use crate::blobservice::BlobService;
use crate::directoryservice::DirectoryPutter;
use crate::directoryservice::DirectoryService;
use crate::proto::node::Node;
use crate::proto::Directory;
use crate::proto::DirectoryNode;
use crate::proto::FileNode;
use crate::proto::SymlinkNode;
use crate::B3Digest;
use crate::Error as CastoreError;
use futures::stream::BoxStream;
use futures::Future;
use futures::{Stream, StreamExt};
use std::fs::FileType;
use std::os::unix::fs::MetadataExt;
use std::pin::Pin;
use tracing::Level;
#[cfg(target_family = "unix")]
use std::os::unix::ffi::OsStrExt;
use std::{
collections::HashMap,
fmt::Debug,
os::unix::prelude::PermissionsExt,
path::{Path, PathBuf},
};
use tracing::instrument;
use walkdir::DirEntry;
use walkdir::WalkDir;
#[derive(Debug, thiserror::Error)]
pub enum Error {
#[error("failed to upload directory at {0}: {1}")]
UploadDirectoryError(PathBuf, CastoreError),
#[error("invalid encoding encountered for entry {0:?}")]
InvalidEncoding(PathBuf),
#[error("unable to stat {0}: {1}")]
UnableToStat(PathBuf, std::io::Error),
#[error("unable to open {0}: {1}")]
UnableToOpen(PathBuf, std::io::Error),
#[error("unable to read {0}: {1}")]
UnableToRead(PathBuf, std::io::Error),
#[error("unsupported file {0} type: {1:?}")]
UnsupportedFileType(PathBuf, FileType),
}
impl From<CastoreError> for Error {
fn from(value: CastoreError) -> Self {
match value {
CastoreError::InvalidRequest(_) => panic!("tvix bug"),
CastoreError::StorageError(_) => panic!("error"),
}
}
}
impl From<Error> for std::io::Error {
fn from(value: Error) -> Self {
std::io::Error::new(std::io::ErrorKind::Other, value)
}
}
/// 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 })
}
}
/// Uploads the file at the provided [Path] the the [BlobService].
#[instrument(skip(blob_service), fields(path), err)]
async fn upload_blob_at_path<BS>(blob_service: BS, path: PathBuf) -> Result<B3Digest, Error>
where
BS: BlobService,
{
let mut file = match tokio::fs::File::open(&path).await {
Ok(file) => file,
Err(e) => return Err(Error::UnableToRead(path, e)),
};
let mut writer = blob_service.open_write().await;
if let Err(e) = tokio::io::copy(&mut file, &mut writer).await {
return Err(Error::UnableToRead(path, e));
};
let digest = writer
.close()
.await
.map_err(|e| Error::UnableToRead(path, e))?;
Ok(digest)
}
/// 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
}
/// Ingests elements from the given stream of [IngestionEntry] into a the passed [DirectoryService].
///
/// The stream must have the following invariants:
/// - All children entries must come before their parents.
/// - The last entry must be the root node which must have a single path component.
/// - Every entry should have a unique path.
///
/// Internally we maintain a [HashMap] of [PathBuf] to partially populated [Directory] at that
/// path. Once we receive an [IngestionEntry] for the directory itself, we remove it from the
/// map and upload it to the [DirectoryService] through a lazily created [DirectoryPutter].
///
/// On success, returns the root node.
#[instrument(skip_all, ret(level = Level::TRACE), err)]
pub async fn ingest_entries<'a, DS, S>(directory_service: DS, mut entries: S) -> Result<Node, Error>
where
DS: AsRef<dyn DirectoryService>,
S: Stream<Item = Result<IngestionEntry<'a>, Error>> + Send + std::marker::Unpin,
{
// For a given path, this holds the [Directory] structs as they are populated.
let mut directories: HashMap<PathBuf, Directory> = HashMap::default();
let mut maybe_directory_putter: Option<Box<dyn DirectoryPutter>> = None;
let root_node = loop {
let mut entry = entries
.next()
.await
// The last entry of the stream must have 1 path component, after which
// we break the loop manually.
.expect("Tvix bug: unexpected end of stream")?;
let name = entry
.path()
.file_name()
// If this is the root node, it will have an empty name.
.unwrap_or_default()
.as_bytes()
.to_owned()
.into();
let node = match &mut entry {
IngestionEntry::Dir { .. } => {
// If the entry is a directory, we traversed all its children (and
// populated it in `directories`).
// If we don't have it in there, it's an empty directory.
let directory = directories
.remove(entry.path())
// In that case, it contained no children
.unwrap_or_default();
let directory_size = directory.size();
let directory_digest = directory.digest();
// Use the directory_putter to upload the directory.
// If we don't have one yet (as that's the first one to upload),
// initialize the putter.
maybe_directory_putter
.get_or_insert_with(|| directory_service.as_ref().put_multiple_start())
.put(directory)
.await?;
Node::Directory(DirectoryNode {
name,
digest: directory_digest.into(),
size: directory_size,
})
}
IngestionEntry::Symlink { ref target, .. } => Node::Symlink(SymlinkNode {
name,
target: target.as_os_str().as_bytes().to_owned().into(),
}),
IngestionEntry::Regular {
size,
executable,
digest,
..
} => Node::File(FileNode {
name,
digest: digest.await?.into(),
size: *size,
executable: *executable,
}),
IngestionEntry::Unknown { path, file_type } => {
return Err(Error::UnsupportedFileType(path.clone(), *file_type));
}
};
if entry.path().components().count() == 1 {
break node;
}
// record node in parent directory, creating a new [Directory] if not there yet.
directories
.entry(entry.path().parent().unwrap().to_path_buf())
.or_default()
.add(node);
};
// if there were directories uploaded, make sure we flush the putter, so
// they're all persisted to the backend.
if let Some(mut directory_putter) = maybe_directory_putter {
let root_directory_digest = directory_putter.close().await?;
#[cfg(debug_assertions)]
{
if let Node::Directory(directory_node) = &root_node {
debug_assert_eq!(
root_directory_digest,
directory_node
.digest
.to_vec()
.try_into()
.expect("invalid digest len")
)
} else {
unreachable!("Tvix bug: directory putter initialized but no root directory node");
}
}
};
Ok(root_node)
}
type BlobFut<'a> = Pin<Box<dyn Future<Output = Result<B3Digest, Error>> + Send + 'a>>;
pub enum IngestionEntry<'a> {
Regular {
path: PathBuf,
size: u64,
executable: bool,
digest: BlobFut<'a>,
},
Symlink {
path: PathBuf,
target: PathBuf,
},
Dir {
path: PathBuf,
},
Unknown {
path: PathBuf,
file_type: FileType,
},
}
impl<'a> IngestionEntry<'a> {
fn path(&self) -> &Path {
match self {
IngestionEntry::Regular { path, .. } => path,
IngestionEntry::Symlink { path, .. } => path,
IngestionEntry::Dir { path } => path,
IngestionEntry::Unknown { path, .. } => path,
}
}
}
