Struct tvix_eval::vm::ImportCache

struct ImportCache(HashMap<PathBuf, Value>);

Tuple Fields

0: HashMap<PathBuf, Value>

Implementations

impl ImportCache

The ImportCache holds the Value resulting from importing a certain file, so that the same file doesn’t need to be re-evaluated multiple times. Currently the real path of the imported file (determined using std::fs::canonicalize(), not to be confused with our crate::value::canon_path()) is used to identify the file, just like C++ Nix does.

Errors while determining the real path are currently just ignored, since we pass around some fake paths like /__corepkgs__/fetchurl.nix.

In the future, we could use something more sophisticated, like file hashes. However, a consideration is that the eval cache is observable via impurities like pointer equality and builtins.trace.

fn get(&self, path: PathBuf) -> Option<&Value>

fn insert(&mut self, path: PathBuf, value: Value) -> Option<Value>

Trait Implementations

impl Default for ImportCache

fn default() -> ImportCache

Returns the “default value” for a type.