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).

1 files changed, 17 insertions, 22 deletions

diff --git a/core/state/state_test.go b/core/state/state_test.go
index 3bc63c148..bbae3685b 100644
--- a/core/state/state_test.go
+++ b/core/state/state_test.go
@@ -21,14 +21,14 @@ import (
 	"math/big"
 	"testing"
 
-	checker "gopkg.in/check.v1"
-
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/ethdb"
+	checker "gopkg.in/check.v1"
 )
 
 type StateSuite struct {
+	db    *ethdb.MemDatabase
 	state *StateDB
 }
 
@@ -48,7 +48,7 @@ func (s *StateSuite) TestDump(c *checker.C) {
 	// write some of them to the trie
 	s.state.updateStateObject(obj1)
 	s.state.updateStateObject(obj2)
-	s.state.Commit(false)
+	s.state.CommitTo(s.db, false)
 
 	// check that dump contains the state objects that are in trie
 	got := string(s.state.Dump())
@@ -87,23 +87,20 @@ func (s *StateSuite) TestDump(c *checker.C) {
 }
 
 func (s *StateSuite) SetUpTest(c *checker.C) {
-	db, _ := ethdb.NewMemDatabase()
-	s.state, _ = New(common.Hash{}, db)
+	s.db, _ = ethdb.NewMemDatabase()
+	s.state, _ = New(common.Hash{}, NewDatabase(s.db))
 }
 
-func TestNull(t *testing.T) {
-	db, _ := ethdb.NewMemDatabase()
-	state, _ := New(common.Hash{}, db)
-
+func (s *StateSuite) TestNull(c *checker.C) {
 	address := common.HexToAddress("0x823140710bf13990e4500136726d8b55")
-	state.CreateAccount(address)
+	s.state.CreateAccount(address)
 	//value := common.FromHex("0x823140710bf13990e4500136726d8b55")
 	var value common.Hash
-	state.SetState(address, common.Hash{}, value)
-	state.Commit(false)
-	value = state.GetState(address, common.Hash{})
+	s.state.SetState(address, common.Hash{}, value)
+	s.state.CommitTo(s.db, false)
+	value = s.state.GetState(address, common.Hash{})
 	if !common.EmptyHash(value) {
-		t.Errorf("expected empty hash. got %x", value)
+		c.Errorf("expected empty hash. got %x", value)
 	}
 }
 
@@ -129,17 +126,15 @@ func (s *StateSuite) TestSnapshot(c *checker.C) {
 	c.Assert(data1, checker.DeepEquals, res)
 }
 
-func TestSnapshotEmpty(t *testing.T) {
-	db, _ := ethdb.NewMemDatabase()
-	state, _ := New(common.Hash{}, db)
-	state.RevertToSnapshot(state.Snapshot())
+func (s *StateSuite) TestSnapshotEmpty(c *checker.C) {
+	s.state.RevertToSnapshot(s.state.Snapshot())
 }
 
 // use testing instead of checker because checker does not support
 // printing/logging in tests (-check.vv does not work)
 func TestSnapshot2(t *testing.T) {
 	db, _ := ethdb.NewMemDatabase()
-	state, _ := New(common.Hash{}, db)
+	state, _ := New(common.Hash{}, NewDatabase(db))
 
 	stateobjaddr0 := toAddr([]byte("so0"))
 	stateobjaddr1 := toAddr([]byte("so1"))
@@ -160,7 +155,7 @@ func TestSnapshot2(t *testing.T) {
 	so0.deleted = false
 	state.setStateObject(so0)
 
-	root, _ := state.Commit(false)
+	root, _ := state.CommitTo(db, false)
 	state.Reset(root)
 
 	// and one with deleted == true
@@ -182,8 +177,8 @@ func TestSnapshot2(t *testing.T) {
 
 	so0Restored := state.getStateObject(stateobjaddr0)
 	// Update lazily-loaded values before comparing.
-	so0Restored.GetState(db, storageaddr)
-	so0Restored.Code(db)
+	so0Restored.GetState(state.db, storageaddr)
+	so0Restored.Code(state.db)
 	// non-deleted is equal (restored)
 	compareStateObjects(so0Restored, so0, t)