add .Close() method to interface and all implementations.

elasticsearch/elasticsearch.go

@@ -55,6 +55,8 @@ type ElasticsearchStorage struct {
 	bi esutil.BulkIndexer
 }
 
+func (ess *ElasticsearchStorage) Close() {}
+
 func (ess *ElasticsearchStorage) Init() error {
 	if ess.IndexName == "" {
 		ess.IndexName = "events"

mysql/mysql.go

@@ -13,3 +13,7 @@ type MySQLBackend struct {
 	QueryKindsLimit   int
 	QueryTagsLimit    int
 }
+
+func (b *MySQLBackend) Close() {
+	b.DB.Close()
+}

postgresql/postgresql.go

@@ -13,3 +13,7 @@ type PostgresBackend struct {
 	QueryKindsLimit   int
 	QueryTagsLimit    int
 }
+
+func (b *PostgresBackend) Close() {
+	b.DB.Close()
+}

sqlite3/sqlite3.go

@@ -10,3 +10,7 @@ type SQLite3Backend struct {
 	MaxOpenConns int
 	MaxIdleConns int
 }
+
+func (b *SQLite3Backend) Close() {
+	b.DB.Close()
+}

store.go

@@ -12,6 +12,9 @@ type Store interface {
 	// allowing a storage to initialize its internal resources.
 	Init() error
 
+	// Close must be called after you're done using the store, to free up resources and so on.
+	Close()
+
 	// QueryEvents is invoked upon a client's REQ as described in NIP-01.
 	// it should return a channel with the events as they're recovered from a database.
 	// the channel should be closed after the events are all delivered.