ipld-eth-server/pkg/btc/streamer.go
2020-05-29 22:02:47 -05:00

87 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 btc
import (
"github.com/btcsuite/btcd/rpcclient"
"github.com/btcsuite/btcd/wire"
"github.com/btcsuite/btcutil"
"github.com/sirupsen/logrus"
"github.com/vulcanize/ipfs-chain-watcher/pkg/shared"
)
const (
PayloadChanBufferSize = 20000 // the max eth sub buffer size
)
// PayloadStreamer satisfies the PayloadStreamer interface for bitcoin
type PayloadStreamer struct {
Config *rpcclient.ConnConfig
}
// NewPayloadStreamer creates a pointer to a new PayloadStreamer which satisfies the PayloadStreamer interface for bitcoin
func NewPayloadStreamer(clientConfig *rpcclient.ConnConfig) *PayloadStreamer {
return &PayloadStreamer{
Config: clientConfig,
}
}
// Stream is the main loop for subscribing to data from the btc block notifications
// Satisfies the shared.PayloadStreamer interface
func (ps *PayloadStreamer) Stream(payloadChan chan shared.RawChainData) (shared.ClientSubscription, error) {
logrus.Info("streaming block payloads from btc")
blockNotificationHandler := rpcclient.NotificationHandlers{
// Notification handler for block connections, forwards new block data to the payloadChan
OnFilteredBlockConnected: func(height int32, header *wire.BlockHeader, txs []*btcutil.Tx) {
payloadChan <- BlockPayload{
BlockHeight: int64(height),
Header: header,
Txs: txs,
}
},
}
// Create a new client, and connect to btc ws server
client, err := rpcclient.New(ps.Config, &blockNotificationHandler)
if err != nil {
return nil, err
}
// Register for block connect notifications.
if err := client.NotifyBlocks(); err != nil {
return nil, err
}
client.WaitForShutdown()
return &ClientSubscription{client: client}, nil
}
// ClientSubscription is a wrapper around the underlying btcd rpc client
// to fit the shared.ClientSubscription interface
type ClientSubscription struct {
client *rpcclient.Client
}
// Unsubscribe satisfies the rpc.Subscription interface
func (bcs *ClientSubscription) Unsubscribe() {
bcs.client.Shutdown()
}
// Err() satisfies the rpc.Subscription interface with a dummy err channel
func (bcs *ClientSubscription) Err() <-chan error {
errChan := make(chan error)
return errChan
}