),
            new GreaterOrEqualDynamoCriteria<int>(nameof(Session.Clicks), 100)));

    return await _dynaMightContext.GetFilteredPage<Session>(config, cancellationToken);
}

Adding a new click in an atomic operation

public async Task<Session> AddClick(CancellationToken cancellationToken)
{
    var config = AtomicBuilder
        .Create()
        .SetKey(nameof(Session.UserId), "userId1")
        .SetKey(nameof(Session.SessionId), "sessionId1")
        .AddOperation(new IncrementByAtomicOperation<int>(nameof(Session.Clicks), 1));

    return await _dynaMightContext.ExecuteAtomicOperation<Session>(config, cancellationToken);
}

Creating a read batch

public async Task<List<Session>> BatchRead(CancellationToken cancellationToken)
{
    var batch = _dynaMightContext.CreateBatchGet<Session>();
    batch.AddKey("userId1");
    batch.AddKey("userId2");
    
    await batch.ExecuteAsync(cancellationToken);

    return batch.Results;
}

​

License

​ This project is licensed under the BSD 3-Clause License.

Contributors