mirror of
https://github.com/nspcc-dev/neo-go.git
synced 2024-11-22 19:29:39 +00:00
6b21ad9922
Everywhere including examples, external interop APIs, bindings generators
code and in other valuable places. A couple of `interface{}` usages are
intentionally left in the CHANGELOG.md, documentation and tests.
366 lines
12 KiB
Go
366 lines
12 KiB
Go
package actor
|
|
|
|
import (
|
|
"context"
|
|
"errors"
|
|
"fmt"
|
|
"strings"
|
|
"time"
|
|
|
|
"github.com/nspcc-dev/neo-go/pkg/core/block"
|
|
"github.com/nspcc-dev/neo-go/pkg/core/state"
|
|
"github.com/nspcc-dev/neo-go/pkg/neorpc"
|
|
"github.com/nspcc-dev/neo-go/pkg/neorpc/result"
|
|
"github.com/nspcc-dev/neo-go/pkg/smartcontract/trigger"
|
|
"github.com/nspcc-dev/neo-go/pkg/util"
|
|
)
|
|
|
|
// PollingWaiterRetryCount is a threshold for a number of subsequent failed
|
|
// attempts to get block count from the RPC server for PollingWaiter. If it fails
|
|
// to retrieve block count PollingWaiterRetryCount times in a raw then transaction
|
|
// awaiting attempt considered to be failed and an error is returned.
|
|
const PollingWaiterRetryCount = 3
|
|
|
|
var (
|
|
// ErrTxNotAccepted is returned when transaction wasn't accepted to the chain
|
|
// even after ValidUntilBlock block persist.
|
|
ErrTxNotAccepted = errors.New("transaction was not accepted to chain")
|
|
// ErrContextDone is returned when Waiter context has been done in the middle
|
|
// of transaction awaiting process and no result was received yet.
|
|
ErrContextDone = errors.New("waiter context done")
|
|
// ErrAwaitingNotSupported is returned from Wait method if Waiter instance
|
|
// doesn't support transaction awaiting.
|
|
ErrAwaitingNotSupported = errors.New("awaiting not supported")
|
|
// ErrMissedEvent is returned when RPCEventWaiter closes receiver channel
|
|
// which happens if missed event was received from the RPC server.
|
|
ErrMissedEvent = errors.New("some event was missed")
|
|
)
|
|
|
|
type (
|
|
// Waiter is an interface providing transaction awaiting functionality to Actor.
|
|
Waiter interface {
|
|
// Wait allows to wait until transaction will be accepted to the chain. It can be
|
|
// used as a wrapper for Send or SignAndSend and accepts transaction hash,
|
|
// ValidUntilBlock value and an error. It returns transaction execution result
|
|
// or an error if transaction wasn't accepted to the chain. Notice that "already
|
|
// exists" err value is not treated as an error by this routine because it
|
|
// means that the transactions given might be already accepted or soon going
|
|
// to be accepted. Such transaction can be waited for in a usual way, potentially
|
|
// with positive result, so that's what will happen.
|
|
Wait(h util.Uint256, vub uint32, err error) (*state.AppExecResult, error)
|
|
// WaitAny waits until at least one of the specified transactions will be accepted
|
|
// to the chain until vub (including). It returns execution result of this
|
|
// transaction or an error if none of the transactions was accepted to the chain.
|
|
// It uses underlying RPCPollingWaiter or RPCEventWaiter context to interrupt
|
|
// awaiting process, but additional ctx can be passed as an argument for the same
|
|
// purpose.
|
|
WaitAny(ctx context.Context, vub uint32, hashes ...util.Uint256) (*state.AppExecResult, error)
|
|
}
|
|
// RPCPollingWaiter is an interface that enables transaction awaiting functionality
|
|
// for Actor instance based on periodical BlockCount and ApplicationLog polls.
|
|
RPCPollingWaiter interface {
|
|
// Context should return the RPC client context to be able to gracefully
|
|
// shut down all running processes (if so).
|
|
Context() context.Context
|
|
GetVersion() (*result.Version, error)
|
|
GetBlockCount() (uint32, error)
|
|
GetApplicationLog(hash util.Uint256, trig *trigger.Type) (*result.ApplicationLog, error)
|
|
}
|
|
// RPCEventWaiter is an interface that enables improved transaction awaiting functionality
|
|
// for Actor instance based on web-socket Block and ApplicationLog notifications. RPCEventWaiter
|
|
// contains RPCPollingWaiter under the hood and falls back to polling when subscription-based
|
|
// awaiting fails.
|
|
RPCEventWaiter interface {
|
|
RPCPollingWaiter
|
|
|
|
ReceiveBlocks(flt *neorpc.BlockFilter, rcvr chan<- *block.Block) (string, error)
|
|
ReceiveExecutions(flt *neorpc.ExecutionFilter, rcvr chan<- *state.AppExecResult) (string, error)
|
|
Unsubscribe(id string) error
|
|
}
|
|
)
|
|
|
|
// NullWaiter is a Waiter stub that doesn't support transaction awaiting functionality.
|
|
type NullWaiter struct{}
|
|
|
|
// PollingWaiter is a polling-based Waiter.
|
|
type PollingWaiter struct {
|
|
polling RPCPollingWaiter
|
|
version *result.Version
|
|
}
|
|
|
|
// EventWaiter is a websocket-based Waiter.
|
|
type EventWaiter struct {
|
|
ws RPCEventWaiter
|
|
polling Waiter
|
|
}
|
|
|
|
// errIsAlreadyExists is a temporary helper until we have #2248 solved. Both C#
|
|
// and Go nodes return this string (possibly among other data).
|
|
func errIsAlreadyExists(err error) bool {
|
|
return strings.Contains(strings.ToLower(err.Error()), "already exists")
|
|
}
|
|
|
|
// newWaiter creates Waiter instance. It can be either websocket-based or
|
|
// polling-base, otherwise Waiter stub is returned.
|
|
func newWaiter(ra RPCActor, v *result.Version) Waiter {
|
|
if eventW, ok := ra.(RPCEventWaiter); ok {
|
|
return &EventWaiter{
|
|
ws: eventW,
|
|
polling: &PollingWaiter{
|
|
polling: eventW,
|
|
version: v,
|
|
},
|
|
}
|
|
}
|
|
if pollW, ok := ra.(RPCPollingWaiter); ok {
|
|
return &PollingWaiter{
|
|
polling: pollW,
|
|
version: v,
|
|
}
|
|
}
|
|
return NewNullWaiter()
|
|
}
|
|
|
|
// NewNullWaiter creates an instance of Waiter stub.
|
|
func NewNullWaiter() NullWaiter {
|
|
return NullWaiter{}
|
|
}
|
|
|
|
// Wait implements Waiter interface.
|
|
func (NullWaiter) Wait(h util.Uint256, vub uint32, err error) (*state.AppExecResult, error) {
|
|
return nil, ErrAwaitingNotSupported
|
|
}
|
|
|
|
// WaitAny implements Waiter interface.
|
|
func (NullWaiter) WaitAny(ctx context.Context, vub uint32, hashes ...util.Uint256) (*state.AppExecResult, error) {
|
|
return nil, ErrAwaitingNotSupported
|
|
}
|
|
|
|
// NewPollingWaiter creates an instance of Waiter supporting poll-based transaction awaiting.
|
|
func NewPollingWaiter(waiter RPCPollingWaiter) (*PollingWaiter, error) {
|
|
v, err := waiter.GetVersion()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
return &PollingWaiter{
|
|
polling: waiter,
|
|
version: v,
|
|
}, nil
|
|
}
|
|
|
|
// Wait implements Waiter interface.
|
|
func (w *PollingWaiter) Wait(h util.Uint256, vub uint32, err error) (*state.AppExecResult, error) {
|
|
if err != nil && !errIsAlreadyExists(err) {
|
|
return nil, err
|
|
}
|
|
return w.WaitAny(context.TODO(), vub, h)
|
|
}
|
|
|
|
// WaitAny implements Waiter interface.
|
|
func (w *PollingWaiter) WaitAny(ctx context.Context, vub uint32, hashes ...util.Uint256) (*state.AppExecResult, error) {
|
|
var (
|
|
currentHeight uint32
|
|
failedAttempt int
|
|
pollTime = time.Millisecond * time.Duration(w.version.Protocol.MillisecondsPerBlock) / 2
|
|
)
|
|
if pollTime == 0 {
|
|
pollTime = time.Second
|
|
}
|
|
timer := time.NewTicker(pollTime)
|
|
defer timer.Stop()
|
|
for {
|
|
select {
|
|
case <-timer.C:
|
|
blockCount, err := w.polling.GetBlockCount()
|
|
if err != nil {
|
|
failedAttempt++
|
|
if failedAttempt > PollingWaiterRetryCount {
|
|
return nil, fmt.Errorf("failed to retrieve block count: %w", err)
|
|
}
|
|
continue
|
|
}
|
|
failedAttempt = 0
|
|
if blockCount-1 > currentHeight {
|
|
currentHeight = blockCount - 1
|
|
}
|
|
t := trigger.Application
|
|
for _, h := range hashes {
|
|
res, err := w.polling.GetApplicationLog(h, &t)
|
|
if err == nil {
|
|
return &state.AppExecResult{
|
|
Container: res.Container,
|
|
Execution: res.Executions[0],
|
|
}, nil
|
|
}
|
|
}
|
|
if currentHeight >= vub {
|
|
return nil, ErrTxNotAccepted
|
|
}
|
|
case <-w.polling.Context().Done():
|
|
return nil, fmt.Errorf("%w: %v", ErrContextDone, w.polling.Context().Err()) //nolint:errorlint // errorlint: non-wrapping format verb for fmt.Errorf. Use `%w` to format errors
|
|
case <-ctx.Done():
|
|
return nil, fmt.Errorf("%w: %v", ErrContextDone, ctx.Err()) //nolint:errorlint // errorlint: non-wrapping format verb for fmt.Errorf. Use `%w` to format errors
|
|
}
|
|
}
|
|
}
|
|
|
|
// NewEventWaiter creates an instance of Waiter supporting websocket event-based transaction awaiting.
|
|
// EventWaiter contains PollingWaiter under the hood and falls back to polling when subscription-based
|
|
// awaiting fails.
|
|
func NewEventWaiter(waiter RPCEventWaiter) (*EventWaiter, error) {
|
|
polling, err := NewPollingWaiter(waiter)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
return &EventWaiter{
|
|
ws: waiter,
|
|
polling: polling,
|
|
}, nil
|
|
}
|
|
|
|
// Wait implements Waiter interface.
|
|
func (w *EventWaiter) Wait(h util.Uint256, vub uint32, err error) (res *state.AppExecResult, waitErr error) {
|
|
if err != nil && !errIsAlreadyExists(err) {
|
|
return nil, err
|
|
}
|
|
return w.WaitAny(context.TODO(), vub, h)
|
|
}
|
|
|
|
// WaitAny implements Waiter interface.
|
|
func (w *EventWaiter) WaitAny(ctx context.Context, vub uint32, hashes ...util.Uint256) (res *state.AppExecResult, waitErr error) {
|
|
var (
|
|
wsWaitErr error
|
|
waitersActive int
|
|
bRcvr = make(chan *block.Block, 2)
|
|
aerRcvr = make(chan *state.AppExecResult, len(hashes))
|
|
unsubErrs = make(chan error)
|
|
exit = make(chan struct{})
|
|
)
|
|
|
|
// Execution event preceded the block event, thus wait until the VUB-th block to be sure.
|
|
since := vub
|
|
blocksID, err := w.ws.ReceiveBlocks(&neorpc.BlockFilter{Since: &since}, bRcvr)
|
|
if err != nil {
|
|
wsWaitErr = fmt.Errorf("failed to subscribe for new blocks: %w", err)
|
|
} else {
|
|
waitersActive++
|
|
go func() {
|
|
<-exit
|
|
err = w.ws.Unsubscribe(blocksID)
|
|
if err != nil {
|
|
unsubErrs <- fmt.Errorf("failed to unsubscribe from blocks (id: %s): %w", blocksID, err)
|
|
return
|
|
}
|
|
unsubErrs <- nil
|
|
}()
|
|
}
|
|
if wsWaitErr == nil {
|
|
trig := trigger.Application
|
|
for _, h := range hashes {
|
|
txsID, err := w.ws.ReceiveExecutions(&neorpc.ExecutionFilter{Container: &h}, aerRcvr)
|
|
if err != nil {
|
|
wsWaitErr = fmt.Errorf("failed to subscribe for execution results: %w", err)
|
|
break
|
|
}
|
|
waitersActive++
|
|
go func() {
|
|
<-exit
|
|
err = w.ws.Unsubscribe(txsID)
|
|
if err != nil {
|
|
unsubErrs <- fmt.Errorf("failed to unsubscribe from transactions (id: %s): %w", txsID, err)
|
|
return
|
|
}
|
|
unsubErrs <- nil
|
|
}()
|
|
// There is a potential race between subscription and acceptance, so
|
|
// do a polling check once _after_ the subscription.
|
|
appLog, err := w.ws.GetApplicationLog(h, &trig)
|
|
if err == nil {
|
|
res = &state.AppExecResult{
|
|
Container: appLog.Container,
|
|
Execution: appLog.Executions[0],
|
|
}
|
|
break // We have the result, no need for other subscriptions.
|
|
}
|
|
}
|
|
}
|
|
|
|
if wsWaitErr == nil && res == nil {
|
|
select {
|
|
case _, ok := <-bRcvr:
|
|
if !ok {
|
|
// We're toast, retry with non-ws client.
|
|
bRcvr = nil
|
|
aerRcvr = nil
|
|
wsWaitErr = ErrMissedEvent
|
|
break
|
|
}
|
|
waitErr = ErrTxNotAccepted
|
|
case aer, ok := <-aerRcvr:
|
|
if !ok {
|
|
// We're toast, retry with non-ws client.
|
|
bRcvr = nil
|
|
aerRcvr = nil
|
|
wsWaitErr = ErrMissedEvent
|
|
break
|
|
}
|
|
res = aer
|
|
case <-w.ws.Context().Done():
|
|
waitErr = fmt.Errorf("%w: %v", ErrContextDone, w.ws.Context().Err()) //nolint:errorlint // errorlint: non-wrapping format verb for fmt.Errorf. Use `%w` to format errors
|
|
case <-ctx.Done():
|
|
waitErr = fmt.Errorf("%w: %v", ErrContextDone, ctx.Err()) //nolint:errorlint // errorlint: non-wrapping format verb for fmt.Errorf. Use `%w` to format errors
|
|
}
|
|
}
|
|
close(exit)
|
|
|
|
if waitersActive > 0 {
|
|
// Drain receivers to avoid other notification receivers blocking.
|
|
drainLoop:
|
|
for {
|
|
select {
|
|
case _, ok := <-bRcvr:
|
|
if !ok { // Missed event means both channels are closed.
|
|
bRcvr = nil
|
|
aerRcvr = nil
|
|
}
|
|
case _, ok := <-aerRcvr:
|
|
if !ok { // Missed event means both channels are closed.
|
|
bRcvr = nil
|
|
aerRcvr = nil
|
|
}
|
|
case unsubErr := <-unsubErrs:
|
|
if unsubErr != nil {
|
|
errFmt := "unsubscription error: %v"
|
|
errArgs := []any{unsubErr}
|
|
if waitErr != nil {
|
|
errFmt = "%w; " + errFmt
|
|
errArgs = append([]any{waitErr}, errArgs...)
|
|
}
|
|
waitErr = fmt.Errorf(errFmt, errArgs...)
|
|
}
|
|
waitersActive--
|
|
// Wait until all receiver channels finish their work.
|
|
if waitersActive == 0 {
|
|
break drainLoop
|
|
}
|
|
}
|
|
}
|
|
}
|
|
if bRcvr != nil {
|
|
close(bRcvr)
|
|
}
|
|
if aerRcvr != nil {
|
|
close(aerRcvr)
|
|
}
|
|
close(unsubErrs)
|
|
|
|
// Rollback to a poll-based waiter if needed.
|
|
if wsWaitErr != nil && waitErr == nil {
|
|
res, waitErr = w.polling.WaitAny(ctx, vub, hashes...)
|
|
if waitErr != nil {
|
|
// Wrap the poll-based error, it's more important.
|
|
waitErr = fmt.Errorf("event-based error: %v; poll-based waiter error: %w", wsWaitErr, waitErr) //nolint:errorlint // errorlint: non-wrapping format verb for fmt.Errorf. Use `%w` to format errors
|
|
}
|
|
}
|
|
return
|
|
}
|