les: expose les API as private API service

les/api.go

@@ -25,51 +25,50 @@ import (
 )
 
 var (
-	errNoStableCheckpoint = errors.New("no stable checkpoint provided")
+	errNoCheckpoint = errors.New("no local checkpoint provided")
 )
 
-// PublicLesServerAPI  provides an API to access the les server.
-// It offers only methods that operate on public data that is freely available to anyone.
-type PublicLesServerAPI struct {
+// PrivateLesServerAPI provides a private API to access the les server.
+type PrivateLesServerAPI struct {
 	server *LesServer
 }
 
-// NewPublicLesServerAPI creates a new les server API.
-func NewPublicLesServerAPI(server *LesServer) *PublicLesServerAPI {
-	return &PublicLesServerAPI{
+// NewPrivateLesServerAPI creates a new les server API.
+func NewPrivateLesServerAPI(server *LesServer) *PrivateLesServerAPI {
+	return &PrivateLesServerAPI{
 		server: server,
 	}
 }
 
-// Checkpoint returns the latest checkpoint package.
+// Checkpoint returns the latest local checkpoint package.
 //
 // The checkpoint package consists of 4 strings:
 //   result[0], hex encoded latest section index
 //   result[1], 32 bytes hex encoded latest section head hash
 //   result[2], 32 bytes hex encoded latest section canonical hash trie root hash
 //   result[3], 32 bytes hex encoded latest section bloom trie root hash
-func (api *PublicLesServerAPI) LatestCheckpoint() ([4]string, error) {
+func (api *PrivateLesServerAPI) LatestCheckpoint() ([4]string, error) {
 	var res [4]string
 	sectionIdx, sectionHead, chtRoot, bloomTrieRoot := api.server.latestCheckpoint()
 	if sectionHead == (common.Hash{}) || chtRoot == (common.Hash{}) || bloomTrieRoot == (common.Hash{}) {
-		return res, errNoStableCheckpoint
+		return res, errNoCheckpoint
 	}
 	res[0] = hexutil.Encode(big.NewInt(int64(sectionIdx)).Bytes())
 	res[1], res[2], res[3] = sectionHead.Hex(), chtRoot.Hex(), bloomTrieRoot.Hex()
 	return res, nil
 }
 
-// GetCheckpoint returns the specific checkpoint package.
+// GetCheckpoint returns the specific local checkpoint package.
 //
 // The checkpoint package consists of 3 strings:
 //   result[0], 32 bytes hex encoded latest section head hash
 //   result[1], 32 bytes hex encoded latest section canonical hash trie root hash
 //   result[2], 32 bytes hex encoded latest section bloom trie root hash
-func (api *PublicLesServerAPI) GetCheckpoint(index uint64) ([3]string, error) {
+func (api *PrivateLesServerAPI) GetCheckpoint(index uint64) ([3]string, error) {
 	var res [3]string
 	sectionHead, chtRoot, bloomTrieRoot := api.server.getCheckpoint(index)
 	if sectionHead == (common.Hash{}) || chtRoot == (common.Hash{}) || bloomTrieRoot == (common.Hash{}) {
-		return res, errNoStableCheckpoint
+		return res, errNoCheckpoint
 	}
 	res[0], res[1], res[2] = sectionHead.Hex(), chtRoot.Hex(), bloomTrieRoot.Hex()
 	return res, nil

les/server.go

@@ -188,15 +188,15 @@ func (s *LesServer) APIs() []rpc.API {
 		{
 			Namespace: "les",
 			Version:   "1.0",
-			Service:   NewPublicLesServerAPI(s),
-			Public:    true,
+			Service:   NewPrivateLesServerAPI(s),
+			Public:    false,
 		},
 	}
 }
 
 // latestCheckpoint finds the common stored section index and returns a set of
 // post-processed trie roots (CHT and BloomTrie) associated with
-// the appropriate section index and head hash as a checkpoint package.
+// the appropriate section index and head hash as a local checkpoint package.
 //
 // Note for cht, the section size in LES1 is 4K, so indexer still uses LES/1
 // 4k section size for backwards server compatibility. For bloomTrie, the size
@@ -219,6 +219,9 @@ func (s *LesServer) latestCheckpoint() (uint64, common.Hash, common.Hash, common
 
 // getCheckpoint returns a set of post-processed trie roots (CHT and BloomTrie)
 // associated with the appropriate head hash by specific section index.
+//
+// The returned checkpoint is only the checkpoint generated by the local indexers,
+// not the stable checkpoint registered in the registrar contract.
 func (s *LesServer) getCheckpoint(index uint64) (common.Hash, common.Hash, common.Hash) {
 	// convert last LES/2 section index back to LES/1 index for chtIndexer.SectionHead
 	latest := (index+1)*(light.CHTFrequencyClient/light.CHTFrequencyServer) - 1
@@ -315,6 +318,7 @@ func (s *LesServer) recoverCheckpoint() *light.TrustedCheckpoint {
 		headHash         = rawdb.ReadHeadHeaderHash(s.chaindb)
 		headNumber       = rawdb.ReadHeaderNumber(s.chaindb, headHash)
 	)
+	// Short circuit if there is no local checkpoint generated.
 	if headNumber == nil || sectionCnt == 0 {
 		return nil
 	}
@@ -322,7 +326,9 @@ func (s *LesServer) recoverCheckpoint() *light.TrustedCheckpoint {
 	for stable == nil || stable.SectionIdx < unstableIdx {
 		if (unstableIdx+1)*light.CheckpointFrequency+light.CheckpointConfirmations <= *headNumber {
 			iter, err := s.registrar.FilterNewCheckpointEvent(*headNumber, unstableIdx, light.CheckpointFrequency, light.CheckpointProcessConfirmations)
-			if err == nil {
+			if err != nil {
+				continue
+			}
 			for iter.Next() {
 				sectionHead := s.bloomTrieIndexer.SectionHead(unstableIdx)
 				checkpoint := &light.TrustedCheckpoint{
@@ -334,13 +340,12 @@ func (s *LesServer) recoverCheckpoint() *light.TrustedCheckpoint {
 				if checkpoint.HashEqual(common.Hash(iter.Event.CheckpointHash)) {
 					light.WriteTrustedCheckpoint(s.chaindb, checkpoint)
 					iter.Close()
-						log.Info("Recover checkpoint", "index", checkpoint.SectionIdx, "hash", checkpoint.Hash().Hex())
+					log.Info("Recover stable checkpoint", "index", checkpoint.SectionIdx, "hash", checkpoint.Hash().Hex())
 					return checkpoint
 				}
 			}
 			iter.Close()
 		}
-		}
 		if unstableIdx == 0 {
 			break
 		}
@@ -349,7 +354,7 @@ func (s *LesServer) recoverCheckpoint() *light.TrustedCheckpoint {
 	if stable == nil {
 		log.Info("No stable checkpoint")
 	} else {
-		log.Info("Recover checkpoint", "index", stable.SectionIdx, "hash", stable.Hash().Hex())
+		log.Info("Recover stable checkpoint", "index", stable.SectionIdx, "hash", stable.Hash().Hex())
 	}
 	return stable
 }