core/state: access trie through Database interface, track errors (#14589)

With this commit, core/state's access to the underlying key/value database is
mediated through an interface. Database errors are tracked in StateDB and
returned by CommitTo or the new Error method.

Motivation for this change: We can remove the light client's duplicated copy of
core/state. The light client now supports node iteration, so tracing and storage
enumeration can work with the light client (not implemented in this commit).

3 files changed, 29 insertions, 46 deletions

diff --git a/les/api_backend.go b/les/api_backend.go
index 7d69046de..7a3c2447c 100644
--- a/les/api_backend.go
+++ b/les/api_backend.go
@@ -24,13 +24,13 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/math"
 	"github.com/ethereum/go-ethereum/core"
+	"github.com/ethereum/go-ethereum/core/state"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/core/vm"
 	"github.com/ethereum/go-ethereum/eth/downloader"
 	"github.com/ethereum/go-ethereum/eth/gasprice"
 	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/event"
-	"github.com/ethereum/go-ethereum/internal/ethapi"
 	"github.com/ethereum/go-ethereum/light"
 	"github.com/ethereum/go-ethereum/params"
 	"github.com/ethereum/go-ethereum/rpc"
@@ -70,12 +70,12 @@ func (b *LesApiBackend) BlockByNumber(ctx context.Context, blockNr rpc.BlockNumb
 	return b.GetBlock(ctx, header.Hash())
 }
 
-func (b *LesApiBackend) StateAndHeaderByNumber(ctx context.Context, blockNr rpc.BlockNumber) (ethapi.State, *types.Header, error) {
+func (b *LesApiBackend) StateAndHeaderByNumber(ctx context.Context, blockNr rpc.BlockNumber) (*state.StateDB, *types.Header, error) {
 	header, err := b.HeaderByNumber(ctx, blockNr)
 	if header == nil || err != nil {
 		return nil, nil, err
 	}
-	return light.NewLightState(light.StateTrieID(header), b.eth.odr), header, nil
+	return light.NewState(ctx, header, b.eth.odr), header, nil
 }
 
 func (b *LesApiBackend) GetBlock(ctx context.Context, blockHash common.Hash) (*types.Block, error) {
@@ -90,18 +90,10 @@ func (b *LesApiBackend) GetTd(blockHash common.Hash) *big.Int {
 	return b.eth.blockchain.GetTdByHash(blockHash)
 }
 
-func (b *LesApiBackend) GetEVM(ctx context.Context, msg core.Message, state ethapi.State, header *types.Header, vmCfg vm.Config) (*vm.EVM, func() error, error) {
-	stateDb := state.(*light.LightState).Copy()
-	addr := msg.From()
-	from, err := stateDb.GetOrNewStateObject(ctx, addr)
-	if err != nil {
-		return nil, nil, err
-	}
-	from.SetBalance(math.MaxBig256)
-
-	vmstate := light.NewVMState(ctx, stateDb)
+func (b *LesApiBackend) GetEVM(ctx context.Context, msg core.Message, state *state.StateDB, header *types.Header, vmCfg vm.Config) (*vm.EVM, func() error, error) {
+	state.SetBalance(msg.From(), math.MaxBig256)
 	context := core.NewEVMContext(msg, header, b.eth.blockchain, nil)
-	return vm.NewEVM(context, vmstate, b.eth.chainConfig, vmCfg), vmstate.Error, nil
+	return vm.NewEVM(context, state, b.eth.chainConfig, vmCfg), state.Error, nil
 }
 
 func (b *LesApiBackend) SendTx(ctx context.Context, signedTx *types.Transaction) error {
diff --git a/les/odr_test.go b/les/odr_test.go
index 7b34996ce..3a0fd6738 100644
--- a/les/odr_test.go
+++ b/les/odr_test.go
@@ -75,24 +75,23 @@ func odrAccounts(ctx context.Context, db ethdb.Database, config *params.ChainCon
 	dummyAddr := common.HexToAddress("1234567812345678123456781234567812345678")
 	acc := []common.Address{testBankAddress, acc1Addr, acc2Addr, dummyAddr}
 
-	var res []byte
+	var (
+		res []byte
+		st  *state.StateDB
+		err error
+	)
 	for _, addr := range acc {
 		if bc != nil {
 			header := bc.GetHeaderByHash(bhash)
-			st, err := state.New(header.Root, db)
-			if err == nil {
-				bal := st.GetBalance(addr)
-				rlp, _ := rlp.EncodeToBytes(bal)
-				res = append(res, rlp...)
-			}
+			st, err = state.New(header.Root, state.NewDatabase(db))
 		} else {
 			header := lc.GetHeaderByHash(bhash)
-			st := light.NewLightState(light.StateTrieID(header), lc.Odr())
-			bal, err := st.GetBalance(ctx, addr)
-			if err == nil {
-				rlp, _ := rlp.EncodeToBytes(bal)
-				res = append(res, rlp...)
-			}
+			st = light.NewState(ctx, header, lc.Odr())
+		}
+		if err == nil {
+			bal := st.GetBalance(addr)
+			rlp, _ := rlp.EncodeToBytes(bal)
+			res = append(res, rlp...)
 		}
 	}
 
@@ -115,7 +114,7 @@ func odrContractCall(ctx context.Context, db ethdb.Database, config *params.Chai
 		data[35] = byte(i)
 		if bc != nil {
 			header := bc.GetHeaderByHash(bhash)
-			statedb, err := state.New(header.Root, db)
+			statedb, err := state.New(header.Root, state.NewDatabase(db))
 
 			if err == nil {
 				from := statedb.GetOrNewStateObject(testBankAddress)
@@ -133,23 +132,15 @@ func odrContractCall(ctx context.Context, db ethdb.Database, config *params.Chai
 			}
 		} else {
 			header := lc.GetHeaderByHash(bhash)
-			state := light.NewLightState(light.StateTrieID(header), lc.Odr())
-			vmstate := light.NewVMState(ctx, state)
-			from, err := state.GetOrNewStateObject(ctx, testBankAddress)
-			if err == nil {
-				from.SetBalance(math.MaxBig256)
-
-				msg := callmsg{types.NewMessage(from.Address(), &testContractAddr, 0, new(big.Int), big.NewInt(100000), new(big.Int), data, false)}
-
-				context := core.NewEVMContext(msg, header, lc, nil)
-				vmenv := vm.NewEVM(context, vmstate, config, vm.Config{})
-
-				//vmenv := light.NewEnv(ctx, state, config, lc, msg, header, vm.Config{})
-				gp := new(core.GasPool).AddGas(math.MaxBig256)
-				ret, _, _ := core.ApplyMessage(vmenv, msg, gp)
-				if vmstate.Error() == nil {
-					res = append(res, ret...)
-				}
+			state := light.NewState(ctx, header, lc.Odr())
+			state.SetBalance(testBankAddress, math.MaxBig256)
+			msg := callmsg{types.NewMessage(testBankAddress, &testContractAddr, 0, new(big.Int), big.NewInt(100000), new(big.Int), data, false)}
+			context := core.NewEVMContext(msg, header, lc, nil)
+			vmenv := vm.NewEVM(context, state, config, vm.Config{})
+			gp := new(core.GasPool).AddGas(math.MaxBig256)
+			ret, _, _ := core.ApplyMessage(vmenv, msg, gp)
+			if state.Error() == nil {
+				res = append(res, ret...)
 			}
 		}
 	}
diff --git a/les/request_test.go b/les/request_test.go
index 3add5f20d..6b594462d 100644
--- a/les/request_test.go
+++ b/les/request_test.go
@@ -62,7 +62,7 @@ func tfCodeAccess(db ethdb.Database, bhash common.Hash, number uint64) light.Odr
 		return nil
 	}
 	sti := light.StateTrieID(header)
-	ci := light.StorageTrieID(sti, testContractAddr, common.Hash{})
+	ci := light.StorageTrieID(sti, crypto.Keccak256Hash(testContractAddr[:]), common.Hash{})
 	return &light.CodeRequest{Id: ci, Hash: crypto.Keccak256Hash(testContractCodeDeployed)}
 }