1 files changed, 168 insertions, 0 deletions
diff --git a/tvix/castore/src/directoryservice/sled.rs b/tvix/castore/src/directoryservice/sled.rs
new file mode 100644
index 0000000000..e4a4c2bbed
--- /dev/null
+++ b/tvix/castore/src/directoryservice/sled.rs
@@ -0,0 +1,168 @@
+use crate::proto::Directory;
+use crate::{proto, B3Digest, Error};
+use futures::stream::BoxStream;
+use prost::Message;
+use std::ops::Deref;
+use std::path::Path;
+use tonic::async_trait;
+use tracing::{instrument, warn};
+
+use super::utils::traverse_directory;
+use super::{ClosureValidator, DirectoryPutter, DirectoryService};
+
+#[derive(Clone)]
+pub struct SledDirectoryService {
+    db: sled::Db,
+}
+
+impl SledDirectoryService {
+    pub fn new<P: AsRef<Path>>(p: P) -> Result<Self, sled::Error> {
+        let config = sled::Config::default()
+            .use_compression(false) // is a required parameter
+            .path(p);
+        let db = config.open()?;
+
+        Ok(Self { db })
+    }
+
+    pub fn new_temporary() -> Result<Self, sled::Error> {
+        let config = sled::Config::default().temporary(true);
+        let db = config.open()?;
+
+        Ok(Self { db })
+    }
+}
+
+#[async_trait]
+impl DirectoryService for SledDirectoryService {
+    #[instrument(skip(self, digest), fields(directory.digest = %digest))]
+    async fn get(&self, digest: &B3Digest) -> Result<Option<proto::Directory>, Error> {
+        match self.db.get(digest.as_slice()) {
+            // The directory was not found, return
+            Ok(None) => Ok(None),
+
+            // The directory was found, try to parse the data as Directory message
+            Ok(Some(data)) => match Directory::decode(&*data) {
+                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 {
+                        return Err(Error::StorageError(format!(
+                            "requested directory with digest {}, but got {}",
+                            digest, actual_digest
+                        )));
+                    }
+
+                    // Validate the Directory itself is valid.
+                    if let Err(e) = directory.validate() {
+                        warn!("directory failed validation: {}", e.to_string());
+                        return Err(Error::StorageError(format!(
+                            "directory {} failed validation: {}",
+                            actual_digest, e,
+                        )));
+                    }
+
+                    Ok(Some(directory))
+                }
+                Err(e) => {
+                    warn!("unable to parse directory {}: {}", digest, e);
+                    Err(Error::StorageError(e.to_string()))
+                }
+            },
+            // some storage error?
+            Err(e) => Err(Error::StorageError(e.to_string())),
+        }
+    }
+
+    #[instrument(skip(self, directory), fields(directory.digest = %directory.digest()))]
+    async fn put(&self, directory: proto::Directory) -> Result<B3Digest, Error> {
+        let digest = directory.digest();
+
+        // validate the directory itself.
+        if let Err(e) = directory.validate() {
+            return Err(Error::InvalidRequest(format!(
+                "directory {} failed validation: {}",
+                digest, e,
+            )));
+        }
+        // store it
+        let result = self.db.insert(digest.as_slice(), directory.encode_to_vec());
+        if let Err(e) = result {
+            return Err(Error::StorageError(e.to_string()));
+        }
+        Ok(digest)
+    }
+
+    #[instrument(skip_all, fields(directory.digest = %root_directory_digest))]
+    fn get_recursive(
+        &self,
+        root_directory_digest: &B3Digest,
+    ) -> BoxStream<Result<proto::Directory, Error>> {
+        traverse_directory(self.clone(), root_directory_digest)
+    }
+
+    #[instrument(skip_all)]
+    fn put_multiple_start(&self) -> Box<(dyn DirectoryPutter + 'static)>
+    where
+        Self: Clone,
+    {
+        Box::new(SledDirectoryPutter {
+            tree: self.db.deref().clone(),
+            directory_validator: Some(Default::default()),
+        })
+    }
+}
+
+/// Buffers Directory messages to be uploaded and inserts them in a batch
+/// transaction on close.
+pub struct SledDirectoryPutter {
+    tree: sled::Tree,
+
+    /// The directories (inside the directory validator) that we insert later,
+    /// or None, if they were already inserted.
+    directory_validator: Option<ClosureValidator>,
+}
+
+#[async_trait]
+impl DirectoryPutter for SledDirectoryPutter {
+    #[instrument(level = "trace", skip_all, fields(directory.digest=%directory.digest()), err)]
+    async fn put(&mut self, directory: proto::Directory) -> Result<(), Error> {
+        match self.directory_validator {
+            None => return Err(Error::StorageError("already closed".to_string())),
+            Some(ref mut validator) => {
+                validator.add(directory)?;
+            }
+        }
+
+        Ok(())
+    }
+
+    #[instrument(level = "trace", skip_all, ret, err)]
+    async fn close(&mut self) -> Result<B3Digest, Error> {
+        match self.directory_validator.take() {
+            None => Err(Error::InvalidRequest("already closed".to_string())),
+            Some(validator) => {
+                // retrieve the validated directories.
+                let directories = validator.finalize()?;
+
+                // Get the root digest, which is at the end (cf. insertion order)
+                let root_digest = directories
+                    .last()
+                    .ok_or_else(|| Error::InvalidRequest("got no directories".to_string()))?
+                    .digest();
+
+                let mut batch = sled::Batch::default();
+                for directory in directories {
+                    batch.insert(directory.digest().as_slice(), directory.encode_to_vec());
+                }
+
+                self.tree
+                    .apply_batch(batch)
+                    .map_err(|e| Error::StorageError(format!("unable to apply batch: {}", e)))?;
+
+                Ok(root_digest)
+            }
+        }
+    }
+}