sdk: add redb example

Signed-off-by: Yuki Kishimoto <yukikishimoto@protonmail.com>

crates/nostr-sdk/Cargo.toml

@@ -53,6 +53,7 @@ nostr-indexeddb = { workspace = true, optional = true }
 
 [dev-dependencies]
 nostr-connect.workspace = true
+nostr-redb.workspace = true
 tokio = { workspace = true, features = ["macros"] }
 tracing-subscriber = { workspace = true, features = ["env-filter"] }
 
@@ -88,6 +89,9 @@ required-features = ["all-nips"]
 name = "nostrdb"
 required-features = ["ndb"]
 
+[[example]]
+name = "redb"
+
 [[example]]
 name = "stream-events"
 

crates/nostr-sdk/examples/redb.rs

@@ -0,0 +1,63 @@
+// Copyright (c) 2022-2023 Yuki Kishimoto
+// Copyright (c) 2023-2024 Rust Nostr Developers
+// Distributed under the MIT software license
+
+use nostr_redb::NostrRedb;
+use nostr_sdk::prelude::*;
+
+#[tokio::main]
+async fn main() -> Result<()> {
+    tracing_subscriber::fmt::init();
+
+    let keys = Keys::parse("nsec1ufnus6pju578ste3v90xd5m2decpuzpql2295m3sknqcjzyys9ls0qlc85")?;
+
+    let database = NostrRedb::persistent("./db/nostr-redb")?;
+    let client: Client = ClientBuilder::default()
+        .signer(keys.clone())
+        .database(database)
+        .build();
+
+    client.add_relay("wss://relay.damus.io").await?;
+    client.add_relay("wss://nostr.wine").await?;
+    client.add_relay("wss://nostr.oxtr.dev").await?;
+
+    client.connect().await;
+
+    // Publish a text note
+    let builder = EventBuilder::text_note("Hello world");
+    client.send_event_builder(builder).await?;
+
+    // Negentropy sync
+    let filter = Filter::new().author(keys.public_key());
+    let (tx, mut rx) = SyncProgress::channel();
+    let opts = SyncOptions::default().progress(tx);
+
+    tokio::spawn(async move {
+        while rx.changed().await.is_ok() {
+            let progress = *rx.borrow_and_update();
+            if progress.total > 0 {
+                println!("{:.2}%", progress.percentage() * 100.0);
+            }
+        }
+    });
+    let output = client.sync(filter, &opts).await?;
+
+    println!("Local: {}", output.local.len());
+    println!("Remote: {}", output.remote.len());
+    println!("Sent: {}", output.sent.len());
+    println!("Received: {}", output.received.len());
+    println!("Failures:");
+    for (url, map) in output.send_failures.iter() {
+        println!("* '{url}':");
+        for (id, e) in map.iter() {
+            println!("  - {id}: {e}");
+        }
+    }
+
+    // Query events from database
+    let filter = Filter::new().author(keys.public_key()).limit(10);
+    let events = client.database().query(vec![filter]).await?;
+    println!("Events: {events:?}");
+
+    Ok(())
+}