lnd.xprv/chainntnfs/bitcoindnotify/bitcoind_dev.go

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// +build dev
package bitcoindnotify
import (
"fmt"
"time"
"github.com/btcsuite/btcd/chaincfg/chainhash"
"github.com/btcsuite/btcwallet/chain"
"github.com/lightningnetwork/lnd/chainntnfs"
)
// UnsafeStart starts the notifier with a specified best height and optional
// best hash. Its bestBlock and txNotifier are initialized with bestHeight and
// optionally bestHash. The parameter generateBlocks is necessary for the
// bitcoind notifier to ensure we drain all notifications up to syncHeight,
// since if they are generated ahead of UnsafeStart the chainConn may start up
// with an outdated best block and miss sending ntfns. Used for testing.
func (b *BitcoindNotifier) UnsafeStart(bestHeight int32, bestHash *chainhash.Hash,
syncHeight int32, generateBlocks func() error) error {
// Connect to bitcoind, and register for notifications on connected,
// and disconnected blocks.
if err := b.chainConn.Start(); err != nil {
return err
}
if err := b.chainConn.NotifyBlocks(); err != nil {
return err
}
b.txNotifier = chainntnfs.NewTxNotifier(
uint32(bestHeight), reorgSafetyLimit, b.confirmHintCache,
b.spendHintCache,
)
if generateBlocks != nil {
// Ensure no block notifications are pending when we start the
// notification dispatcher goroutine.
// First generate the blocks, then drain the notifications
// for the generated blocks.
if err := generateBlocks(); err != nil {
return err
}
timeout := time.After(60 * time.Second)
loop:
for {
select {
case ntfn := <-b.chainConn.Notifications():
switch update := ntfn.(type) {
case chain.BlockConnected:
if update.Height >= syncHeight {
break loop
}
}
case <-timeout:
return fmt.Errorf("unable to catch up to height %d",
syncHeight)
}
}
}
// Run notificationDispatcher after setting the notifier's best block
// to avoid a race condition.
b.bestBlock = chainntnfs.BlockEpoch{Height: bestHeight, Hash: bestHash}
if bestHash == nil {
hash, err := b.chainConn.GetBlockHash(int64(bestHeight))
if err != nil {
return err
}
b.bestBlock.Hash = hash
}
b.wg.Add(1)
go b.notificationDispatcher()
return nil
}