Add nostr-sdk-db crate

Cargo.toml

@@ -5,9 +5,7 @@ members = [
     "bindings/nostr-sdk-ffi",
     "bindings/nostr-sdk-js",
     "bindings/uniffi-bindgen",
-    "crates/nostr",
-    "crates/nostr-sdk",
-    "crates/nostr-sdk-net",
+    "crates/*",
 ]
 default-members = ["crates/*"]
 resolver = "2"

crates/nostr-sdk-db/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "nostr-sdk-db"
+version = "0.1.0"
+edition = "2021"
+description = "Nostr SDK Database"
+authors = ["Yuki Kishimoto <[email protected]>"]
+homepage.workspace = true
+repository.workspace = true
+license.workspace = true
+readme = "README.md"
+rust-version.workspace = true
+keywords = ["nostr", "sdk", "db"]
+
+[dependencies]
+async-trait = "0.1"
+nostr = { version = "0.24", path = "../nostr", default-features = false, features = ["std"] }

crates/nostr-sdk-db/src/lib.rs

@@ -0,0 +1,41 @@
+// Copyright (c) 2022-2023 Yuki Kishimoto
+// Distributed under the MIT software license
+
+//! Nostr SDK Database
+
+#![warn(missing_docs)]
+#![warn(rustdoc::bare_urls)]
+
+use async_trait::async_trait;
+use nostr::{Event, EventId, Filter, Url};
+
+/// Nostr SDK Database
+#[async_trait]
+pub trait NostrDatabase {
+    /// Error
+    type Err;
+
+    /// Save [`Event`] into store
+    async fn save_event(&self, event: &Event) -> Result<(), Self::Err>;
+
+    /// Save [`EventId`] seen by relay
+    ///
+    /// Useful for NIP65 (gossip)
+    async fn save_event_id_seen_by_relay(
+        &self,
+        event_id: EventId,
+        relay_url: Url,
+    ) -> Result<(), Self::Err>;
+
+    /// Get list of relays that have seen the [`EventId`]
+    async fn event_recently_seen_on_relays(&self, event_id: EventId)
+        -> Result<Vec<Url>, Self::Err>;
+
+    /// Query store with filters
+    async fn query(&self, filters: Vec<Filter>) -> Result<Vec<Event>, Self::Err>;
+
+    /// Get event IDs by filters
+    ///
+    /// Uuseful for negentropy reconciliation
+    async fn event_ids_by_filters(&self, filters: Vec<Filter>) -> Result<Vec<EventId>, Self::Err>;
+}