EN-7307: transaction execution simulator #2218

bogdan-rosianu · 2020-08-12T14:53:32Z

Transaction execution simulator. It will work via the API endpoint /transaction/simulate which receives the same request as the /transaction/send.
Created a new component that will simulate the execution of a transaction without affecting the state of the blockchain. In order to achieve this, some components of the new transaction processor were disabled or changed to read-only.

Testing steps:

Run a testnet with the branch's configuration (be careful that the new endpoint has to be added to the api.toml file)
Send requests to the /transaction/simulate endpoint. Multiple scenarios are expected:

move-balance transaction with invalid fields / insufficient balance / gas limit and so on. the proper error message should be returned
move-balance transaction with ok values. The response should signal that the transaction is correct. Please check that the receiver account hasn't updated the balance (the state was not affected). Also, in case that the gas limit was higher than the needed one, you should see a receipt inside the response
same two above scenarios, but for smart contract calls.

sasurobert · 2020-08-12T16:51:10Z

api/transaction/routes.go

+	}
+
+	executionResults.Hash = hex.EncodeToString(txHash)
+


delete empty line

sasurobert · 2020-08-12T16:51:25Z

cmd/node/factory/structs.go

@@ -2,6 +2,7 @@ package factory

 import (
 	"errors"
+	"github.com/ElrondNetwork/elrond-go/epochStart/bootstrap/disabled"


sasurobert · 2020-08-12T16:53:09Z

cmd/node/factory/structs.go

@@ -1323,6 +1332,13 @@ func newShardBlockProcessor(
 		return nil, errors.New("could not create transaction statisticsProcessor: " + err.Error())
 	}

+	txSimulatorProcessorArgs := argsNewTxProcessor


do the same for the underlying smart contract processor - you need to feed diabled fee handler and new intermediate processor for the simulator.

sasurobert · 2020-08-12T16:55:28Z

cmd/node/factory/structs.go

@@ -1323,6 +1332,13 @@ func newShardBlockProcessor(
 		return nil, errors.New("could not create transaction statisticsProcessor: " + err.Error())
 	}

+	txSimulatorProcessorArgs := argsNewTxProcessor
+	txSimulatorProcessorArgs.Accounts = disabled.NewAccountsAdapter()


instead of disabled accounts adapter - you have to create a read only accounts adapter. thus you need a new component which gets the accountsDB as parameter and does all the reading from it, and in case of writes it writes into a cache, or it has an empty implementation

node/txsimulator/interface.go

sasurobert · 2020-08-12T16:56:49Z

node/txsimulator/txSimulator.go

+
+// ProcessTx will process the transaction in a special environment, where state-writing is not allowed
+func (ts *transactionSimulator) ProcessTx(accounts state.AccountsAdapter, tx *transaction.Transaction) (*transaction.SimulationResults, error) {
+	newAccounts, err := NewReadOnlyAccountsDB(accounts)


you can create this only once - at constructor level. and you have access to all the current state. no need to recreate for every simulation process.

sasurobert · 2020-08-12T16:57:19Z

node/txsimulator/wrappedAccountsDB.go

+
+// JournalLen will call the original accounts' function with the same name
+func (w *readOnlyAccountsDB) JournalLen() int {
+	w.mutAccounts.RLock()


no need for mutex.

# Conflicts: # api/mock/facade.go # cmd/node/factory/structs.go # cmd/node/main.go

sasurobert · 2020-08-17T06:55:40Z

facade/nodeFacade_test.go

 )

 //TODO increase code coverage

+type interf interface {


delete this :) no need for that and for the next 20 lines

pushed by mistake. removed

sasurobert · 2020-08-17T06:56:01Z

node/txsimulator/txSimulator.go

+}
+
+// New returns a new instance of a transactionSimulator
+func New(txProcessor TransactionProcessor, accountsAdapter state.AccountsAdapter) (*transactionSimulator, error) {


the package is called txsimulator so the constructor's call will result in txsimulator.New(). txsimulator.NewTxSimulator() would have been redundant

sasurobert · 2020-08-17T06:57:21Z

process/transaction/metaProcess.go

@@ -20,6 +21,16 @@ type metaTxProcessor struct {
 	txTypeHandler process.TxTypeHandler
 }

+// GetSmartContractResults returns the smart contract results
+func (txProc *metaTxProcessor) GetSmartContractResults() map[string]data.TransactionHandler {
+	return make(map[string]data.TransactionHandler)


this seems wrong.

meta sc processor creates smart contract results as well. you do not these. As in txSimulator you could have the scrForwarder and receiptForwarders and take those data from there.

done. refactored and created structs for a more friendly API result

sasurobert · 2020-08-17T06:59:02Z

process/transaction/metaProcess.go

+}
+
+// SetAccountsAdapter updates the accounts adapter
+func (txProc *metaTxProcessor) SetAccountsAdapter(accounts state.AccountsAdapter) {


no need for this set.

good catch. this resulted in overwriting the read-only accounts db into the real one

sasurobert · 2020-08-17T06:59:12Z

process/transaction/shardProcess.go

+
+// GetSmartContractResults returns the smart contract results in the current round
+func (txProc *txProcessor) GetSmartContractResults() map[string]data.TransactionHandler {
+	return txProc.scrForwarder.GetAllCurrentFinishedTxs()


same as above

sasurobert · 2020-08-17T06:59:15Z

process/transaction/shardProcess.go

+// SetAccountsAdapter will update the accounts adapter if the provided one is not nil
+func (txProc *txProcessor) SetAccountsAdapter(accounts state.AccountsAdapter) {
+	if !check.IfNil(accounts) {
+		txProc.accounts = accounts


no need for this set.

sasurobert · 2020-08-17T17:27:54Z

cmd/node/main.go

 	)
 	processComponents, err := factory.ProcessComponentsFactory(processArgs)
 	if err != nil {
 		return err
 	}

+	transactionSimulator, err := txsimulator.New(*txSimulatorProcessorArgs)


New what ? make a better naming for the constructor.

ok. renamed

sasurobert · 2020-08-17T17:34:44Z

node/txsimulator/txSimulator.go

+	if err != nil {
+		return err
+	}
+	receiptsForwarder, err := ts.intermProcContainer.Get(block.ReceiptBlock)


there is no receipt block in case of metachain - thus this will fail.
What you should do it iterate all processors and call createblockstarted. Receipts are created only in intra shard move balance transfers with too much gas.

done. in case of meta, apply only the smart contract results and in case of shard, also the receipts. and on defer now it closes all the processors

valentin-lup

Tested on AZ-WEU with proxy EN-7303-tx-simulation
Upgrade path master -> EN-7307-tx-execution-simulator tested on AZ-UKS

LucianMincu

System tests passed.

EN-7307: transaction execution simulator (WIP)

feba353

sasurobert requested changes Aug 12, 2020

View reviewed changes

bogdan-rosianu added 4 commits August 14, 2020 15:32

EN-7307: fix after review

2eb28d3

EN-7307: added missing comment

92f122b

EN-7307: fixed nil pointer bug + adjustments

062290b

Merge branch 'development' into EN-7307-tx-execution-simulator

249fb52

# Conflicts: # api/mock/facade.go # cmd/node/factory/structs.go # cmd/node/main.go

sasurobert requested changes Aug 17, 2020

View reviewed changes

EN-7307: fix after review

a1827bd

bogdan-rosianu marked this pull request as ready for review August 17, 2020 11:41

bogdan-rosianu changed the title ~~EN-7307: transaction execution simulator (WIP)~~ EN-7307: transaction execution simulator Aug 17, 2020

bogdan-rosianu self-assigned this Aug 17, 2020

sasurobert requested changes Aug 17, 2020

View reviewed changes

bogdan-rosianu added 3 commits August 18, 2020 10:13

EN-7307: fix after review

74da90e

EN-7307: read only accounts db unit tests

b12b2b4

EN-7307: tx simulator unit tests

d8420c4

valentin-lup previously approved these changes Aug 18, 2020

View reviewed changes

sasurobert approved these changes Aug 18, 2020

View reviewed changes

sasurobert previously approved these changes Aug 18, 2020

View reviewed changes

BeniaminDrasovean self-requested a review August 18, 2020 11:55

BeniaminDrasovean previously approved these changes Aug 18, 2020

View reviewed changes

EN-7307: made tx simulation route disabled by default

5ab702d

bogdan-rosianu dismissed stale reviews from BeniaminDrasovean, sasurobert, and valentin-lup via 5ab702d August 18, 2020 16:00

Merge branch 'development' into EN-7307-tx-execution-simulator

d2da626

sasurobert approved these changes Aug 20, 2020

View reviewed changes

BeniaminDrasovean approved these changes Aug 20, 2020

View reviewed changes

Merge branch 'development' into EN-7307-tx-execution-simulator

715eea0

LucianMincu approved these changes Aug 20, 2020

View reviewed changes

LucianMincu merged commit 8af6755 into development Aug 20, 2020

LucianMincu deleted the EN-7307-tx-execution-simulator branch August 20, 2020 17:15

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

EN-7307: transaction execution simulator #2218

EN-7307: transaction execution simulator #2218

bogdan-rosianu commented Aug 12, 2020 •

edited

sasurobert Aug 12, 2020

bogdan-rosianu Aug 14, 2020

sasurobert Aug 12, 2020

bogdan-rosianu Aug 14, 2020

sasurobert Aug 12, 2020

bogdan-rosianu Aug 14, 2020

sasurobert Aug 12, 2020

bogdan-rosianu Aug 14, 2020

sasurobert Aug 12, 2020

bogdan-rosianu Aug 14, 2020

sasurobert Aug 12, 2020

bogdan-rosianu Aug 14, 2020

sasurobert Aug 17, 2020

bogdan-rosianu Aug 17, 2020

sasurobert Aug 17, 2020

bogdan-rosianu Aug 17, 2020 •

edited

sasurobert Aug 17, 2020

sasurobert Aug 17, 2020

bogdan-rosianu Aug 17, 2020

sasurobert Aug 17, 2020

bogdan-rosianu Aug 17, 2020

sasurobert Aug 17, 2020

bogdan-rosianu Aug 17, 2020

sasurobert Aug 17, 2020

bogdan-rosianu Aug 17, 2020

sasurobert Aug 17, 2020

bogdan-rosianu Aug 18, 2020

sasurobert Aug 17, 2020

bogdan-rosianu Aug 18, 2020

valentin-lup left a comment

LucianMincu left a comment

EN-7307: transaction execution simulator #2218

EN-7307: transaction execution simulator #2218

Conversation

bogdan-rosianu commented Aug 12, 2020 • edited

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

bogdan-rosianu Aug 17, 2020 • edited

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

valentin-lup left a comment

Choose a reason for hiding this comment

LucianMincu left a comment

Choose a reason for hiding this comment

bogdan-rosianu commented Aug 12, 2020 •

edited

bogdan-rosianu Aug 17, 2020 •

edited