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Diffstat (limited to 'tvix/castore/src/import/mod.rs')
| -rw-r--r-- | tvix/castore/src/import/mod.rs | 216 |
1 files changed, 216 insertions, 0 deletions
diff --git a/tvix/castore/src/import/mod.rs b/tvix/castore/src/import/mod.rs new file mode 100644 index 0000000000..d2b1ee9ff7 --- /dev/null +++ b/tvix/castore/src/import/mod.rs @@ -0,0 +1,216 @@ +//! Deals with ingesting contents into castore. +//! The main library function here is [ingest_entries], receiving a stream of +//! [IngestionEntry]. +//! +//! Specific implementations, such as ingesting from the filesystem, live in +//! child modules. + +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 futures::Future; +use futures::{Stream, StreamExt}; +use std::fs::FileType; +use std::pin::Pin; +use tracing::Level; + +#[cfg(target_family = "unix")] +use std::os::unix::ffi::OsStrExt; + +use std::{ + collections::HashMap, + path::{Path, PathBuf}, +}; +use tracing::instrument; + +mod error; +pub use error::Error; + +pub mod fs; + +/// Ingests [IngestionEntry] from the given stream into a the passed [DirectoryService]. +/// On success, returns the root [Node]. +/// +/// 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) +} + +/// 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) +} + +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, + } + } +} |