ipld-eth-server/pkg/super_node/api.go

89 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 super_node
import (
"context"
"github.com/ethereum/go-ethereum/rpc"
log "github.com/sirupsen/logrus"
"github.com/vulcanize/vulcanizedb/pkg/core"
)
// APIName is the namespace used for the state diffing service API
const APIName = "vdb"
// APIVersion is the version of the state diffing service API
const APIVersion = "0.0.1"
// PublicSuperNodeAPI is the public api for the super node
type PublicSuperNodeAPI struct {
sn SuperNode
}
// NewPublicSuperNodeAPI creates a new PublicSuperNodeAPI with the provided underlying SyncPublishScreenAndServe process
func NewPublicSuperNodeAPI(superNodeInterface SuperNode) *PublicSuperNodeAPI {
return &PublicSuperNodeAPI{
sn: superNodeInterface,
}
}
// Stream is the public method to setup a subscription that fires off super node payloads as they are processed
func (api *PublicSuperNodeAPI) Stream(ctx context.Context, params SubscriptionSettings) (*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 stream events
rpcSub := notifier.CreateSubscription()
go func() {
// subscribe to events from the SyncPublishScreenAndServe service
payloadChannel := make(chan Payload, PayloadChanBufferSize)
quitChan := make(chan bool, 1)
go api.sn.Subscribe(rpcSub.ID, payloadChannel, quitChan, params)
// loop and await payloads and relay them to the subscriber using notifier
for {
select {
case packet := <-payloadChannel:
if err := notifier.Notify(rpcSub.ID, packet); err != nil {
log.Error("Failed to send super node packet", "err", err)
api.sn.Unsubscribe(rpcSub.ID)
return
}
case <-rpcSub.Err():
api.sn.Unsubscribe(rpcSub.ID)
return
case <-quitChan:
// don't need to unsubscribe to super node, the service does so before sending the quit signal this way
return
}
}
}()
return rpcSub, nil
}
// Node is a public rpc method to allow transformers to fetch the node info for the super node
func (api *PublicSuperNodeAPI) Node() core.Node {
return api.sn.Node()
}