refactoring ensureIndex in sql pump

pumps/sql.go

@@ -375,51 +375,56 @@ func (c *SQLPump) buildIndexName(indexBaseName, tableName string) string {
 	return fmt.Sprintf("%s_%s", tableName, indexBaseName)
 }
 
+func (c *SQLPump) createIndex(indexBaseName, tableName, column string, wg *sync.WaitGroup) error {
+	if wg != nil {
+		defer wg.Done()
+	}
+	indexName := c.buildIndexName(indexBaseName, tableName)
+	option := ""
+	if c.dbType == "postgres" {
+		option = "CONCURRENTLY"
+	}
+
+	columnExist := c.db.Migrator().HasColumn(&analytics.AnalyticsRecord{}, column)
+	if !columnExist {
+		return errors.New("cannot create index for non existent column " + column)
+	}
+
+	sql := fmt.Sprintf("CREATE INDEX %s IF NOT EXISTS %s ON %s (%s)", option, indexName, tableName, column)
+	err := c.db.Exec(sql).Error
+	if err != nil {
+		c.log.Errorf("error creating index %s for table %s : %s", indexName, tableName, err.Error())
+		return err
+	}
+
+	c.log.Infof("Index %s created for table %s", indexName, tableName)
+	return nil
+}
+
 // ensureIndex check that all indexes for the analytics SQL table are in place
 func (c *SQLPump) ensureIndex(tableName string, background bool) error {
 	if !c.db.Migrator().HasTable(tableName) {
 		return errors.New("cannot create indexes as table doesn't exist: " + tableName)
 	}
 
 	// waitgroup to facilitate testing and track when all indexes are created
-	var wg sync.WaitGroup
-	wg.Add(len(indexes))
-	createIndexFn := func(indexBaseName, column string) error {
-		defer wg.Done()
-		indexName := c.buildIndexName(indexBaseName, tableName)
-		option := ""
-		if c.dbType == "postgres" {
-			option = "CONCURRENTLY"
-		}
-
-		columnExist := c.db.Migrator().HasColumn(&analytics.AnalyticsRecord{}, column)
-		if !columnExist {
-			return errors.New("cannot create index for non existent column " + column)
-		}
-
-		sql := fmt.Sprintf("CREATE INDEX %s IF NOT EXISTS %s ON %s (%s)", option, indexName, tableName, column)
-		err := c.db.Exec(sql).Error
-		if err != nil {
-			c.log.Errorf("error creating index %s for table %s : %s", indexName, tableName, err.Error())
-			return err
-		}
-
-		c.log.Infof("Index %s created for table %s", indexName, tableName)
-		return nil
+	var wg *sync.WaitGroup
+	if background {
+		wg = &sync.WaitGroup{}
+		wg.Add(len(indexes))
 	}
 
 	for _, idx := range indexes {
 		indexName := tableName + idx.baseName
-
 		if !c.db.Migrator().HasIndex(tableName, indexName) {
 			if background {
 				go func(baseName, cols string) {
-					if err := createIndexFn(baseName, cols); err != nil {
+					if err := c.createIndex(baseName, tableName, cols, wg); err != nil {
 						c.log.Error(err)
 					}
 				}(idx.baseName, idx.column)
 			} else {
-				if err := createIndexFn(idx.baseName, idx.column); err != nil {
+				if err := c.createIndex(idx.baseName, tableName, idx.column, wg); err != nil {
 					return err
 				}
 			}