lnd.xprv/channeldb/db.go
2017-12-17 18:40:05 -08:00

551 lines
15 KiB
Go

package channeldb
import (
"bytes"
"encoding/binary"
"fmt"
"os"
"path/filepath"
"sync"
"github.com/boltdb/bolt"
"github.com/roasbeef/btcd/btcec"
"github.com/roasbeef/btcd/wire"
)
const (
dbName = "channel.db"
dbFilePermission = 0600
)
// migration is a function which takes a prior outdated version of the database
// instances and mutates the key/bucket structure to arrive at a more
// up-to-date version of the database.
type migration func(tx *bolt.Tx) error
type version struct {
number uint32
migration migration
}
var (
// dbVersions is storing all versions of database. If current version
// of database don't match with latest version this list will be used
// for retrieving all migration function that are need to apply to the
// current db.
dbVersions = []version{
{
// The base DB version requires no migration.
number: 0,
migration: nil,
},
}
// Big endian is the preferred byte order, due to cursor scans over
// integer keys iterating in order.
byteOrder = binary.BigEndian
)
var bufPool = &sync.Pool{
New: func() interface{} { return new(bytes.Buffer) },
}
// DB is the primary datastore for the lnd daemon. The database stores
// information related to nodes, routing data, open/closed channels, fee
// schedules, and reputation data.
type DB struct {
*bolt.DB
dbPath string
}
// Open opens an existing channeldb. Any necessary schemas migrations due to
// updates will take place as necessary.
func Open(dbPath string) (*DB, error) {
path := filepath.Join(dbPath, dbName)
if !fileExists(path) {
if err := createChannelDB(dbPath); err != nil {
return nil, err
}
}
bdb, err := bolt.Open(path, dbFilePermission, nil)
if err != nil {
return nil, err
}
chanDB := &DB{
DB: bdb,
dbPath: dbPath,
}
// Synchronize the version of database and apply migrations if needed.
if err := chanDB.syncVersions(dbVersions); err != nil {
bdb.Close()
return nil, err
}
return chanDB, nil
}
// Wipe completely deletes all saved state within all used buckets within the
// database. The deletion is done in a single transaction, therefore this
// operation is fully atomic.
func (d *DB) Wipe() error {
return d.Update(func(tx *bolt.Tx) error {
err := tx.DeleteBucket(openChannelBucket)
if err != nil && err != bolt.ErrBucketNotFound {
return err
}
err = tx.DeleteBucket(closedChannelBucket)
if err != nil && err != bolt.ErrBucketNotFound {
return err
}
err = tx.DeleteBucket(invoiceBucket)
if err != nil && err != bolt.ErrBucketNotFound {
return err
}
err = tx.DeleteBucket(nodeInfoBucket)
if err != nil && err != bolt.ErrBucketNotFound {
return err
}
err = tx.DeleteBucket(nodeBucket)
if err != nil && err != bolt.ErrBucketNotFound {
return err
}
err = tx.DeleteBucket(edgeBucket)
if err != nil && err != bolt.ErrBucketNotFound {
return err
}
err = tx.DeleteBucket(edgeIndexBucket)
if err != nil && err != bolt.ErrBucketNotFound {
return err
}
err = tx.DeleteBucket(graphMetaBucket)
if err != nil && err != bolt.ErrBucketNotFound {
return err
}
return nil
})
}
// createChannelDB creates and initializes a fresh version of channeldb. In
// the case that the target path has not yet been created or doesn't yet exist,
// then the path is created. Additionally, all required top-level buckets used
// within the database are created.
func createChannelDB(dbPath string) error {
if !fileExists(dbPath) {
if err := os.MkdirAll(dbPath, 0700); err != nil {
return err
}
}
path := filepath.Join(dbPath, dbName)
bdb, err := bolt.Open(path, dbFilePermission, nil)
if err != nil {
return err
}
err = bdb.Update(func(tx *bolt.Tx) error {
if _, err := tx.CreateBucket(openChannelBucket); err != nil {
return err
}
if _, err := tx.CreateBucket(closedChannelBucket); err != nil {
return err
}
if _, err := tx.CreateBucket(invoiceBucket); err != nil {
return err
}
if _, err := tx.CreateBucket(nodeInfoBucket); err != nil {
return err
}
if _, err := tx.CreateBucket(nodeBucket); err != nil {
return err
}
if _, err := tx.CreateBucket(edgeBucket); err != nil {
return err
}
if _, err := tx.CreateBucket(edgeIndexBucket); err != nil {
return err
}
if _, err := tx.CreateBucket(graphMetaBucket); err != nil {
return err
}
if _, err := tx.CreateBucket(metaBucket); err != nil {
return err
}
meta := &Meta{
DbVersionNumber: getLatestDBVersion(dbVersions),
}
return putMeta(meta, tx)
})
if err != nil {
return fmt.Errorf("unable to create new channeldb")
}
return bdb.Close()
}
// fileExists returns true if the file exists, and false otherwise.
func fileExists(path string) bool {
if _, err := os.Stat(path); err != nil {
if os.IsNotExist(err) {
return false
}
}
return true
}
// FetchOpenChannels returns all stored currently active/open channels
// associated with the target nodeID. In the case that no active channels are
// known to have been created with this node, then a zero-length slice is
// returned.
func (d *DB) FetchOpenChannels(nodeID *btcec.PublicKey) ([]*OpenChannel, error) {
var channels []*OpenChannel
err := d.View(func(tx *bolt.Tx) error {
// Get the bucket dedicated to storing the metadata for open
// channels.
openChanBucket := tx.Bucket(openChannelBucket)
if openChanBucket == nil {
return nil
}
// Within this top level bucket, fetch the bucket dedicated to
// storing open channel data specific to the remote node.
pub := nodeID.SerializeCompressed()
nodeChanBucket := openChanBucket.Bucket(pub)
if nodeChanBucket == nil {
return nil
}
// Next, we'll need to go down an additional layer in order to
// retrieve the channels for each chain the node knows of.
return nodeChanBucket.ForEach(func(chainHash, v []byte) error {
// If there's a value, it's not a bucket so ignore it.
if v != nil {
return nil
}
// If we've found a valid chainhash bucket, then we'll
// retrieve that so we can extract all the channels.
chainBucket := nodeChanBucket.Bucket(chainHash)
if chainBucket == nil {
return fmt.Errorf("unable to read bucket for "+
"chain=%x", chainHash[:])
}
// Finally, we both of the necessary buckets retrieved,
// fetch all the active channels related to this node.
nodeChannels, err := d.fetchNodeChannels(chainBucket)
if err != nil {
return fmt.Errorf("unable to read channel for "+
"chain_hash=%x, node_key=%x: %v",
chainHash[:], pub, err)
}
channels = nodeChannels
return nil
})
})
return channels, err
}
// fetchNodeChannels retrieves all active channels from the target chainBucket
// which is under a node's dedicated channel bucket. This function is typically
// used to fetch all the active channels related to a particular node.
func (d *DB) fetchNodeChannels(chainBucket *bolt.Bucket) ([]*OpenChannel, error) {
var channels []*OpenChannel
// A node may have channels on several chains, so for each known chain,
// we'll extract all the channels.
err := chainBucket.ForEach(func(chanPoint, v []byte) error {
// If there's a value, it's not a bucket so ignore it.
if v != nil {
return nil
}
// Once we've found a valid channel bucket, we'll extract it
// from the node's chain bucket.
chanBucket := chainBucket.Bucket(chanPoint)
var outPoint wire.OutPoint
err := readOutpoint(bytes.NewReader(chanPoint), &outPoint)
if err != nil {
return err
}
oChannel, err := fetchOpenChannel(chanBucket, &outPoint)
if err != nil {
return fmt.Errorf("unable to read channel data for "+
"chan_point=%v: %v", outPoint, err)
}
oChannel.Db = d
channels = append(channels, oChannel)
return nil
})
if err != nil {
return nil, err
}
return channels, nil
}
// FetchAllChannels attempts to retrieve all open channels currently stored
// within the database.
func (d *DB) FetchAllChannels() ([]*OpenChannel, error) {
return fetchChannels(d, false)
}
// FetchPendingChannels will return channels that have completed the process of
// generating and broadcasting funding transactions, but whose funding
// transactions have yet to be confirmed on the blockchain.
func (d *DB) FetchPendingChannels() ([]*OpenChannel, error) {
return fetchChannels(d, true)
}
// fetchChannels attempts to retrieve channels currently stored in the
// database. The pendingOnly parameter determines whether only pending channels
// will be returned. If no active channels exist within the network, then
// ErrNoActiveChannels is returned.
func fetchChannels(d *DB, pendingOnly bool) ([]*OpenChannel, error) {
var channels []*OpenChannel
err := d.View(func(tx *bolt.Tx) error {
// Get the bucket dedicated to storing the metadata for open
// channels.
openChanBucket := tx.Bucket(openChannelBucket)
if openChanBucket == nil {
return ErrNoActiveChannels
}
// Next, fetch the bucket dedicated to storing metadata related
// to all nodes. All keys within this bucket are the serialized
// public keys of all our direct counterparties.
nodeMetaBucket := tx.Bucket(nodeInfoBucket)
if nodeMetaBucket == nil {
return fmt.Errorf("node bucket not created")
}
// Finally for each node public key in the bucket, fetch all
// the channels related to this particular node.
return nodeMetaBucket.ForEach(func(k, v []byte) error {
nodeChanBucket := openChanBucket.Bucket(k)
if nodeChanBucket == nil {
return nil
}
return nodeChanBucket.ForEach(func(chainHash, v []byte) error {
// If there's a value, it's not a bucket so
// ignore it.
if v != nil {
return nil
}
// If we've found a valid chainhash bucket,
// then we'll retrieve that so we can extract
// all the channels.
chainBucket := nodeChanBucket.Bucket(chainHash)
if chainBucket == nil {
return fmt.Errorf("unable to read "+
"bucket for chain=%x", chainHash[:])
}
nodeChans, err := d.fetchNodeChannels(chainBucket)
if err != nil {
return fmt.Errorf("unable to read "+
"channel for chain_hash=%x, "+
"node_key=%x: %v", chainHash[:], k, err)
}
// TODO(roasbeef): simplify
if pendingOnly {
for _, channel := range nodeChans {
if channel.IsPending {
channels = append(channels, channel)
}
}
} else {
channels = append(channels, nodeChans...)
}
return nil
})
})
})
return channels, err
}
// FetchClosedChannels attempts to fetch all closed channels from the database.
// The pendingOnly bool toggles if channels that aren't yet fully closed should
// be returned in the response or not. When a channel was cooperatively closed,
// it becomes fully closed after a single confirmation. When a channel was
// forcibly closed, it will become fully closed after _all_ the pending funds
// (if any) have been swept.
func (d *DB) FetchClosedChannels(pendingOnly bool) ([]*ChannelCloseSummary, error) {
var chanSummaries []*ChannelCloseSummary
if err := d.View(func(tx *bolt.Tx) error {
closeBucket := tx.Bucket(closedChannelBucket)
if closeBucket == nil {
return ErrNoClosedChannels
}
return closeBucket.ForEach(func(chanID []byte, summaryBytes []byte) error {
summaryReader := bytes.NewReader(summaryBytes)
chanSummary, err := deserializeCloseChannelSummary(summaryReader)
if err != nil {
return err
}
// If the query specified to only include pending
// channels, then we'll skip any channels which aren't
// currently pending.
if !chanSummary.IsPending && pendingOnly {
return nil
}
chanSummaries = append(chanSummaries, chanSummary)
return nil
})
}); err != nil {
return nil, err
}
return chanSummaries, nil
}
// MarkChanFullyClosed marks a channel as fully closed within the database. A
// channel should be marked as fully closed if the channel was initially
// cooperatively closed and it's reach a single confirmation, or after all the
// pending funds in a channel that has been forcibly closed have been swept.
func (d *DB) MarkChanFullyClosed(chanPoint *wire.OutPoint) error {
return d.Update(func(tx *bolt.Tx) error {
var b bytes.Buffer
if err := writeOutpoint(&b, chanPoint); err != nil {
return err
}
chanID := b.Bytes()
closedChanBucket, err := tx.CreateBucketIfNotExists(
closedChannelBucket,
)
if err != nil {
return err
}
chanSummaryBytes := closedChanBucket.Get(chanID)
if chanSummaryBytes == nil {
return fmt.Errorf("no closed channel by that chanID " +
"found")
}
chanSummaryReader := bytes.NewReader(chanSummaryBytes)
chanSummary, err := deserializeCloseChannelSummary(
chanSummaryReader,
)
if err != nil {
return err
}
chanSummary.IsPending = false
var newSummary bytes.Buffer
err = serializeChannelCloseSummary(&newSummary, chanSummary)
if err != nil {
return err
}
return closedChanBucket.Put(chanID, newSummary.Bytes())
})
}
// syncVersions function is used for safe db version synchronization. It
// applies migration functions to the current database and recovers the
// previous state of db if at least one error/panic appeared during migration.
func (d *DB) syncVersions(versions []version) error {
meta, err := d.FetchMeta(nil)
if err != nil {
if err == ErrMetaNotFound {
meta = &Meta{}
} else {
return err
}
}
// If the current database version matches the latest version number,
// then we don't need to perform any migrations.
latestVersion := getLatestDBVersion(versions)
log.Infof("Checking for schema update: latest_version=%v, "+
"db_version=%v", latestVersion, meta.DbVersionNumber)
if meta.DbVersionNumber == latestVersion {
return nil
}
log.Infof("Performing database schema migration")
// Otherwise, we fetch the migrations which need to applied, and
// execute them serially within a single database transaction to ensure
// the migration is atomic.
migrations, migrationVersions := getMigrationsToApply(versions,
meta.DbVersionNumber)
return d.Update(func(tx *bolt.Tx) error {
for i, migration := range migrations {
if migration == nil {
continue
}
log.Infof("Applying migration #%v", migrationVersions[i])
if err := migration(tx); err != nil {
log.Infof("Unable to apply migration #%v",
migrationVersions[i])
return err
}
}
meta.DbVersionNumber = latestVersion
return putMeta(meta, tx)
})
}
// ChannelGraph returns a new instance of the directed channel graph.
func (d *DB) ChannelGraph() *ChannelGraph {
return &ChannelGraph{d}
}
func getLatestDBVersion(versions []version) uint32 {
return versions[len(versions)-1].number
}
// getMigrationsToApply retrieves the migration function that should be
// applied to the database.
func getMigrationsToApply(versions []version, version uint32) ([]migration, []uint32) {
migrations := make([]migration, 0, len(versions))
migrationVersions := make([]uint32, 0, len(versions))
for _, v := range versions {
if v.number > version {
migrations = append(migrations, v.migration)
migrationVersions = append(migrationVersions, v.number)
}
}
return migrations, migrationVersions
}