Trait Storage 

pub trait Storage: Send + Sync {
    // Required methods
    fn store(
        &self,
        key: &str,
        data: &[u8],
    ) -> impl Future<Output = Result<(), PlatformError>> + Send;
    fn retrieve(
        &self,
        key: &str,
    ) -> impl Future<Output = Result<Option<Vec<u8>>, PlatformError>> + Send;
    fn delete(
        &self,
        key: &str,
    ) -> impl Future<Output = Result<(), PlatformError>> + Send;
    fn list_keys(
        &self,
        prefix: &str,
    ) -> impl Future<Output = Result<Vec<String>, PlatformError>> + Send;
    fn delete_prefix(
        &self,
        prefix: &str,
    ) -> impl Future<Output = Result<u64, PlatformError>> + Send;
    fn exists(
        &self,
        key: &str,
    ) -> impl Future<Output = Result<bool, PlatformError>> + Send;
}

Persistent key-value byte storage trait.

Abstracts platform-specific secure storage (Keychain, encrypted SQLite, browser IndexedDB). Keys are UTF-8 strings; values are opaque byte slices. The testing implementation stores data in an in-memory HashMap. See ADR-006.

Required Methods

fn store( &self, key: &str, data: &[u8], ) -> impl Future<Output = Result<(), PlatformError>> + Send

Store a byte slice under the given key.

Overwrites any existing value for the same key.

Errors

Returns PlatformError::StorageError if the write fails.

fn retrieve( &self, key: &str, ) -> impl Future<Output = Result<Option<Vec<u8>>, PlatformError>> + Send

Retrieve the byte slice stored under the given key.

Returns None if the key does not exist.

Errors

Returns PlatformError::StorageError if the read fails.

fn delete( &self, key: &str, ) -> impl Future<Output = Result<(), PlatformError>> + Send

Delete the value stored under the given key.

No-op if the key does not exist.

Errors

Returns PlatformError::StorageError if the delete fails.

fn list_keys( &self, prefix: &str, ) -> impl Future<Output = Result<Vec<String>, PlatformError>> + Send

List all keys matching the given prefix in lexicographic order.

Useful for KeyPackage buffer management and event log range queries.

Errors

Returns PlatformError::StorageError if the operation fails.

fn delete_prefix( &self, prefix: &str, ) -> impl Future<Output = Result<u64, PlatformError>> + Send

Delete all keys matching the given prefix.

Returns the number of keys deleted. Used for context cleanup. See ADR-006 acceptance criterion 4 (InMemoryStorage).

Errors

Returns PlatformError::StorageError if the operation fails.

fn exists( &self, key: &str, ) -> impl Future<Output = Result<bool, PlatformError>> + Send

Check whether a key exists without reading its value.

Used for UCAN nonce replay prevention. See ADR-006 acceptance criterion 4 (InMemoryStorage).

Errors

Returns PlatformError::StorageError if the operation fails.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementations on Foreign Types

impl<T: Storage> Storage for Arc<T>

Blanket implementation of Storage for Arc<T> where T: Storage.

Enables sharing a single storage backend across multiple owners (e.g., ProtocolStore, identity layer, and FFI bridge) via Arc. Delegates all operations to the inner T via Deref.

This is essential for ProtocolStore<Arc<S>> to work when the storage backend is shared via Arc (e.g., the FFI bridge’s global STORAGE_PROVIDER). See issue #329.

fn store( &self, key: &str, data: &[u8], ) -> impl Future<Output = Result<(), PlatformError>> + Send

fn retrieve( &self, key: &str, ) -> impl Future<Output = Result<Option<Vec<u8>>, PlatformError>> + Send

fn delete( &self, key: &str, ) -> impl Future<Output = Result<(), PlatformError>> + Send

fn list_keys( &self, prefix: &str, ) -> impl Future<Output = Result<Vec<String>, PlatformError>> + Send

fn delete_prefix( &self, prefix: &str, ) -> impl Future<Output = Result<u64, PlatformError>> + Send

fn exists( &self, key: &str, ) -> impl Future<Output = Result<bool, PlatformError>> + Send

Implementors