ipld-eth-server/pkg/serve/subscription.go
2020-08-31 10:59:41 -05:00

61 lines
1.7 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 serve
import (
"errors"
"github.com/ethereum/go-ethereum/rpc"
)
type Flag int32
const (
EmptyFlag Flag = iota
BackFillCompleteFlag
)
// Subscription holds the information for an individual client subscription to the watcher
type Subscription struct {
ID rpc.ID
PayloadChan chan<- SubscriptionPayload
QuitChan chan<- bool
}
// SubscriptionPayload is the struct for a watcher data subscription payload
// It carries data of a type specific to the chain being supported/queried and an error message
type SubscriptionPayload struct {
Data []byte `json:"data"` // e.g. for Ethereum rlp serialized eth.StreamPayload
Height int64 `json:"height"`
Err string `json:"err"` // field for error
Flag Flag `json:"flag"` // field for message
}
func (sp SubscriptionPayload) Error() error {
if sp.Err == "" {
return nil
}
return errors.New(sp.Err)
}
func (sp SubscriptionPayload) BackFillComplete() bool {
if sp.Flag == BackFillCompleteFlag {
return true
}
return false
}