85 lines
2.8 KiB
Go
85 lines
2.8 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 seed_node
|
|
|
|
import (
|
|
"context"
|
|
|
|
"github.com/ethereum/go-ethereum/rpc"
|
|
log "github.com/sirupsen/logrus"
|
|
|
|
"github.com/vulcanize/vulcanizedb/libraries/shared/streamer"
|
|
"github.com/vulcanize/vulcanizedb/pkg/config"
|
|
)
|
|
|
|
// APIName is the namespace used for the state diffing service API
|
|
const APIName = "vulcanizedb"
|
|
|
|
// APIVersion is the version of the state diffing service API
|
|
const APIVersion = "0.0.1"
|
|
|
|
// PublicSeedNodeAPI is the public api for the seed node
|
|
type PublicSeedNodeAPI struct {
|
|
snp Processor
|
|
}
|
|
|
|
// NewPublicSeedNodeAPI creates a new PublicSeedNodeAPI with the provided underlying SyncPublishScreenAndServe process
|
|
func NewPublicSeedNodeAPI(seedNodeProcessor Processor) *PublicSeedNodeAPI {
|
|
return &PublicSeedNodeAPI{
|
|
snp: seedNodeProcessor,
|
|
}
|
|
}
|
|
|
|
// Stream is the public method to setup a subscription that fires off SyncPublishScreenAndServe payloads as they are created
|
|
func (api *PublicSeedNodeAPI) Stream(ctx context.Context, streamFilters config.Subscription) (*rpc.Subscription, error) {
|
|
// ensure that the RPC connection supports subscriptions
|
|
notifier, supported := rpc.NotifierFromContext(ctx)
|
|
if !supported {
|
|
return nil, rpc.ErrNotificationsUnsupported
|
|
}
|
|
|
|
// create subscription and start waiting for statediff events
|
|
rpcSub := notifier.CreateSubscription()
|
|
|
|
go func() {
|
|
// subscribe to events from the SyncPublishScreenAndServe service
|
|
payloadChannel := make(chan streamer.SeedNodePayload, payloadChanBufferSize)
|
|
quitChan := make(chan bool, 1)
|
|
go api.snp.Subscribe(rpcSub.ID, payloadChannel, quitChan, streamFilters)
|
|
|
|
// loop and await state diff payloads and relay them to the subscriber with then notifier
|
|
for {
|
|
select {
|
|
case packet := <-payloadChannel:
|
|
if notifyErr := notifier.Notify(rpcSub.ID, packet); notifyErr != nil {
|
|
log.Error("Failed to send state diff packet", "err", notifyErr)
|
|
api.snp.Unsubscribe(rpcSub.ID)
|
|
return
|
|
}
|
|
case <-rpcSub.Err():
|
|
api.snp.Unsubscribe(rpcSub.ID)
|
|
return
|
|
case <-quitChan:
|
|
// don't need to unsubscribe, SyncPublishScreenAndServe service does so before sending the quit signal
|
|
return
|
|
}
|
|
}
|
|
}()
|
|
|
|
return rpcSub, nil
|
|
}
|