nada

Compression-focused encoding for zero-heavy Solidity calldata and bytecode.

nada provides an efficient way to encode and decode byte arrays where runs of 0x00 are replaced with a compact marker (0xFF) followed by the length of the run. This is particularly useful for reducing the size of calldata and bytecode in environments like Ethereum.

How it Works

• 0xFF 0x00 is a reserved sequence
• 0xFF 0x01 encodes a single 0xFF
• 0xFF 0x02 encodes a double 0xFF
• 0xFF N (3 ≤ N ≤ 255) encodes N zero bytes
• All other bytes are passed through unchanged

This encoding helps reduce the size of sequences with a high proportion of zero bytes, which are common in Solidity calldata and bytecode.

Example

Installation

To add nada to your project, use

> cargo add nada

Usage

Here is a simple example of how to use the encode and decode functions:

let data = vec![0x01, 0x00, 0x00, 0xFF];
let encoded = nada::encode(data);
let decoded = nada::decode(encoded);

assert_eq!(decoded, Ok(data));

decode returns a DecodeError if the input ends unexpectedly, such as when a 0xFF marker is found without a following run length byte, indicating incomplete or malformed encoded data. It also returns an error if the reserved sequence 0xFF00 is encountered.

License

Apache License, Version 2.0