tracetx

eth/api_pre_exec.go

@@ -2,15 +2,21 @@ package eth
 
 import (
 	"context"
+	"errors"
+	"fmt"
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"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/tracers"
+	"github.com/ethereum/go-ethereum/internal/ethapi"
 	"github.com/ethereum/go-ethereum/rpc"
 	"golang.org/x/crypto/sha3"
 	"hash"
 	"math/big"
+	"time"
 )
 
 type helpHash struct {
@@ -40,6 +46,14 @@ type PreExecTx struct {
 	From, To, Data, Value, Gas, GasPrice, Nonce string
 }
 
+type preData struct {
+	block   *types.Block
+	tx      *types.Transaction
+	msg     types.Message
+	stateDb *state.StateDB
+	header  *types.Header
+}
+
 // PreExecAPI provides pre exec info for rpc
 type PreExecAPI struct {
 	e *Ethereum
@@ -81,36 +95,117 @@ func (api *PreExecAPI) getBlockAndMsg(origin *PreExecTx, number *big.Int) (*type
 	return block, msg
 }
 
+func (api *PreExecAPI) prepareData(ctx context.Context, origin *PreExecTx) (*preData, error) {
+	var (
+		d   preData
+		err error
+	)
+	bc := api.e.blockchain
+	d.header, err = api.e.APIBackend.HeaderByNumber(ctx, rpc.LatestBlockNumber)
+	if err != nil {
+		return nil, err
+	}
+	latestNumber := d.header.Number
+	parent := api.e.blockchain.GetBlockByNumber(latestNumber.Uint64())
+	d.stateDb, err = state.New(parent.Header().Root, bc.StateCache(), bc.Snapshots())
+	if err != nil {
+		return nil, err
+	}
+	d.block, d.msg = api.getBlockAndMsg(origin, latestNumber)
+	d.tx = d.block.Transactions()[0]
+	return &d, nil
+}
+
 func (api *PreExecAPI) GetLogs(ctx context.Context, origin *PreExecTx) (*types.Receipt, error) {
 	var (
 		bc = api.e.blockchain
 	)
-	header, err := api.e.APIBackend.HeaderByNumber(ctx, rpc.LatestBlockNumber)
+	d, err := api.prepareData(ctx, origin)
 	if err != nil {
 		return nil, err
 	}
-	latestNumber := header.Number
-
-	parent := bc.GetBlockByNumber(latestNumber.Uint64())
-	stateDb, err := state.New(parent.Header().Root, bc.StateCache(), bc.Snapshots())
-	if err != nil {
-		return nil, err
-	}
-
-	block, msg := api.getBlockAndMsg(origin, latestNumber)
-	tx := block.Transactions()[0]
-	gas := tx.Gas()
+	gas := d.tx.Gas()
 	gp := new(core.GasPool).AddGas(gas)
 
-	stateDb.Prepare(tx.Hash(), block.Hash(), 0)
+	d.stateDb.Prepare(d.tx.Hash(), d.block.Hash(), 0)
 	receipt, err := core.ApplyTransactionForPreExec(
-		bc.Config(), bc, nil, gp, stateDb, header, tx, msg, &gas, *bc.GetVMConfig())
+		bc.Config(), bc, nil, gp, d.stateDb, d.header, d.tx, d.msg, &gas, *bc.GetVMConfig())
 	if err != nil {
 		return nil, err
 	}
 	return receipt, nil
 }
 
-func (api *PreExecAPI) TraceTx(ctx context.Context, tx *PreExecTx) (interface{}, error) {
-	return tx.From, nil
+func (api *PreExecAPI) TraceTx(ctx context.Context, origin *PreExecTx, config *tracers.TraceConfig) (interface{}, error) {
+	var (
+		bc     = api.e.blockchain
+		tracer vm.Tracer
+		err    error
+	)
+	d, err := api.prepareData(ctx, origin)
+	if err != nil {
+		return nil, err
+	}
+	txContext := core.NewEVMTxContext(d.msg)
+
+	switch {
+	case config != nil && config.Tracer != nil:
+		// Define a meaningful timeout of a single transaction trace
+		timeout := 5 * time.Second
+		if config.Timeout != nil {
+			if timeout, err = time.ParseDuration(*config.Timeout); err != nil {
+				return nil, err
+			}
+		}
+		// Constuct the JavaScript tracer to execute with
+		if tracer, err = tracers.New(*config.Tracer, txContext); err != nil {
+			return nil, err
+		}
+		// Handle timeouts and RPC cancellations
+		deadlineCtx, cancel := context.WithTimeout(ctx, timeout)
+		go func() {
+			<-deadlineCtx.Done()
+			if deadlineCtx.Err() == context.DeadlineExceeded {
+				tracer.(*tracers.Tracer).Stop(errors.New("execution timeout"))
+			}
+		}()
+		defer cancel()
+
+	case config == nil:
+		tracer = vm.NewStructLogger(nil)
+
+	default:
+		tracer = vm.NewStructLogger(config.LogConfig)
+	}
+	// Run the transaction with tracing enabled.
+	vmenv := vm.NewEVM(core.NewEVMBlockContext(d.header, bc, nil), txContext, d.stateDb, bc.Config(), vm.Config{Debug: true, Tracer: tracer})
+
+	// Call Prepare to clear out the statedb access list
+	d.stateDb.Prepare(d.tx.Hash(), d.block.Hash(), 0)
+
+	result, err := core.ApplyMessage(vmenv, d.msg, new(core.GasPool).AddGas(d.msg.Gas()))
+	if err != nil {
+		return nil, fmt.Errorf("tracing failed: %v", err)
+	}
+	// Depending on the tracer type, format and return the output.
+	switch tracer := tracer.(type) {
+	case *vm.StructLogger:
+		// If the result contains a revert reason, return it.
+		returnVal := fmt.Sprintf("%x", result.Return())
+		if len(result.Revert()) > 0 {
+			returnVal = fmt.Sprintf("%x", result.Revert())
+		}
+		return &ethapi.ExecutionResult{
+			Gas:         result.UsedGas,
+			Failed:      result.Failed(),
+			ReturnValue: returnVal,
+			StructLogs:  ethapi.FormatLogs(tracer.StructLogs()),
+		}, nil
+
+	case *tracers.Tracer:
+		return tracer.GetResult()
+
+	default:
+		panic(fmt.Sprintf("bad tracer type %T", tracer))
+	}
 }