auto peer discovery: gossip known peers during sync, discover from_hash automatically

tinyweb_forum/db.py

@@ -246,6 +246,28 @@ class ForumDB:
         finally:
             self.return_db(db)
 
+    def add_known_peer(self, instance_hash):
+        """Add a discovered peer to the sync list (auto-discovery)."""
+        db = self.get_db()
+        try:
+            db.execute(
+                "INSERT OR IGNORE INTO synced_instances (instance_hash) VALUES (?)",
+                (instance_hash,),
+            )
+            db.commit()
+        finally:
+            self.return_db(db)
+
+    def get_all_known_hashes(self):
+        """Get all known instance hashes for peer discovery gossip."""
+        db = self.get_db()
+        try:
+            return [r["instance_hash"] for r in db.execute(
+                "SELECT instance_hash FROM synced_instances"
+            ).fetchall()]
+        finally:
+            self.return_db(db)
+
     def upsert_synced_instance(self, instance_hash, name=""):
         db = self.get_db()
         try: