package volume
import (
"github.com/syndtr/goleveldb/leveldb"
"encoding/binary"
"path/filepath"
"strconv"
)
//文件索引结构体
type LevelDBIndex struct { path string
db *leveldb.DB
}
//创建leveldb索引
func NewLevelDBIndex(dir string, vid uint64) (index *LevelDBIndex, err error) { path := filepath.Join(dir, strconv.FormatUint(vid, 10) + ".index")
index = new(LevelDBIndex)
index.path = path
index.db, err = leveldb.OpenFile(path, nil)
return index, err
}
//实现index接口
//文件是否存在 物理存在
func (l *LevelDBIndex)Has(fid uint64) bool { key := make([]byte, 8)
binary.BigEndian.PutUint64(key, fid)
_, err := l.db.Get(key, nil)
return err == nil
}
//获取文件
func (l *LevelDBIndex)Get(fid uint64) (*FileInfo, error) { key := make([]byte, 8)
binary.BigEndian.PutUint64(key, fid)
data, err := l.db.Get(key, nil)
if err != nil { return nil, err
}
fi := new(FileInfo)
return fi, fi.UnMarshalBinary(data)
}
//存储文件
func (l *LevelDBIndex)Set(fi *FileInfo) error { data := fi.MarshalBinary()
return l.db.Put(data[:8], data, nil)
}
//删除文件
func (l *LevelDBIndex)Delete(fid uint64) error { key := make([]byte, 8)
binary.BigEndian.PutUint64(key, fid)
return l.db.Delete(key, nil)
}
//关闭资源
func (l *LevelDBIndex)Close() error { return l.db.Close()
}