// 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
}
