core/state: access trie through Database interface, track errors (eth…

…ereum#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).

accounts/abi/bind/backends/simulated.go

@@ -90,7 +90,7 @@ func (b *SimulatedBackend) Rollback() {
 func (b *SimulatedBackend) rollback() {
 	blocks, _ := core.GenerateChain(b.config, b.blockchain.CurrentBlock(), b.database, 1, func(int, *core.BlockGen) {})
 	b.pendingBlock = blocks[0]
-	b.pendingState, _ = state.New(b.pendingBlock.Root(), b.database)
+	b.pendingState, _ = state.New(b.pendingBlock.Root(), state.NewDatabase(b.database))
 }
 
 // CodeAt returns the code associated with a certain account in the blockchain.
@@ -279,7 +279,7 @@ func (b *SimulatedBackend) SendTransaction(ctx context.Context, tx *types.Transa
 		block.AddTx(tx)
 	})
 	b.pendingBlock = blocks[0]
-	b.pendingState, _ = state.New(b.pendingBlock.Root(), b.database)
+	b.pendingState, _ = state.New(b.pendingBlock.Root(), state.NewDatabase(b.database))
 	return nil
 }
 

cmd/evm/runner.go

@@ -98,8 +98,8 @@ func runCmd(ctx *cli.Context) error {
 		_, statedb = gen.ToBlock()
 		chainConfig = gen.Config
 	} else {
-		var db, _ = ethdb.NewMemDatabase()
-		statedb, _ = state.New(common.Hash{}, db)
+		db, _ := ethdb.NewMemDatabase()
+		statedb, _ = state.New(common.Hash{}, state.NewDatabase(db))
 	}
 	if ctx.GlobalString(SenderFlag.Name) != "" {
 		sender = common.HexToAddress(ctx.GlobalString(SenderFlag.Name))
@@ -188,7 +188,7 @@ func runCmd(ctx *cli.Context) error {
 	execTime := time.Since(tstart)
 
 	if ctx.GlobalBool(DumpFlag.Name) {
-		statedb.Commit(true)
+		statedb.IntermediateRoot(true)
 		fmt.Println(string(statedb.Dump()))
 	}
 

cmd/geth/chaincmd.go

@@ -312,7 +312,7 @@ func dump(ctx *cli.Context) error {
 			fmt.Println("{}")
 			utils.Fatalf("block not found")
 		} else {
-			state, err := state.New(block.Root(), chainDb)
+			state, err := state.New(block.Root(), state.NewDatabase(chainDb))
 			if err != nil {
 				utils.Fatalf("could not create new state: %v", err)
 			}

core/block_validator.go

@@ -52,16 +52,10 @@ func NewBlockValidator(config *params.ChainConfig, blockchain *BlockChain, engin
 // validated at this point.
 func (v *BlockValidator) ValidateBody(block *types.Block) error {
 	// Check whether the block's known, and if not, that it's linkable
-	if v.bc.HasBlock(block.Hash()) {
-		if _, err := state.New(block.Root(), v.bc.chainDb); err == nil {
-			return ErrKnownBlock
-		}
+	if v.bc.HasBlockAndState(block.Hash()) {
+		return ErrKnownBlock
 	}
-	parent := v.bc.GetBlock(block.ParentHash(), block.NumberU64()-1)
-	if parent == nil {
-		return consensus.ErrUnknownAncestor
-	}
-	if _, err := state.New(parent.Root(), v.bc.chainDb); err != nil {
+	if !v.bc.HasBlockAndState(block.ParentHash()) {
 		return consensus.ErrUnknownAncestor
 	}
 	// Header validity is known at this point, check the uncles and transactions

core/blockchain.go

@@ -92,7 +92,7 @@ type BlockChain struct {
 	currentBlock     *types.Block // Current head of the block chain
 	currentFastBlock *types.Block // Current head of the fast-sync chain (may be above the block chain!)
 
-	stateCache   *state.StateDB // State database to reuse between imports (contains state cache)
+	stateCache   state.Database // State database to reuse between imports (contains state cache)
 	bodyCache    *lru.Cache     // Cache for the most recent block bodies
 	bodyRLPCache *lru.Cache     // Cache for the most recent block bodies in RLP encoded format
 	blockCache   *lru.Cache     // Cache for the most recent entire blocks
@@ -125,6 +125,7 @@ func NewBlockChain(chainDb ethdb.Database, config *params.ChainConfig, engine co
 	bc := &BlockChain{
 		config:       config,
 		chainDb:      chainDb,
+		stateCache:   state.NewDatabase(chainDb),
 		eventMux:     mux,
 		quit:         make(chan struct{}),
 		bodyCache:    bodyCache,
@@ -190,7 +191,7 @@ func (bc *BlockChain) loadLastState() error {
 		return bc.Reset()
 	}
 	// Make sure the state associated with the block is available
-	if _, err := state.New(currentBlock.Root(), bc.chainDb); err != nil {
+	if _, err := state.New(currentBlock.Root(), bc.stateCache); err != nil {
 		// Dangling block without a state associated, init from scratch
 		log.Warn("Head state missing, resetting chain", "number", currentBlock.Number(), "hash", currentBlock.Hash())
 		return bc.Reset()
@@ -214,12 +215,6 @@ func (bc *BlockChain) loadLastState() error {
 			bc.currentFastBlock = block
 		}
 	}
-	// Initialize a statedb cache to ensure singleton account bloom filter generation
-	statedb, err := state.New(bc.currentBlock.Root(), bc.chainDb)
-	if err != nil {
-		return err
-	}
-	bc.stateCache = statedb
 
 	// Issue a status log for the user
 	headerTd := bc.GetTd(currentHeader.Hash(), currentHeader.Number.Uint64())
@@ -261,7 +256,7 @@ func (bc *BlockChain) SetHead(head uint64) error {
 		bc.currentBlock = bc.GetBlock(currentHeader.Hash(), currentHeader.Number.Uint64())
 	}
 	if bc.currentBlock != nil {
-		if _, err := state.New(bc.currentBlock.Root(), bc.chainDb); err != nil {
+		if _, err := state.New(bc.currentBlock.Root(), bc.stateCache); err != nil {
 			// Rewound state missing, rolled back to before pivot, reset to genesis
 			bc.currentBlock = nil
 		}
@@ -384,7 +379,7 @@ func (bc *BlockChain) State() (*state.StateDB, error) {
 
 // StateAt returns a new mutable state based on a particular point in time.
 func (bc *BlockChain) StateAt(root common.Hash) (*state.StateDB, error) {
-	return bc.stateCache.New(root)
+	return state.New(root, bc.stateCache)
 }
 
 // Reset purges the entire blockchain, restoring it to its genesis state.
@@ -531,7 +526,7 @@ func (bc *BlockChain) HasBlockAndState(hash common.Hash) bool {
 		return false
 	}
 	// Ensure the associated state is also present
-	_, err := state.New(block.Root(), bc.chainDb)
+	_, err := bc.stateCache.OpenTrie(block.Root())
 	return err == nil
 }
 
@@ -959,31 +954,30 @@ func (bc *BlockChain) InsertChain(chain types.Blocks) (int, error) {
 		}
 		// Create a new statedb using the parent block and report an
 		// error if it fails.
-		switch {
-		case i == 0:
-			err = bc.stateCache.Reset(bc.GetBlock(block.ParentHash(), block.NumberU64()-1).Root())
-		default:
-			err = bc.stateCache.Reset(chain[i-1].Root())
+		var parent *types.Block
+		if i == 0 {
+			parent = bc.GetBlock(block.ParentHash(), block.NumberU64()-1)
+		} else {
+			parent = chain[i-1]
 		}
+		state, err := state.New(parent.Root(), bc.stateCache)
 		if err != nil {
-			bc.reportBlock(block, nil, err)
 			return i, err
 		}
 		// Process block using the parent state as reference point.
-		receipts, logs, usedGas, err := bc.processor.Process(block, bc.stateCache, bc.vmConfig)
+		receipts, logs, usedGas, err := bc.processor.Process(block, state, bc.vmConfig)
 		if err != nil {
 			bc.reportBlock(block, receipts, err)
 			return i, err
 		}
 		// Validate the state using the default validator
-		err = bc.Validator().ValidateState(block, bc.GetBlock(block.ParentHash(), block.NumberU64()-1), bc.stateCache, receipts, usedGas)
+		err = bc.Validator().ValidateState(block, parent, state, receipts, usedGas)
 		if err != nil {
 			bc.reportBlock(block, receipts, err)
 			return i, err
 		}
 		// Write state changes to database
-		_, err = bc.stateCache.Commit(bc.config.IsEIP158(block.Number()))
-		if err != nil {
+		if _, err = state.CommitTo(bc.chainDb, bc.config.IsEIP158(block.Number())); err != nil {
 			return i, err
 		}
 
@@ -1021,7 +1015,7 @@ func (bc *BlockChain) InsertChain(chain types.Blocks) (int, error) {
 				return i, err
 			}
 			// Write hash preimages
-			if err := WritePreimages(bc.chainDb, block.NumberU64(), bc.stateCache.Preimages()); err != nil {
+			if err := WritePreimages(bc.chainDb, block.NumberU64(), state.Preimages()); err != nil {
 				return i, err
 			}
 		case SideStatTy:

core/blockchain_test.go

@@ -131,7 +131,7 @@ func testBlockChainImport(chain types.Blocks, blockchain *BlockChain) error {
 			}
 			return err
 		}
-		statedb, err := state.New(blockchain.GetBlockByHash(block.ParentHash()).Root(), blockchain.chainDb)
+		statedb, err := state.New(blockchain.GetBlockByHash(block.ParentHash()).Root(), blockchain.stateCache)
 		if err != nil {
 			return err
 		}
@@ -148,7 +148,7 @@ func testBlockChainImport(chain types.Blocks, blockchain *BlockChain) error {
 		blockchain.mu.Lock()
 		WriteTd(blockchain.chainDb, block.Hash(), block.NumberU64(), new(big.Int).Add(block.Difficulty(), blockchain.GetTdByHash(block.ParentHash())))
 		WriteBlock(blockchain.chainDb, block)
-		statedb.Commit(false)
+		statedb.CommitTo(blockchain.chainDb, false)
 		blockchain.mu.Unlock()
 	}
 	return nil
@@ -1131,23 +1131,23 @@ func TestEIP161AccountRemoval(t *testing.T) {
 	if _, err := blockchain.InsertChain(types.Blocks{blocks[0]}); err != nil {
 		t.Fatal(err)
 	}
-	if !blockchain.stateCache.Exist(theAddr) {
+	if st, _ := blockchain.State(); !st.Exist(theAddr) {
 		t.Error("expected account to exist")
 	}
 
 	// account needs to be deleted post eip 161
 	if _, err := blockchain.InsertChain(types.Blocks{blocks[1]}); err != nil {
 		t.Fatal(err)
 	}
-	if blockchain.stateCache.Exist(theAddr) {
+	if st, _ := blockchain.State(); st.Exist(theAddr) {
 		t.Error("account should not exist")
 	}
 
 	// account musn't be created post eip 161
 	if _, err := blockchain.InsertChain(types.Blocks{blocks[2]}); err != nil {
 		t.Fatal(err)
 	}
-	if blockchain.stateCache.Exist(theAddr) {
+	if st, _ := blockchain.State(); st.Exist(theAddr) {
 		t.Error("account should not exist")
 	}
 }

core/chain_makers.go

@@ -181,15 +181,15 @@ func GenerateChain(config *params.ChainConfig, parent *types.Block, db ethdb.Dat
 			gen(i, b)
 		}
 		ethash.AccumulateRewards(statedb, h, b.uncles)
-		root, err := statedb.Commit(config.IsEIP158(h.Number))
+		root, err := statedb.CommitTo(db, config.IsEIP158(h.Number))
 		if err != nil {
 			panic(fmt.Sprintf("state write error: %v", err))
 		}
 		h.Root = root
 		return types.NewBlock(h, b.txs, b.uncles, b.receipts), b.receipts
 	}
 	for i := 0; i < n; i++ {
-		statedb, err := state.New(parent.Root(), db)
+		statedb, err := state.New(parent.Root(), state.NewDatabase(db))
 		if err != nil {
 			panic(err)
 		}

core/genesis.go

@@ -176,7 +176,7 @@ func (g *Genesis) configOrDefault(ghash common.Hash) *params.ChainConfig {
 // ToBlock creates the block and state of a genesis specification.
 func (g *Genesis) ToBlock() (*types.Block, *state.StateDB) {
 	db, _ := ethdb.NewMemDatabase()
-	statedb, _ := state.New(common.Hash{}, db)
+	statedb, _ := state.New(common.Hash{}, state.NewDatabase(db))
 	for addr, account := range g.Alloc {
 		statedb.AddBalance(addr, account.Balance)
 		statedb.SetCode(addr, account.Code)