// Create an index on the path.
func (col *Col) Index(idxPath []string) (err error) {
col.db.schemaLock.Lock()
defer col.db.schemaLock.Unlock()
idxName := strings.Join(idxPath, INDEX_PATH_SEP)
if _, exists := col.indexPaths[idxName]; exists {
return fmt.Errorf("Path %v is already indexed", idxPath)
}
col.indexPaths[idxName] = idxPath
idxDir := path.Join(col.db.path, col.name, idxName)
if err = os.MkdirAll(idxDir, 0700); err != nil {
return err
}
for i := 0; i < col.db.numParts; i++ {
if col.hts[i][idxName], err = data.OpenHashTable(path.Join(idxDir, strconv.Itoa(i))); err != nil {
return err
}
}
// Put all documents on the new index
col.ForEachDoc(func(id int, doc []byte) (moveOn bool) {
var docObj map[string]interface{}
if err := json.Unmarshal(doc, &docObj); err != nil {
// Skip corrupted document
return true
}
for _, idxVal := range GetIn(docObj, idxPath) {
if idxVal != nil {
hashKey := StrHash(fmt.Sprint(idxVal))
col.hts[hashKey%col.db.numParts][idxName].Put(hashKey, id)
}
}
return true
})
return
}
// Load collection schema including index schema.
func (col *Col) load() error {
if err := os.MkdirAll(path.Join(col.db.path, col.name), 0700); err != nil {
return err
}
col.parts = make([]*data.Partition, col.db.numParts)
col.hts = make([]map[string]*data.HashTable, col.db.numParts)
for i := 0; i < col.db.numParts; i++ {
col.hts[i] = make(map[string]*data.HashTable)
}
col.indexPaths = make(map[string][]string)
// Open collection document partitions
for i := 0; i < col.db.numParts; i++ {
var err error
if col.parts[i], err = data.OpenPartition(
path.Join(col.db.path, col.name, DOC_DATA_FILE+strconv.Itoa(i)),
path.Join(col.db.path, col.name, DOC_LOOKUP_FILE+strconv.Itoa(i))); err != nil {
return err
}
}
// Look for index directories
colDirContent, err := ioutil.ReadDir(path.Join(col.db.path, col.name))
if err != nil {
return err
}
for _, htDir := range colDirContent {
if !htDir.IsDir() {
continue
}
// Open index partitions
idxName := htDir.Name()
idxPath := strings.Split(idxName, INDEX_PATH_SEP)
col.indexPaths[idxName] = idxPath
for i := 0; i < col.db.numParts; i++ {
if col.hts[i] == nil {
col.hts[i] = make(map[string]*data.HashTable)
}
if col.hts[i][idxName], err = data.OpenHashTable(
path.Join(col.db.path, col.name, idxName, strconv.Itoa(i))); err != nil {
return err
}
}
}
return nil
}