feat(store/v2): build the migration manager in the root store factory

store/v2/commitment/iavl/exporter.go

@@ -38,3 +38,16 @@ func (e *Exporter) Close() error {
 
 	return nil
 }
+
+// EmptyExporter is a Exporter for an empty tree.
+type EmptyExporter struct{}
+
+// Next returns ExportDone.
+func (e *EmptyExporter) Next() (*snapshotstypes.SnapshotIAVLItem, error) {
+	return nil, commitment.ErrorExportDone
+}
+
+// Close does nothing.
+func (e *EmptyExporter) Close() error {
+	return nil
+}

store/v2/commitment/iavl/tree.go

@@ -21,6 +21,8 @@ var (
 // IavlTree is a wrapper around iavl.MutableTree.
 type IavlTree struct {
 	tree *iavl.MutableTree
+	// it is only used for new store key during the migration process.
+	initialVersion uint64
 }
 
 // NewIavlTree creates a new IavlTree instance.
@@ -58,6 +60,17 @@ func (t *IavlTree) WorkingHash() []byte {
 
 // LoadVersion loads the state at the given version.
 func (t *IavlTree) LoadVersion(version uint64) error {
+	if t.initialVersion > 0 {
+		// If the initial version is set and the tree is empty,
+		// we don't need to load the version.
+		latestVersion, err := t.tree.GetLatestVersion()
+		if err != nil {
+			return err
+		}
+		if latestVersion == 0 {
+			return nil
+		}
+	}
 	return t.tree.LoadVersionForOverwriting(int64(version))
 }
 
@@ -106,6 +119,7 @@ func (t *IavlTree) GetLatestVersion() (uint64, error) {
 // SetInitialVersion sets the initial version of the database.
 func (t *IavlTree) SetInitialVersion(version uint64) error {
 	t.tree.SetInitialVersion(version)
+	t.initialVersion = version
 	return nil
 }
 
@@ -125,6 +139,9 @@ func (t *IavlTree) PausePruning(pause bool) {
 
 // Export exports the tree exporter at the given version.
 func (t *IavlTree) Export(version uint64) (commitment.Exporter, error) {
+	if version < t.initialVersion {
+		return &EmptyExporter{}, nil
+	}
 	tree, err := t.tree.GetImmutable(int64(version))
 	if err != nil {
 		return nil, err

store/v2/commitment/metadata.go

@@ -11,9 +11,9 @@ import (
 )
 
 const (
-	commitInfoKeyFmt      = "c/%d" // c/<version>
-	latestVersionKey      = "c/latest"
-	removedStoreKeyPrefix = "c/removed/" // c/removed/<version>/<store-name>
+	commitInfoKeyFmt      = "s/%d" // c/<version>
+	latestVersionKey      = "s/latest"
+	removedStoreKeyPrefix = "s/removed/" // c/removed/<version>/<store-name>
 )
 
 // MetadataStore is a store for metadata related to the commitment store.
@@ -69,7 +69,10 @@ func (m *MetadataStore) GetCommitInfo(version uint64) (*proof.CommitInfo, error)
 
 	cInfo := &proof.CommitInfo{}
 	if err := cInfo.Unmarshal(value); err != nil {
-		return nil, err
+		cInfo, err = proof.ConvertV1CommitInfo(value)
+		if err != nil {
+			return nil, err
+		}
 	}
 
 	return cInfo, nil

store/v2/go.mod

@@ -21,6 +21,7 @@ require (
 	github.com/syndtr/goleveldb v1.0.1-0.20220721030215-126854af5e6d
 	go.uber.org/mock v0.5.0
 	golang.org/x/sync v0.8.0
+	google.golang.org/protobuf v1.35.1
 )
 
 require (
@@ -61,6 +62,5 @@ require (
 	golang.org/x/exp v0.0.0-20231006140011-7918f672742d // indirect
 	golang.org/x/sys v0.26.0 // indirect
 	golang.org/x/text v0.19.0 // indirect
-	google.golang.org/protobuf v1.35.1 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

store/v2/proof/proof.go

@@ -7,6 +7,7 @@ import (
 
 	errors "cosmossdk.io/errors/v2"
 	storeerrors "cosmossdk.io/store/v2/errors"
+	v1types "cosmossdk.io/store/v2/proof/v1/types"
 )
 
 // Proof operation types
@@ -228,3 +229,30 @@ func InnerHash(left, right []byte) []byte {
 	h := sha256.Sum256(data)
 	return h[:]
 }
+
+func ConvertV1CommitInfo(value []byte) (*CommitInfo, error) {
+	v1CommitInfo := &v1types.CommitInfo{}
+	if err := v1CommitInfo.Unmarshal(value); err != nil {
+		return nil, err
+	}
+	cInfo := &CommitInfo{
+		Version:    uint64(v1CommitInfo.Version),
+		StoreInfos: make([]StoreInfo, len(v1CommitInfo.StoreInfos)),
+		Timestamp:  v1CommitInfo.Timestamp,
+	}
+	for i, v1StoreInfo := range v1CommitInfo.StoreInfos {
+		cInfo.StoreInfos[i] = StoreInfo{
+			Name: []byte(v1StoreInfo.Name),
+			CommitID: CommitID{
+				Version: uint64(v1StoreInfo.CommitId.Version),
+				Hash:    v1StoreInfo.CommitId.Hash,
+			},
+			Structure: "iavl",
+		}
+	}
+
+	var err error
+	cInfo.CommitHash, _, err = cInfo.GetStoreProof([]byte{})
+
+	return cInfo, err
+}