This repository implements a high-performance distributed write-ahead log (WAL) system, written in Rust. It comprises a core WAL library (walrus-rust) with configurable storage backends (mmap, fd, io_uring), a Raft consensus library (openraft) for distributed metadata management, and a distributed application (distributed-walrus) that provides a TCP-based client-server architecture for topic-based streaming with lease-based write fencing and automatic segment rollover. The system is benchmarked against Kafka and RocksDB, includes a formal TLA+ specification, and is designed for crash-safe, low-latency persistent streaming. The architecture is layered: the Walrus WAL engine provides durable, topic-partitioned log storage with configurable fsync schedules and read consistency modes. The Octopii framework layer integrates QUIC transport and a flexible state machine. Openraft (vendored) provides full Raft consensus with leader election, log replication, snapshotting, and linearizable reads. The distributed-walrus application ties these together with a node controller, metadata state machine, and monitor loop for segment rollover. While primarily an application, the repository has strong research elements: extensive performance benchmarks (scaling, batch, multithreaded), formal verification via TLA+, and a focus on characterization of trade-offs between durability, latency, and throughput. The codebase is well-structured with clear abstractions, though it contains some duplicated code across the walrus and octopii directories and a large vendored copy of openraft.
Pktgen is a high-performance, scriptable packet generator built on top of DPDK. It generates wire-rate traffic with support for Ethernet, IPv4/IPv6, TCP/UDP, GRE, GTP-U, MPLS, VLAN, and other encapsulations. The application provides an interactive CLI with auto-complete, history, and environment variables, as well as Lua scripting for automation. It includes features like latency measurement, packet capture/replay, range-based packet field sweeping, random bitfield generation, and RFC 2544 throughput testing. The architecture is a monolithic DPDK application with modular libraries for CLI, Lua bindings, hash maps, vectors, plugins, and common utilities. It is designed for network testing, benchmarking, and research scenarios requiring precise traffic generation and measurement.
ExprTk is a header-only C++ library for runtime mathematical expression parsing and evaluation. It provides a complete system for defining mathematical expressions as strings, compiling them into an internal AST representation, and evaluating them with variable values. The library supports scalar, vector, and string types, arithmetic operations, trigonometric functions, logarithms, control structures (if, for, while, switch), user-defined functions, and assignment operations within expressions. It employs sophisticated parsing techniques including constant folding, strength reduction optimizations, and runtime safety checks for vector bounds and loop execution time. The architecture consists of three main components: symbol table (for variables/constants/functions), expression (holding the parsed AST), and parser (compiling expression strings).
python-hyperscan is a CPython extension providing Python bindings for Vectorscan (a fork of Intel's Hyperscan), a high-performance multiple regex matching library. The library enables efficient pattern matching with statically linked binaries and cross-platform support. It exposes most of the Hyperscan C API through Python classes including Database for pattern compilation, Scan for text scanning, Stream for streaming processing, and Scratch for thread-safe scratch space management. The implementation features proper buffer protocol support, sophisticated GIL handling for both traditional and free-threaded Python models, and careful resource management. The build system uses scikit-build-core with CMake to statically link Hyperscan/Vectorscan along with dependencies like PCRE and Boost, producing binary wheels for multiple platforms.
Iodine is a high-performance concurrent web server for Ruby applications, built as a wrapper around the C-based facil.io framework. It provides native HTTP/WebSocket/Server-Sent Events support, Rack compliance for serving Ruby web applications, and a built-in Pub/Sub system with optional Redis scaling for horizontal distribution. The architecture follows a master-worker model using multiple processes and threads to handle thousands of concurrent connections, with critical networking components implemented in C for performance and Ruby bindings for developer productivity. Key features include static file serving with gzip and X-Sendfile support, a secure Mustache template engine with automatic HTML escaping, a fast JSON parser claiming 20-90% speed improvements over Ruby's standard library, and TLS support (though marked as having known issues for production use). The server integrates with Rack applications through a custom handler and provides upgrade hooks for WebSocket/SSE protocols via the Rack environment. Pub/Sub functionality uses an engine pattern allowing swap between internal cluster-based and external Redis backends. Entry points include the `exe/iodine` CLI executable and programmatic controls via `Iodine.listen`, `Iodine.start`, and `Iodine.stop`. Data flows involve HTTP requests parsed by the C-based HTTP processor, routed to Rack applications or static file handlers, with WebSocket connections upgraded via Rack's `env['rack.upgrade?']` mechanism. The Pub/Sub system operates independently for real-time messaging across processes or machines. External dependencies include the vendored facil.io C library, OpenSSL development headers for TLS support, and optionally the Redis gem for clustered Pub/Sub.
This is a mature, cross-platform Java library that provides thread-to-CPU-core binding (affinity) to reduce context switching and improve cache locality for low-latency and high-performance applications. It primarily uses JNA to invoke OS-specific system calls (sched_setaffinity on Linux, SetThreadAffinityMask on Windows, etc.) and offers a fallback to a no-op implementation. The library includes CPU topology detection via /proc/cpuinfo parsing, a file-based inter-process lock mechanism (AffinityLock) to reserve cores across JVMs, a high-resolution timer based on the RDTSC instruction via JNI, and a ThreadFactory for automatic affinity assignment. The architecture is a classic Java library with a clean public API (Affinity, AffinityLock, AffinityThreadFactory) and a set of platform-specific implementations hidden behind the IAffinity interface. The codebase is well-structured, extensively tested (including multi-process and OSGi tests), and actively maintained by the OpenHFT/Chronicle Software team. It is not a data_research project.
nanoexpress is a professional backend framework for Node.js built on top of uWebSockets.js for high performance. It provides HTTP server functionality with routing, middleware support, WebSocket capabilities, request validation using AJV, Swagger/OpenAPI documentation generation, and utilities for file serving, compression, and cookie handling. The framework follows a modular architecture with core components including App (application wrapper), Config (configuration handling), and Route (routing system with middleware chain). It emphasizes performance while maintaining Express-like usability patterns.
masscan is a high-performance network port scanner capable of scanning the entire IPv4 Internet in under 5 minutes. Unlike typical scanners, it implements a custom TCP/IP stack to avoid kernel overhead, uses randomized probe ordering via a Feistel cipher (BlackRock) for stealth, and supports both IPv4 and IPv6. The scanner is architecturally a multithreaded C application with separate transmit and receive threads per network adapter, a lock-free ring buffer for inter-thread communication, and a plugin system for output formats (XML, JSON, binary, Redis) and protocol parsers (HTTP, SSH, SSL, SMB, etc.). Key entry points include main.c (initialization), main-conf.c (configuration), transmit_thread() (probe generation), and receive_thread() (response handling). External dependencies are minimal: libpcap (loaded dynamically) for raw packet I/O, and optional PF_RING for higher throughput. Lua scripting is also supported for custom extensions.
Sled is an embedded key-value store written in Rust that provides ACID transactions, crash safety, and high concurrency. It uses a lock-free architecture based on a lock-free pagecache, lock-free log, and lock-free B+ tree with epoch-based memory reclamation. The database supports multiple keyspaces, watch prefixes, merge operators, and a crash-safe monotonic ID generator. Currently in active development with a major rewrite underway (komora project), it is alpha software with known instability and frequent breaking changes, but demonstrates advanced concurrent data structure techniques.
Firefly is a high-performance asynchronous networking framework for the JVM, written in Java and Kotlin. It provides a comprehensive set of I/O primitives including HTTP/1.1, HTTP/2, WebSocket (RFC 6455), TCP, and UDP, with both client and server implementations. The framework is designed around Kotlin coroutines and Java NIO2 (AIO), offering non-blocking, backpressure-aware streams and a router-based HTTP server with support for content negotiation, CORS, static file serving, and HTTP/2 upgrade. It also includes built-in SLF4J logging with XML configuration, a JSON serialization service, a WeChat enterprise bot module, and a JNI helper for native code integration. The codebase is modular (firefly-common, firefly-net, firefly-slf4j, firefly-serialization, firefly-wechat, firefly-example) and demonstrates deep protocol-level craftsmanship with custom HPACK, Huffman coding, and state-machine parsers. While primarily a library for building network services, it also serves as a reference implementation for protocol handling on the JVM.
Etl-engine is a Java-based ETL (Extract, Transform, Load) library designed for high-performance data synchronization. It provides a lightweight, extensible framework built around three core components: Node (data sources/destinations/transformations), Pipe (thread-safe buffered queues for data transfer), and Dataflow (orchestrator for pipeline execution). The library supports various data sources including JDBC databases (PostgreSQL, MySQL, Oracle, ClickHouse, DuckDB) and file outputs, with built-in capabilities for batch processing, automatic error handling/retry, and detailed logging. The architecture follows a producer-consumer pattern using Java's concurrency utilities, enabling efficient parallel data processing. Sample implementations demonstrate common ETL scenarios like database-to-database transfers, conditional data routing, and value transformation.
sax-wasm is a high-performance SAX-style XML/HTML/JSX parser written in Rust and compiled to WebAssembly, with JavaScript/TypeScript bindings for Node.js and browsers. It provides streaming parsing of byte streams, emitting events for tags, attributes, text nodes, processing instructions, comments, CDATA, and doctype declarations. The parser is non-validating and focuses on raw speed, using SIMD instructions and optimized grapheme cluster handling. It includes a comprehensive TypeScript API with async generator support for streaming reads from ReadableStream. The repository contains the full Rust source, JS/TS bindings, build tooling (wasm-bindgen, wasm-opt), and extensive test suites covering XML, JSX, Angular templates, edge cases with multi-byte characters, and write-boundary splitting. While the parser is highly optimized and well-tested, the project appears to be in a stale maintenance state with no recent commits (last commit dated 2026-09-13, likely erroneous) and a small community following.
This is a lightweight SMTP server written in Go, designed to receive large volumes of email, parse MIME content, and store messages in MongoDB. It includes a web interface for viewing messages, managing greylisting, and real-time notifications via WebSockets (using the embedded Incus library). The server implements core SMTP commands (HELO/EHLO, MAIL, RCPT, DATA, AUTH, STARTTLS, XCLIENT) and supports TLS, greylisting, and spam filtering via regex. The architecture is monolithic: a single binary runs both the SMTP listener and an HTTP server for the web UI. The codebase is functional but shows signs of age: it uses deprecated dependencies (gopkg.in/mgo.v2, github.com/robfig/config, github.com/gosexy/redis), lacks a go.mod file, and has no automated tests. The SMTP protocol handling is reasonably robust, and the MIME parsing is non-trivial, but the overall project would benefit from modernization and testing.