tvl-depot/tvix/castore/src/directoryservice/traverse.rs
Florian Klink abc0553eb8 feat(tvix/castore/directory/traverse): use castore Paths
This switches from using std::path::Path to using castore paths.

We can drop some error handling in descend_to, as absolute (or redundant)
paths are not representable.

We however now need to convert from a std::path::Path to our
representation, and decide to accept .. canonicalization, as paths in
EvalIO might contain this. Dealing .. to hop into another store path, if
we encounter this, should be dealt with in a previous step.

Change-Id: I5e94693808420c5d56587c68731252b54755bf93
Reviewed-on: https://cl.tvl.fyi/c/depot/+/11575
Autosubmit: flokli <flokli@flokli.de>
Reviewed-by: Connor Brewster <cbrewster@hey.com>
Tested-by: BuildkiteCI
2024-05-02 15:26:29 +00:00

197 lines
7.1 KiB
Rust

use super::DirectoryService;
use crate::{proto::NamedNode, B3Digest, Error, Path};
use tracing::{instrument, warn};
/// This descends from a (root) node to the given (sub)path, returning the Node
/// at that path, or none, if there's nothing at that path.
#[instrument(skip(directory_service, path), fields(%path))]
pub async fn descend_to<DS>(
directory_service: DS,
root_node: crate::proto::node::Node,
path: impl AsRef<Path> + std::fmt::Display,
) -> Result<Option<crate::proto::node::Node>, Error>
where
DS: AsRef<dyn DirectoryService>,
{
let mut cur_node = root_node;
let mut it = path.as_ref().components();
loop {
match it.next() {
None => {
// the (remaining) path is empty, return the node we're current at.
return Ok(Some(cur_node));
}
Some(first_component) => {
match cur_node {
crate::proto::node::Node::File(_) | crate::proto::node::Node::Symlink(_) => {
// There's still some path left, but the current node is no directory.
// This means the path doesn't exist, as we can't reach it.
return Ok(None);
}
crate::proto::node::Node::Directory(directory_node) => {
let digest: B3Digest = directory_node.digest.try_into().map_err(|_e| {
Error::StorageError("invalid digest length".to_string())
})?;
// fetch the linked node from the directory_service
match directory_service.as_ref().get(&digest).await? {
// If we didn't get the directory node that's linked, that's a store inconsistency, bail out!
None => {
warn!("directory {} does not exist", digest);
return Err(Error::StorageError(format!(
"directory {} does not exist",
digest
)));
}
Some(directory) => {
// look for first_component in the [Directory].
// FUTUREWORK: as the nodes() iterator returns in a sorted fashion, we
// could stop as soon as e.name is larger than the search string.
let child_node =
directory.nodes().find(|n| n.get_name() == first_component);
match child_node {
// child node not found means there's no such element inside the directory.
None => {
return Ok(None);
}
// child node found, return to top-of loop to find the next
// node in the path.
Some(child_node) => {
cur_node = child_node;
}
}
}
}
}
}
}
}
}
}
#[cfg(test)]
mod tests {
use crate::{
directoryservice,
fixtures::{DIRECTORY_COMPLICATED, DIRECTORY_WITH_KEEP},
PathBuf,
};
use super::descend_to;
#[tokio::test]
async fn test_descend_to() {
let directory_service = directoryservice::from_addr("memory://").await.unwrap();
let mut handle = directory_service.put_multiple_start();
handle
.put(DIRECTORY_WITH_KEEP.clone())
.await
.expect("must succeed");
handle
.put(DIRECTORY_COMPLICATED.clone())
.await
.expect("must succeed");
handle.close().await.expect("must upload");
// construct the node for DIRECTORY_COMPLICATED
let node_directory_complicated =
crate::proto::node::Node::Directory(crate::proto::DirectoryNode {
name: "doesntmatter".into(),
digest: DIRECTORY_COMPLICATED.digest().into(),
size: DIRECTORY_COMPLICATED.size(),
});
// construct the node for DIRECTORY_COMPLICATED
let node_directory_with_keep = crate::proto::node::Node::Directory(
DIRECTORY_COMPLICATED.directories.first().unwrap().clone(),
);
// construct the node for the .keep file
let node_file_keep =
crate::proto::node::Node::File(DIRECTORY_WITH_KEEP.files.first().unwrap().clone());
// traversal to an empty subpath should return the root node.
{
let resp = descend_to(
&directory_service,
node_directory_complicated.clone(),
"".parse::<PathBuf>().unwrap(),
)
.await
.expect("must succeed");
assert_eq!(Some(node_directory_complicated.clone()), resp);
}
// traversal to `keep` should return the node for DIRECTORY_WITH_KEEP
{
let resp = descend_to(
&directory_service,
node_directory_complicated.clone(),
"keep".parse::<PathBuf>().unwrap(),
)
.await
.expect("must succeed");
assert_eq!(Some(node_directory_with_keep), resp);
}
// traversal to `keep/.keep` should return the node for the .keep file
{
let resp = descend_to(
&directory_service,
node_directory_complicated.clone(),
"keep/.keep".parse::<PathBuf>().unwrap(),
)
.await
.expect("must succeed");
assert_eq!(Some(node_file_keep.clone()), resp);
}
// traversal to `void` should return None (doesn't exist)
{
let resp = descend_to(
&directory_service,
node_directory_complicated.clone(),
"void".parse::<PathBuf>().unwrap(),
)
.await
.expect("must succeed");
assert_eq!(None, resp);
}
// traversal to `v/oid` should return None (doesn't exist)
{
let resp = descend_to(
&directory_service,
node_directory_complicated.clone(),
"v/oid".parse::<PathBuf>().unwrap(),
)
.await
.expect("must succeed");
assert_eq!(None, resp);
}
// traversal to `keep/.keep/404` should return None (the path can't be
// reached, as keep/.keep already is a file)
{
let resp = descend_to(
&directory_service,
node_directory_complicated.clone(),
"keep/.keep/foo".parse::<PathBuf>().unwrap(),
)
.await
.expect("must succeed");
assert_eq!(None, resp);
}
}
}