migrate direct usages blockstore.{Get=>View}.

chain/store/store.go

@@ -108,6 +108,8 @@ type ChainStore struct {
 	localbs bstore.Blockstore
 	ds      dstore.Batching
 
+	localviewer bstore.Viewer
+
 	heaviestLk sync.Mutex
 	heaviest   *types.TipSet
 
@@ -150,6 +152,10 @@ func NewChainStore(bs bstore.Blockstore, localbs bstore.Blockstore, ds dstore.Ba
 		journal:  j,
 	}
 
+	if v, ok := localbs.(bstore.Viewer); ok {
+		cs.localviewer = v
+	}
+
 	cs.evtTypes = [1]journal.EventType{
 		evtTypeHeadChange: j.RegisterEventType("sync", "head_change"),
 	}
@@ -545,14 +551,22 @@ func (cs *ChainStore) Contains(ts *types.TipSet) (bool, error) {
 // GetBlock fetches a BlockHeader with the supplied CID. It returns
 // blockstore.ErrNotFound if the block was not found in the BlockStore.
 func (cs *ChainStore) GetBlock(c cid.Cid) (*types.BlockHeader, error) {
+	if cs.localviewer == nil {
 		sb, err := cs.localbs.Get(c)
 		if err != nil {
 			return nil, err
 		}
-
 		return types.DecodeBlock(sb.RawData())
 	}
 
+	var blk *types.BlockHeader
+	err := cs.localviewer.View(c, func(b []byte) (err error) {
+		blk, err = types.DecodeBlock(b)
+		return err
+	})
+	return blk, err
+}
+
 func (cs *ChainStore) LoadTipSet(tsk types.TipSetKey) (*types.TipSet, error) {
 	v, ok := cs.tsCache.Get(tsk)
 	if ok {
@@ -816,25 +830,41 @@ func (cs *ChainStore) GetCMessage(c cid.Cid) (types.ChainMsg, error) {
 }
 
 func (cs *ChainStore) GetMessage(c cid.Cid) (*types.Message, error) {
+	if cs.localviewer == nil {
 		sb, err := cs.localbs.Get(c)
 		if err != nil {
 			log.Errorf("get message get failed: %s: %s", c, err)
 			return nil, err
 		}
-
 		return types.DecodeMessage(sb.RawData())
 	}
 
+	var msg *types.Message
+	err := cs.localviewer.View(c, func(b []byte) (err error) {
+		msg, err = types.DecodeMessage(b)
+		return err
+	})
+	return msg, err
+}
+
 func (cs *ChainStore) GetSignedMessage(c cid.Cid) (*types.SignedMessage, error) {
+	if cs.localviewer == nil {
 		sb, err := cs.localbs.Get(c)
 		if err != nil {
 			log.Errorf("get message get failed: %s: %s", c, err)
 			return nil, err
 		}
-
 		return types.DecodeSignedMessage(sb.RawData())
 	}
 
+	var msg *types.SignedMessage
+	err := cs.localviewer.View(c, func(b []byte) (err error) {
+		msg, err = types.DecodeSignedMessage(b)
+		return err
+	})
+	return msg, err
+}
+
 func (cs *ChainStore) readAMTCids(root cid.Cid) ([]cid.Cid, error) {
 	ctx := context.TODO()
 	// block headers use adt0, for now.