Merge pull request #96 from ethcore/shutdown_gracefully

shutdown gracefully on incompatible db open

pbtc/commands/import.rs

@@ -6,7 +6,7 @@ use util::{open_db, init_db};
 pub fn import(cfg: Config, matches: &ArgMatches) -> Result<(), String> {
 	let db = open_db(&cfg);
 	// TODO: this might be unnecessary here!
-	init_db(&cfg, &db);
+	try!(init_db(&cfg, &db));
 
 	let mut writer = create_sync_blocks_writer(db);
 

pbtc/commands/start.rs

@@ -8,7 +8,7 @@ pub fn start(cfg: config::Config) -> Result<(), String> {
 	let mut el = p2p::event_loop();
 
 	let db = open_db(&cfg);
-	init_db(&cfg, &db);
+	try!(init_db(&cfg, &db));
 
 	let p2p_cfg = p2p::Config {
 		threads: 4,

pbtc/util.rs

@@ -23,13 +23,15 @@ pub fn node_table_path() -> PathBuf {
 	node_table
 }
 
-pub fn init_db(cfg: &Config, db: &Arc<db::Store>) {
+pub fn init_db(cfg: &Config, db: &Arc<db::Store>) -> Result<(), String> {
 	// insert genesis block if db is empty
 	let genesis_block = cfg.magic.genesis_block();
 	match db.block_hash(0) {
-		Some(ref db_genesis_block_hash) if db_genesis_block_hash != &genesis_block.hash() => panic!("Trying to open database with incompatible genesis block"),
+		Some(ref db_genesis_block_hash) if db_genesis_block_hash != &genesis_block.hash() => Err("Trying to open database with incompatible genesis block".into()),
-		Some(_) => (),
+		Some(_) => Ok(()),
-		None => db.insert_block(&genesis_block)
+		None => {
-			.expect("Failed to insert genesis block to the database"),
+			db.insert_block(&genesis_block).expect("Failed to insert genesis block to the database");
+			Ok(())
+		}
 	}
 }