Initial pragma support.

litestream/api.go

@@ -49,7 +49,7 @@ type ReplicaOptions struct {
 }
 
 // NewReplica creates a read-replica from a Litestream client.
-func NewReplica(name string, client litestream.ReplicaClient, options ReplicaOptions) {
+func NewReplica(name string, client ReplicaClient, options ReplicaOptions) {
 	if options.Logger != nil {
 		options.Logger = options.Logger.With("name", name)
 	} else {
@@ -61,6 +61,7 @@ func NewReplica(name string, client litestream.ReplicaClient, options ReplicaOpt
 	if options.CacheSize == 0 {
 		options.CacheSize = DefaultCacheSize
 	}
+	options.MinLevel = max(0, min(options.MinLevel, litestream.SnapshotLevel))
 
 	liteMtx.Lock()
 	defer liteMtx.Unlock()
@@ -78,9 +79,9 @@ func RemoveReplica(name string) {
 	delete(liteDBs, name)
 }
 
-// NewPrimary creates a new primary that replicates through a client.
+// NewPrimary creates a new primary that replicates through client.
 // If restore is not nil, the database is first restored.
-func NewPrimary(ctx context.Context, path string, client litestream.ReplicaClient, restore *litestream.RestoreOptions) (*litestream.DB, error) {
+func NewPrimary(ctx context.Context, path string, client ReplicaClient, restore *RestoreOptions) (*litestream.DB, error) {
 	lsdb := litestream.NewDB(path)
 	lsdb.Replica = litestream.NewReplicaWithClient(lsdb, client)
 
@@ -97,3 +98,8 @@ func NewPrimary(ctx context.Context, path string, client litestream.ReplicaClien
 	}
 	return lsdb, nil
 }
+
+type (
+	ReplicaClient  = litestream.ReplicaClient
+	RestoreOptions = litestream.RestoreOptions
+)

litestream/api_test.go

@@ -0,0 +1,104 @@
+package litestream
+
+import (
+	"path/filepath"
+	"testing"
+	"time"
+
+	"github.com/benbjohnson/litestream"
+	"github.com/benbjohnson/litestream/file"
+	"github.com/ncruces/go-sqlite3/driver"
+	_ "github.com/ncruces/go-sqlite3/embed"
+)
+
+func Test_integration(t *testing.T) {
+	dir := t.TempDir()
+	dbpath := filepath.Join(dir, "test.db")
+	backup := filepath.Join(dir, "backup", "test.db")
+
+	db, err := driver.Open(dbpath)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer db.Close()
+
+	client := file.NewReplicaClient(backup)
+	NewReplica("test.db", client, ReplicaOptions{})
+
+	if err := setupPrimary(t, dbpath, client); err != nil {
+		t.Fatal(err)
+	}
+
+	replica, err := driver.Open("file:test.db?vfs=litestream")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer replica.Close()
+
+	_, err = db.ExecContext(t.Context(), `CREATE TABLE users (id INT, name VARCHAR(10))`)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	_, err = db.ExecContext(t.Context(),
+		`INSERT INTO users (id, name) VALUES (0, 'go'), (1, 'zig'), (2, 'whatever')`)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	time.Sleep(DefaultPollInterval + litestream.DefaultMonitorInterval)
+
+	rows, err := replica.QueryContext(t.Context(), `SELECT id, name FROM users`)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer rows.Close()
+
+	row := 0
+	ids := []int{0, 1, 2}
+	names := []string{"go", "zig", "whatever"}
+	for ; rows.Next(); row++ {
+		var id int
+		var name string
+		err := rows.Scan(&id, &name)
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		if id != ids[row] {
+			t.Errorf("got %d, want %d", id, ids[row])
+		}
+		if name != names[row] {
+			t.Errorf("got %q, want %q", name, names[row])
+		}
+	}
+	if row != 3 {
+		t.Errorf("got %d, want %d", row, len(ids))
+	}
+
+	var lag int
+	err = replica.QueryRowContext(t.Context(), `PRAGMA litestream_lag`).Scan(&lag)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if lag < 0 || lag > 2 {
+		t.Errorf("got %d", lag)
+	}
+
+	var txid string
+	err = replica.QueryRowContext(t.Context(), `PRAGMA litestream_txid`).Scan(&txid)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if txid != "0000000000000001" {
+		t.Errorf("got %q", txid)
+	}
+}
+
+func setupPrimary(tb testing.TB, path string, client ReplicaClient) error {
+	db, err := NewPrimary(tb.Context(), path, client, nil)
+	if err == nil {
+		tb.Cleanup(func() { db.Close(tb.Context()) })
+	}
+	return err
+}

litestream/go.mod

@@ -3,8 +3,8 @@ module github.com/ncruces/go-sqlite3/litestream
 go 1.24.4
 
 require (
-	github.com/benbjohnson/litestream v0.5.2
+	github.com/benbjohnson/litestream v0.5.3-0.20251109214555-48dc960260f0
-	github.com/ncruces/go-sqlite3 v0.30.1
+	github.com/ncruces/go-sqlite3 v0.30.2
 	github.com/ncruces/wbt v0.2.0
 	github.com/superfly/ltx v0.5.0
 	golang.org/x/sync v0.18.0

litestream/go.sum

@@ -60,8 +60,8 @@ github.com/aws/aws-sdk-go-v2/service/sts v1.35.1 h1:iF4Xxkc0H9c/K2dS0zZw3SCkj0Z7
 github.com/aws/aws-sdk-go-v2/service/sts v1.35.1/go.mod h1:0bxIatfN0aLq4mjoLDeBpOjOke68OsFlXPDFJ7V0MYw=
 github.com/aws/smithy-go v1.22.5 h1:P9ATCXPMb2mPjYBgueqJNCA5S9UfktsW0tTxi+a7eqw=
 github.com/aws/smithy-go v1.22.5/go.mod h1:t1ufH5HMublsJYulve2RKmHDC15xu1f26kHCp/HgceI=
-github.com/benbjohnson/litestream v0.5.2 h1:uD9I17n6RgUgyCwPM/Sw2YXNmMGixecUB5kmJ4FL08o=
+github.com/benbjohnson/litestream v0.5.3-0.20251109214555-48dc960260f0 h1:190qM2axbs1p7NyRm5/ygqrDdcIYhc5QXPTK04Cgyno=
-github.com/benbjohnson/litestream v0.5.2/go.mod h1:jSW6AGqbxmJnEXGjMHchlZclGphzbJ6jGrGo5fYIDhU=
+github.com/benbjohnson/litestream v0.5.3-0.20251109214555-48dc960260f0/go.mod h1:0gjSLi7Qm5INdtdo6YJMFMsS5e/KM2s3CFYF3OtLmY8=
 github.com/beorn7/perks v1.0.1 h1:VlbKKnNfV8bJzeqoa4cOKqO6bYr3WgKZxO8Z16+hsOM=
 github.com/beorn7/perks v1.0.1/go.mod h1:G2ZrVWU2WbWT9wwq4/hrbKbnv/1ERSJQ0ibhJ6rlkpw=
 github.com/cespare/xxhash/v2 v2.3.0 h1:UL815xU9SqsFlibzuggzjXhog7bL6oX9BbNZnL2UFvs=
@@ -113,8 +113,8 @@ github.com/nats-io/nkeys v0.4.11 h1:q44qGV008kYd9W1b1nEBkNzvnWxtRSQ7A8BoqRrcfa0=
 github.com/nats-io/nkeys v0.4.11/go.mod h1:szDimtgmfOi9n25JpfIdGw12tZFYXqhGxjhVxsatHVE=
 github.com/nats-io/nuid v1.0.1 h1:5iA8DT8V7q8WK2EScv2padNa/rTESc1KdnPw4TC2paw=
 github.com/nats-io/nuid v1.0.1/go.mod h1:19wcPz3Ph3q0Jbyiqsd0kePYG7A95tJPxeL+1OSON2c=
-github.com/ncruces/go-sqlite3 v0.30.1 h1:pHC3YsyRdJv4pCMB4MO1Q2BXw/CAa+Hoj7GSaKtVk+g=
+github.com/ncruces/go-sqlite3 v0.30.2 h1:1GVbHAkKAOwjJd3JYl8ldrYROudfZUOah7oXPD7VZbQ=
-github.com/ncruces/go-sqlite3 v0.30.1/go.mod h1:UVsWrQaq1qkcal5/vT5lOJnZCVlR5rsThKdwidjFsKc=
+github.com/ncruces/go-sqlite3 v0.30.2/go.mod h1:AxKu9sRxkludimFocbktlY6LiYSkxiI5gTA8r+os/Nw=
 github.com/ncruces/go-sqlite3/litestream/modernc v0.30.1 h1:3SNAOrm+qmLprkZybcvBrVNHyt0QYHljUGxmOXnL+K0=
 github.com/ncruces/go-sqlite3/litestream/modernc v0.30.1/go.mod h1:GSM2gXEOb9HIFFtsl0IUtnpvpDmVi7Kbp8z5GzwA0Tw=
 github.com/ncruces/julianday v1.0.0 h1:fH0OKwa7NWvniGQtxdJRxAgkBMolni2BjDHaWTxqt7M=
@@ -143,6 +143,8 @@ github.com/rogpeppe/go-internal v1.12.0 h1:exVL4IDcn6na9z1rAb56Vxr+CgyK3nn3O+epU
 github.com/rogpeppe/go-internal v1.12.0/go.mod h1:E+RYuTGaKKdloAfM02xzb0FW3Paa99yedzYV+kq4uf4=
 github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
 github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
+github.com/studio-b12/gowebdav v0.11.0 h1:qbQzq4USxY28ZYsGJUfO5jR+xkFtcnwWgitp4Zp1irU=
+github.com/studio-b12/gowebdav v0.11.0/go.mod h1:bHA7t77X/QFExdeAnDzK6vKM34kEZAcE1OX4MfiwjkE=
 github.com/superfly/ltx v0.5.0 h1:dXNrcT3ZtMb6iKZopIV7z5UBscnapg0b0F02loQsk5o=
 github.com/superfly/ltx v0.5.0/go.mod h1:Nf50QAIXU/ET4ua3AuQ2fh31MbgNQZA7r/DYx6Os77s=
 github.com/tetratelabs/wazero v1.10.1 h1:2DugeJf6VVk58KTPszlNfeeN8AhhpwcZqkJj2wwFuH8=

litestream/vfs.go

@@ -6,6 +6,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"strconv"
 	"sync"
 	"time"
 
@@ -160,6 +161,34 @@ func (f *liteFile) DeviceCharacteristics() vfs.DeviceCharacteristic {
 	return 0
 }
 
+func (f *liteFile) Pragma(name, value string) (string, error) {
+	switch name {
+	case "litestream_txid":
+		txid := f.txid
+		if txid == 0 {
+			// Outside transaction.
+			f.db.mtx.Lock()
+			txid = f.db.txids[f.db.opts.MinLevel]
+			f.db.mtx.Unlock()
+		}
+		return txid.String(), nil
+
+	case "litestream_lag":
+		f.db.mtx.Lock()
+		lastPoll := f.db.lastPoll
+		f.db.mtx.Unlock()
+
+		if lastPoll.IsZero() {
+			// Never polled successfully.
+			return "-1", nil
+		}
+		lag := time.Since(lastPoll) / time.Second
+		return strconv.FormatInt(int64(lag), 10), nil
+	}
+
+	return "", sqlite3.NOTFOUND
+}
+
 func (f *liteFile) SetDB(conn any) {
 	f.conn = conn.(*sqlite3.Conn)
 }
@@ -216,7 +245,7 @@ func (f *liteDB) pollReplica(ctx context.Context) (*pageIndex, ltx.TXID, error)
 
 	// Limit polling interval.
 	if time.Since(f.lastPoll) < f.opts.PollInterval {
-		return f.pages, f.txids[0], nil
+		return f.pages, f.txids[f.opts.MinLevel], nil
 	}
 
 	for level := range pollLevels(f.opts.MinLevel) {
@@ -227,7 +256,7 @@ func (f *liteDB) pollReplica(ctx context.Context) (*pageIndex, ltx.TXID, error)
 	}
 
 	f.lastPoll = time.Now()
-	return f.pages, f.txids[0], nil
+	return f.pages, f.txids[f.opts.MinLevel], nil
 }
 
 // +checklocks:f.mtx