eth/tracers: move tracing APIs into eth/tracers

cmd/utils/flags.go

@@ -45,6 +45,7 @@ import (
 	"github.com/ethereum/go-ethereum/eth"
 	"github.com/ethereum/go-ethereum/eth/downloader"
 	"github.com/ethereum/go-ethereum/eth/gasprice"
+	"github.com/ethereum/go-ethereum/eth/tracers"
 	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/ethstats"
 	"github.com/ethereum/go-ethereum/graphql"
@@ -1724,6 +1725,7 @@ func RegisterEthService(stack *node.Node, cfg *eth.Config) ethapi.Backend {
 		if err != nil {
 			Fatalf("Failed to register the Ethereum service: %v", err)
 		}
+		stack.RegisterAPIs(tracers.APIs(backend.ApiBackend))
 		return backend.ApiBackend
 	}
 	backend, err := eth.New(stack, cfg)
@@ -1736,6 +1738,7 @@ func RegisterEthService(stack *node.Node, cfg *eth.Config) ethapi.Backend {
 			Fatalf("Failed to create the LES server: %v", err)
 		}
 	}
+	stack.RegisterAPIs(tracers.APIs(backend.APIBackend))
 	return backend.APIBackend
 }
 

eth/api.go

@@ -426,10 +426,11 @@ func (api *PrivateDebugAPI) StorageRangeAt(blockHash common.Hash, txIndex int, c
 	if block == nil {
 		return StorageRangeResult{}, fmt.Errorf("block %#x not found", blockHash)
 	}
-	_, _, statedb, err := api.computeTxEnv(block, txIndex, 0)
+	_, _, statedb, release, err := api.eth.stateAtTransaction(block, txIndex, 0)
 	if err != nil {
 		return StorageRangeResult{}, err
 	}
+	defer release()
 	st := statedb.StorageTrie(contractAddress)
 	if st == nil {
 		return StorageRangeResult{}, fmt.Errorf("account %x doesn't exist", contractAddress)

eth/api_backend.go

@@ -326,3 +326,15 @@ func (b *EthAPIBackend) Miner() *miner.Miner {
 func (b *EthAPIBackend) StartMining(threads int) error {
 	return b.eth.StartMining(threads)
 }
+
+func (b *EthAPIBackend) StateAtBlock(ctx context.Context, block *types.Block, reexec uint64) (*state.StateDB, func(), error) {
+	return b.eth.stateAtBlock(block, reexec)
+}
+
+func (b *EthAPIBackend) StatesInRange(ctx context.Context, fromBlock *types.Block, toBlock *types.Block, reexec uint64) ([]*state.StateDB, func(), error) {
+	return b.eth.statesInRange(fromBlock, toBlock, reexec)
+}
+
+func (b *EthAPIBackend) StateAtTransaction(ctx context.Context, block *types.Block, txIndex int, reexec uint64) (core.Message, vm.BlockContext, *state.StateDB, func(), error) {
+	return b.eth.stateAtTransaction(block, txIndex, reexec)
+}

eth/state_accessor.go

@@ -0,0 +1,230 @@
+// Copyright 2021 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package eth
+
+import (
+	"errors"
+	"fmt"
+	"time"
+
+	"github.com/ethereum/go-ethereum/common"
+	"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/log"
+	"github.com/ethereum/go-ethereum/trie"
+)
+
+// stateAtBlock retrieves the state database associated with a certain block.
+// If no state is locally available for the given block, a number of blocks are
+// attempted to be reexecuted to generate the desired state.
+func (eth *Ethereum) stateAtBlock(block *types.Block, reexec uint64) (statedb *state.StateDB, release func(), err error) {
+	// If we have the state fully available, use that
+	statedb, err = eth.blockchain.StateAt(block.Root())
+	if err == nil {
+		return statedb, func() {}, nil
+	}
+	// Otherwise try to reexec blocks until we find a state or reach our limit
+	origin := block.NumberU64()
+	database := state.NewDatabaseWithConfig(eth.chainDb, &trie.Config{Cache: 16, Preimages: true})
+
+	for i := uint64(0); i < reexec; i++ {
+		if block.NumberU64() == 0 {
+			return nil, nil, errors.New("genesis state is missing")
+		}
+		parent := eth.blockchain.GetBlock(block.ParentHash(), block.NumberU64()-1)
+		if parent == nil {
+			return nil, nil, fmt.Errorf("missing block %v %d", block.ParentHash(), block.NumberU64()-1)
+		}
+		block = parent
+
+		statedb, err = state.New(block.Root(), database, nil)
+		if err == nil {
+			break
+		}
+	}
+	if err != nil {
+		switch err.(type) {
+		case *trie.MissingNodeError:
+			return nil, nil, fmt.Errorf("required historical state unavailable (reexec=%d)", reexec)
+		default:
+			return nil, nil, err
+		}
+	}
+	// State was available at historical point, regenerate
+	var (
+		start  = time.Now()
+		logged time.Time
+		parent common.Hash
+	)
+	defer func() {
+		if err != nil && parent != (common.Hash{}) {
+			database.TrieDB().Dereference(parent)
+		}
+	}()
+	for block.NumberU64() < origin {
+		// Print progress logs if long enough time elapsed
+		if time.Since(logged) > 8*time.Second {
+			log.Info("Regenerating historical state", "block", block.NumberU64()+1, "target", origin, "remaining", origin-block.NumberU64()-1, "elapsed", time.Since(start))
+			logged = time.Now()
+		}
+		// Retrieve the next block to regenerate and process it
+		if block = eth.blockchain.GetBlockByNumber(block.NumberU64() + 1); block == nil {
+			return nil, nil, fmt.Errorf("block #%d not found", block.NumberU64()+1)
+		}
+		_, _, _, err := eth.blockchain.Processor().Process(block, statedb, vm.Config{})
+		if err != nil {
+			return nil, nil, fmt.Errorf("processing block %d failed: %v", block.NumberU64(), err)
+		}
+		// Finalize the state so any modifications are written to the trie
+		root, err := statedb.Commit(eth.blockchain.Config().IsEIP158(block.Number()))
+		if err != nil {
+			return nil, nil, err
+		}
+		statedb, err = state.New(root, database, nil)
+		if err != nil {
+			return nil, nil, fmt.Errorf("state reset after block %d failed: %v", block.NumberU64(), err)
+		}
+		database.TrieDB().Reference(root, common.Hash{})
+		if parent != (common.Hash{}) {
+			database.TrieDB().Dereference(parent)
+		}
+		parent = root
+	}
+	nodes, imgs := database.TrieDB().Size()
+	log.Info("Historical state regenerated", "block", block.NumberU64(), "elapsed", time.Since(start), "nodes", nodes, "preimages", imgs)
+	return statedb, func() { database.TrieDB().Dereference(parent) }, nil
+}
+
+// statesInRange retrieves a batch of state databases associated with the specific
+// block ranges. If no state is locally available for the given range, a number of
+// blocks are attempted to be reexecuted to generate the ancestor state.
+func (eth *Ethereum) statesInRange(fromBlock, toBlock *types.Block, reexec uint64) (states []*state.StateDB, release func(), err error) {
+	statedb, err := eth.blockchain.StateAt(fromBlock.Root())
+	if err != nil {
+		statedb, _, err = eth.stateAtBlock(fromBlock, reexec)
+	}
+	if err != nil {
+		return nil, nil, err
+	}
+	states = append(states, statedb.Copy())
+
+	var (
+		logged   time.Time
+		parent   common.Hash
+		start    = time.Now()
+		refs     = []common.Hash{fromBlock.Root()}
+		database = state.NewDatabaseWithConfig(eth.chainDb, &trie.Config{Cache: 16, Preimages: true})
+	)
+	// Release all resources(including the states referenced by `stateAtBlock`)
+	// if error is returned.
+	defer func() {
+		if err != nil {
+			for _, ref := range refs {
+				database.TrieDB().Dereference(ref)
+			}
+		}
+	}()
+	for i := fromBlock.NumberU64() + 1; i <= toBlock.NumberU64(); i++ {
+		// Print progress logs if long enough time elapsed
+		if time.Since(logged) > 8*time.Second {
+			logged = time.Now()
+			log.Info("Regenerating historical state", "block", i, "target", fromBlock.NumberU64(), "remaining", toBlock.NumberU64()-i, "elapsed", time.Since(start))
+		}
+		// Retrieve the next block to regenerate and process it
+		block := eth.blockchain.GetBlockByNumber(i)
+		if block == nil {
+			return nil, nil, fmt.Errorf("block #%d not found", i)
+		}
+		_, _, _, err := eth.blockchain.Processor().Process(block, statedb, vm.Config{})
+		if err != nil {
+			return nil, nil, fmt.Errorf("processing block %d failed: %v", block.NumberU64(), err)
+		}
+		// Finalize the state so any modifications are written to the trie
+		root, err := statedb.Commit(eth.blockchain.Config().IsEIP158(block.Number()))
+		if err != nil {
+			return nil, nil, err
+		}
+		statedb, err := eth.blockchain.StateAt(root)
+		if err != nil {
+			return nil, nil, fmt.Errorf("state reset after block %d failed: %v", block.NumberU64(), err)
+		}
+		states = append(states, statedb.Copy())
+
+		// Reference the trie twice, once for us, once for the tracer
+		database.TrieDB().Reference(root, common.Hash{})
+		database.TrieDB().Reference(root, common.Hash{})
+		refs = append(refs, root)
+
+		// Dereference all past tries we ourselves are done working with
+		if parent != (common.Hash{}) {
+			database.TrieDB().Dereference(parent)
+		}
+		parent = root
+	}
+	// release is handler to release all states referenced, including
+	// the one referenced in `stateAtBlock`.
+	release = func() {
+		for _, ref := range refs {
+			database.TrieDB().Dereference(ref)
+		}
+	}
+	return states, release, nil
+}
+
+// stateAtTransaction returns the execution environment of a certain transaction.
+func (eth *Ethereum) stateAtTransaction(block *types.Block, txIndex int, reexec uint64) (core.Message, vm.BlockContext, *state.StateDB, func(), error) {
+	// Short circuit if it's genesis block.
+	if block.NumberU64() == 0 {
+		return nil, vm.BlockContext{}, nil, nil, errors.New("no transaction in genesis")
+	}
+	// Create the parent state database
+	parent := eth.blockchain.GetBlock(block.ParentHash(), block.NumberU64()-1)
+	if parent == nil {
+		return nil, vm.BlockContext{}, nil, nil, fmt.Errorf("parent %#x not found", block.ParentHash())
+	}
+	statedb, release, err := eth.stateAtBlock(parent, reexec)
+	if err != nil {
+		return nil, vm.BlockContext{}, nil, nil, err
+	}
+	if txIndex == 0 && len(block.Transactions()) == 0 {
+		return nil, vm.BlockContext{}, statedb, release, nil
+	}
+	// Recompute transactions up to the target index.
+	signer := types.MakeSigner(eth.blockchain.Config(), block.Number())
+	for idx, tx := range block.Transactions() {
+		// Assemble the transaction call message and return if the requested offset
+		msg, _ := tx.AsMessage(signer)
+		txContext := core.NewEVMTxContext(msg)
+		context := core.NewEVMBlockContext(block.Header(), eth.blockchain, nil)
+		if idx == txIndex {
+			return msg, context, statedb, release, nil
+		}
+		// Not yet the searched for transaction, execute on top of the current state
+		vmenv := vm.NewEVM(context, txContext, statedb, eth.blockchain.Config(), vm.Config{})
+		if _, err := core.ApplyMessage(vmenv, msg, new(core.GasPool).AddGas(tx.Gas())); err != nil {
+			release()
+			return nil, vm.BlockContext{}, nil, nil, fmt.Errorf("transaction %#x failed: %v", tx.Hash(), err)
+		}
+		// Ensure any modifications are committed to the state
+		// Only delete empty objects if EIP158/161 (a.k.a Spurious Dragon) is in effect
+		statedb.Finalise(vmenv.ChainConfig().IsEIP158(block.Number()))
+	}
+	release()
+	return nil, vm.BlockContext{}, nil, nil, fmt.Errorf("transaction index %d out of range for block %#x", txIndex, block.Hash())
+}