Aedes is a barebone MQTT broker library for Node.js, supporting MQTT 3.1 and 3.1.1. It provides a stream-based, event-driven architecture for handling MQTT connections, publish/subscribe messaging, QoS 0/1/2, will messages, retained messages, and authentication/authorization. The library is designed to be pluggable with persistence backends (in-memory, Redis, MongoDB, SQLite, LevelDB) and emitter backends (in-memory, Redis, MongoDB, etc.) for clustering and high availability. Aedes is the successor to Mosca, focusing on performance and stability. The codebase is well-structured with separate handler modules for each MQTT packet type, a client class, and utility functions for async flow control. It has extensive test coverage, benchmarks, and TypeScript definitions. Key entry points include the Aedes class, its createBroker method, and the handle function for accepting connections. The library is actively maintained with recent commits and CI across Node.js 20, 22, and 24. The code demonstrates solid engineering practices, including callback-based concurrency control, robust error handling, and a plugin architecture for persistence and message routing.
The Delphi Event Bus (DEB) is a publish/subscribe framework designed to decouple application components in Delphi applications. It provides an attribute-based API for declaring subscribers, supports thread-specific event delivery (main, background, async), and enables contextual routing of events. The library is built on Delphi's RTTI system to automatically discover and register subscriber methods marked with custom attributes. The architecture centers around a central event bus (accessible via a global singleton or multiple instances) that manages subscriptions and dispatches events. Core components include subscription management (EventBus.Core.pas), RTTI helpers for attribute discovery (EventBus.Helpers.pas), and subscription data structures (EventBus.Subscribers.pas). The library demonstrates strong engineering practices through its thread-safe implementation, comprehensive test suite using DUnitX, and multiple sample applications showcasing usage in VCL and FireMonkey contexts. Key features include interface-typed events for type-safe data transfer, channel-based string messaging, and a dedicated thread pool for background operations (introduced in version 2.1). The library targets Delphi 2010 and later, including Alexandria, and is designed with a 'keep it simple' philosophy, minimizing configuration through convention over configuration.
This is a Prometheus exporter for NATS server monitoring. It polls NATS server HTTP monitoring endpoints (varz, connz, subz, routez, healthz, jsz, etc.) and exposes metrics in Prometheus format. The architecture is a standalone binary with an embeddable library API. Key entry points are the CLI (main.go) and the exporter.NewExporter function. Data flow: on each scrape, collectors make HTTP requests to NATS monitoring endpoints, parse JSON responses, and convert them to Prometheus gauge metrics. The exporter supports TLS, basic auth, custom metric prefixes, and multiple NATS servers (though one per exporter is recommended). It includes pre-built Grafana dashboards for both NATS core and JetStream metrics. The codebase is well-structured with separate packages for collectors, exporter, and test utilities. It uses reflection-based metric extraction for simple endpoints and custom collectors for complex ones like JetStream, connections, and gateways. The project is actively maintained with recent commits and modern dependencies.
This repository provides the ROS 2 Middleware (RMW) implementation for eProsima Fast DDS, a high-performance DDS (Data Distribution Service) implementation. It translates the standard ROS 2 RMW API (publish, subscribe, services, clients, events) into Fast DDS operations, enabling ROS 2 nodes to communicate over DDS. The codebase is structured into three packages: `rmw_fastrtps_cpp` (static typesupport using compile-time code generation), `rmw_fastrtps_dynamic_cpp` (runtime introspection-based typesupport), and `rmw_fastrtps_shared_cpp` (shared logic for both variants). It supports advanced features such as content-filtered subscriptions, loaned messages, zero-copy data sharing via buffer backends (including GPU offloading), DDS security (PKI-DH, AES-GCM, access control), and comprehensive QoS mapping. The architecture follows a layered design where the shared package contains the core RMW implementations, and the two variant packages provide thin wrappers that differ only in how type support is resolved. This is a foundational infrastructure package for ROS 2, not an end-user application; it is selected at runtime via the `RMW_IMPLEMENTATION` environment variable.