[#42] registry: Optimize Count() for `ObjSelector`

It is the heaviest function executing on setup stage.
The culprit is the linear dependency between its execution
time and the amount of objects in registry. The solution is to store
object by status. While the optimization doesn't work for objects with
no status, it is currently provided by all scenarios.

Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>

internal/registry/obj_info.go

@@ -18,27 +18,35 @@ type ObjectInfo struct {
 }
 
 func (o ObjectInfo) EncodeBinary(w *io.BinWriter) {
+	o.encodeFilterableFields(w)
 	w.WriteU64LE(o.Id)
-	w.WriteU64LE(uint64(o.CreatedAt))
 	w.WriteString(o.CID)
 	w.WriteString(o.OID)
 	w.WriteString(o.S3Bucket)
 	w.WriteString(o.S3Key)
-	w.WriteString(o.Status)
 	w.WriteString(o.PayloadHash)
 }
 
+func (o ObjectInfo) encodeFilterableFields(w *io.BinWriter) {
+	w.WriteU64LE(uint64(o.CreatedAt))
+	w.WriteString(o.Status)
+}
+
 func (o *ObjectInfo) DecodeBinary(r *io.BinReader) {
+	o.decodeFilterableFields(r)
 	o.Id = r.ReadU64LE()
-	o.CreatedAt = int64(r.ReadU64LE())
 	o.CID = r.ReadString()
 	o.OID = r.ReadString()
 	o.S3Bucket = r.ReadString()
 	o.S3Key = r.ReadString()
-	o.Status = r.ReadString()
 	o.PayloadHash = r.ReadString()
 }
 
+func (o *ObjectInfo) decodeFilterableFields(r *io.BinReader) {
+	o.CreatedAt = int64(r.ReadU64LE())
+	o.Status = r.ReadString()
+}
+
 func (o ObjectInfo) Marshal() ([]byte, error) {
 	w := io.NewBufBinWriter()
 	o.EncodeBinary(w.BinWriter)

internal/registry/obj_info_test.go

@@ -87,13 +87,13 @@ func TestObjectInfoEncodeBinary(t *testing.T) {
 
 func randomObjectInfo() ObjectInfo {
 	return ObjectInfo{
-		Id:          rand.Uint64(),
 		CreatedAt:   int64(rand.Uint64()),
+		Status:      statusCreated,
+		Id:          rand.Uint64(),
 		CID:         randString(32),
 		OID:         randString(32),
 		S3Bucket:    randString(32),
 		S3Key:       randString(32),
-		Status:      "created",
 		PayloadHash: randString(64),
 	}
 }

internal/registry/obj_registry.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"encoding/binary"
 	"errors"
+	"fmt"
 	"os"
 	"time"
 
@@ -21,8 +22,6 @@ const (
 	statusCreated = "created"
 )
 
-const bucketName = "_object"
-
 // NewObjRegistry creates a new instance of object registry that stores information
 // about objects in the specified bolt database. As registry uses read-write
 // connection to the database, there may be only one instance of object registry
@@ -46,7 +45,7 @@ func NewObjRegistry(ctx context.Context, dbFilePath string) *ObjRegistry {
 
 func (o *ObjRegistry) AddObject(cid, oid, s3Bucket, s3Key, payloadHash string) error {
 	return o.boltDB.Update(func(tx *bbolt.Tx) error {
-		b, err := tx.CreateBucketIfNotExists([]byte(bucketName))
+		b, err := tx.CreateBucketIfNotExists([]byte(statusCreated))
 		if err != nil {
 			return err
 		}
@@ -75,14 +74,14 @@ func (o *ObjRegistry) AddObject(cid, oid, s3Bucket, s3Key, payloadHash string) e
 	})
 }
 
-func (o *ObjRegistry) SetObjectStatus(id uint64, newStatus string) error {
+func (o *ObjRegistry) SetObjectStatus(id uint64, oldStatus, newStatus string) error {
 	return o.boltDB.Update(func(tx *bbolt.Tx) error {
-		b, err := tx.CreateBucketIfNotExists([]byte(bucketName))
-		if err != nil {
-			return err
+		oldB := tx.Bucket([]byte(oldStatus))
+		if oldB == nil {
+			return fmt.Errorf("bucket doesn't exist: '%s'", oldStatus)
 		}
 
-		objBytes := b.Get(encodeId(id))
+		objBytes := oldB.Get(encodeId(id))
 		if objBytes == nil {
 			return errors.New("object doesn't exist")
 		}
@@ -93,22 +92,24 @@ func (o *ObjRegistry) SetObjectStatus(id uint64, newStatus string) error {
 		}
 		obj.Status = newStatus
 
-		objBytes, err = obj.Marshal()
+		objBytes, err := obj.Marshal()
 		if err != nil {
 			return err
 		}
-		return b.Put(encodeId(id), objBytes)
+
+		newB, err := tx.CreateBucketIfNotExists([]byte(newStatus))
+		if err != nil {
+			return err
+		}
+		return newB.Put(encodeId(id), objBytes)
 	})
 }
 
 func (o *ObjRegistry) DeleteObject(id uint64) error {
 	return o.boltDB.Update(func(tx *bbolt.Tx) error {
-		b, err := tx.CreateBucketIfNotExists([]byte(bucketName))
-		if err != nil {
-			return err
-		}
-
-		return b.Delete(encodeId(id))
+		return tx.ForEach(func(_ []byte, b *bbolt.Bucket) error {
+			return b.Delete(encodeId(id))
+		})
 	})
 }
 

internal/registry/obj_selector.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"time"
 
+	"github.com/nspcc-dev/neo-go/pkg/io"
 	"go.etcd.io/bbolt"
 )
 
@@ -58,15 +59,23 @@ func (o *ObjSelector) NextObject() *ObjectInfo {
 func (o *ObjSelector) Count() (int, error) {
 	var count = 0
 	err := o.boltDB.View(func(tx *bbolt.Tx) error {
-		b := tx.Bucket([]byte(bucketName))
+		b := tx.Bucket([]byte(o.filter.Status))
 		if b == nil {
 			return nil
 		}
 
+		if o.filter.Age == 0 {
+			count = b.Stats().KeyN
+			return nil
+		}
+
 		return b.ForEach(func(_, objBytes []byte) error {
 			if objBytes != nil {
+				r := io.NewBinReaderFromBuf(objBytes)
+
 				var obj ObjectInfo
-				if err := obj.Unmarshal(objBytes); err != nil {
+				obj.decodeFilterableFields(r)
+				if r.Err != nil {
 					// Ignore malformed objects
 					return nil
 				}
@@ -94,7 +103,7 @@ func (o *ObjSelector) selectLoop() {
 
 		// cache the objects
 		err := o.boltDB.View(func(tx *bbolt.Tx) error {
-			b := tx.Bucket([]byte(bucketName))
+			b := tx.Bucket([]byte(o.filter.Status))
 			if b == nil {
 				return nil
 			}