1 files changed, 54 insertions, 0 deletions
diff --git a/tvix/store/src/directoryservice/mod.rs b/tvix/store/src/directoryservice/mod.rs
new file mode 100644
index 000000000000..f387d28948f0
--- /dev/null
+++ b/tvix/store/src/directoryservice/mod.rs
@@ -0,0 +1,54 @@
+use crate::{proto, B3Digest, Error};
+mod grpc;
+mod memory;
+mod sled;
+mod traverse;
+mod utils;
+
+pub use self::grpc::GRPCDirectoryService;
+pub use self::memory::MemoryDirectoryService;
+pub use self::sled::SledDirectoryService;
+pub use self::traverse::traverse_to;
+pub use self::utils::DirectoryTraverser;
+
+/// The base trait all Directory services need to implement.
+/// This is a simple get and put of [crate::proto::Directory], returning their
+/// digest.
+pub trait DirectoryService {
+    type DirectoriesIterator: Iterator<Item = Result<proto::Directory, Error>> + Send;
+    type DirectoryPutter: DirectoryPutter;
+
+    /// Get looks up a single Directory message by its digest.
+    /// In case the directory is not found, Ok(None) is returned.
+    fn get(&self, digest: &B3Digest) -> Result<Option<proto::Directory>, Error>;
+    /// Get uploads a single Directory message, and returns the calculated
+    /// digest, or an error.
+    fn put(&self, directory: proto::Directory) -> Result<B3Digest, Error>;
+
+    /// Looks up a closure of [proto::Directory].
+    /// Ideally this would be a `impl Iterator<Item = Result<proto::Directory, Error>>`,
+    /// and we'd be able to add a default implementation for it here, but
+    /// we can't have that yet.
+    fn get_recursive(&self, root_directory_digest: &B3Digest) -> Self::DirectoriesIterator;
+
+    /// Allows persisting a closure of [proto::Directory], which is a graph of
+    /// connected Directory messages.
+    fn put_multiple_start(&self) -> Self::DirectoryPutter;
+}
+
+/// Provides a handle to put a closure of connected [proto::Directory] elements.
+///
+/// The consumer can periodically call [put], starting from the leaves. Once
+/// the root is reached, [close] can be called to retrieve the root digest (or
+/// an error).
+pub trait DirectoryPutter {
+    /// Put a individual [proto::Directory] into the store.
+    /// Error semantics and behaviour is up to the specific implementation of
+    /// this trait.
+    /// Due to bursting, the returned error might refer to an object previously
+    /// sent via `put`.
+    fn put(&mut self, directory: proto::Directory) -> Result<(), Error>;
+
+    /// Close the stream, and wait for any errors.
+    fn close(&mut self) -> Result<B3Digest, Error>;
+}