(VDB-280) Consume vat contract storage diffs

pkg/transformers/storage_diffs/shared/errors.go

@@ -16,7 +16,9 @@
 
 package shared
 
-import "fmt"
+import (
+	"fmt"
+)
 
 type ErrContractNotFound struct {
 	Contract string
@@ -36,6 +38,14 @@ func (e ErrHeaderMismatch) Error() string {
 	return fmt.Sprintf("header hash in row does not match db at height %d - row: %s, db: %s", e.BlockHeight, e.DbHash, e.DiffHash)
 }
 
+type ErrMetadataMalformed struct {
+	MissingData Key
+}
+
+func (e ErrMetadataMalformed) Error() string {
+	return fmt.Sprintf("storage metadata malformed: missing %s", e.MissingData)
+}
+
 type ErrRowMalformed struct {
 	Length int
 }

pkg/transformers/storage_diffs/shared/value.go

@@ -24,10 +24,11 @@ const (
 	Address
 )
 
-type Key int
+type Key string
 
 const (
-	Ilk Key = iota
+	Ilk Key = "ilk"
+	Guy Key = "guy"
 )
 
 type StorageValueMetadata struct {
@@ -35,3 +36,11 @@ type StorageValueMetadata struct {
 	Keys map[Key]string
 	Type ValueType
 }
+
+func GetStorageValueMetadata(name string, keys map[Key]string, t ValueType) StorageValueMetadata {
+	return StorageValueMetadata{
+		Name: name,
+		Keys: keys,
+		Type: t,
+	}
+}