Add les chain reader for istanbul (ethereum#771)

les/backend.go

@@ -26,6 +26,7 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/ethereum/go-ethereum/consensus"
+	istanbulBackend "github.com/ethereum/go-ethereum/consensus/istanbul/backend"
 	"github.com/ethereum/go-ethereum/contract_comm"
 	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/core/bloombits"
@@ -55,12 +56,13 @@ type LightEthereum struct {
 	shutdownChan chan bool
 
 	// Handlers
-	peers      *peerSet
-	txPool     *light.TxPool
-	blockchain *light.LightChain
-	serverPool *serverPool
-	reqDist    *requestDistributor
-	retriever  *retrieveManager
+	peers       *peerSet
+	txPool      *light.TxPool
+	blockchain  *light.LightChain
+	serverPool  *serverPool
+	reqDist     *requestDistributor
+	retriever   *retrieveManager
+	chainreader *LightChainReader
 
 	bloomRequests chan chan *bloombits.Retrieval // Channel receiving bloom data retrieval requests
 	bloomIndexer  *core.ChainIndexer
@@ -169,6 +171,17 @@ func New(ctx *node.ServiceContext, config *eth.Config) (*LightEthereum, error) {
 		return nil, err
 	}
 	leth.ApiBackend = &LesApiBackend{leth}
+
+	leth.chainreader = &LightChainReader{
+		config:     leth.chainConfig,
+		blockchain: leth.blockchain,
+	}
+
+	// If the engine is istanbul, then inject the blockchain
+	if istanbul, isIstanbul := leth.engine.(*istanbulBackend.Backend); isIstanbul {
+		istanbul.SetChain(leth.chainreader, nil)
+	}
+
 	return leth, nil
 }
 

les/lightchainreader.go

@@ -0,0 +1,35 @@
+package les
+
+import (
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/light"
+	"github.com/ethereum/go-ethereum/params"
+)
+
+type LightChainReader struct {
+	config     *params.ChainConfig
+	blockchain *light.LightChain
+}
+
+// Config returns the chain configuration.
+func (lcr *LightChainReader) Config() *params.ChainConfig {
+	return lcr.config
+}
+
+func (lcr *LightChainReader) CurrentHeader() *types.Header {
+	return lcr.blockchain.CurrentHeader()
+}
+func (lcr *LightChainReader) GetHeaderByNumber(number uint64) *types.Header {
+	return lcr.blockchain.GetHeaderByNumber(number)
+}
+func (lcr *LightChainReader) GetHeaderByHash(hash common.Hash) *types.Header {
+	return lcr.blockchain.GetHeaderByHash(hash)
+}
+func (lcr *LightChainReader) GetHeader(hash common.Hash, number uint64) *types.Header {
+	return lcr.blockchain.GetHeader(hash, number)
+}
+func (lcr *LightChainReader) GetBlock(hash common.Hash, number uint64) *types.Block {
+	panic("GetBlock cannot be called on LightChainReader")
+	return nil
+}