Function entry_key 

pub fn entry_key(
    kind: &str,
    entry_paths: &[PathBuf],
    cwd: &Path,
    salt: u64,
) -> u64

A stable key for a set of entry paths (canonicalized, order-independent). The transitive content check on load is what actually guards freshness; this only needs to be collision-free across distinct bundle requests.

kind namespaces the consumers: the same file compiled two ways (different module name, different aux payload) must not share one slot. salt carries extra pipeline state that changes the output without changing any input file – the bundler options and the native module table. cwd is the directory the bundle is built from, which decides how every bare specifier resolves.