feat(NIP-15): Implement NIP15

NIP15 sends an EOSE notice to clients after all stored events are sent
to allow loading indicators and other use cases.

src/db.rs

@@ -575,6 +575,12 @@ pub async fn db_query(
                     })
                     .ok();
             }
+            query_tx
+                .blocking_send(QueryResult {
+                    sub_id: sub.get_id(),
+                    event: "EOSE".to_string(),
+                })
+                .ok();
             debug!(
                 "query completed ({} rows) in {:?}",
                 row_count,

src/info.rs

@@ -35,7 +35,7 @@ impl From<config::Info> for RelayInfo {
             description: i.description,
             pubkey: i.pubkey,
             contact: i.contact,
-            supported_nips: Some(vec![1, 2, 11]),
+            supported_nips: Some(vec![1, 2, 11, 15]),
             software: Some("https://git.sr.ht/~gheartsfield/nostr-rs-relay".to_owned()),
             version: CARGO_PKG_VERSION.map(|x| x.to_owned()),
         }

src/main.rs

@@ -424,11 +424,16 @@ async fn nostr_server(
             },
             Some(query_result) = query_rx.recv() => {
                 // database informed us of a query result we asked for
+                let subesc = query_result.sub_id.replace("\"", "");
+                if query_result.event == "EOSE" {
+                    let send_str = format!("[\"EOSE\",\"{}\"]", subesc);
+                    ws_stream.send(Message::Text(send_str)).await.ok();
+                } else {
                     client_received_event_count += 1;
                     // send a result
-                let subesc = query_result.sub_id.replace("\"", "");
                     let send_str = format!("[\"EVENT\",\"{}\",{}]", subesc, &query_result.event);
                     ws_stream.send(Message::Text(send_str)).await.ok();
+                }
             },
             // TODO: consider logging the LaggedRecv error
             Ok(global_event) = bcast_rx.recv() => {