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package leveldb
import ( "bytes" "fmt"
"github.com/chrislusf/seaweedfs/weed/filer2" "github.com/chrislusf/seaweedfs/weed/glog" weed_util "github.com/chrislusf/seaweedfs/weed/util" "github.com/syndtr/goleveldb/leveldb" leveldb_util "github.com/syndtr/goleveldb/leveldb/util" )
const ( DIR_FILE_SEPARATOR = byte(0x00) )
func init() { filer2.Stores = append(filer2.Stores, &LevelDBStore{}) }
type LevelDBStore struct { db *leveldb.DB }
func (store *LevelDBStore) GetName() string { return "leveldb" }
func (store *LevelDBStore) Initialize(configuration filer2.Configuration) (err error) { dir := configuration.GetString("dir") return store.initialize(dir) }
func (store *LevelDBStore) initialize(dir string) (err error) { if err := weed_util.TestFolderWritable(dir); err != nil { return fmt.Errorf("Check Level Folder %s Writable: %s", dir, err) }
if store.db, err = leveldb.OpenFile(dir, nil); err != nil { return } return }
func (store *LevelDBStore) InsertEntry(entry *filer2.Entry) (err error) { key := genKey(entry.DirAndName())
value, err := entry.EncodeAttributesAndChunks() if err != nil { return fmt.Errorf("encoding %s %+v: %v", entry.FullPath, entry.Attr, err) }
err = store.db.Put(key, value, nil)
if err != nil { return fmt.Errorf("persisting %s : %v", entry.FullPath, err) }
// println("saved", entry.FullPath, "chunks", len(entry.Chunks))
return nil }
func (store *LevelDBStore) UpdateEntry(entry *filer2.Entry) (err error) {
return store.InsertEntry(entry) }
func (store *LevelDBStore) FindEntry(fullpath filer2.FullPath) (entry *filer2.Entry, err error) { key := genKey(fullpath.DirAndName())
data, err := store.db.Get(key, nil)
if err == leveldb.ErrNotFound { return nil, filer2.ErrNotFound } if err != nil { return nil, fmt.Errorf("get %s : %v", entry.FullPath, err) }
entry = &filer2.Entry{ FullPath: fullpath, } err = entry.DecodeAttributesAndChunks(data) if err != nil { return entry, fmt.Errorf("decode %s : %v", entry.FullPath, err) }
// println("read", entry.FullPath, "chunks", len(entry.Chunks), "data", len(data), string(data))
return entry, nil }
func (store *LevelDBStore) DeleteEntry(fullpath filer2.FullPath) (err error) { key := genKey(fullpath.DirAndName())
err = store.db.Delete(key, nil) if err != nil { return fmt.Errorf("delete %s : %v", fullpath, err) }
return nil }
func (store *LevelDBStore) ListDirectoryEntries(fullpath filer2.FullPath, startFileName string, inclusive bool, limit int) (entries []*filer2.Entry, err error) {
directoryPrefix := genDirectoryKeyPrefix(fullpath, "")
iter := store.db.NewIterator(&leveldb_util.Range{Start: genDirectoryKeyPrefix(fullpath, startFileName)}, nil) for iter.Next() { key := iter.Key() if !bytes.HasPrefix(key, directoryPrefix) { break } fileName := getNameFromKey(key) if fileName == "" { continue } if fileName == startFileName && !inclusive { continue } limit-- if limit < 0 { break } entry := &filer2.Entry{ FullPath: filer2.NewFullPath(string(fullpath), fileName), } if decodeErr := entry.DecodeAttributesAndChunks(iter.Value()); decodeErr != nil { err = decodeErr glog.V(0).Infof("list %s : %v", entry.FullPath, err) break } entries = append(entries, entry) } iter.Release()
return entries, err }
func genKey(dirPath, fileName string) (key []byte) { key = []byte(dirPath) key = append(key, DIR_FILE_SEPARATOR) key = append(key, []byte(fileName)...) return key }
func genDirectoryKeyPrefix(fullpath filer2.FullPath, startFileName string) (keyPrefix []byte) { keyPrefix = []byte(string(fullpath)) keyPrefix = append(keyPrefix, DIR_FILE_SEPARATOR) if len(startFileName) > 0 { keyPrefix = append(keyPrefix, []byte(startFileName)...) } return keyPrefix }
func getNameFromKey(key []byte) string {
sepIndex := len(key) - 1 for sepIndex >= 0 && key[sepIndex] != DIR_FILE_SEPARATOR { sepIndex-- }
return string(key[sepIndex+1:])
}
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