ipld-eth-server/libraries/shared/streamer/seed_node_streamer.go
2019-12-02 13:24:58 -06:00

85 lines
3.1 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/>.
// Streamer is used by watchers to stream eth data from a vulcanizedb seed node
package streamer
import (
"encoding/json"
"math/big"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/rpc"
"github.com/vulcanize/vulcanizedb/pkg/config"
"github.com/vulcanize/vulcanizedb/pkg/core"
)
// ISeedNodeStreamer is the interface for streaming SeedNodePayloads from a vulcanizeDB seed node
type ISeedNodeStreamer interface {
Stream(payloadChan chan SeedNodePayload, streamFilters config.Subscription) (*rpc.ClientSubscription, error)
}
// SeedNodeStreamer is the underlying struct for the ISeedNodeStreamer interface
type SeedNodeStreamer struct {
Client core.RpcClient
}
// NewSeedNodeStreamer creates a pointer to a new SeedNodeStreamer which satisfies the ISeedNodeStreamer interface
func NewSeedNodeStreamer(client core.RpcClient) *SeedNodeStreamer {
return &SeedNodeStreamer{
Client: client,
}
}
// Stream is the main loop for subscribing to data from a vulcanizedb seed node
func (sds *SeedNodeStreamer) Stream(payloadChan chan SeedNodePayload, streamFilters config.Subscription) (*rpc.ClientSubscription, error) {
return sds.Client.Subscribe("vulcanizedb", payloadChan, "stream", streamFilters)
}
// Payload holds the data returned from the seed node to the requesting client
type SeedNodePayload struct {
BlockNumber *big.Int `json:"blockNumber"`
HeadersRlp [][]byte `json:"headersRlp"`
UnclesRlp [][]byte `json:"unclesRlp"`
TransactionsRlp [][]byte `json:"transactionsRlp"`
ReceiptsRlp [][]byte `json:"receiptsRlp"`
StateNodesRlp map[common.Hash][]byte `json:"stateNodesRlp"`
StorageNodesRlp map[common.Hash]map[common.Hash][]byte `json:"storageNodesRlp"`
ErrMsg string `json:"errMsg"`
encoded []byte
err error
}
func (sd *SeedNodePayload) ensureEncoded() {
if sd.encoded == nil && sd.err == nil {
sd.encoded, sd.err = json.Marshal(sd)
}
}
// Length to implement Encoder interface for StateDiff
func (sd *SeedNodePayload) Length() int {
sd.ensureEncoded()
return len(sd.encoded)
}
// Encode to implement Encoder interface for StateDiff
func (sd *SeedNodePayload) Encode() ([]byte, error) {
sd.ensureEncoded()
return sd.encoded, sd.err
}