Expand description
Interleaved rANS (Asymmetric Numeral Systems) entropy coder.
Compresses byte streams to the Shannon entropy limit — optimal compression ratio at Huffman-like speed. Used as the terminal compressor for cold/S3 tier partitions where ratio matters more than decompression speed.
4-stream interleaving breaks the sequential dependency chain: the CPU processes all streams simultaneously, achieving high throughput despite the inherently sequential nature of ANS.
Wire format:
[4 bytes] uncompressed size (LE u32)
[256 × 4 bytes] frequency table (LE u32 per byte value)
[4 bytes] compressed size (LE u32)
[N bytes] interleaved rANS bitstream (4 streams)