seaweedfs/weed/filer2/leveldb2/leveldb2_store.go
2019-07-21 21:51:38 -07:00

209 lines
5.4 KiB
Go

package leveldb
import (
"bytes"
"context"
"crypto/md5"
"fmt"
"io"
"os"
"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"
"github.com/syndtr/goleveldb/leveldb/opt"
leveldb_util "github.com/syndtr/goleveldb/leveldb/util"
)
func init() {
filer2.Stores = append(filer2.Stores, &LevelDB2Store{})
}
type LevelDB2Store struct {
dbs []*leveldb.DB
dbCount int
}
func (store *LevelDB2Store) GetName() string {
return "leveldb2"
}
func (store *LevelDB2Store) Initialize(configuration weed_util.Configuration) (err error) {
dir := configuration.GetString("dir")
return store.initialize(dir, 8)
}
func (store *LevelDB2Store) initialize(dir string, dbCount int) (err error) {
glog.Infof("filer store leveldb2 dir: %s", dir)
if err := weed_util.TestFolderWritable(dir); err != nil {
return fmt.Errorf("Check Level Folder %s Writable: %s", dir, err)
}
opts := &opt.Options{
BlockCacheCapacity: 32 * 1024 * 1024, // default value is 8MiB
WriteBuffer: 16 * 1024 * 1024, // default value is 4MiB
CompactionTableSizeMultiplier: 4,
}
for d := 0; d < dbCount; d++ {
dbFolder := fmt.Sprintf("%s/%02d", dir, d)
os.MkdirAll(dbFolder, 0755)
db, dbErr := leveldb.OpenFile(dbFolder, opts)
if dbErr != nil {
glog.Errorf("filer store open dir %s: %v", dbFolder, dbErr)
return
}
store.dbs = append(store.dbs, db)
}
store.dbCount = dbCount
return
}
func (store *LevelDB2Store) BeginTransaction(ctx context.Context) (context.Context, error) {
return ctx, nil
}
func (store *LevelDB2Store) CommitTransaction(ctx context.Context) error {
return nil
}
func (store *LevelDB2Store) RollbackTransaction(ctx context.Context) error {
return nil
}
func (store *LevelDB2Store) InsertEntry(ctx context.Context, entry *filer2.Entry) (err error) {
dir, name := entry.DirAndName()
key, partitionId := genKey(dir, name, store.dbCount)
value, err := entry.EncodeAttributesAndChunks()
if err != nil {
return fmt.Errorf("encoding %s %+v: %v", entry.FullPath, entry.Attr, err)
}
err = store.dbs[partitionId].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 *LevelDB2Store) UpdateEntry(ctx context.Context, entry *filer2.Entry) (err error) {
return store.InsertEntry(ctx, entry)
}
func (store *LevelDB2Store) FindEntry(ctx context.Context, fullpath filer2.FullPath) (entry *filer2.Entry, err error) {
dir, name := fullpath.DirAndName()
key, partitionId := genKey(dir, name, store.dbCount)
data, err := store.dbs[partitionId].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 *LevelDB2Store) DeleteEntry(ctx context.Context, fullpath filer2.FullPath) (err error) {
dir, name := fullpath.DirAndName()
key, partitionId := genKey(dir, name, store.dbCount)
err = store.dbs[partitionId].Delete(key, nil)
if err != nil {
return fmt.Errorf("delete %s : %v", fullpath, err)
}
return nil
}
func (store *LevelDB2Store) ListDirectoryEntries(ctx context.Context, fullpath filer2.FullPath, startFileName string, inclusive bool,
limit int) (entries []*filer2.Entry, err error) {
directoryPrefix, partitionId := genDirectoryKeyPrefix(fullpath, "", store.dbCount)
lastFileStart, _ := genDirectoryKeyPrefix(fullpath, startFileName, store.dbCount)
iter := store.dbs[partitionId].NewIterator(&leveldb_util.Range{Start: lastFileStart}, 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),
}
// println("list", entry.FullPath, "chunks", len(entry.Chunks))
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, dbCount int) (key []byte, partitionId int) {
key, partitionId = hashToBytes(dirPath, dbCount)
key = append(key, []byte(fileName)...)
return key, partitionId
}
func genDirectoryKeyPrefix(fullpath filer2.FullPath, startFileName string, dbCount int) (keyPrefix []byte, partitionId int) {
keyPrefix, partitionId = hashToBytes(string(fullpath), dbCount)
if len(startFileName) > 0 {
keyPrefix = append(keyPrefix, []byte(startFileName)...)
}
return keyPrefix, partitionId
}
func getNameFromKey(key []byte) string {
return string(key[md5.Size:])
}
// hash directory, and use last byte for partitioning
func hashToBytes(dir string, dbCount int) ([]byte, int) {
h := md5.New()
io.WriteString(h, dir)
b := h.Sum(nil)
x := b[len(b)-1]
return b, int(x) % dbCount
}