frostfs-node/pkg/local_object_storage/engine/shards.go
Leonard Lyubich 09750484f9 [#176] localstore: Draft storage engine structure and ops
Implement the primary structure and operation of the local object
storage engine.

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
2020-12-11 17:19:37 +03:00

71 lines
1.7 KiB
Go

package engine
import (
"fmt"
"github.com/google/uuid"
"github.com/nspcc-dev/hrw"
"github.com/nspcc-dev/neofs-api-go/pkg/object"
"github.com/nspcc-dev/neofs-node/pkg/local_object_storage/shard"
"github.com/pkg/errors"
)
// AddShard adds a new shard to the storage engine.
//
// Returns any error encountered that did not allow adding a shard.
// Otherwise returns the ID of the added shard.
func (e *StorageEngine) AddShard(opts ...shard.Option) (*shard.ID, error) {
e.mtx.Lock()
defer e.mtx.Unlock()
id, err := e.generateShardID()
if err != nil {
return nil, errors.Wrap(err, "could not generate shard ID")
}
e.shards[id.String()] = shard.New(append(opts, shard.WithID(id))...)
return id, nil
}
func (e *StorageEngine) generateShardID() (*shard.ID, error) {
uid, err := uuid.NewRandom()
if err != nil {
return nil, err
}
bin, err := uid.MarshalBinary()
if err != nil {
return nil, err
}
return shard.NewIDFromBytes(bin), nil
}
func (e *StorageEngine) shardWeight(sh *shard.Shard) float64 {
weightValues := sh.WeightValues()
return float64(weightValues.FreeSpace)
}
func (e *StorageEngine) sortShardsByWeight(objAddr fmt.Stringer) []*shard.Shard {
shards := make([]*shard.Shard, 0, len(e.shards))
weights := make([]float64, 0, len(e.shards))
for _, sh := range e.shards {
shards = append(shards, sh)
weights = append(weights, e.shardWeight(sh))
}
hrw.SortSliceByWeightValue(shards, weights, hrw.Hash([]byte(objAddr.String())))
return shards
}
func (e *StorageEngine) iterateOverSortedShards(addr *object.Address, handler func(*shard.Shard) (stop bool)) {
for _, sh := range e.sortShardsByWeight(addr) {
if handler(sh) {
break
}
}
}