pkg/morph/client/client.go

@@ -22,13 +22,13 @@ import (
 	"github.com/nspcc-dev/neo-go/pkg/rpcclient"
 	"github.com/nspcc-dev/neo-go/pkg/rpcclient/actor"
 	"github.com/nspcc-dev/neo-go/pkg/rpcclient/gas"
+	"github.com/nspcc-dev/neo-go/pkg/rpcclient/invoker"
 	"github.com/nspcc-dev/neo-go/pkg/rpcclient/nep17"
 	"github.com/nspcc-dev/neo-go/pkg/rpcclient/rolemgmt"
 	"github.com/nspcc-dev/neo-go/pkg/rpcclient/unwrap"
 	"github.com/nspcc-dev/neo-go/pkg/smartcontract"
 	"github.com/nspcc-dev/neo-go/pkg/smartcontract/trigger"
 	"github.com/nspcc-dev/neo-go/pkg/util"
-	"github.com/nspcc-dev/neo-go/pkg/vm"
 	"github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
 	"github.com/nspcc-dev/neo-go/pkg/vm/vmstate"
 	"github.com/nspcc-dev/neo-go/pkg/wallet"
@@ -207,16 +207,11 @@ func (c *Client) Invoke(contract util.Uint160, fee fixedn.Fixed8, method string,
 	return vub, nil
 }
 
-// defaultPrefetchBatchSize is the default number of items to prefetch.
-// It is dependent on VM limits (2048 items on stack), the default works for simple items.
-// For example, to iterate over 2 field structs, the limit should be divided by 3 = 1 (struct itself) + 2 (fields).
-const defaultPrefetchBatchSize = vm.MaxStackSize - 16
-
 // TestInvokeIterator invokes contract method returning an iterator and executes cb on each element.
 // If cb returns an error, the session is closed and this error is returned as-is.
 // If the remove neo-go node does not support sessions, `unwrap.ErrNoSessionID` is returned.
 // batchSize is the number of items to prefetch: if the number of items in the iterator is less than batchSize, no session will be created.
-// The default batchSize is 2000 (VM is limited by having 2048 items on stack, so if each iterator item is simple, 2000 items won't hit the limit).
+// The default batchSize is 100, the default limit from neo-go.
 func (c *Client) TestInvokeIterator(cb func(stackitem.Item) error, batchSize int, contract util.Uint160, method string, args ...interface{}) error {
 	start := time.Now()
 	success := false
@@ -225,7 +220,7 @@ func (c *Client) TestInvokeIterator(cb func(stackitem.Item) error, batchSize int
 	}()
 
 	if batchSize <= 0 {
-		batchSize = defaultPrefetchBatchSize
+		batchSize = invoker.DefaultIteratorResultItems
 	}
 
 	c.switchLock.RLock()

pkg/morph/client/container/containers_of.go

@@ -40,8 +40,17 @@ func (c *Client) ContainersOf(idUser *user.ID) ([]cid.ID, error) {
 		return nil
 	}
 
+	// We would like to have batch size as big as possible,
+	// to reduce the number of round-trips and avoid creating sessions.
+	// The limit depends on 2 things:
+	// 1. VM limits: max 2048 items on stack.
+	// 2. JSON encoded size for the item with type = 128k.
+	// It turns out, that for container ID the second limit is hit first,
+	// 512 is big enough value and it is beautiful.
+	const batchSize = 512
+
 	cnrHash := c.client.ContractAddress()
-	err := c.client.Morph().TestInvokeIterator(cb, 0, cnrHash, containersOfMethod, rawID)
+	err := c.client.Morph().TestInvokeIterator(cb, batchSize, cnrHash, containersOfMethod, rawID)
 	if err != nil {
 		if errors.Is(err, unwrap.ErrNoSessionID) {
 			return c.List(idUser)