frostfs-node/pkg/local_object_storage/writecache/storage.go
Evgenii Stratonikov 59de521fd1 [] blobstor: implement write-cache
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
2021-04-29 17:36:36 +03:00

130 lines
2.7 KiB
Go

package writecache
import (
"errors"
"os"
"path"
lru "github.com/hashicorp/golang-lru"
"github.com/hashicorp/golang-lru/simplelru"
objectSDK "github.com/nspcc-dev/neofs-api-go/pkg/object"
"github.com/nspcc-dev/neofs-node/pkg/local_object_storage/blobstor/fstree"
"go.etcd.io/bbolt"
"go.uber.org/zap"
)
// store represents persistent storage with in-memory LRU cache
// for flushed items on top of it.
type store struct {
flushed simplelru.LRUCache
db *bbolt.DB
}
const lruKeysCount = 256 * 1024 * 8
const dbName = "small.bolt"
func (c *cache) openStore() error {
if err := os.MkdirAll(c.path, os.ModePerm); err != nil {
return err
}
db, err := bbolt.Open(path.Join(c.path, dbName), os.ModePerm, &bbolt.Options{
NoFreelistSync: true,
NoSync: true,
})
if err != nil {
return err
}
c.fsTree = &fstree.FSTree{
Info: fstree.Info{
Permissions: os.ModePerm,
RootPath: c.path,
},
Depth: 1,
DirNameLen: 1,
}
_ = db.Update(func(tx *bbolt.Tx) error {
_, err := tx.CreateBucketIfNotExists(defaultBucket)
return err
})
c.db = db
c.flushed, _ = lru.New(lruKeysCount)
return nil
}
func (s *store) removeFlushedKeys(n int) ([][]byte, [][]byte) {
var keysMem, keysDisk [][]byte
for i := 0; i < n; i++ {
k, v, ok := s.flushed.RemoveOldest()
if !ok {
break
}
if v.(bool) {
keysMem = append(keysMem, []byte(k.(string)))
} else {
keysDisk = append(keysDisk, []byte(k.(string)))
}
}
return keysMem, keysDisk
}
func (c *cache) evictObjects(putCount int) {
sum := c.flushed.Len() + putCount
if sum <= lruKeysCount {
return
}
keysMem, keysDisk := c.store.removeFlushedKeys(sum - lruKeysCount)
if err := c.deleteFromDB(keysMem); err != nil {
c.log.Error("error while removing objects from write-cache (database)", zap.Error(err))
}
if err := c.deleteFromDisk(keysDisk); err != nil {
c.log.Error("error while removing objects from write-cache (disk)", zap.Error(err))
}
}
func (c *cache) deleteFromDB(keys [][]byte) error {
if len(keys) == 0 {
return nil
}
return c.db.Update(func(tx *bbolt.Tx) error {
b := tx.Bucket(defaultBucket)
for i := range keys {
if err := b.Delete(keys[i]); err != nil {
return err
}
}
return nil
})
}
func (c *cache) deleteFromDisk(keys [][]byte) error {
var lastErr error
for i := range keys {
addr := objectSDK.NewAddress()
addrStr := string(keys[i])
if err := addr.Parse(addrStr); err != nil {
c.log.Error("can't parse address", zap.String("address", addrStr))
continue
}
if err := c.fsTree.Delete(addr); err != nil && !errors.Is(err, fstree.ErrFileNotFound) {
lastErr = err
c.log.Error("can't remove object from write-cache", zap.Error(err))
continue
}
}
return lastErr
}