database: add MultiStorageDatabase

CHANGELOG.md

@@ -69,6 +69,7 @@
 * database: add `Events::first_owned` and `Events::last_owned` ([Yuki Kishimoto])
 * database: impl `FlatBufferDecodeBorrowed` for `EventBorrow` ([Yuki Kishimoto])
 * database: add `NostrDatabaseWipe` trait ([Yuki Kishimoto])
+* database: add `MultiStorageDatabase` ([Yuki Kishimoto])
 * pool: add `Relay::try_connect` ([Yuki Kishimoto])
 * pool: add `Relay::wait_for_connection` ([Yuki Kishimoto])
 * pool: add `RelayPool::try_connect` ([Yuki Kishimoto])

crates/nostr-database/src/events/mod.rs

@@ -11,6 +11,7 @@ use nostr::prelude::*;
 
 pub mod helper;
 
+use crate::wipe::NostrDatabaseWipe;
 use crate::{DatabaseError, Events, Profile};
 
 /// Database event status
@@ -94,7 +95,7 @@ where
 /// Store for the nostr events.
 #[cfg_attr(target_arch = "wasm32", async_trait(?Send))]
 #[cfg_attr(not(target_arch = "wasm32"), async_trait)]
-pub trait NostrEventsDatabase: fmt::Debug + Send + Sync {
+pub trait NostrEventsDatabase: NostrDatabaseWipe + fmt::Debug + Send + Sync {
     /// Save [`Event`] into store
     ///
     /// **This method assumes that [`Event`] was already verified**

crates/nostr-database/src/lib.rs

@@ -20,6 +20,7 @@ mod events;
 #[cfg(feature = "flatbuf")]
 pub mod flatbuffers;
 pub mod memory;
+pub mod multi;
 pub mod prelude;
 pub mod profile;
 mod wipe;
@@ -50,6 +51,8 @@ pub enum Backend {
     SQLite,
     /// IndexedDB
     IndexedDB,
+    /// Multiple backends
+    MultiBackend,
     /// Custom
     Custom(String),
 }

crates/nostr-database/src/multi.rs

@@ -0,0 +1,106 @@
+// Copyright (c) 2022-2023 Yuki Kishimoto
+// Copyright (c) 2023-2024 Rust Nostr Developers
+// Distributed under the MIT software license
+
+//! Multi-storage
+
+use std::collections::HashSet;
+use std::sync::Arc;
+
+use async_trait::async_trait;
+use nostr::nips::nip01::Coordinate;
+use nostr::{Event, EventId, Filter, RelayUrl, Timestamp};
+
+use crate::events::NostrEventsDatabase;
+use crate::{
+    Backend, DatabaseError, DatabaseEventStatus, Events, NostrDatabase, NostrDatabaseWipe,
+    SaveEventStatus,
+};
+
+/// Multi-storage database
+///
+/// This struct allows using different types of backends.
+// TODO: should be this the `NostrDatabase`? If yes, remove the `NostrDatabase` trait
+#[derive(Debug, Clone)]
+pub struct MultiStorageDatabase {
+    /// Events storage
+    pub events: Arc<dyn NostrEventsDatabase>,
+    // TODO: add future traits here
+}
+
+#[cfg_attr(target_arch = "wasm32", async_trait(?Send))]
+#[cfg_attr(not(target_arch = "wasm32"), async_trait)]
+impl NostrDatabase for MultiStorageDatabase {
+    fn backend(&self) -> Backend {
+        Backend::MultiBackend
+    }
+}
+
+#[cfg_attr(target_arch = "wasm32", async_trait(?Send))]
+#[cfg_attr(not(target_arch = "wasm32"), async_trait)]
+impl NostrEventsDatabase for MultiStorageDatabase {
+    async fn save_event(&self, event: &Event) -> Result<SaveEventStatus, DatabaseError> {
+        self.events.save_event(event).await
+    }
+
+    async fn check_id(&self, event_id: &EventId) -> Result<DatabaseEventStatus, DatabaseError> {
+        self.events.check_id(event_id).await
+    }
+
+    async fn has_coordinate_been_deleted(
+        &self,
+        coordinate: &Coordinate,
+        timestamp: &Timestamp,
+    ) -> Result<bool, DatabaseError> {
+        self.events
+            .has_coordinate_been_deleted(coordinate, timestamp)
+            .await
+    }
+
+    async fn event_id_seen(
+        &self,
+        event_id: EventId,
+        relay_url: RelayUrl,
+    ) -> Result<(), DatabaseError> {
+        self.events.event_id_seen(event_id, relay_url).await
+    }
+
+    async fn event_seen_on_relays(
+        &self,
+        event_id: &EventId,
+    ) -> Result<Option<HashSet<RelayUrl>>, DatabaseError> {
+        self.events.event_seen_on_relays(event_id).await
+    }
+
+    async fn event_by_id(&self, id: &EventId) -> Result<Option<Event>, DatabaseError> {
+        self.events.event_by_id(id).await
+    }
+
+    async fn count(&self, filters: Vec<Filter>) -> Result<usize, DatabaseError> {
+        self.events.count(filters).await
+    }
+
+    async fn query(&self, filters: Vec<Filter>) -> Result<Events, DatabaseError> {
+        self.events.query(filters).await
+    }
+
+    async fn negentropy_items(
+        &self,
+        filter: Filter,
+    ) -> Result<Vec<(EventId, Timestamp)>, DatabaseError> {
+        self.events.negentropy_items(filter).await
+    }
+
+    async fn delete(&self, filter: Filter) -> Result<(), DatabaseError> {
+        self.events.delete(filter).await
+    }
+}
+
+#[cfg_attr(target_arch = "wasm32", async_trait(?Send))]
+#[cfg_attr(not(target_arch = "wasm32"), async_trait)]
+impl NostrDatabaseWipe for MultiStorageDatabase {
+    async fn wipe(&self) -> Result<(), DatabaseError> {
+        self.events.wipe().await?;
+        Ok(())
+    }
+}

crates/nostr-database/src/prelude.rs

@@ -13,4 +13,5 @@ pub use nostr::prelude::*;
 
 // Internal modules
 pub use crate::memory::{self, *};
+pub use crate::multi::{self, *};
 pub use crate::*;