feat(tvix/eval): builtins.storeDir

Returns the store directory through EvalIO::store_dir.

Note that this is _optional_ in Tvix, as an evaluation can occur in a
context where there simply is no store directory. In those contexts,
`builtins.storeDir` returns `null` in Tvix.

This would only happen in contexts like Tvixbolt (or completely
unrelated use-cases) in practice.

Co-Authored-By: Vincent Ambo <tazjin@tvl.su>
Change-Id: I5a752c7e89b2f75bd7efb082dbfa5b25e3b1ff3b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7452
Autosubmit: Adam Joseph <adam@westernsemico.com>
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
This commit is contained in:
Adam Joseph 2022-12-12 21:33:08 +03:00 committed by tazjin
parent 4cb9ada0df
commit 947a56c4b6
2 changed files with 17 additions and 1 deletions

View file

@ -4,7 +4,7 @@ use smol_str::SmolStr;
use std::{
collections::BTreeMap,
env,
rc::Weak,
rc::{Rc, Weak},
time::{SystemTime, UNIX_EPOCH},
};
@ -74,6 +74,16 @@ pub(super) fn builtins() -> BTreeMap<&'static str, Value> {
.map(|b| (b.name(), Value::Builtin(b)))
.collect();
map.insert(
"storeDir",
Value::Thunk(Thunk::new_suspended_native(Rc::new(Box::new(
|vm: &mut VM| match vm.io().store_dir() {
None => Ok(Value::Null),
Some(dir) => Ok(Value::String(dir.into())),
},
)))),
);
// currentTime pins the time at which evaluation was started
{
let seconds = match SystemTime::now().duration_since(UNIX_EPOCH) {

View file

@ -41,6 +41,12 @@ pub trait EvalIO {
/// Read the directory at the specified path and return the names
/// of its entries associated with their [`FileType`].
fn read_dir(&self, path: PathBuf) -> Result<Vec<(SmolStr, FileType)>, ErrorKind>;
/// Returns the root of the store directory, if such a thing
/// exists in the evaluation context.
fn store_dir(&self) -> Option<String> {
None
}
}
/// Implementation of [`EvalIO`] that simply uses the equivalent