diff options
Diffstat (limited to 'tvix/castore')
| -rw-r--r-- | tvix/castore/src/import.rs | 452 |
1 files changed, 232 insertions, 220 deletions
diff --git a/tvix/castore/src/import.rs b/tvix/castore/src/import.rs index e16bda1f6489..049c177efcaa 100644 --- a/tvix/castore/src/import.rs +++ b/tvix/castore/src/import.rs @@ -6,11 +6,14 @@ 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 async_stream::stream; -use futures::pin_mut; +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")] @@ -26,9 +29,6 @@ use tracing::instrument; use walkdir::DirEntry; use walkdir::WalkDir; -#[cfg(debug_assertions)] -use std::collections::HashSet; - #[derive(Debug, thiserror::Error)] pub enum Error { #[error("failed to upload directory at {0}: {1}")] @@ -65,274 +65,253 @@ impl From<Error> for std::io::Error { } } -/// Walk the filesystem at a given path and returns a level-keyed list of directory entries. +/// 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. /// -/// Level here is in the context of graph theory, e.g. 2-level nodes -/// are nodes that are at depth 2. +/// 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), err)] -pub fn walk_path_for_ingestion<P>(path: P) -> Result<Vec<Vec<DirEntry>>, Error> +#[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 - P: AsRef<Path> + std::fmt::Debug, + BS: BlobService + Clone + 'a, { - let mut entries_per_depths: Vec<Vec<DirEntry>> = vec![Vec::new()]; - for entry in WalkDir::new(path.as_ref()) + let iter = WalkDir::new(path) .follow_links(false) .follow_root_links(false) - .contents_first(false) - .sort_by_file_name() - .into_iter() - { - // Entry could be a NotFound, if the root path specified does not exist. - let entry = entry.map_err(|e| { - Error::UnableToOpen( - PathBuf::from(path.as_ref()), - e.into_io_error().expect("walkdir err must be some"), - ) - })?; - - if entry.depth() >= entries_per_depths.len() { - debug_assert!( - entry.depth() == entries_per_depths.len(), - "Received unexpected entry with depth {} during descent, previously at {}", - entry.depth(), - entries_per_depths.len() - ); - - entries_per_depths.push(vec![entry]); - } else { - entries_per_depths[entry.depth()].push(entry); - } - } + .contents_first(true) + .into_iter(); - Ok(entries_per_depths) + dir_entry_iter_to_ingestion_stream(blob_service, iter, path) } -/// Convert a leveled-key vector of filesystem entries into a stream of -/// [DirEntry] in a way that honors the Merkle invariant, i.e. from bottom to top. -pub fn leveled_entries_to_stream( - entries_per_depths: Vec<Vec<DirEntry>>, -) -> impl Stream<Item = DirEntry> { - stream! { - for level in entries_per_depths.into_iter().rev() { - for entry in level.into_iter() { - yield entry; - } - } +/// 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<'a, BS, DS, P>( +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: AsRef<dyn BlobService>, + BS: BlobService + Clone, DS: AsRef<dyn DirectoryService>, { - // produce the leveled-key vector of DirEntry. - let entries_per_depths = walk_path_for_ingestion(path)?; - let direntry_stream = leveled_entries_to_stream(entries_per_depths); - pin_mut!(direntry_stream); - - ingest_entries(blob_service, directory_service, direntry_stream).await + let entry_stream = walk_path_for_ingestion(blob_service, path.as_ref()); + ingest_entries(directory_service, entry_stream).await } -/// The Merkle invariant checker is an internal structure to perform bookkeeping of all directory -/// entries we are ingesting and verifying we are ingesting them in the right order. -/// -/// That is, whenever we process an entry `L`, we would like to verify if we didn't process earlier -/// an entry `P` such that `P` is an **ancestor** of `L`. -/// -/// If such a thing happened, it means that we have processed something like: +/// Ingests elements from the given stream of [DirEntry] into a the passed [DirectoryService]. /// -///```no_trust -/// A -/// / \ -/// B C -/// / \ \ -/// G F P <--------- processed before this one -/// / \ | -/// D E | -/// \ | -/// L <-----------------------------+ -/// ``` +/// 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. /// -/// This is exactly what must never happen. +/// 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]. /// -/// Note: this checker is local, it can only see what happens on our side, not on the remote side, -/// i.e. the different remote services. -#[derive(Default)] -#[cfg(debug_assertions)] -struct MerkleInvariantChecker { - seen: HashSet<PathBuf>, -} - -#[cfg(debug_assertions)] -impl MerkleInvariantChecker { - /// See a directory entry and remember it. - fn see(&mut self, node: &DirEntry) { - self.seen.insert(node.path().to_owned()); - } - - /// Returns a potential ancestor already seen for that directory entry. - fn find_ancestor<'a>(&self, node: &'a DirEntry) -> Option<&'a Path> { - node.path().ancestors().find(|p| self.seen.contains(*p)) - } -} - -/// Ingests elements from the given stream of [`DirEntry`] into a the passed [`BlobService`] and -/// [`DirectoryService`]. -/// It does not follow symlinks at the root, they will be ingested as actual symlinks. +/// On success, returns the root node. #[instrument(skip_all, ret(level = Level::TRACE), err)] -pub async fn ingest_entries<'a, BS, DS, S>( - blob_service: BS, +pub async fn ingest_entries<'a, DS, S>( directory_service: DS, #[allow(unused_mut)] mut direntry_stream: S, ) -> Result<Node, Error> where - BS: AsRef<dyn BlobService>, DS: AsRef<dyn DirectoryService>, - S: Stream<Item = DirEntry> + std::marker::Unpin, + S: Stream<Item = Result<IngestionEntry<'a>, Error>> + Send + std::marker::Unpin, { - #[cfg(debug_assertions)] - let mut invariant_checker: MerkleInvariantChecker = Default::default(); - - #[cfg(debug_assertions)] - let mut direntry_stream = direntry_stream.inspect(|e| { - // If we find an ancestor before we see this entry, this means that the caller - // broke the contract, refer to the documentation of the invariant checker to - // understand the reasoning here. - if let Some(ancestor) = invariant_checker.find_ancestor(e) { - panic!( - "Tvix bug: merkle invariant checker discovered that {} was processed before {}!", - ancestor.display(), - e.path().display() - ); - } - - invariant_checker.see(e); - }); - // 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; - // We need to process a directory's children before processing - // the directory itself in order to have all the data needed - // to compute the hash. - let root_node = loop { - let entry = match direntry_stream.next().await { - Some(entry) => entry, - None => { - // The last entry of the stream must have depth 0, after which - // we break the loop manually. - panic!("Tvix bug: unexpected end of stream"); + let mut entry = direntry_stream + .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)); } - }; - let file_type = entry.file_type(); - - let node = if file_type.is_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: entry.file_name().as_bytes().to_owned().into(), - digest: directory_digest.into(), - size: directory_size, - }) - } else if file_type.is_symlink() { - let target: bytes::Bytes = std::fs::read_link(entry.path()) - .map_err(|e| Error::UnableToStat(entry.path().to_path_buf(), e))? - .as_os_str() - .as_bytes() - .to_owned() - .into(); - - Node::Symlink(SymlinkNode { - name: entry.file_name().as_bytes().to_owned().into(), - target, - }) - } else if file_type.is_file() { - let metadata = entry - .metadata() - .map_err(|e| Error::UnableToStat(entry.path().to_path_buf(), e.into()))?; - - let mut file = tokio::fs::File::open(entry.path()) - .await - .map_err(|e| Error::UnableToOpen(entry.path().to_path_buf(), e))?; - - let mut writer = blob_service.as_ref().open_write().await; - - if let Err(e) = tokio::io::copy(&mut file, &mut writer).await { - return Err(Error::UnableToRead(entry.path().to_path_buf(), e)); - }; - - let digest = writer - .close() - .await - .map_err(|e| Error::UnableToRead(entry.path().to_path_buf(), e))?; - - Node::File(FileNode { - name: entry.file_name().as_bytes().to_vec().into(), - digest: digest.into(), - size: metadata.len(), - // If it's executable by the user, it'll become executable. - // This matches nix's dump() function behaviour. - executable: metadata.permissions().mode() & 64 != 0, - }) - } else { - return Err(Error::UnsupportedFileType( - entry.path().to_path_buf(), - file_type, - )); }; - if entry.depth() == 0 { + if entry.path().components().count() == 1 { break node; - } else { - // calculate the parent path, and make sure we register the node there. - // NOTE: entry.depth() > 0 - let parent_path = entry.path().parent().unwrap().to_path_buf(); - - // record node in parent directory, creating a new [proto:Directory] if not there yet. - let parent_directory = directories.entry(parent_path).or_default(); - match node { - Node::Directory(e) => parent_directory.directories.push(e), - Node::File(e) => parent_directory.files.push(e), - Node::Symlink(e) => parent_directory.symlinks.push(e), - } } + + // 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 @@ -359,3 +338,36 @@ where 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, + } + } +} |