fixup! light: implement GetGovStateByNumber and InsertDexonHeaderChain (Stub)

4 files changed, 86 insertions, 7 deletions

diff --git a/core/headerchain.go b/core/headerchain.go
index ef77aa28a..62a2bf805 100644
--- a/core/headerchain.go
+++ b/core/headerchain.go
@@ -465,7 +465,7 @@ func (c *headerVerifierCache) configuration(round uint64) *params.DexconConfig {
 
 func (hc *HeaderChain) ValidateDexonHeaderChain(chain []*types.HeaderWithGovState,
 	gov dexcon.GovernanceStateFetcher,
-	verifierCache *dexCore.TSigVerifierCache, validator Validator) (int, error) {
+	verifierCache *dexCore.TSigVerifierCache, validator HeaderValidator) (int, error) {
 	// Do a sanity check that the provided chain is actually ordered and linked
 	for i := 1; i < len(chain); i++ {
 		if chain[i].Number.Uint64() != chain[i-1].Number.Uint64()+1 || chain[i].ParentHash != chain[i-1].Hash() {
@@ -534,7 +534,7 @@ func (hc *HeaderChain) ValidateDexonHeaderChain(chain []*types.HeaderWithGovStat
 
 func (hc *HeaderChain) VerifyDexonHeader(header *types.Header,
 	gov dexcon.GovernanceStateFetcher,
-	verifierCache *dexCore.TSigVerifierCache, validator Validator) error {
+	verifierCache *dexCore.TSigVerifierCache, validator HeaderValidator) error {
 
 	if parent := hc.GetHeader(header.ParentHash, header.Number.Uint64()-1); parent == nil {
 		return consensus.ErrUnknownAncestor
diff --git a/core/types.go b/core/types.go
index 04a787b1e..8369f2328 100644
--- a/core/types.go
+++ b/core/types.go
@@ -39,6 +39,10 @@ type Validator interface {
 	ValidateWitnessData(height uint64, data common.Hash) error
 }
 
+type HeaderValidator interface {
+	ValidateWitnessData(height uint64, data common.Hash) error
+}
+
 // Processor is an interface for processing blocks using a given initial state.
 //
 // Process takes the block to be processed and the statedb upon which the
diff --git a/light/lightchain.go b/light/lightchain.go
index a6cdd6f86..232178308 100644
--- a/light/lightchain.go
+++ b/light/lightchain.go
@@ -74,7 +74,8 @@ type LightChain struct {
 	procInterrupt int32 // interrupt signaler for block processing
 	wg            sync.WaitGroup
 
-	engine consensus.Engine
+	engine    consensus.Engine
+	validator core.HeaderValidator
 }
 
 // NewLightChain returns a fully initialised light chain using information
@@ -118,6 +119,7 @@ func NewLightChain(odr OdrBackend, config *params.ChainConfig, engine consensus.
 			log.Error("Chain rewind was successful, resuming normal operation")
 		}
 	}
+	bc.validator = &HeaderValidator{chain: bc}
 	return bc, nil
 }
 
@@ -304,7 +306,18 @@ func (self *LightChain) GetBlockByNumber(ctx context.Context, number uint64) (*t
 }
 
 func (self *LightChain) GetGovStateByNumber(number uint64) (*types.GovState, error) {
-	return nil, fmt.Errorf("not implemented yet")
+	header := self.GetHeaderByNumber(number)
+	if header == nil {
+		return nil, fmt.Errorf("header not found")
+	}
+
+	govState := rawdb.ReadGovState(self.chainDb, header.Hash())
+	if govState == nil {
+		log.Debug("gov state not found in db")
+		return nil, fmt.Errorf("gov state not found in db")
+	}
+	log.Debug("Read gov state from db success")
+	return govState, nil
 }
 
 // Stop stops the blockchain service. If any imports are currently in progress
@@ -401,9 +414,45 @@ func (self *LightChain) InsertHeaderChain(chain []*types.Header, checkFreq int)
 	return i, err
 }
 
-func (self *LightChain) InsertDexonHeaderChain([]*types.HeaderWithGovState,
-	dexcon.GovernanceStateFetcher, *dexCore.TSigVerifierCache) (int, error) {
-	return 0, fmt.Errorf("not implemented yet")
+func (self *LightChain) InsertDexonHeaderChain(chain []*types.HeaderWithGovState,
+	gov dexcon.GovernanceStateFetcher, verifierCache *dexCore.TSigVerifierCache) (int, error) {
+	start := time.Now()
+	if i, err := self.hc.ValidateDexonHeaderChain(chain, gov, verifierCache, self.validator); err != nil {
+		return i, err
+	}
+
+	// Make sure only one thread manipulates the chain at once
+	self.chainmu.Lock()
+	defer func() {
+		self.chainmu.Unlock()
+		time.Sleep(time.Millisecond * 10) // ugly hack; do not hog chain lock in case syncing is CPU-limited by validation
+	}()
+
+	self.wg.Add(1)
+	defer self.wg.Done()
+
+	var events []interface{}
+	whFunc := func(header *types.HeaderWithGovState) error {
+		self.mu.Lock()
+		defer self.mu.Unlock()
+
+		status, err := self.hc.WriteDexonHeader(header)
+
+		switch status {
+		case core.CanonStatTy:
+			log.Debug("Inserted new header", "number", header.Number, "hash", header.Hash())
+			events = append(events, core.ChainEvent{Block: types.NewBlockWithHeader(header.Header), Hash: header.Hash()})
+
+		case core.SideStatTy:
+			log.Debug("Inserted forked header", "number", header.Number, "hash", header.Hash())
+			events = append(events, core.ChainSideEvent{Block: types.NewBlockWithHeader(header.Header)})
+			panic("fork found")
+		}
+		return err
+	}
+	i, err := self.hc.InsertDexonHeaderChain(chain, whFunc, start)
+	self.postChainEvents(events)
+	return i, err
 }
 
 // CurrentHeader retrieves the current head header of the canonical chain. The
diff --git a/light/validator.go b/light/validator.go
new file mode 100644
index 000000000..7f776bcfb
--- /dev/null
+++ b/light/validator.go
@@ -0,0 +1,26 @@
+package light
+
+import (
+	"github.com/dexon-foundation/dexon/common"
+	"github.com/dexon-foundation/dexon/consensus"
+	"github.com/dexon-foundation/dexon/log"
+)
+
+type HeaderValidator struct {
+	chain *LightChain
+}
+
+func (v *HeaderValidator) ValidateWitnessData(height uint64, blockHash common.Hash) error {
+	b := v.chain.GetHeaderByNumber(height)
+	if b == nil {
+		log.Error("can not find block %v either pending or confirmed block", height)
+		return consensus.ErrWitnessMismatch
+	}
+
+	if b.Hash() != blockHash {
+		log.Error("invalid witness block %s vs %s",
+			b.Hash().String(), blockHash.String())
+		return consensus.ErrWitnessMismatch
+	}
+	return nil
+}