densol

Transparent LZ4 compression for Anchor account fields.
Store less data, pay less rent.

What it is

densol lets you compress a Vec<u8> field inside any Anchor account with a single attribute. The compression runs fully on-chain using LZ4 via lz4_flex, which keeps its hash table on the stack (16 KB) and stays within the SBF VM's 32 KB heap limit.

I built this to answer a question I couldn't find answered anywhere: is on-chain compression actually worth the extra compute units? So I measured it.

Install

# Cargo.toml
densol = "0.1"

Usage

use densol::Lz4 as Strategy;
use densol::Compress;

#[account]
#[derive(Compress)]
pub struct MyAccount {
    #[compress]
    pub data: Vec<u8>,
}

// Generated methods:
// account.set_data(&raw_bytes)?;  // compress + store
// account.get_data()?;            // load + decompress

The Strategy alias is how the derive macro knows which algorithm to use. Swap it for a different type implementing Compressor to change algorithms at compile time.

Features

densol = { version = "0.1", default-features = false, features = ["lz4", "discriminant"] }

lz4 — LZ4 strategy via lz4_flex · discriminant — 1-byte algorithm tag prepended to output · derive — re-exports #[derive(Compress)] · std — implements std::error::Error for errors