1 files changed, 143 insertions, 0 deletions
diff --git a/tvix/castore/src/import/fs.rs b/tvix/castore/src/import/fs.rs
new file mode 100644
index 000000000000..a87a0278da4d
--- /dev/null
+++ b/tvix/castore/src/import/fs.rs
@@ -0,0 +1,143 @@
+use std::os::unix::fs::MetadataExt;
+use std::os::unix::fs::PermissionsExt;
+use std::path::Path;
+
+use futures::stream::BoxStream;
+use tracing::instrument;
+use walkdir::DirEntry;
+use walkdir::WalkDir;
+
+use crate::blobservice::BlobService;
+use crate::directoryservice::DirectoryService;
+use crate::proto::node::Node;
+
+use super::ingest_entries;
+use super::upload_blob_at_path;
+use super::Error;
+use super::IngestionEntry;
+
+///! Imports that deal with a real filesystem.
+
+/// Ingests the contents at a given path into the tvix store, interacting with a [BlobService] and
+/// [DirectoryService]. It returns the root node or an error.
+///
+/// It does not follow symlinks at the root, they will be ingested as actual symlinks.
+#[instrument(skip(blob_service, directory_service), fields(path), err)]
+pub async fn ingest_path<BS, DS, P>(
+    blob_service: BS,
+    directory_service: DS,
+    path: P,
+) -> Result<Node, Error>
+where
+    P: AsRef<Path> + std::fmt::Debug,
+    BS: BlobService + Clone,
+    DS: AsRef<dyn DirectoryService>,
+{
+    let entry_stream = walk_path_for_ingestion(blob_service, path.as_ref());
+    ingest_entries(directory_service, entry_stream).await
+}
+
+/// Walk the filesystem at a given path and returns a stream of ingestion entries.
+///
+/// This is how [`ingest_path`] assembles the set of entries to pass on [`ingest_entries`].
+/// This low-level function can be used if additional filtering or processing is required on the
+/// entries.
+///
+/// It does not follow symlinks at the root, they will be ingested as actual symlinks.
+///
+/// This function will walk the filesystem using `walkdir` and will consume
+/// `O(#number of entries)` space.
+#[instrument(fields(path), skip(blob_service))]
+fn walk_path_for_ingestion<'a, BS>(
+    blob_service: BS,
+    path: &'a Path,
+) -> BoxStream<'a, Result<IngestionEntry<'a>, Error>>
+where
+    BS: BlobService + Clone + 'a,
+{
+    let iter = WalkDir::new(path)
+        .follow_links(false)
+        .follow_root_links(false)
+        .contents_first(true)
+        .into_iter();
+
+    dir_entry_iter_to_ingestion_stream(blob_service, iter, path)
+}
+
+/// Converts an iterator of [walkdir::DirEntry]s into a stream of ingestion entries.
+/// This can then be fed into [ingest_entries] to ingest all the entries into the castore.
+///
+/// The root is the [Path] in the filesystem that is being ingested into the castore.
+pub fn dir_entry_iter_to_ingestion_stream<'a, BS, I>(
+    blob_service: BS,
+    iter: I,
+    root: &'a Path,
+) -> BoxStream<'a, Result<IngestionEntry<'a>, Error>>
+where
+    BS: BlobService + Clone + 'a,
+    I: Iterator<Item = Result<DirEntry, walkdir::Error>> + Send + 'a,
+{
+    let prefix = root.parent().unwrap_or_else(|| Path::new(""));
+
+    let iter = iter.map(move |entry| match entry {
+        Ok(entry) => dir_entry_to_ingestion_entry(blob_service.clone(), &entry, prefix),
+        Err(error) => Err(Error::UnableToStat(
+            root.to_path_buf(),
+            error.into_io_error().expect("walkdir err must be some"),
+        )),
+    });
+
+    Box::pin(futures::stream::iter(iter))
+}
+
+/// Converts a [walkdir::DirEntry] into an [IngestionEntry], uploading blobs to the
+/// provided [BlobService].
+///
+/// The prefix path is stripped from the path of each entry. This is usually the parent path
+/// of the path being ingested so that the last element of the stream only has one component.
+fn dir_entry_to_ingestion_entry<'a, BS>(
+    blob_service: BS,
+    entry: &DirEntry,
+    prefix: &Path,
+) -> Result<IngestionEntry<'a>, Error>
+where
+    BS: BlobService + 'a,
+{
+    let file_type = entry.file_type();
+
+    let path = entry
+        .path()
+        .strip_prefix(prefix)
+        .expect("Tvix bug: failed to strip root path prefix")
+        .to_path_buf();
+
+    if file_type.is_dir() {
+        Ok(IngestionEntry::Dir { path })
+    } else if file_type.is_symlink() {
+        let target = std::fs::read_link(entry.path())
+            .map_err(|e| Error::UnableToStat(entry.path().to_path_buf(), e))?;
+
+        Ok(IngestionEntry::Symlink { path, target })
+    } else if file_type.is_file() {
+        let metadata = entry
+            .metadata()
+            .map_err(|e| Error::UnableToStat(entry.path().to_path_buf(), e.into()))?;
+
+        // TODO: In the future, for small files, hash right away and upload async.
+        let digest = Box::pin(upload_blob_at_path(
+            blob_service,
+            entry.path().to_path_buf(),
+        ));
+
+        Ok(IngestionEntry::Regular {
+            path,
+            size: metadata.size(),
+            // If it's executable by the user, it'll become executable.
+            // This matches nix's dump() function behaviour.
+            executable: metadata.permissions().mode() & 64 != 0,
+            digest,
+        })
+    } else {
+        Ok(IngestionEntry::Unknown { path, file_type })
+    }
+}