sync: Add rescan progress.

asset/dcr/sync.go

@@ -7,6 +7,7 @@ import (
 
 	"decred.org/dcrwallet/v3/p2p"
 	"decred.org/dcrwallet/v3/spv"
+	dcrwallet "decred.org/dcrwallet/v3/wallet"
 	"github.com/decred/dcrd/addrmgr/v2"
 )
 
@@ -81,7 +82,11 @@ func (w *Wallet) IsSynced() bool {
 	return false
 }
 
-// RescanFromHeight rescans the wallet from the specified height.
-func (w *Wallet) RescanFromHeight(ctx context.Context, startHeight int32) error {
-	return w.mainWallet.RescanFromHeight(ctx, w.syncer, startHeight)
+// RescanProgressFromHeight rescans for relevant transactions in all blocks in
+// the main chain starting at startHeight. Progress notifications and any
+// errors are sent to the channel p. This function blocks until the rescan
+// completes or ends in an error. p is closed before returning.
+func (w *Wallet) RescanProgressFromHeight(ctx context.Context,
+	startHeight int32, p chan<- dcrwallet.RescanProgress) {
+	w.mainWallet.RescanProgressFromHeight(ctx, w.syncer, startHeight, p)
 }

asset/dcr/wallet.go

@@ -79,8 +79,6 @@ func (w *Wallet) CloseWallet() error {
 	}
 
 	w.log.Info("Wallet closed")
-	w.mainWallet = nil
-	w.db = nil
 	return nil
 }
 

cgo/sync.go

@@ -7,6 +7,7 @@ import (
 	"strings"
 
 	"decred.org/dcrwallet/v3/spv"
+	dcrwallet "decred.org/dcrwallet/v3/wallet"
 )
 
 //export syncWallet
@@ -42,6 +43,10 @@ func syncWallet(cName, cPeers *C.char) *C.char {
 		},
 		FetchMissingCFiltersStarted: func() {
 			w.syncStatusMtx.Lock()
+			if w.rescanning {
+				w.syncStatusMtx.Unlock()
+				return
+			}
 			w.syncStatusCode = SSCFetchingCFilters
 			w.syncStatusMtx.Unlock()
 			w.log.Info("Fetching missing cfilters started.")
@@ -57,6 +62,10 @@ func syncWallet(cName, cPeers *C.char) *C.char {
 		},
 		FetchHeadersStarted: func() {
 			w.syncStatusMtx.Lock()
+			if w.rescanning {
+				w.syncStatusMtx.Unlock()
+				return
+			}
 			w.syncStatusCode = SSCFetchingHeaders
 			w.syncStatusMtx.Unlock()
 			w.log.Info("Fetching headers started.")
@@ -72,6 +81,10 @@ func syncWallet(cName, cPeers *C.char) *C.char {
 		},
 		DiscoverAddressesStarted: func() {
 			w.syncStatusMtx.Lock()
+			if w.rescanning {
+				w.syncStatusMtx.Unlock()
+				return
+			}
 			w.syncStatusCode = SSCDiscoveringAddrs
 			w.syncStatusMtx.Unlock()
 			w.log.Info("Discover addresses started.")
@@ -81,6 +94,10 @@ func syncWallet(cName, cPeers *C.char) *C.char {
 		},
 		RescanStarted: func() {
 			w.syncStatusMtx.Lock()
+			if w.rescanning {
+				w.syncStatusMtx.Unlock()
+				return
+			}
 			w.syncStatusCode = SSCRescanning
 			w.syncStatusMtx.Unlock()
 			w.log.Info("Rescan started.")
@@ -156,32 +173,57 @@ func syncWalletStatus(cName *C.char) *C.char {
 
 //export rescanFromHeight
 func rescanFromHeight(cName, cHeight *C.char) *C.char {
+	height, err := strconv.ParseUint(goString(cHeight), 10, 32)
+	if err != nil {
+		return errCResponse("height is not an uint32: %v", err)
+	}
 	walletsMtx.Lock()
 	defer walletsMtx.Unlock()
 	name := goString(cName)
 	w, exists := wallets[name]
 	if !exists {
 		return errCResponse("wallet with name %q does not exist", name)
 	}
-	height, err := strconv.ParseUint(goString(cHeight), 10, 32)
-	if err != nil {
-		return errCResponse("height is not an uint32: %v", err)
-	}
-	// We don't seem to get any feedback from wallet when doing rescans here.
-	// Just set status to rescanning and then to complete when done.
 	w.syncStatusMtx.Lock()
+	if w.rescanning {
+		w.syncStatusMtx.Unlock()
+		return errCResponse("wallet %q already rescanning", name)
+	}
 	w.syncStatusCode = SSCRescanning
 	w.rescanning = true
+	w.rescanHeight = int(height)
 	w.syncStatusMtx.Unlock()
+	w.Add(1)
 	go func() {
 		defer func() {
 			w.syncStatusMtx.Lock()
 			w.syncStatusCode = SSCComplete
 			w.rescanning = false
 			w.syncStatusMtx.Unlock()
+			w.Done()
+		}()
+		prog := make(chan dcrwallet.RescanProgress)
+		go func() {
+			w.RescanProgressFromHeight(ctx, int32(height), prog)
 		}()
-		if err := w.RescanFromHeight(ctx, int32(height)); err != nil {
-			log.Errorf("rescan wallet %q error: %v", name, err)
+		for {
+			select {
+			case p, open := <-prog:
+				if !open {
+					return
+				}
+				if p.Err != nil {
+					log.Errorf("rescan wallet %q error: %v", name, err)
+					return
+				}
+				w.syncStatusMtx.Lock()
+				w.rescanHeight = int(p.ScannedThrough)
+				w.syncStatusMtx.Unlock()
+			case <-ctx.Done():
+				return
+			case <-w.shutdown:
+				return
+			}
 		}
 	}()
 	return successCResponse("rescan from height %d for wallet %q started", height, name)

cgo/walletloader.go

@@ -18,6 +18,9 @@ type wallet struct {
 	*dcr.Wallet
 	log slog.Logger
 
+	sync.WaitGroup
+	shutdown chan struct{}
+
 	syncStatusMtx                                                       sync.RWMutex
 	syncStatusCode                                                      SyncStatusCode
 	targetHeight, cfiltersHeight, headersHeight, rescanHeight, numPeers int
@@ -73,8 +76,9 @@ func createWallet(cName, cDataDir, cNet, cPass, cMnemonic *C.char) *C.char {
 	}
 
 	wallets[name] = &wallet{
-		Wallet: w,
-		log:    logger,
+		Wallet:   w,
+		log:      logger,
+		shutdown: make(chan struct{}),
 	}
 	return successCResponse("wallet created")
 }
@@ -114,8 +118,9 @@ func createWatchOnlyWallet(cName, cDataDir, cNet, cPub *C.char) *C.char {
 	}
 
 	wallets[name] = &wallet{
-		Wallet: w,
-		log:    logger,
+		Wallet:   w,
+		log:      logger,
+		shutdown: make(chan struct{}),
 	}
 	return successCResponse("wallet created")
 }
@@ -156,8 +161,9 @@ func loadWallet(cName, cDataDir, cNet *C.char) *C.char {
 	}
 
 	wallets[name] = &wallet{
-		Wallet: w,
-		log:    logger,
+		Wallet:   w,
+		log:      logger,
+		shutdown: make(chan struct{}),
 	}
 	return successCResponse(fmt.Sprintf("wallet %q loaded", name))
 }
@@ -217,6 +223,8 @@ func closeWallet(cName *C.char) *C.char {
 	if !exists {
 		return errCResponse("wallet with name %q does not exist", name)
 	}
+	close(w.shutdown)
+	w.Wait()
 	if err := w.CloseWallet(); err != nil {
 		return errCResponse("close wallet %q error: %v", name, err.Error())
 	}