[#1577] container: Reduce iterations through container list

* Separated iteration through container ids from `ContainersOf()`
  so that it could be reused.
* When listing containers we used to iterate through the
  the whole list of containers twice: first when reading from
  a contract, then when sending them. Now we can send batches
  of containers when reading from the contract.

Signed-off-by: Ekaterina Lebedeva <ekaterina.lebedeva@yadro.com>

cmd/frostfs-node/container.go

@@ -222,6 +222,7 @@ type morphContainerReader struct {
 
 	lister interface {
 		ContainersOf(*user.ID) ([]cid.ID, error)
+		IterateContainersOf(*user.ID, func(cid.ID) error) error
 	}
 }
 
@@ -237,6 +238,10 @@ func (x *morphContainerReader) ContainersOf(id *user.ID) ([]cid.ID, error) {
 	return x.lister.ContainersOf(id)
 }
 
+func (x *morphContainerReader) IterateContainersOf(id *user.ID, processCID func(cid.ID) error) error {
+	return x.lister.IterateContainersOf(id, processCID)
+}
+
 type morphContainerWriter struct {
 	neoClient *cntClient.Client
 }

pkg/morph/client/container/containers_of.go

@@ -2,9 +2,7 @@ package container
 
 import (
 	"errors"
-	"fmt"
 
-	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/morph/client"
 	cid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/container/id"
 	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/user"
 	"github.com/nspcc-dev/neo-go/pkg/rpcclient/unwrap"
@@ -16,27 +14,37 @@ import (
 //
 // If remote RPC does not support neo-go session API, fallback to List() method.
 func (c *Client) ContainersOf(idUser *user.ID) ([]cid.ID, error) {
-	var rawID []byte
+	var cidList []cid.ID
+	var err error
 
+	cb := func(id cid.ID) error {
+		cidList = append(cidList, id)
+		return nil
+	}
+	if err = c.IterateContainersOf(idUser, cb); err != nil {
+		return nil, err
+	}
+	return cidList, nil
+}
+
+// iterateContainers iterates over a list of container identifiers
+// belonging to the specified user of FrostFS system and executes
+// `cb` on each element. If idUser is nil, calls it on the list of all containers.
+func (c *Client) IterateContainersOf(idUser *user.ID, cb func(item cid.ID) error) error {
+	var rawID []byte
 	if idUser != nil {
 		rawID = idUser.WalletBytes()
 	}
 
-	var cidList []cid.ID
+	cnrHash := c.client.ContractAddress()
-	cb := func(item stackitem.Item) error {
+	itemCb := func(item stackitem.Item) error {
-		rawID, err := client.BytesFromStackItem(item)
+		id, err := getCIDfromStackItem(item)
 		if err != nil {
-			return fmt.Errorf("get byte array from stack item (%s): %w", containersOfMethod, err)
+			return err
 		}
-
+		if err = cb(id); err != nil {
-		var id cid.ID
+			return err
-
-		err = id.Decode(rawID)
-		if err != nil {
-			return fmt.Errorf("decode container ID: %w", err)
 		}
-
-		cidList = append(cidList, id)
 		return nil
 	}
 
@@ -49,14 +57,10 @@ func (c *Client) ContainersOf(idUser *user.ID) ([]cid.ID, error) {
 	// 512 is big enough value and it is beautiful.
 	const batchSize = 512
 
-	cnrHash := c.client.ContractAddress()
+	err := c.client.Morph().TestInvokeIterator(itemCb, batchSize, cnrHash, containersOfMethod, rawID)
-	err := c.client.Morph().TestInvokeIterator(cb, batchSize, cnrHash, containersOfMethod, rawID)
+	if err != nil && errors.Is(err, unwrap.ErrNoSessionID) {
-	if err != nil {
+		return c.iterate(idUser, cb)
-		if errors.Is(err, unwrap.ErrNoSessionID) {
-			return c.list(idUser)
-		}
-		return nil, err
 	}
 
-	return cidList, nil
+	return err
 }

pkg/morph/client/container/list.go

@@ -6,15 +6,16 @@ import (
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/morph/client"
 	cid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/container/id"
 	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/user"
+	"github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
 )
 
-// list returns a list of container identifiers belonging
+// iterate iterates through a list of container identifiers belonging
 // to the specified user of FrostFS system. The list is composed
 // through Container contract call.
 //
-// Returns the identifiers of all FrostFS containers if pointer
+// Iterates through the identifiers of all FrostFS containers if pointer
 // to user identifier is nil.
-func (c *Client) list(idUser *user.ID) ([]cid.ID, error) {
+func (c *Client) iterate(idUser *user.ID, cb func(cid.ID) error) error {
 	var rawID []byte
 
 	if idUser != nil {
@@ -27,32 +28,41 @@ func (c *Client) list(idUser *user.ID) ([]cid.ID, error) {
 
 	res, err := c.client.TestInvoke(prm)
 	if err != nil {
-		return nil, fmt.Errorf("test invoke (%s): %w", listMethod, err)
+		return fmt.Errorf("test invoke (%s): %w", listMethod, err)
 	} else if ln := len(res); ln != 1 {
-		return nil, fmt.Errorf("unexpected stack item count (%s): %d", listMethod, ln)
+		return fmt.Errorf("unexpected stack item count (%s): %d", listMethod, ln)
 	}
 
 	res, err = client.ArrayFromStackItem(res[0])
 	if err != nil {
-		return nil, fmt.Errorf("get stack item array from stack item (%s): %w", listMethod, err)
+		return fmt.Errorf("get stack item array from stack item (%s): %w", listMethod, err)
 	}
 
-	cidList := make([]cid.ID, 0, len(res))
 	for i := range res {
-		rawID, err := client.BytesFromStackItem(res[i])
+		id, err := getCIDfromStackItem(res[i])
 		if err != nil {
-			return nil, fmt.Errorf("get byte array from stack item (%s): %w", listMethod, err)
+			return err
 		}
 
-		var id cid.ID
+		if err = cb(id); err != nil {
-
+			return err
-		err = id.Decode(rawID)
-		if err != nil {
-			return nil, fmt.Errorf("decode container ID: %w", err)
 		}
-
-		cidList = append(cidList, id)
 	}
 
-	return cidList, nil
+	return nil
+}
+
+func getCIDfromStackItem(item stackitem.Item) (cid.ID, error) {
+	rawID, err := client.BytesFromStackItem(item)
+	if err != nil {
+		return cid.ID{}, fmt.Errorf("get byte array from stack item (%s): %w", listMethod, err)
+	}
+
+	var id cid.ID
+
+	err = id.Decode(rawID)
+	if err != nil {
+		return cid.ID{}, fmt.Errorf("decode container ID: %w", err)
+	}
+	return id, nil
 }

pkg/services/container/morph/executor.go

@@ -30,6 +30,7 @@ type Reader interface {
 	// to the specified user of FrostFS system. Returns the identifiers
 	// of all FrostFS containers if pointer to owner identifier is nil.
 	ContainersOf(*user.ID) ([]cid.ID, error)
+	IterateContainersOf(*user.ID, func(cid.ID) error) error
 }
 
 // Writer is an interface of container storage updater.
@@ -201,7 +202,7 @@ func (s *morphExecutor) List(_ context.Context, body *container.ListRequestBody)
 	return res, nil
 }
 
-func (s *morphExecutor) ListStream(_ context.Context, req *container.ListStreamRequest, stream containerSvc.ListStream) error {
+func (s *morphExecutor) ListStream(ctx context.Context, req *container.ListStreamRequest, stream containerSvc.ListStream) error {
 	body := req.GetBody()
 	idV2 := body.GetOwnerID()
 	if idV2 == nil {
@@ -215,20 +216,41 @@ func (s *morphExecutor) ListStream(_ context.Context, req *container.ListStreamR
 		return fmt.Errorf("invalid user ID: %w", err)
 	}
 
-	cnrs, err := s.rdr.ContainersOf(&id)
-	if err != nil {
-		return err
-	}
-
-	cidList := make([]refs.ContainerID, len(cnrs))
-	for i := range cnrs {
-		cnrs[i].WriteToV2(&cidList[i])
-	}
-
 	resBody := new(container.ListStreamResponseBody)
-	resBody.SetContainerIDs(cidList)
 	r := new(container.ListStreamResponse)
 	r.SetBody(resBody)
 
-	return stream.Send(r)
+	var cidList []refs.ContainerID
+
+	// Amount of containers to send at once.
+	const batchSize = 1000
+
+	processCID := func(id cid.ID) error {
+		select {
+		case <-ctx.Done():
+			return ctx.Err()
+		default:
+		}
+
+		var refID refs.ContainerID
+		id.WriteToV2(&refID)
+		cidList = append(cidList, refID)
+		if len(cidList) == batchSize {
+			r.GetBody().SetContainerIDs(cidList)
+			cidList = cidList[:0]
+			return stream.Send(r)
+		}
+		return nil
+	}
+
+	if err = s.rdr.IterateContainersOf(&id, processCID); err != nil {
+		return err
+	}
+
+	if len(cidList) > 0 {
+		r.GetBody().SetContainerIDs(cidList)
+		return stream.Send(r)
+	}
+
+	return nil
 }