cmd/evm: add state transition tool for testing (#20958)

This PR implements the EVM state transition tool, which is intended
to be the replacement for our retesteth client implementation.
Documentation is present in the cmd/evm/README.md file.

Co-authored-by: Felix Lange <fjl@twurst.com>
This commit is contained in:
Martin Holst Swende
2020-06-30 10:12:51 +02:00
committed by GitHub
parent dd91c7ce6a
commit e376d2fb31
37 changed files with 1509 additions and 48 deletions

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// Copyright 2020 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 t8ntool
import (
"fmt"
"math/big"
"os"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/common/math"
"github.com/ethereum/go-ethereum/consensus/misc"
"github.com/ethereum/go-ethereum/core"
"github.com/ethereum/go-ethereum/core/rawdb"
"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/crypto"
"github.com/ethereum/go-ethereum/ethdb"
"github.com/ethereum/go-ethereum/log"
"github.com/ethereum/go-ethereum/params"
"github.com/ethereum/go-ethereum/rlp"
"golang.org/x/crypto/sha3"
)
type Prestate struct {
Env stEnv `json:"env"`
Pre core.GenesisAlloc `json:"pre"`
}
// ExecutionResult contains the execution status after running a state test, any
// error that might have occurred and a dump of the final state if requested.
type ExecutionResult struct {
StateRoot common.Hash `json:"stateRoot"`
TxRoot common.Hash `json:"txRoot"`
ReceiptRoot common.Hash `json:"receiptRoot"`
LogsHash common.Hash `json:"logsHash"`
Bloom types.Bloom `json:"logsBloom" gencodec:"required"`
Receipts types.Receipts `json:"receipts"`
Rejected []int `json:"rejected,omitempty"`
}
type ommer struct {
Delta uint64 `json:"delta"`
Address common.Address `json:"address"`
}
//go:generate gencodec -type stEnv -field-override stEnvMarshaling -out gen_stenv.go
type stEnv struct {
Coinbase common.Address `json:"currentCoinbase" gencodec:"required"`
Difficulty *big.Int `json:"currentDifficulty" gencodec:"required"`
GasLimit uint64 `json:"currentGasLimit" gencodec:"required"`
Number uint64 `json:"currentNumber" gencodec:"required"`
Timestamp uint64 `json:"currentTimestamp" gencodec:"required"`
BlockHashes map[math.HexOrDecimal64]common.Hash `json:"blockHashes,omitempty"`
Ommers []ommer `json:"ommers,omitempty"`
}
type stEnvMarshaling struct {
Coinbase common.UnprefixedAddress
Difficulty *math.HexOrDecimal256
GasLimit math.HexOrDecimal64
Number math.HexOrDecimal64
Timestamp math.HexOrDecimal64
}
// Apply applies a set of transactions to a pre-state
func (pre *Prestate) Apply(vmConfig vm.Config, chainConfig *params.ChainConfig,
txs types.Transactions, miningReward int64,
getTracerFn func(txIndex int) (tracer vm.Tracer, err error)) (*state.StateDB, *ExecutionResult, error) {
// Capture errors for BLOCKHASH operation, if we haven't been supplied the
// required blockhashes
var hashError error
getHash := func(num uint64) common.Hash {
if pre.Env.BlockHashes == nil {
hashError = fmt.Errorf("getHash(%d) invoked, no blockhashes provided", num)
return common.Hash{}
}
h, ok := pre.Env.BlockHashes[math.HexOrDecimal64(num)]
if !ok {
hashError = fmt.Errorf("getHash(%d) invoked, blockhash for that block not provided", num)
}
return h
}
var (
statedb = MakePreState(rawdb.NewMemoryDatabase(), pre.Pre)
signer = types.MakeSigner(chainConfig, new(big.Int).SetUint64(pre.Env.Number))
gaspool = new(core.GasPool)
blockHash = common.Hash{0x13, 0x37}
rejectedTxs []int
includedTxs types.Transactions
gasUsed = uint64(0)
receipts = make(types.Receipts, 0)
txIndex = 0
)
gaspool.AddGas(pre.Env.GasLimit)
vmContext := vm.Context{
CanTransfer: core.CanTransfer,
Transfer: core.Transfer,
Coinbase: pre.Env.Coinbase,
BlockNumber: new(big.Int).SetUint64(pre.Env.Number),
Time: new(big.Int).SetUint64(pre.Env.Timestamp),
Difficulty: pre.Env.Difficulty,
GasLimit: pre.Env.GasLimit,
GetHash: getHash,
// GasPrice and Origin needs to be set per transaction
}
// If DAO is supported/enabled, we need to handle it here. In geth 'proper', it's
// done in StateProcessor.Process(block, ...), right before transactions are applied.
if chainConfig.DAOForkSupport &&
chainConfig.DAOForkBlock != nil &&
chainConfig.DAOForkBlock.Cmp(new(big.Int).SetUint64(pre.Env.Number)) == 0 {
misc.ApplyDAOHardFork(statedb)
}
for i, tx := range txs {
msg, err := tx.AsMessage(signer)
if err != nil {
log.Info("rejected tx", "index", i, "hash", tx.Hash(), "error", err)
rejectedTxs = append(rejectedTxs, i)
continue
}
tracer, err := getTracerFn(txIndex)
if err != nil {
return nil, nil, err
}
vmConfig.Tracer = tracer
vmConfig.Debug = (tracer != nil)
statedb.Prepare(tx.Hash(), blockHash, txIndex)
vmContext.GasPrice = msg.GasPrice()
vmContext.Origin = msg.From()
evm := vm.NewEVM(vmContext, statedb, chainConfig, vmConfig)
snapshot := statedb.Snapshot()
// (ret []byte, usedGas uint64, failed bool, err error)
msgResult, err := core.ApplyMessage(evm, msg, gaspool)
if err != nil {
statedb.RevertToSnapshot(snapshot)
log.Info("rejected tx", "index", i, "hash", tx.Hash(), "from", msg.From(), "error", err)
rejectedTxs = append(rejectedTxs, i)
continue
}
includedTxs = append(includedTxs, tx)
if hashError != nil {
return nil, nil, NewError(ErrorMissingBlockhash, hashError)
}
gasUsed += msgResult.UsedGas
// Create a new receipt for the transaction, storing the intermediate root and gas used by the tx
{
var root []byte
if chainConfig.IsByzantium(vmContext.BlockNumber) {
statedb.Finalise(true)
} else {
root = statedb.IntermediateRoot(chainConfig.IsEIP158(vmContext.BlockNumber)).Bytes()
}
receipt := types.NewReceipt(root, msgResult.Failed(), gasUsed)
receipt.TxHash = tx.Hash()
receipt.GasUsed = msgResult.UsedGas
// if the transaction created a contract, store the creation address in the receipt.
if msg.To() == nil {
receipt.ContractAddress = crypto.CreateAddress(evm.Context.Origin, tx.Nonce())
}
// Set the receipt logs and create a bloom for filtering
receipt.Logs = statedb.GetLogs(tx.Hash())
receipt.Bloom = types.CreateBloom(types.Receipts{receipt})
// These three are non-consensus fields
//receipt.BlockHash
//receipt.BlockNumber =
receipt.TransactionIndex = uint(txIndex)
receipts = append(receipts, receipt)
}
txIndex++
}
statedb.IntermediateRoot(chainConfig.IsEIP158(vmContext.BlockNumber))
// Add mining reward?
if miningReward > 0 {
// Add mining reward. The mining reward may be `0`, which only makes a difference in the cases
// where
// - the coinbase suicided, or
// - there are only 'bad' transactions, which aren't executed. In those cases,
// the coinbase gets no txfee, so isn't created, and thus needs to be touched
var (
blockReward = big.NewInt(miningReward)
minerReward = new(big.Int).Set(blockReward)
perOmmer = new(big.Int).Div(blockReward, big.NewInt(32))
)
for _, ommer := range pre.Env.Ommers {
// Add 1/32th for each ommer included
minerReward.Add(minerReward, perOmmer)
// Add (8-delta)/8
reward := big.NewInt(8)
reward.Sub(reward, big.NewInt(0).SetUint64(ommer.Delta))
reward.Mul(reward, blockReward)
reward.Div(reward, big.NewInt(8))
statedb.AddBalance(ommer.Address, reward)
}
statedb.AddBalance(pre.Env.Coinbase, minerReward)
}
// Commit block
root, err := statedb.Commit(chainConfig.IsEIP158(vmContext.BlockNumber))
if err != nil {
fmt.Fprintf(os.Stderr, "Could not commit state: %v", err)
return nil, nil, NewError(ErrorEVM, fmt.Errorf("could not commit state: %v", err))
}
execRs := &ExecutionResult{
StateRoot: root,
TxRoot: types.DeriveSha(includedTxs),
ReceiptRoot: types.DeriveSha(receipts),
Bloom: types.CreateBloom(receipts),
LogsHash: rlpHash(statedb.Logs()),
Receipts: receipts,
Rejected: rejectedTxs,
}
return statedb, execRs, nil
}
func MakePreState(db ethdb.Database, accounts core.GenesisAlloc) *state.StateDB {
sdb := state.NewDatabase(db)
statedb, _ := state.New(common.Hash{}, sdb, nil)
for addr, a := range accounts {
statedb.SetCode(addr, a.Code)
statedb.SetNonce(addr, a.Nonce)
statedb.SetBalance(addr, a.Balance)
for k, v := range a.Storage {
statedb.SetState(addr, k, v)
}
}
// Commit and re-open to start with a clean state.
root, _ := statedb.Commit(false)
statedb, _ = state.New(root, sdb, nil)
return statedb
}
func rlpHash(x interface{}) (h common.Hash) {
hw := sha3.NewLegacyKeccak256()
rlp.Encode(hw, x)
hw.Sum(h[:0])
return h
}

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// Copyright 2020 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 t8ntool
import (
"fmt"
"strings"
"github.com/ethereum/go-ethereum/core/vm"
"github.com/ethereum/go-ethereum/tests"
"gopkg.in/urfave/cli.v1"
)
var (
TraceFlag = cli.BoolFlag{
Name: "trace",
Usage: "Output full trace logs to files <txhash>.jsonl",
}
TraceDisableMemoryFlag = cli.BoolFlag{
Name: "trace.nomemory",
Usage: "Disable full memory dump in traces",
}
TraceDisableStackFlag = cli.BoolFlag{
Name: "trace.nostack",
Usage: "Disable stack output in traces",
}
OutputAllocFlag = cli.StringFlag{
Name: "output.alloc",
Usage: "Determines where to put the `alloc` of the post-state.\n" +
"\t`stdout` - into the stdout output\n" +
"\t`stderr` - into the stderr output\n" +
"\t<file> - into the file <file> ",
Value: "alloc.json",
}
OutputResultFlag = cli.StringFlag{
Name: "output.result",
Usage: "Determines where to put the `result` (stateroot, txroot etc) of the post-state.\n" +
"\t`stdout` - into the stdout output\n" +
"\t`stderr` - into the stderr output\n" +
"\t<file> - into the file <file> ",
Value: "result.json",
}
InputAllocFlag = cli.StringFlag{
Name: "input.alloc",
Usage: "`stdin` or file name of where to find the prestate alloc to use.",
Value: "alloc.json",
}
InputEnvFlag = cli.StringFlag{
Name: "input.env",
Usage: "`stdin` or file name of where to find the prestate env to use.",
Value: "env.json",
}
InputTxsFlag = cli.StringFlag{
Name: "input.txs",
Usage: "`stdin` or file name of where to find the transactions to apply.",
Value: "txs.json",
}
RewardFlag = cli.Int64Flag{
Name: "state.reward",
Usage: "Mining reward. Set to -1 to disable",
Value: 0,
}
ChainIDFlag = cli.Int64Flag{
Name: "state.chainid",
Usage: "ChainID to use",
Value: 1,
}
ForknameFlag = cli.StringFlag{
Name: "state.fork",
Usage: fmt.Sprintf("Name of ruleset to use."+
"\n\tAvailable forknames:"+
"\n\t %v"+
"\n\tAvailable extra eips:"+
"\n\t %v"+
"\n\tSyntax <forkname>(+ExtraEip)",
strings.Join(tests.AvailableForks(), "\n\t "),
strings.Join(vm.ActivateableEips(), ", ")),
Value: "Istanbul",
}
VerbosityFlag = cli.IntFlag{
Name: "verbosity",
Usage: "sets the verbosity level",
Value: 3,
}
)

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// Code generated by github.com/fjl/gencodec. DO NOT EDIT.
package t8ntool
import (
"encoding/json"
"errors"
"math/big"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/common/math"
)
var _ = (*stEnvMarshaling)(nil)
// MarshalJSON marshals as JSON.
func (s stEnv) MarshalJSON() ([]byte, error) {
type stEnv struct {
Coinbase common.UnprefixedAddress `json:"currentCoinbase" gencodec:"required"`
Difficulty *math.HexOrDecimal256 `json:"currentDifficulty" gencodec:"required"`
GasLimit math.HexOrDecimal64 `json:"currentGasLimit" gencodec:"required"`
Number math.HexOrDecimal64 `json:"currentNumber" gencodec:"required"`
Timestamp math.HexOrDecimal64 `json:"currentTimestamp" gencodec:"required"`
BlockHashes map[math.HexOrDecimal64]common.Hash `json:"blockHashes,omitempty"`
Ommers []ommer `json:"ommers,omitempty"`
}
var enc stEnv
enc.Coinbase = common.UnprefixedAddress(s.Coinbase)
enc.Difficulty = (*math.HexOrDecimal256)(s.Difficulty)
enc.GasLimit = math.HexOrDecimal64(s.GasLimit)
enc.Number = math.HexOrDecimal64(s.Number)
enc.Timestamp = math.HexOrDecimal64(s.Timestamp)
enc.BlockHashes = s.BlockHashes
enc.Ommers = s.Ommers
return json.Marshal(&enc)
}
// UnmarshalJSON unmarshals from JSON.
func (s *stEnv) UnmarshalJSON(input []byte) error {
type stEnv struct {
Coinbase *common.UnprefixedAddress `json:"currentCoinbase" gencodec:"required"`
Difficulty *math.HexOrDecimal256 `json:"currentDifficulty" gencodec:"required"`
GasLimit *math.HexOrDecimal64 `json:"currentGasLimit" gencodec:"required"`
Number *math.HexOrDecimal64 `json:"currentNumber" gencodec:"required"`
Timestamp *math.HexOrDecimal64 `json:"currentTimestamp" gencodec:"required"`
BlockHashes map[math.HexOrDecimal64]common.Hash `json:"blockHashes,omitempty"`
Ommers []ommer `json:"ommers,omitempty"`
}
var dec stEnv
if err := json.Unmarshal(input, &dec); err != nil {
return err
}
if dec.Coinbase == nil {
return errors.New("missing required field 'currentCoinbase' for stEnv")
}
s.Coinbase = common.Address(*dec.Coinbase)
if dec.Difficulty == nil {
return errors.New("missing required field 'currentDifficulty' for stEnv")
}
s.Difficulty = (*big.Int)(dec.Difficulty)
if dec.GasLimit == nil {
return errors.New("missing required field 'currentGasLimit' for stEnv")
}
s.GasLimit = uint64(*dec.GasLimit)
if dec.Number == nil {
return errors.New("missing required field 'currentNumber' for stEnv")
}
s.Number = uint64(*dec.Number)
if dec.Timestamp == nil {
return errors.New("missing required field 'currentTimestamp' for stEnv")
}
s.Timestamp = uint64(*dec.Timestamp)
if dec.BlockHashes != nil {
s.BlockHashes = dec.BlockHashes
}
if dec.Ommers != nil {
s.Ommers = dec.Ommers
}
return nil
}

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// Copyright 2020 The go-ethereum Authors
// This file is part of go-ethereum.
//
// go-ethereum is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// go-ethereum 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.
package t8ntool
import (
"encoding/json"
"fmt"
"io/ioutil"
"math/big"
"os"
"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/params"
"github.com/ethereum/go-ethereum/tests"
"gopkg.in/urfave/cli.v1"
)
const (
ErrorEVM = 2
ErrorVMConfig = 3
ErrorMissingBlockhash = 4
ErrorJson = 10
ErrorIO = 11
stdinSelector = "stdin"
)
type NumberedError struct {
errorCode int
err error
}
func NewError(errorCode int, err error) *NumberedError {
return &NumberedError{errorCode, err}
}
func (n *NumberedError) Error() string {
return fmt.Sprintf("ERROR(%d): %v", n.errorCode, n.err.Error())
}
func (n *NumberedError) Code() int {
return n.errorCode
}
type input struct {
Alloc core.GenesisAlloc `json:"alloc,omitempty"`
Env *stEnv `json:"env,omitempty"`
Txs types.Transactions `json:"txs,omitempty"`
}
func Main(ctx *cli.Context) error {
// Configure the go-ethereum logger
glogger := log.NewGlogHandler(log.StreamHandler(os.Stderr, log.TerminalFormat(false)))
glogger.Verbosity(log.Lvl(ctx.Int(VerbosityFlag.Name)))
log.Root().SetHandler(glogger)
var (
err error
tracer vm.Tracer
)
var getTracer func(txIndex int) (vm.Tracer, error)
if ctx.Bool(TraceFlag.Name) {
// Configure the EVM logger
logConfig := &vm.LogConfig{
DisableStack: ctx.Bool(TraceDisableStackFlag.Name),
DisableMemory: ctx.Bool(TraceDisableMemoryFlag.Name),
Debug: true,
}
var prevFile *os.File
// This one closes the last file
defer func() {
if prevFile != nil {
prevFile.Close()
}
}()
getTracer = func(txIndex int) (vm.Tracer, error) {
if prevFile != nil {
prevFile.Close()
}
traceFile, err := os.Create(fmt.Sprintf("trace-%d.jsonl", txIndex))
if err != nil {
return nil, NewError(ErrorIO, fmt.Errorf("failed creating trace-file: %v", err))
}
prevFile = traceFile
return vm.NewJSONLogger(logConfig, traceFile), nil
}
} else {
getTracer = func(txIndex int) (tracer vm.Tracer, err error) {
return nil, nil
}
}
// We need to load three things: alloc, env and transactions. May be either in
// stdin input or in files.
// Check if anything needs to be read from stdin
var (
prestate Prestate
txs types.Transactions // txs to apply
allocStr = ctx.String(InputAllocFlag.Name)
envStr = ctx.String(InputEnvFlag.Name)
txStr = ctx.String(InputTxsFlag.Name)
inputData = &input{}
)
if allocStr == stdinSelector || envStr == stdinSelector || txStr == stdinSelector {
decoder := json.NewDecoder(os.Stdin)
decoder.Decode(inputData)
}
if allocStr != stdinSelector {
inFile, err := os.Open(allocStr)
if err != nil {
return NewError(ErrorIO, fmt.Errorf("failed reading alloc file: %v", err))
}
defer inFile.Close()
decoder := json.NewDecoder(inFile)
if err := decoder.Decode(&inputData.Alloc); err != nil {
return NewError(ErrorJson, fmt.Errorf("Failed unmarshaling alloc-file: %v", err))
}
}
if envStr != stdinSelector {
inFile, err := os.Open(envStr)
if err != nil {
return NewError(ErrorIO, fmt.Errorf("failed reading env file: %v", err))
}
defer inFile.Close()
decoder := json.NewDecoder(inFile)
var env stEnv
if err := decoder.Decode(&env); err != nil {
return NewError(ErrorJson, fmt.Errorf("Failed unmarshaling env-file: %v", err))
}
inputData.Env = &env
}
if txStr != stdinSelector {
inFile, err := os.Open(txStr)
if err != nil {
return NewError(ErrorIO, fmt.Errorf("failed reading txs file: %v", err))
}
defer inFile.Close()
decoder := json.NewDecoder(inFile)
var txs types.Transactions
if err := decoder.Decode(&txs); err != nil {
return NewError(ErrorJson, fmt.Errorf("Failed unmarshaling txs-file: %v", err))
}
inputData.Txs = txs
}
prestate.Pre = inputData.Alloc
prestate.Env = *inputData.Env
txs = inputData.Txs
// Iterate over all the tests, run them and aggregate the results
vmConfig := vm.Config{
Tracer: tracer,
Debug: (tracer != nil),
}
// Construct the chainconfig
var chainConfig *params.ChainConfig
if cConf, extraEips, err := tests.GetChainConfig(ctx.String(ForknameFlag.Name)); err != nil {
return NewError(ErrorVMConfig, fmt.Errorf("Failed constructing chain configuration: %v", err))
} else {
chainConfig = cConf
vmConfig.ExtraEips = extraEips
}
// Set the chain id
chainConfig.ChainID = big.NewInt(ctx.Int64(ChainIDFlag.Name))
// Run the test and aggregate the result
state, result, err := prestate.Apply(vmConfig, chainConfig, txs, ctx.Int64(RewardFlag.Name), getTracer)
if err != nil {
return err
}
// Dump the excution result
//postAlloc := state.DumpGenesisFormat(false, false, false)
collector := make(Alloc)
state.DumpToCollector(collector, false, false, false, nil, -1)
return dispatchOutput(ctx, result, collector)
}
type Alloc map[common.Address]core.GenesisAccount
func (g Alloc) OnRoot(common.Hash) {}
func (g Alloc) OnAccount(addr common.Address, dumpAccount state.DumpAccount) {
balance, _ := new(big.Int).SetString(dumpAccount.Balance, 10)
var storage map[common.Hash]common.Hash
if dumpAccount.Storage != nil {
storage = make(map[common.Hash]common.Hash)
for k, v := range dumpAccount.Storage {
storage[k] = common.HexToHash(v)
}
}
genesisAccount := core.GenesisAccount{
Code: common.FromHex(dumpAccount.Code),
Storage: storage,
Balance: balance,
Nonce: dumpAccount.Nonce,
}
g[addr] = genesisAccount
}
// saveFile marshalls the object to the given file
func saveFile(filename string, data interface{}) error {
b, err := json.MarshalIndent(data, "", " ")
if err != nil {
return NewError(ErrorJson, fmt.Errorf("failed marshalling output: %v", err))
}
if err = ioutil.WriteFile(filename, b, 0644); err != nil {
return NewError(ErrorIO, fmt.Errorf("failed writing output: %v", err))
}
return nil
}
// dispatchOutput writes the output data to either stderr or stdout, or to the specified
// files
func dispatchOutput(ctx *cli.Context, result *ExecutionResult, alloc Alloc) error {
stdOutObject := make(map[string]interface{})
stdErrObject := make(map[string]interface{})
dispatch := func(fName, name string, obj interface{}) error {
switch fName {
case "stdout":
stdOutObject[name] = obj
case "stderr":
stdErrObject[name] = obj
default: // save to file
if err := saveFile(fName, obj); err != nil {
return err
}
}
return nil
}
if err := dispatch(ctx.String(OutputAllocFlag.Name), "alloc", alloc); err != nil {
return err
}
if err := dispatch(ctx.String(OutputResultFlag.Name), "result", result); err != nil {
return err
}
if len(stdOutObject) > 0 {
b, err := json.MarshalIndent(stdOutObject, "", " ")
if err != nil {
return NewError(ErrorJson, fmt.Errorf("failed marshalling output: %v", err))
}
os.Stdout.Write(b)
}
if len(stdErrObject) > 0 {
b, err := json.MarshalIndent(stdErrObject, "", " ")
if err != nil {
return NewError(ErrorJson, fmt.Errorf("failed marshalling output: %v", err))
}
os.Stderr.Write(b)
}
return nil
}