[db] add ReadState() method

Author: dustinxie

db/kvstore.go

@@ -6,9 +6,11 @@
 package db
 
 import (
-	"github.com/iotexproject/iotex-core/v2/pkg/lifecycle"
+	"github.com/pkg/errors"
 
 	"github.com/iotexproject/iotex-core/v2/db/batch"
+	"github.com/iotexproject/iotex-core/v2/pkg/lifecycle"
+	"github.com/iotexproject/iotex-core/v2/state"
 )
 
 type (
@@ -62,3 +64,34 @@ type (
 		SeekPrev([]byte, uint64) ([]byte, error)
 	}
 )
+
+func ReadStates(kvStore KVStore, namespace string, keys [][]byte) ([][]byte, [][]byte, error) {
+	var (
+		ks, values [][]byte
+		err        error
+	)
+	if keys == nil {
+		ks, values, err = kvStore.Filter(namespace, func(k, v []byte) bool { return true }, nil, nil)
+		if err != nil {
+			if errors.Cause(err) == ErrNotExist || errors.Cause(err) == ErrBucketNotExist {
+				return nil, nil, errors.Wrapf(state.ErrStateNotExist, "failed to get states of ns = %x", namespace)
+			}
+			return nil, nil, err
+		}
+		return ks, values, nil
+	}
+	for _, key := range keys {
+		value, err := kvStore.Get(namespace, key)
+		switch errors.Cause(err) {
+		case ErrNotExist, ErrBucketNotExist:
+			values = append(values, nil)
+			ks = append(ks, key)
+		case nil:
+			values = append(values, value)
+			ks = append(ks, key)
+		default:
+			return nil, nil, err
+		}
+	}
+	return ks, values, nil
+}

state/factory/statedb.go

@@ -393,7 +393,7 @@ func (sdb *stateDB) States(opts ...protocol.StateOption) (uint64, state.Iterator
 	if cfg.Key != nil {
 		return sdb.currentChainHeight, nil, errors.Wrap(ErrNotSupported, "Read states with key option has not been implemented yet")
 	}
-	keys, values, err := readStates(sdb.dao.atHeight(sdb.currentChainHeight), cfg.Namespace, cfg.Keys)
+	keys, values, err := db.ReadStates(sdb.dao.atHeight(sdb.currentChainHeight), cfg.Namespace, cfg.Keys)
 	if err != nil {
 		return 0, nil, err
 	}

state/factory/util.go

@@ -19,7 +19,6 @@ import (
 	"github.com/iotexproject/iotex-core/v2/db"
 	"github.com/iotexproject/iotex-core/v2/db/trie"
 	"github.com/iotexproject/iotex-core/v2/db/trie/mptrie"
-	"github.com/iotexproject/iotex-core/v2/state"
 )
 
 func processOptions(opts ...protocol.StateOption) (*protocol.StateConfig, error) {
@@ -117,37 +116,6 @@ func protocolCommit(ctx context.Context, sr protocol.StateManager) error {
 	return nil
 }
 
-func readStates(kvStore db.KVStore, namespace string, keys [][]byte) ([][]byte, [][]byte, error) {
-	var (
-		ks, values [][]byte
-		err        error
-	)
-	if keys == nil {
-		ks, values, err = kvStore.Filter(namespace, func(k, v []byte) bool { return true }, nil, nil)
-		if err != nil {
-			if errors.Cause(err) == db.ErrNotExist || errors.Cause(err) == db.ErrBucketNotExist {
-				return nil, nil, errors.Wrapf(state.ErrStateNotExist, "failed to get states of ns = %x", namespace)
-			}
-			return nil, nil, err
-		}
-		return ks, values, nil
-	}
-	for _, key := range keys {
-		value, err := kvStore.Get(namespace, key)
-		switch errors.Cause(err) {
-		case db.ErrNotExist, db.ErrBucketNotExist:
-			values = append(values, nil)
-			ks = append(ks, key)
-		case nil:
-			values = append(values, value)
-			ks = append(ks, key)
-		default:
-			return nil, nil, err
-		}
-	}
-	return ks, values, nil
-}
-
 func newTwoLayerTrie(ns string, dao db.KVStore, rootKey string, create bool) (trie.TwoLayerTrie, error) {
 	dbForTrie, err := trie.NewKVStore(ns, dao)
 	if err != nil {

state/factory/workingsetstore.go

@@ -138,9 +138,9 @@ func (store *stateDBWorkingSetStore) Get(ns string, key []byte) ([]byte, error)
 func (store *stateDBWorkingSetStore) States(ns string, keys [][]byte) ([][]byte, [][]byte, error) {
 	if store.readBuffer {
 		// TODO: after the 180 HF, we can revert readBuffer, and always go this case
-		return readStates(store.flusher.KVStoreWithBuffer(), ns, keys)
+		return db.ReadStates(store.flusher.KVStoreWithBuffer(), ns, keys)
 	}
-	return readStates(store.flusher.BaseKVStore(), ns, keys)
+	return db.ReadStates(store.flusher.BaseKVStore(), ns, keys)
 }
 
 func (store *stateDBWorkingSetStore) Finalize(height uint64) error {