$ show fast-pack/FastPFOR
The FastPFOR library is a C++ implementation focused on high-speed integer compression, particularly optimized for decoding 32-bit integers in data-intensive applications. It achieves performance through SIMD acceleration (SSE/AVX2/NEON) and asymmetric design prioritizing decompression speed over compression. The library provides a variety of codecs (FastPFor variants, SimdGroupSimple, VarInt, Simple8b/16, etc.) accessible via a factory pattern, enabling efficient storage and retrieval of integer arrays in scenarios like inverted indexes and columnar databases. Architecture centers around an abstract IntegerCODEC interface with concrete implementations for each codec, managed by CODECFactory. Low-level utilities include bitpacking helpers for arbitrary-width operations and aligned memory allocators. Build system (CMake) supports cross-platform compilation with configurable SIMD modes and optional Snappy integration. The library is validated through extensive benchmarks, unit tests, and real-world usage in systems like DuckDB and Apache Lucene.
The LLM identified 2 files worth highlighting for reuse:
Provides inline functions for packing/unpacking integers at arbitrary bit widths (0-64) using bitwise operations. Self-contained, dependency-free, and used throughout the library for low-level bit manipulation in codecs. Extractable for any project needing bit-level integer manipulation.
Offers aligned memory allocation/deallocation functions using platform-specific intrinsics or standard fallbacks. Self-contained header providing portable cache-line aligned memory allocation, essential for SIMD operations and performance-critical applications.