diff options
Diffstat (limited to 'tvix/store/src/sled_directory_service.rs')
| -rw-r--r-- | tvix/store/src/sled_directory_service.rs | 300 |
1 files changed, 0 insertions, 300 deletions
diff --git a/tvix/store/src/sled_directory_service.rs b/tvix/store/src/sled_directory_service.rs deleted file mode 100644 index 4b2c6ed54d62..000000000000 --- a/tvix/store/src/sled_directory_service.rs +++ /dev/null @@ -1,300 +0,0 @@ -use data_encoding::BASE64; -use std::collections::HashMap; -use std::collections::HashSet; -use std::collections::VecDeque; -use std::path::PathBuf; -use tokio::sync::mpsc::channel; -use tokio::sync::mpsc::Sender; - -use prost::Message; -use tokio::task; -use tokio_stream::wrappers::ReceiverStream; - -use crate::proto::directory_service_server::DirectoryService; -use crate::proto::get_directory_request::ByWhat; -use crate::proto::Directory; -use crate::proto::GetDirectoryRequest; -use crate::proto::PutDirectoryResponse; -use tonic::{Request, Response, Result, Status, Streaming}; -use tracing::{debug, instrument, warn}; - -pub struct SledDirectoryService { - db: sled::Db, -} - -impl SledDirectoryService { - pub fn new(p: PathBuf) -> Result<Self, anyhow::Error> { - let config = sled::Config::default().use_compression(true).path(p); - let db = config.open()?; - - Ok(Self { db }) - } -} - -/// Lookup a directory, optionally recurse, and send the result to the passed sender. -/// We pass in a txn, that has been opened on the outside. -/// It's up to the user to wrap this in a TransactionError appropriately. -/// This will open a sled txn to ensure a consistent view. -fn send_directories( - txn: &sled::transaction::TransactionalTree, - tx: &Sender<Result<Directory>>, - req: GetDirectoryRequest, -) -> Result<(), Status> { - // keep the list of directories to traverse - let mut deq: VecDeque<Vec<u8>> = VecDeque::new(); - - // look at the digest in the request and put it in the top of the queue. - match &req.by_what { - None => return Err(Status::invalid_argument("by_what needs to be specified")), - Some(ByWhat::Digest(digest)) => { - if digest.len() != 32 { - return Err(Status::invalid_argument("invalid digest length")); - } - deq.push_back(digest.clone()); - } - } - - // keep a list of all the Directory messages already sent, so we can omit sending the same. - let mut sent_directory_dgsts: HashSet<Vec<u8>> = HashSet::new(); - - // look up the directory at the top of the queue - while let Some(ref digest) = deq.pop_front() { - let digest_b64: String = BASE64.encode(digest); - - match txn.get(digest) { - // The directory was not found, abort - Ok(None) => { - return Err(Status::not_found(format!( - "directory {} not found", - digest_b64 - ))) - } - // The directory was found, try to parse the data as Directory message - Ok(Some(data)) => match Directory::decode(&*data) { - Err(e) => { - warn!("unable to parse directory {}: {}", digest_b64, e); - return Err(Status::internal(format!( - "unable to parse directory {}", - digest_b64 - ))); - } - Ok(directory) => { - // Validate the retrieved Directory indeed has the - // digest we expect it to have, to detect corruptions. - let actual_digest = directory.digest(); - if actual_digest != digest.clone() { - return Err(Status::data_loss(format!( - "requested directory with digest {}, but got {}", - digest_b64, - BASE64.encode(&actual_digest) - ))); - } - - // if recursion was requested, all its children need to be added to the queue. - // If a Directory message with the same digest has already - // been sent previously, we can skip enqueueing it. - // Same applies to when it already is in the queue. - if req.recursive { - for child_directory_node in &directory.directories { - if !sent_directory_dgsts.contains(&child_directory_node.digest) - && !deq.contains(&child_directory_node.digest) - { - deq.push_back(child_directory_node.digest.clone()); - } - } - } - - // send the directory message to the client - if let Err(e) = tx.blocking_send(Ok(directory)) { - debug!("error sending: {}", e); - return Err(Status::internal("error sending")); - } - - sent_directory_dgsts.insert(digest.to_vec()); - } - }, - // some storage error? - Err(e) => { - // TODO: check what this error really means - warn!("storage error: {}", e); - return Err(Status::internal("storage error")); - } - }; - } - - // nothing left, we're done - Ok(()) -} - -/// Consume directories, and insert them into the database. -/// Reject directory messages that refer to Directories not sent in the same stream. -fn insert_directories( - txn: &sled::transaction::TransactionalTree, - directories: &Vec<Directory>, -) -> Result<Vec<u8>, Status> { - // This keeps track of the seen directory keys, and their size. - // This is used to validate the size field of a reference to a previously sent directory. - // We don't need to keep the contents around, they're stored in the DB. - let mut seen_directories_sizes: HashMap<Vec<u8>, u32> = HashMap::new(); - let mut last_directory_dgst: Option<Vec<u8>> = None; - - for directory in directories { - // validate the directory itself. - if let Err(e) = directory.validate() { - return Err(Status::invalid_argument(format!( - "directory {} failed validation: {}", - BASE64.encode(&directory.digest()), - e, - ))); - } - - // for each child directory this directory refers to, we need - // to ensure it has been seen already in this stream, and that the size - // matches what we recorded. - for child_directory in &directory.directories { - match seen_directories_sizes.get(&child_directory.digest) { - None => { - return Err(Status::invalid_argument(format!( - "child directory '{}' ({}) in directory '{}' not seen yet", - child_directory.name, - BASE64.encode(&child_directory.digest), - BASE64.encode(&directory.digest()), - ))); - } - Some(seen_child_directory_size) => { - if seen_child_directory_size != &child_directory.size { - return Err(Status::invalid_argument(format!( - "child directory '{}' ({}) in directory '{}' referred with wrong size, expected {}, actual {}", - child_directory.name, - BASE64.encode(&child_directory.digest), - BASE64.encode(&directory.digest()), - seen_child_directory_size, - child_directory.size, - ))); - } - } - } - } - - // TODO: do we want to verify this somehow is connected to the current graph? - // theoretically, this currently allows uploading multiple - // disconnected graphs at the same time… - - let dgst = directory.digest(); - seen_directories_sizes.insert(dgst.clone(), directory.size()); - last_directory_dgst = Some(dgst.clone()); - - // check if the directory already exists in the database. We can skip - // inserting if it's already there, as that'd be a no-op. - match txn.get(dgst.clone()) { - Ok(None) => { - // insert the directory into the database - if let Err(e) = txn.insert(dgst, directory.encode_to_vec()) { - match e { - // TODO: conflict is a problem, as the whole transaction closure is retried? - sled::transaction::UnabortableTransactionError::Conflict => todo!(), - sled::transaction::UnabortableTransactionError::Storage(e) => { - warn!("storage error: {}", e); - return Err(Status::internal("storage error")); - } - } - } - } - Ok(Some(_)) => continue, - Err(e) => { - warn!("storage error: {}", e); - return Err(Status::internal("storage error")); - } - } - } - - // no more directories to be send. Return the digest of the - // last (root) node, or an error if we don't receive a single one. - match last_directory_dgst { - Some(last_directory_dgst) => Ok(last_directory_dgst), - None => Err(Status::invalid_argument("no directories received")), - } -} - -#[tonic::async_trait] -impl DirectoryService for SledDirectoryService { - type GetStream = ReceiverStream<Result<Directory>>; - - #[instrument(skip(self))] - async fn get( - &self, - request: Request<GetDirectoryRequest>, - ) -> Result<Response<Self::GetStream>, Status> { - let (tx, rx) = channel(5); - - let req_inner = request.into_inner(); - - // clone self.db (cheap), so we don't refer to self in the thread. - let db = self.db.clone(); - - // kick off a thread - task::spawn_blocking(move || { - // open a DB transaction. - let txn_res = db.transaction(|txn| { - send_directories(txn, &tx, req_inner.clone()) - .map_err(sled::transaction::ConflictableTransactionError::Abort) - }); - - // handle transaction errors - match txn_res { - Ok(()) => Ok(()), - Err(sled::transaction::TransactionError::Abort(status)) => { - // if the transaction was aborted, there was an error. Send it to the client - tx.blocking_send(Err(status)) - } - Err(sled::transaction::TransactionError::Storage(e)) => { - warn!("storage error: {}", e); - tx.blocking_send(Err(Status::internal("storage error"))) - } - } - }); - - // NOTE: this always returns an Ok response, with the first item in the - // stream being a potential error, instead of directly returning the - // first error. - // Peeking on the first element seems to be extraordinarily hard, - // and client code considers these two equivalent anyways. - let receiver_stream = ReceiverStream::new(rx); - Ok(Response::new(receiver_stream)) - } - - #[instrument(skip(self, request))] - async fn put( - &self, - request: Request<Streaming<Directory>>, - ) -> Result<Response<PutDirectoryResponse>> { - let mut req_inner = request.into_inner(); - - // TODO: for now, we collect all Directory messages into a Vec, and - // pass it to the helper function. - // Ideally, we would validate things as we receive it, and have a way - // to reject early - but the semantics of transactions (and its - // retries) don't allow us to discard things that early anyways. - let mut directories: Vec<Directory> = Vec::new(); - - while let Some(directory) = req_inner.message().await? { - directories.push(directory) - } - - let txn_res = self.db.transaction(|txn| { - insert_directories(txn, &directories) - .map_err(sled::transaction::ConflictableTransactionError::Abort) - }); - - match txn_res { - Ok(last_directory_dgst) => Ok(Response::new(PutDirectoryResponse { - root_digest: last_directory_dgst, - })), - Err(sled::transaction::TransactionError::Storage(e)) => { - warn!("storage error: {}", e); - Err(Status::internal("storage error")) - } - Err(sled::transaction::TransactionError::Abort(e)) => Err(e), - } - } -} |