core: create a header chain structure shared by core.BlockChain and light.LightChain

core/blockchain_test.go

@@ -472,11 +472,16 @@ func makeBlockChainWithDiff(genesis *types.Block, d []int, seed byte) []*types.B
 
 func chm(genesis *types.Block, db ethdb.Database) *BlockChain {
 	var eventMux event.TypeMux
-	bc := &BlockChain{chainDb: db, genesisBlock: genesis, eventMux: &eventMux, pow: FakePow{}, rand: rand.New(rand.NewSource(0))}
-	bc.headerCache, _ = lru.New(100)
+	bc := &BlockChain{
+		chainDb: db,
+		genesisBlock: genesis,
+		eventMux: &eventMux,
+		pow: FakePow{},
+	}
+	valFn := func() HeaderValidator { return bc.Validator() }
+	bc.hc, _ = NewHeaderChain(db, valFn, bc.getProcInterrupt)
 	bc.bodyCache, _ = lru.New(100)
 	bc.bodyRLPCache, _ = lru.New(100)
-	bc.tdCache, _ = lru.New(100)
 	bc.blockCache, _ = lru.New(100)
 	bc.futureBlocks, _ = lru.New(100)
 	bc.SetValidator(bproc{})

core/types.go

@@ -38,14 +38,22 @@ import (
 // ValidateHeader validates the given header and parent and returns an error
 // if it failed to do so.
 //
-// ValidateStack validates the given statedb and optionally the receipts and
+// ValidateState validates the given statedb and optionally the receipts and
 // gas used. The implementor should decide what to do with the given input.
 type Validator interface {
+	HeaderValidator
 	ValidateBlock(block *types.Block) error
-	ValidateHeader(header, parent *types.Header, checkPow bool) error
 	ValidateState(block, parent *types.Block, state *state.StateDB, receipts types.Receipts, usedGas *big.Int) error
 }
 
+// HeaderValidator is an interface for validating headers only
+//
+// ValidateHeader validates the given header and parent and returns an error
+// if it failed to do so.
+type HeaderValidator interface {
+	ValidateHeader(header, parent *types.Header, checkPow bool) 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