// Index returns a list of items that match on the index function // Index is thread-safe so long as you treat all items as immutable func (c *threadSafeMap) Index(indexName string, obj interface{}) ([]interface{}, error) { c.lock.RLock() defer c.lock.RUnlock() indexFunc := c.indexers[indexName] if indexFunc == nil { return nil, fmt.Errorf("Index with name %s does not exist", indexName) } indexKeys, err := indexFunc(obj) if err != nil { return nil, err } index := c.indices[indexName] // need to de-dupe the return list. Since multiple keys are allowed, this can happen. returnKeySet := sets.String{} for _, indexKey := range indexKeys { set := index[indexKey] for _, key := range set.List() { returnKeySet.Insert(key) } } list := make([]interface{}, 0, returnKeySet.Len()) for absoluteKey := range returnKeySet { list = append(list, c.items[absoluteKey]) } return list, nil }