diff options
Diffstat (limited to 'tvix/glue/src/tvix_store_io.rs')
| -rw-r--r-- | tvix/glue/src/tvix_store_io.rs | 359 |
1 files changed, 359 insertions, 0 deletions
diff --git a/tvix/glue/src/tvix_store_io.rs b/tvix/glue/src/tvix_store_io.rs new file mode 100644 index 0000000000..9be896ffc4 --- /dev/null +++ b/tvix/glue/src/tvix_store_io.rs @@ -0,0 +1,359 @@ +//! This module provides an implementation of EvalIO talking to tvix-store. + +use nix_compat::store_path::{self, StorePath}; +use std::{io, path::Path, path::PathBuf, sync::Arc}; +use tokio::io::AsyncReadExt; +use tracing::{error, instrument, warn}; +use tvix_eval::{EvalIO, FileType, StdIO}; + +use tvix_castore::{ + blobservice::BlobService, + directoryservice::{self, DirectoryService}, + import, + proto::{node::Node, NamedNode}, + B3Digest, +}; +use tvix_store::{ + nar::calculate_size_and_sha256, + pathinfoservice::PathInfoService, + proto::{NarInfo, PathInfo}, +}; + +/// Implements [EvalIO], asking given [PathInfoService], [DirectoryService] +/// and [BlobService]. +/// +/// In case the given path does not exist in these stores, we ask StdIO. +/// This is to both cover cases of syntactically valid store paths, that exist +/// on the filesystem (still managed by Nix), as well as being able to read +/// files outside store paths. +pub struct TvixStoreIO { + blob_service: Arc<dyn BlobService>, + directory_service: Arc<dyn DirectoryService>, + path_info_service: Arc<dyn PathInfoService>, + std_io: StdIO, + tokio_handle: tokio::runtime::Handle, +} + +impl TvixStoreIO { + pub fn new( + blob_service: Arc<dyn BlobService>, + directory_service: Arc<dyn DirectoryService>, + path_info_service: Arc<dyn PathInfoService>, + tokio_handle: tokio::runtime::Handle, + ) -> Self { + Self { + blob_service, + directory_service, + path_info_service, + std_io: StdIO {}, + tokio_handle, + } + } + + /// for a given [StorePath] and additional [Path] inside the store path, + /// look up the [PathInfo], and if it exists, and then use + /// [directoryservice::traverse_to] to return the + /// [Node] specified by `sub_path`. + #[instrument(skip(self), ret, err)] + fn store_path_to_root_node( + &self, + store_path: &StorePath, + sub_path: &Path, + ) -> Result<Option<Node>, io::Error> { + let path_info_service = self.path_info_service.clone(); + let task = self.tokio_handle.spawn({ + let digest = *store_path.digest(); + async move { path_info_service.get(digest).await } + }); + let path_info = match self.tokio_handle.block_on(task).unwrap()? { + // If there's no PathInfo found, early exit + None => return Ok(None), + Some(path_info) => path_info, + }; + + let root_node = { + match path_info.node { + None => { + warn!( + "returned PathInfo {:?} node is None, this shouldn't happen.", + &path_info + ); + return Ok(None); + } + Some(root_node) => match root_node.node { + None => { + warn!("node for {:?} is None, this shouldn't happen.", &root_node); + return Ok(None); + } + Some(root_node) => root_node, + }, + } + }; + + let directory_service = self.directory_service.clone(); + let sub_path = sub_path.to_owned(); + let task = self.tokio_handle.spawn(async move { + directoryservice::descend_to(directory_service, root_node, &sub_path).await + }); + + Ok(self.tokio_handle.block_on(task).unwrap()?) + } +} + +impl EvalIO for TvixStoreIO { + #[instrument(skip(self), ret, err)] + fn path_exists(&self, path: &Path) -> Result<bool, io::Error> { + if let Ok((store_path, sub_path)) = + StorePath::from_absolute_path_full(&path.to_string_lossy()) + { + if self + .store_path_to_root_node(&store_path, &sub_path)? + .is_some() + { + Ok(true) + } else { + // As tvix-store doesn't manage /nix/store on the filesystem, + // we still need to also ask self.std_io here. + self.std_io.path_exists(path) + } + } else { + // The store path is no store path, so do regular StdIO. + self.std_io.path_exists(path) + } + } + + #[instrument(skip(self), ret, err)] + fn read_to_string(&self, path: &Path) -> Result<String, io::Error> { + if let Ok((store_path, sub_path)) = + StorePath::from_absolute_path_full(&path.to_string_lossy()) + { + if let Some(node) = self.store_path_to_root_node(&store_path, &sub_path)? { + // depending on the node type, treat read_to_string differently + match node { + Node::Directory(_) => { + // This would normally be a io::ErrorKind::IsADirectory (still unstable) + Err(io::Error::new( + io::ErrorKind::Unsupported, + format!("tried to read directory at {:?} to string", path), + )) + } + Node::File(file_node) => { + let digest: B3Digest = + file_node.digest.clone().try_into().map_err(|_e| { + error!( + file_node = ?file_node, + "invalid digest" + ); + io::Error::new( + io::ErrorKind::InvalidData, + format!("invalid digest length in file node: {:?}", file_node), + ) + })?; + + let blob_service = self.blob_service.clone(); + + let task = self.tokio_handle.spawn(async move { + let mut reader = { + let resp = blob_service.open_read(&digest).await?; + match resp { + Some(blob_reader) => blob_reader, + None => { + error!( + blob.digest = %digest, + "blob not found", + ); + Err(io::Error::new( + io::ErrorKind::NotFound, + format!("blob {} not found", &digest), + ))? + } + } + }; + + let mut buf = String::new(); + + reader.read_to_string(&mut buf).await?; + Ok(buf) + }); + + self.tokio_handle.block_on(task).unwrap() + } + Node::Symlink(_symlink_node) => Err(io::Error::new( + io::ErrorKind::Unsupported, + "read_to_string for symlinks is unsupported", + ))?, + } + } else { + // As tvix-store doesn't manage /nix/store on the filesystem, + // we still need to also ask self.std_io here. + self.std_io.read_to_string(path) + } + } else { + // The store path is no store path, so do regular StdIO. + self.std_io.read_to_string(path) + } + } + + #[instrument(skip(self), ret, err)] + fn read_dir(&self, path: &Path) -> Result<Vec<(bytes::Bytes, FileType)>, io::Error> { + if let Ok((store_path, sub_path)) = + StorePath::from_absolute_path_full(&path.to_string_lossy()) + { + if let Some(node) = self.store_path_to_root_node(&store_path, &sub_path)? { + match node { + Node::Directory(directory_node) => { + // fetch the Directory itself. + let digest: B3Digest = + directory_node.digest.clone().try_into().map_err(|_e| { + io::Error::new( + io::ErrorKind::InvalidData, + format!( + "invalid digest length in directory node: {:?}", + directory_node + ), + ) + })?; + + let directory_service = self.directory_service.clone(); + let digest_clone = digest.clone(); + let task = self + .tokio_handle + .spawn(async move { directory_service.get(&digest_clone).await }); + if let Some(directory) = self.tokio_handle.block_on(task).unwrap()? { + let mut children: Vec<(bytes::Bytes, FileType)> = Vec::new(); + for node in directory.nodes() { + children.push(match node { + Node::Directory(e) => (e.name, FileType::Directory), + Node::File(e) => (e.name, FileType::Regular), + Node::Symlink(e) => (e.name, FileType::Symlink), + }) + } + Ok(children) + } else { + // If we didn't get the directory node that's linked, that's a store inconsistency! + error!( + directory.digest = %digest, + path = ?path, + "directory not found", + ); + Err(io::Error::new( + io::ErrorKind::NotFound, + format!("directory {digest} does not exist"), + ))? + } + } + Node::File(_file_node) => { + // This would normally be a io::ErrorKind::NotADirectory (still unstable) + Err(io::Error::new( + io::ErrorKind::Unsupported, + "tried to readdir path {:?}, which is a file", + ))? + } + Node::Symlink(_symlink_node) => Err(io::Error::new( + io::ErrorKind::Unsupported, + "read_dir for symlinks is unsupported", + ))?, + } + } else { + self.std_io.read_dir(path) + } + } else { + self.std_io.read_dir(path) + } + } + + #[instrument(skip(self), ret, err)] + fn import_path(&self, path: &std::path::Path) -> Result<PathBuf, std::io::Error> { + let p = path.to_owned(); + let blob_service = self.blob_service.clone(); + let directory_service = self.directory_service.clone(); + let path_info_service = self.path_info_service.clone(); + + let task = self.tokio_handle.spawn(async move { + import_path_with_pathinfo(blob_service, directory_service, path_info_service, &p).await + }); + + let path_info = self.tokio_handle.block_on(task).unwrap()?; + + // from the [PathInfo], extract the store path (as string). + Ok({ + let mut path = PathBuf::from(nix_compat::store_path::STORE_DIR_WITH_SLASH); + + let root_node_name = path_info.node.unwrap().node.unwrap().get_name().to_vec(); + + // This must be a string, otherwise it would have failed validation. + let root_node_name = String::from_utf8(root_node_name).unwrap(); + + // append to the PathBuf + path.push(root_node_name); + + // and return it + path + }) + } + + #[instrument(skip(self), ret)] + fn store_dir(&self) -> Option<String> { + Some("/nix/store".to_string()) + } +} + +/// Imports a given path on the filesystem into the store, and returns the +/// [PathInfo] describing the path, that was sent to +/// [PathInfoService]. +#[instrument(skip(blob_service, directory_service, path_info_service), ret, err)] +async fn import_path_with_pathinfo( + blob_service: Arc<dyn BlobService>, + directory_service: Arc<dyn DirectoryService>, + path_info_service: Arc<dyn PathInfoService>, + path: &std::path::Path, +) -> Result<PathInfo, io::Error> { + // Call [import::ingest_path], which will walk over the given path and return a root_node. + let root_node = import::ingest_path(blob_service.clone(), directory_service.clone(), path) + .await + .expect("error during import_path"); + + // Render the NAR. + let (nar_size, nar_sha256) = + calculate_size_and_sha256(&root_node, blob_service.clone(), directory_service.clone()) + .await + .expect("error during nar calculation"); // TODO: handle error + + // TODO: make a path_to_name helper function? + let name = path + .file_name() + .expect("path must not be ..") + .to_str() + .expect("path must be valid unicode"); + + let output_path = store_path::build_nar_based_store_path(&nar_sha256, name); + + // assemble a new root_node with a name that is derived from the nar hash. + let root_node = root_node.rename(output_path.to_string().into_bytes().into()); + + // assemble the [PathInfo] object. + let path_info = PathInfo { + node: Some(tvix_castore::proto::Node { + node: Some(root_node), + }), + // There's no reference scanning on path contents ingested like this. + references: vec![], + narinfo: Some(NarInfo { + nar_size, + nar_sha256: nar_sha256.to_vec().into(), + signatures: vec![], + reference_names: vec![], + deriver: None, + ca: Some(tvix_store::proto::nar_info::Ca { + r#type: tvix_store::proto::nar_info::ca::Hash::NarSha256.into(), + digest: nar_sha256.to_vec().into(), + }), + }), + }; + + // put into [PathInfoService], and return the [PathInfo] that we get + // back from there (it might contain additional signatures). + let path_info = path_info_service.put(path_info).await?; + + Ok(path_info) +} |