ipld-eth-server/libraries/shared/watcher/event_watcher.go

128 lines
3.9 KiB
Go

// VulcanizeDB
// Copyright © 2019 Vulcanize
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program 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 Affero General Public License for more details.
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
package watcher
import (
"time"
"github.com/sirupsen/logrus"
"github.com/vulcanize/vulcanizedb/libraries/shared/chunker"
"github.com/vulcanize/vulcanizedb/libraries/shared/constants"
"github.com/vulcanize/vulcanizedb/libraries/shared/fetcher"
"github.com/vulcanize/vulcanizedb/libraries/shared/logs"
"github.com/vulcanize/vulcanizedb/libraries/shared/transactions"
"github.com/vulcanize/vulcanizedb/libraries/shared/transformer"
"github.com/vulcanize/vulcanizedb/pkg/eth/core"
"github.com/vulcanize/vulcanizedb/pkg/eth/datastore/postgres/repositories"
"github.com/vulcanize/vulcanizedb/pkg/postgres"
)
const NoNewDataPause = time.Second * 7
type EventWatcher struct {
blockChain core.BlockChain
db *postgres.DB
LogDelegator logs.ILogDelegator
LogExtractor logs.ILogExtractor
}
func NewEventWatcher(db *postgres.DB, bc core.BlockChain) EventWatcher {
extractor := &logs.LogExtractor{
CheckedHeadersRepository: repositories.NewCheckedHeadersRepository(db),
Fetcher: fetcher.NewLogFetcher(bc),
LogRepository: repositories.NewHeaderSyncLogRepository(db),
Syncer: transactions.NewTransactionsSyncer(db, bc),
}
logTransformer := &logs.LogDelegator{
Chunker: chunker.NewLogChunker(),
LogRepository: repositories.NewHeaderSyncLogRepository(db),
}
return EventWatcher{
blockChain: bc,
db: db,
LogExtractor: extractor,
LogDelegator: logTransformer,
}
}
// Adds transformers to the watcher so that their logs will be extracted and delegated.
func (watcher *EventWatcher) AddTransformers(initializers []transformer.EventTransformerInitializer) error {
for _, initializer := range initializers {
t := initializer(watcher.db)
watcher.LogDelegator.AddTransformer(t)
err := watcher.LogExtractor.AddTransformerConfig(t.GetConfig())
if err != nil {
return err
}
}
return nil
}
// Extracts and delegates watched log events.
func (watcher *EventWatcher) Execute(recheckHeaders constants.TransformerExecution) error {
delegateErrsChan := make(chan error)
extractErrsChan := make(chan error)
defer close(delegateErrsChan)
defer close(extractErrsChan)
go watcher.extractLogs(recheckHeaders, extractErrsChan)
go watcher.delegateLogs(delegateErrsChan)
for {
select {
case delegateErr := <-delegateErrsChan:
logrus.Errorf("error delegating logs in event watcher: %s", delegateErr.Error())
return delegateErr
case extractErr := <-extractErrsChan:
logrus.Errorf("error extracting logs in event watcher: %s", extractErr.Error())
return extractErr
}
}
}
func (watcher *EventWatcher) extractLogs(recheckHeaders constants.TransformerExecution, errs chan error) {
err := watcher.LogExtractor.ExtractLogs(recheckHeaders)
if err != nil && err != logs.ErrNoUncheckedHeaders {
errs <- err
return
}
if err == logs.ErrNoUncheckedHeaders {
time.Sleep(NoNewDataPause)
watcher.extractLogs(recheckHeaders, errs)
} else {
watcher.extractLogs(recheckHeaders, errs)
}
}
func (watcher *EventWatcher) delegateLogs(errs chan error) {
err := watcher.LogDelegator.DelegateLogs()
if err != nil && err != logs.ErrNoLogs {
errs <- err
return
}
if err == logs.ErrNoLogs {
time.Sleep(NoNewDataPause)
watcher.delegateLogs(errs)
} else {
watcher.delegateLogs(errs)
}
}