Module lz4 

LZ4 block compression codec for string/log columns.

Uses lz4_flex (pure Rust, WASM-compatible) for fast decompression with reasonable compression ratios (3-5x for typical log text).

Data is split into 4KB blocks for random access: to read row N, decompress only the block containing that row, not the entire column.

Wire format:

[4 bytes] total uncompressed size (LE u32)
[4 bytes] block size (LE u32, default 4096)
[4 bytes] block count (LE u32)
[block_count × 4 bytes] compressed block lengths (LE u32 each)
[block_count × N bytes] compressed blocks (concatenated)

The block length table allows seeking to any block without decompressing preceding blocks.

Structs

Lz4Decoder

LZ4 decoder wrapper.

Lz4Encoder

Streaming LZ4 encoder. Accumulates data and compresses on finish().

Functions

decode

Decompress LZ4 block-compressed bytes back to raw data.

decode_block

Decompress a single block by index (for random access).

encode

Compress raw bytes using LZ4 block compression.

encode_with_block_size

Compress with a custom block size (useful for testing or tuning).