copybook-determinism

Determinism primitives for repeatable output validation in copybook-rs.

Overview

This crate compares two codec output byte streams using BLAKE3 digests and reports bounded byte-level differences. It supports decode-only, encode-only, and full round-trip determinism checks, enabling CI pipelines and tests to verify that codec operations are repeatable.

Usage

use copybook_determinism::{compare_outputs, DeterminismMode, blake3_hex};

let output_a = b"hello world";
let output_b = b"hello world";

let result = compare_outputs(DeterminismMode::DecodeOnly, output_a, output_b);
assert!(result.is_deterministic);

// Stable content hashing
let hash = blake3_hex(b"some data");
assert_eq!(hash.len(), 64); // hex-encoded BLAKE3

Public API

• DeterminismMode — Decode-only, encode-only, or round-trip checking
• DeterminismResult — Hash comparison result with optional byte diffs
• ByteDiff — Single byte-level difference descriptor
• compare_outputs / compare_outputs_with_limit — Compare two byte slices
• find_byte_differences / find_byte_differences_with_limit — Collect diffs
• blake3_hex — Hex-encoded BLAKE3 content hash

License

AGPL-3.0-or-later