Metadata datastore log

cli/backup.go

@@ -51,7 +51,10 @@ func BackupCmd(repoFlag string, rt repo.RepoType, getApi BackupApiFn) *cli.Comma
 			return xerrors.Errorf("getting metadata datastore: %w", err)
 		}
 
-		bds := backupds.Wrap(mds)
+		bds, err := backupds.Wrap(mds, backupds.NoLogdir)
+		if err != nil {
+			return err
+		}
 
 		fpath, err := homedir.Expand(cctx.Args().First())
 		if err != nil {

gen/main.go

@@ -4,15 +4,15 @@ import (
 	"fmt"
 	"os"
 
-	"github.com/filecoin-project/lotus/chain/market"
-
 	gen "github.com/whyrusleeping/cbor-gen"
 
 	"github.com/filecoin-project/lotus/api"
 	"github.com/filecoin-project/lotus/chain/exchange"
+	"github.com/filecoin-project/lotus/chain/market"
 	"github.com/filecoin-project/lotus/chain/types"
 	sectorstorage "github.com/filecoin-project/lotus/extern/sector-storage"
 	"github.com/filecoin-project/lotus/extern/sector-storage/storiface"
+	"github.com/filecoin-project/lotus/lib/backupds"
 	"github.com/filecoin-project/lotus/node/hello"
 	"github.com/filecoin-project/lotus/paychmgr"
 )
@@ -105,4 +105,12 @@ func main() {
 		fmt.Println(err)
 		os.Exit(1)
 	}
+
+	err = gen.WriteTupleEncodersToFile("./lib/backupds/cbor_gen.go", "backupds",
+		backupds.Entry{},
+	)
+	if err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
 }

lib/backupds/datastore.go

@@ -4,27 +4,49 @@ import (
 	"crypto/sha256"
 	"io"
 	"sync"
+	"time"
 
-	logging "github.com/ipfs/go-log/v2"
-	cbg "github.com/whyrusleeping/cbor-gen"
 	"golang.org/x/xerrors"
 
 	"github.com/ipfs/go-datastore"
 	"github.com/ipfs/go-datastore/query"
+	logging "github.com/ipfs/go-log/v2"
+	cbg "github.com/whyrusleeping/cbor-gen"
 )
 
 var log = logging.Logger("backupds")
 
+const NoLogdir = ""
+
 type Datastore struct {
 	child datastore.Batching
 
 	backupLk sync.RWMutex
+
+	log             chan Entry
+	closing, closed chan struct{}
+}
+
+type Entry struct {
+	Key, Value []byte
+	Timestamp  int64
 }
 
-func Wrap(child datastore.Batching) *Datastore {
-	return &Datastore{
+func Wrap(child datastore.Batching, logdir string) (*Datastore, error) {
+	ds := &Datastore{
 		child: child,
 	}
+
+	if logdir != NoLogdir {
+		ds.closing, ds.closed = make(chan struct{}), make(chan struct{})
+		ds.log = make(chan Entry)
+
+		if err := ds.startLog(logdir); err != nil {
+			return nil, err
+		}
+	}
+
+	return ds, nil
 }
 
 // Writes a datastore dump into the provided writer as
@@ -129,6 +151,14 @@ func (d *Datastore) Put(key datastore.Key, value []byte) error {
 	d.backupLk.RLock()
 	defer d.backupLk.RUnlock()
 
+	if d.log != nil {
+		d.log <- Entry{
+			Key:       []byte(key.String()),
+			Value:     value,
+			Timestamp: time.Now().Unix(),
+		}
+	}
+
 	return d.child.Put(key, value)
 }
 
@@ -146,11 +176,24 @@ func (d *Datastore) Sync(prefix datastore.Key) error {
 	return d.child.Sync(prefix)
 }
 
-func (d *Datastore) Close() error {
+func (d *Datastore) CloseLog() error {
 	d.backupLk.RLock()
 	defer d.backupLk.RUnlock()
 
-	return d.child.Close()
+	if d.closing != nil {
+		close(d.closing)
+		<-d.closed
+	}
+
+	return nil
+}
+
+func (d *Datastore) Close() error {
+	if err := d.child.Close(); err != nil {
+		return xerrors.Errorf("closing child datastore: %w", err)
+	}
+
+	return d.CloseLog()
 }
 
 func (d *Datastore) Batch() (datastore.Batch, error) {
@@ -160,17 +203,27 @@ func (d *Datastore) Batch() (datastore.Batch, error) {
 	}
 
 	return &bbatch{
+		d:   d,
 		b:   b,
 		rlk: d.backupLk.RLocker(),
 	}, nil
 }
 
 type bbatch struct {
+	d   *Datastore
 	b   datastore.Batch
 	rlk sync.Locker
 }
 
 func (b *bbatch) Put(key datastore.Key, value []byte) error {
+	if b.d.log != nil {
+		b.d.log <- Entry{
+			Key:       []byte(key.String()),
+			Value:     value,
+			Timestamp: time.Now().Unix(),
+		}
+	}
+
 	return b.b.Put(key, value)
 }