les: light client protocol and API

2 files changed, 9 insertions, 8 deletions

diff --git a/internal/ethapi/api.go b/internal/ethapi/api.go
index 0e8e905aa..806005482 100644
--- a/internal/ethapi/api.go
+++ b/internal/ethapi/api.go
@@ -366,14 +366,15 @@ func NewPublicBlockChainAPI(b Backend) *PublicBlockChainAPI {
 
 // BlockNumber returns the block number of the chain head.
 func (s *PublicBlockChainAPI) BlockNumber() *big.Int {
-	return s.b.HeaderByNumber(rpc.LatestBlockNumber).Number
+	header, _ := s.b.HeaderByNumber(context.Background(), rpc.LatestBlockNumber) // latest header should always be available
+	return header.Number
 }
 
 // GetBalance returns the amount of wei for the given address in the state of the
 // given block number. The rpc.LatestBlockNumber and rpc.PendingBlockNumber meta
 // block numbers are also allowed.
 func (s *PublicBlockChainAPI) GetBalance(ctx context.Context, address common.Address, blockNr rpc.BlockNumber) (*big.Int, error) {
-	state, _, err := s.b.StateAndHeaderByNumber(blockNr)
+	state, _, err := s.b.StateAndHeaderByNumber(ctx, blockNr)
 	if state == nil || err != nil {
 		return nil, err
 	}
@@ -458,7 +459,7 @@ func (s *PublicBlockChainAPI) GetUncleCountByBlockHash(ctx context.Context, bloc
 
 // GetCode returns the code stored at the given address in the state for the given block number.
 func (s *PublicBlockChainAPI) GetCode(ctx context.Context, address common.Address, blockNr rpc.BlockNumber) (string, error) {
-	state, _, err := s.b.StateAndHeaderByNumber(blockNr)
+	state, _, err := s.b.StateAndHeaderByNumber(ctx, blockNr)
 	if state == nil || err != nil {
 		return "", err
 	}
@@ -473,7 +474,7 @@ func (s *PublicBlockChainAPI) GetCode(ctx context.Context, address common.Addres
 // block number. The rpc.LatestBlockNumber and rpc.PendingBlockNumber meta block
 // numbers are also allowed.
 func (s *PublicBlockChainAPI) GetStorageAt(ctx context.Context, address common.Address, key string, blockNr rpc.BlockNumber) (string, error) {
-	state, _, err := s.b.StateAndHeaderByNumber(blockNr)
+	state, _, err := s.b.StateAndHeaderByNumber(ctx, blockNr)
 	if state == nil || err != nil {
 		return "0x", err
 	}
@@ -517,7 +518,7 @@ type CallArgs struct {
 func (s *PublicBlockChainAPI) doCall(ctx context.Context, args CallArgs, blockNr rpc.BlockNumber) (string, *big.Int, error) {
 	defer func(start time.Time) { glog.V(logger.Debug).Infof("call took %v", time.Since(start)) }(time.Now())
 
-	state, header, err := s.b.StateAndHeaderByNumber(blockNr)
+	state, header, err := s.b.StateAndHeaderByNumber(ctx, blockNr)
 	if state == nil || err != nil {
 		return "0x", common.Big0, err
 	}
@@ -859,7 +860,7 @@ func (s *PublicTransactionPoolAPI) GetRawTransactionByBlockHashAndIndex(ctx cont
 
 // GetTransactionCount returns the number of transactions the given address has sent for the given block number
 func (s *PublicTransactionPoolAPI) GetTransactionCount(ctx context.Context, address common.Address, blockNr rpc.BlockNumber) (*rpc.HexNumber, error) {
-	state, _, err := s.b.StateAndHeaderByNumber(blockNr)
+	state, _, err := s.b.StateAndHeaderByNumber(ctx, blockNr)
 	if state == nil || err != nil {
 		return nil, err
 	}
diff --git a/internal/ethapi/backend.go b/internal/ethapi/backend.go
index 0aa3da18d..ec5a84c5c 100644
--- a/internal/ethapi/backend.go
+++ b/internal/ethapi/backend.go
@@ -44,9 +44,9 @@ type Backend interface {
 	AccountManager() *accounts.Manager
 	// BlockChain API
 	SetHead(number uint64)
-	HeaderByNumber(blockNr rpc.BlockNumber) *types.Header
+	HeaderByNumber(ctx context.Context, blockNr rpc.BlockNumber) (*types.Header, error)
 	BlockByNumber(ctx context.Context, blockNr rpc.BlockNumber) (*types.Block, error)
-	StateAndHeaderByNumber(blockNr rpc.BlockNumber) (State, *types.Header, error)
+	StateAndHeaderByNumber(ctx context.Context, blockNr rpc.BlockNumber) (State, *types.Header, error)
 	GetBlock(ctx context.Context, blockHash common.Hash) (*types.Block, error)
 	GetReceipts(ctx context.Context, blockHash common.Hash) (types.Receipts, error)
 	GetTd(blockHash common.Hash) *big.Int