From 3b6c988dd93adc7ad4a35232b9a13c9f312e68e6 Mon Sep 17 00:00:00 2001
From: Philip O'Toole <philip.otoole@yahoo.com>
Date: Sun, 10 Sep 2023 10:13:04 -0400
Subject: [PATCH] Do some syncing and closing

---
 db/db.go             | 32 +++++++++++++++++++++++++++++++-
 db/db_common_test.go | 22 ++++++++++++++++++++++
 snapshot/snapshot.go |  9 +++++++++
 3 files changed, 62 insertions(+), 1 deletion(-)

diff --git a/db/db.go b/db/db.go
index d0a8e46f..bb2e3fe1 100644
--- a/db/db.go
+++ b/db/db.go
@@ -268,6 +268,9 @@ func ReplayWAL(path string, wals []string, deleteMode bool) error {
 		if err != nil {
 			return err
 		}
+		if db.SetSynchronousMode("FULL"); err != nil {
+			return err
+		}
 		if err := db.Checkpoint(); err != nil {
 			return fmt.Errorf("checkpoint WAL %s: %s", wal, err.Error())
 		}
@@ -288,7 +291,16 @@ func ReplayWAL(path string, wals []string, deleteMode bool) error {
 			return err
 		}
 	}
-	return nil
+
+	// Ensure the database file is sync'ed to disk.
+	fd, err := os.OpenFile(path, os.O_RDWR, 0666)
+	if err != nil {
+		return err
+	}
+	if err := fd.Sync(); err != nil {
+		return err
+	}
+	return fd.Close()
 }
 
 // Open opens a file-based database, creating it if it does not exist. After this
@@ -526,6 +538,24 @@ func (db *DB) GetCheckpointing() (int, error) {
 	return n, err
 }
 
+// SetSynchronousMode sets the synchronous mode of the database.
+func (db *DB) SetSynchronousMode(mode string) error {
+	if mode != "OFF" && mode != "NORMAL" && mode != "FULL" && mode != "EXTRA" {
+		return fmt.Errorf("invalid synchronous mode %s", mode)
+	}
+	if _, err := db.rwDB.Exec(fmt.Sprintf("PRAGMA synchronous=%s", mode)); err != nil {
+		return fmt.Errorf("failed to set synchronous mode to %s: %s", mode, err.Error())
+	}
+	return nil
+}
+
+// GetSynchronousMode returns the current synchronous mode.
+func (db *DB) GetSynchronousMode() (int, error) {
+	var n int
+	err := db.rwDB.QueryRow("PRAGMA synchronous").Scan(&n)
+	return n, err
+}
+
 // FKEnabled returns whether Foreign Key constraints are enabled.
 func (db *DB) FKEnabled() bool {
 	return db.fkEnabled
diff --git a/db/db_common_test.go b/db/db_common_test.go
index 03fdf985..15dca5f2 100644
--- a/db/db_common_test.go
+++ b/db/db_common_test.go
@@ -18,6 +18,27 @@ func testCompileOptions(t *testing.T, db *DB) {
 	}
 }
 
+func testSetSynchronousMode(t *testing.T, db *DB) {
+	modes := map[string]int{
+		"OFF":    0,
+		"NORMAL": 1,
+		"FULL":   2,
+		"EXTRA":  3,
+	}
+	for m, i := range modes {
+		if db.SetSynchronousMode(m) != nil {
+			t.Fatalf("failed to set synchronous mode to %s", m)
+		}
+		mm, err := db.GetSynchronousMode()
+		if err != nil {
+			t.Fatalf("failed to get synchronous mode: %s", err.Error())
+		}
+		if mm != i {
+			t.Fatalf("synchonous mode not set to %s", m)
+		}
+	}
+}
+
 func testTableNotExist(t *testing.T, db *DB) {
 	q, err := db.QueryStringStmt("SELECT * FROM foo")
 	if err != nil {
@@ -1468,6 +1489,7 @@ func Test_DatabaseCommonOperations(t *testing.T) {
 		name     string
 		testFunc func(*testing.T, *DB)
 	}{
+		{"SetSynchronousMode", testSetSynchronousMode},
 		{"CompileOptions", testCompileOptions},
 		{"TableNotExist", testTableNotExist},
 		{"TableCreation", testTableCreation},
diff --git a/snapshot/snapshot.go b/snapshot/snapshot.go
index 54e0316d..6327370f 100644
--- a/snapshot/snapshot.go
+++ b/snapshot/snapshot.go
@@ -78,6 +78,12 @@ func ReplayDB(fullSnap *FullSnapshot, r io.Reader, path string) error {
 	if _, err := io.CopyN(sqliteBaseFD, r, dbInfo.Size); err != nil {
 		return fmt.Errorf("error writing SQLite file data: %v", err)
 	}
+	if sqliteBaseFD.Sync() != nil {
+		return fmt.Errorf("error syncing SQLite file: %v", err)
+	}
+	if err := sqliteBaseFD.Close(); err != nil {
+		return fmt.Errorf("error closing SQLite file: %v", err)
+	}
 
 	// Write out any WALs.
 	var walFiles []string
@@ -96,6 +102,9 @@ func ReplayDB(fullSnap *FullSnapshot, r io.Reader, path string) error {
 			if _, err := io.CopyN(walFD, r, wal.Size); err != nil {
 				return fmt.Errorf("error writing WAL file data: %v", err)
 			}
+			if walFD.Sync() != nil {
+				return fmt.Errorf("error syncing WAL file: %v", err)
+			}
 			walFiles = append(walFiles, walName)
 			return nil
 		}(); err != nil {