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peers.go
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peers.go
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package channeldb
import (
"bytes"
"errors"
"fmt"
"time"
"github.com/lightningnetwork/lnd/channeldb/kvdb"
"github.com/lightningnetwork/lnd/routing/route"
)
var (
// peersBucket is the name of a top level bucket in which we store
// information about our peers. Information for different peers is
// stored in buckets keyed by their public key.
//
//
// peers-bucket
// |
// |-- <peer-pubkey>
// | |--flap-count-key: <ts><flap count>
// |
// |-- <peer-pubkey>
// | |--flap-count-key: <ts><flap count>
peersBucket = []byte("peers-bucket")
// flapCountKey is a key used in the peer pubkey sub-bucket that stores
// the timestamp of a peer's last flap count and its all time flap
// count.
flapCountKey = []byte("flap-count")
)
var (
// ErrNoPeerBucket is returned when we try to read entries for a peer
// that is not tracked.
ErrNoPeerBucket = errors.New("peer bucket not found")
)
// FlapCount contains information about a peer's flap count.
type FlapCount struct {
// Count provides the total flap count for a peer.
Count uint32
// LastFlap is the timestamp of the last flap recorded for a peer.
LastFlap time.Time
}
// WriteFlapCounts writes the flap count for a set of peers to disk, creating a
// bucket for the peer's pubkey if necessary. Note that this function overwrites
// the current value.
func (d *DB) WriteFlapCounts(flapCounts map[route.Vertex]*FlapCount) error {
return kvdb.Update(d, func(tx kvdb.RwTx) error {
// Run through our set of flap counts and record them for
// each peer, creating a bucket for the peer pubkey if required.
for peer, flapCount := range flapCounts {
peers := tx.ReadWriteBucket(peersBucket)
peerBucket, err := peers.CreateBucketIfNotExists(
peer[:],
)
if err != nil {
return err
}
var b bytes.Buffer
err = serializeTime(&b, flapCount.LastFlap)
if err != nil {
return err
}
if err = WriteElement(&b, flapCount.Count); err != nil {
return err
}
err = peerBucket.Put(flapCountKey, b.Bytes())
if err != nil {
return err
}
}
return nil
}, func() {})
}
// ReadFlapCount attempts to read the flap count for a peer, failing if the
// peer is not found or we do not have flap count stored.
func (d *DB) ReadFlapCount(pubkey route.Vertex) (*FlapCount, error) {
var flapCount FlapCount
if err := kvdb.View(d, func(tx kvdb.RTx) error {
peers := tx.ReadBucket(peersBucket)
peerBucket := peers.NestedReadBucket(pubkey[:])
if peerBucket == nil {
return ErrNoPeerBucket
}
flapBytes := peerBucket.Get(flapCountKey)
if flapBytes == nil {
return fmt.Errorf("flap count not recorded for: %v",
pubkey)
}
var (
err error
r = bytes.NewReader(flapBytes)
)
flapCount.LastFlap, err = deserializeTime(r)
if err != nil {
return err
}
return ReadElements(r, &flapCount.Count)
}, func() {
flapCount = FlapCount{}
}); err != nil {
return nil, err
}
return &flapCount, nil
}