light: CHT and bloom trie indexers working in light mode (#16534)

This PR enables the indexers to work in light client mode by
downloading a part of these tries (the Merkle proofs of the last
values of the last known section) in order to be able to add new
values and recalculate subsequent hashes. It also adds CHT data to
NodeInfo.

1 files changed, 27 insertions, 7 deletions

diff --git a/les/handler.go b/les/handler.go
index 91a235bf0..ccb4a8844 100644
--- a/les/handler.go
+++ b/les/handler.go
@@ -1206,11 +1206,12 @@ func (pm *ProtocolManager) txStatus(hashes []common.Hash) []txStatus {
 // NodeInfo represents a short summary of the Ethereum sub-protocol metadata
 // known about the host peer.
 type NodeInfo struct {
-	Network    uint64              `json:"network"`    // Ethereum network ID (1=Frontier, 2=Morden, Ropsten=3, Rinkeby=4)
-	Difficulty *big.Int            `json:"difficulty"` // Total difficulty of the host's blockchain
-	Genesis    common.Hash         `json:"genesis"`    // SHA3 hash of the host's genesis block
-	Config     *params.ChainConfig `json:"config"`     // Chain configuration for the fork rules
-	Head       common.Hash         `json:"head"`       // SHA3 hash of the host's best owned block
+	Network    uint64                  `json:"network"`    // Ethereum network ID (1=Frontier, 2=Morden, Ropsten=3, Rinkeby=4)
+	Difficulty *big.Int                `json:"difficulty"` // Total difficulty of the host's blockchain
+	Genesis    common.Hash             `json:"genesis"`    // SHA3 hash of the host's genesis block
+	Config     *params.ChainConfig     `json:"config"`     // Chain configuration for the fork rules
+	Head       common.Hash             `json:"head"`       // SHA3 hash of the host's best owned block
+	CHT        light.TrustedCheckpoint `json:"cht"`        // Trused CHT checkpoint for fast catchup
 }
 
 // NodeInfo retrieves some protocol metadata about the running host node.
@@ -1218,12 +1219,31 @@ func (self *ProtocolManager) NodeInfo() *NodeInfo {
 	head := self.blockchain.CurrentHeader()
 	hash := head.Hash()
 
+	var cht light.TrustedCheckpoint
+
+	sections, _, sectionHead := self.odr.ChtIndexer().Sections()
+	sections2, _, sectionHead2 := self.odr.BloomTrieIndexer().Sections()
+	if sections2 < sections {
+		sections = sections2
+		sectionHead = sectionHead2
+	}
+	if sections > 0 {
+		sectionIndex := sections - 1
+		cht = light.TrustedCheckpoint{
+			SectionIdx:  sectionIndex,
+			SectionHead: sectionHead,
+			CHTRoot:     light.GetChtRoot(self.chainDb, sectionIndex, sectionHead),
+			BloomRoot:   light.GetBloomTrieRoot(self.chainDb, sectionIndex, sectionHead),
+		}
+	}
+
 	return &NodeInfo{
 		Network:    self.networkId,
 		Difficulty: self.blockchain.GetTd(hash, head.Number.Uint64()),
 		Genesis:    self.blockchain.Genesis().Hash(),
 		Config:     self.blockchain.Config(),
 		Head:       hash,
+		CHT:        cht,
 	}
 }
 
@@ -1258,7 +1278,7 @@ func (pc *peerConnection) RequestHeadersByHash(origin common.Hash, amount int, s
 	}
 	_, ok := <-pc.manager.reqDist.queue(rq)
 	if !ok {
-		return ErrNoPeers
+		return light.ErrNoPeers
 	}
 	return nil
 }
@@ -1282,7 +1302,7 @@ func (pc *peerConnection) RequestHeadersByNumber(origin uint64, amount int, skip
 	}
 	_, ok := <-pc.manager.reqDist.queue(rq)
 	if !ok {
-		return ErrNoPeers
+		return light.ErrNoPeers
 	}
 	return nil
 }