$ show apple/swift-nio-http2
SwiftNIO HTTP/2 is a Swift library providing HTTP/2 protocol support for SwiftNIO-based applications. It implements the HTTP/2 specification (RFC 7540) and HPACK header compression (RFC 7541) in pure Swift, with no external dependencies beyond SwiftNIO core. The library features a modular architecture separating frame handling, connection state management, stream multiplexing, and header compression. Key components include a connection state machine for managing HTTP/2 connection lifecycle, stream multiplexing logic for creating child channels per HTTP/2 stream, and an HPACK implementation with Huffman coding. The repository includes extensive unit tests, integration tests, performance benchmarks, and fuzz testing to ensure correctness and performance.
The LLM identified 5 files worth highlighting for reuse:
Implements HPACK Huffman decoding tables using a finite-state machine approach. Contains StaticHuffmanTable for symbol lookup and HuffmanDecoderTable as a state machine for decoding nibbles. Includes base64 decoding utilities to materialize the decoding table. Self-contained with only Swift standard library dependencies, demonstrating non-obvious skill in efficient Huffman decoding algorithm implementation.
Likely implements HTTP/2 frame payload and HPACK integer encoding/decoding per RFC 7540/7541 specifications. Handles variable-length integer representation used throughout HTTP/2 frames and HPACK encoding. Self-contained with clear encode/decode interfaces, demonstrating skill in bit manipulation and handling of HPACK's specific integer encoding format with its tricky edge cases.
Manages per-stream state for HTTP/2 client and server streams using a hybrid linear/binary search circular buffer. Provides efficient stream ID lookup with O(1) for recent streams and O(log n) for older streams. Self-contained data structure with clear interface, demonstrating non-obvious optimization for stream lookup patterns in high-concurrency HTTP/2 connections.
Implements HPACK header table with static and dynamic components as specified in RFC 7541. Manages header field storage with LRU eviction policy for the dynamic table. Provides efficient header lookup and insertion operations. Self-contained caching mechanism demonstrating skill in implementing an LRU cache optimized for header access patterns in HTTP/2 compression.
Implements a circular buffer with frame tracking capabilities for HTTP/2 flow control management. Tracks which frames have been flushed to enable proper flow control credit updates. Self-contained buffering pattern with clear interface, demonstrating skill in buffer management techniques for network protocols where tracking processed vs. buffered data is essential.