chore: switch database engine to sqlite (fixes #9954) (#9965)

Switch the database from LevelDB to SQLite, for greater stability and
simpler code.

Co-authored-by: Tommy van der Vorst <tommy@pixelspark.nl>
Co-authored-by: bt90 <btom1990@googlemail.com>

internal/db/sqlite/db_local_test.go

@@ -0,0 +1,202 @@
+// Copyright (C) 2025 The Syncthing Authors.
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at https://mozilla.org/MPL/2.0/.
+
+package sqlite
+
+import (
+	"testing"
+
+	"github.com/syncthing/syncthing/internal/db"
+	"github.com/syncthing/syncthing/internal/itererr"
+	"github.com/syncthing/syncthing/lib/protocol"
+)
+
+func TestBlocks(t *testing.T) {
+	t.Parallel()
+
+	db, err := OpenTemp()
+	if err != nil {
+		t.Fatal()
+	}
+	t.Cleanup(func() {
+		if err := db.Close(); err != nil {
+			t.Fatal(err)
+		}
+	})
+
+	files := []protocol.FileInfo{
+		{
+			Name: "file1",
+			Blocks: []protocol.BlockInfo{
+				{Hash: []byte{1, 2, 3}, Offset: 0, Size: 42},
+				{Hash: []byte{2, 3, 4}, Offset: 42, Size: 42},
+				{Hash: []byte{3, 4, 5}, Offset: 84, Size: 42},
+			},
+		},
+		{
+			Name: "file2",
+			Blocks: []protocol.BlockInfo{
+				{Hash: []byte{2, 3, 4}, Offset: 0, Size: 42},
+				{Hash: []byte{3, 4, 5}, Offset: 42, Size: 42},
+				{Hash: []byte{4, 5, 6}, Offset: 84, Size: 42},
+			},
+		},
+	}
+
+	if err := db.Update("test", protocol.LocalDeviceID, files); err != nil {
+		t.Fatal(err)
+	}
+
+	// Search for blocks
+
+	vals, err := itererr.Collect(db.AllLocalBlocksWithHash([]byte{1, 2, 3}))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(vals) != 1 {
+		t.Log(vals)
+		t.Fatal("expected one hit")
+	} else if vals[0].BlockIndex != 0 || vals[0].Offset != 0 || vals[0].Size != 42 {
+		t.Log(vals[0])
+		t.Fatal("bad entry")
+	}
+
+	// Get FileInfos for those blocks
+
+	found := 0
+	it, errFn := db.AllLocalFilesWithBlocksHashAnyFolder(vals[0].BlocklistHash)
+	for folder, fileInfo := range it {
+		if folder != folderID {
+			t.Fatal("should be same folder")
+		}
+		if fileInfo.Name != "file1" {
+			t.Fatal("should be file1")
+		}
+		found++
+	}
+	if err := errFn(); err != nil {
+		t.Fatal(err)
+	}
+	if found != 1 {
+		t.Fatal("should find one file")
+	}
+
+	// Get the other blocks
+
+	vals, err = itererr.Collect(db.AllLocalBlocksWithHash([]byte{3, 4, 5}))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(vals) != 2 {
+		t.Log(vals)
+		t.Fatal("expected two hits")
+	}
+	// if vals[0].Index != 2 || vals[0].Offset != 84 || vals[0].Size != 42 {
+	// 	t.Log(vals[0])
+	// 	t.Fatal("bad entry 1")
+	// }
+	// if vals[1].Index != 1 || vals[1].Offset != 42 || vals[1].Size != 42 {
+	// 	t.Log(vals[1])
+	// 	t.Fatal("bad entry 2")
+	// }
+}
+
+func TestBlocksDeleted(t *testing.T) {
+	t.Parallel()
+
+	sdb, err := OpenTemp()
+	if err != nil {
+		t.Fatal()
+	}
+	t.Cleanup(func() {
+		if err := sdb.Close(); err != nil {
+			t.Fatal(err)
+		}
+	})
+
+	// Insert a file
+	file := genFile("foo", 1, 0)
+	if err := sdb.Update(folderID, protocol.LocalDeviceID, []protocol.FileInfo{file}); err != nil {
+		t.Fatal()
+	}
+
+	// We should find one entry for the block hash
+	search := file.Blocks[0].Hash
+	es := mustCollect[db.BlockMapEntry](t)(sdb.AllLocalBlocksWithHash(search))
+	if len(es) != 1 {
+		t.Fatal("expected one hit")
+	}
+
+	// Update the file with a new block hash
+	file.Blocks = genBlocks("foo", 42, 1)
+	if err := sdb.Update(folderID, protocol.LocalDeviceID, []protocol.FileInfo{file}); err != nil {
+		t.Fatal()
+	}
+
+	// Searching for the old hash should yield no hits
+	if hits := mustCollect[db.BlockMapEntry](t)(sdb.AllLocalBlocksWithHash(search)); len(hits) != 0 {
+		t.Log(hits)
+		t.Error("expected no hits")
+	}
+
+	// Searching for the new hash should yield one hits
+	if hits := mustCollect[db.BlockMapEntry](t)(sdb.AllLocalBlocksWithHash(file.Blocks[0].Hash)); len(hits) != 1 {
+		t.Log(hits)
+		t.Error("expected one hit")
+	}
+}
+
+func TestRemoteSequence(t *testing.T) {
+	t.Parallel()
+
+	sdb, err := OpenTemp()
+	if err != nil {
+		t.Fatal()
+	}
+	t.Cleanup(func() {
+		if err := sdb.Close(); err != nil {
+			t.Fatal(err)
+		}
+	})
+
+	// Insert a local file
+	file := genFile("foo", 1, 0)
+	if err := sdb.Update(folderID, protocol.LocalDeviceID, []protocol.FileInfo{file}); err != nil {
+		t.Fatal()
+	}
+
+	// Insert several remote files
+	file = genFile("foo1", 1, 42)
+	if err := sdb.Update(folderID, protocol.DeviceID{42}, []protocol.FileInfo{file}); err != nil {
+		t.Fatal()
+	}
+	if err := sdb.Update(folderID, protocol.DeviceID{43}, []protocol.FileInfo{file}); err != nil {
+		t.Fatal()
+	}
+	file = genFile("foo2", 1, 43)
+	if err := sdb.Update(folderID, protocol.DeviceID{43}, []protocol.FileInfo{file}); err != nil {
+		t.Fatal()
+	}
+	if err := sdb.Update(folderID, protocol.DeviceID{44}, []protocol.FileInfo{file}); err != nil {
+		t.Fatal()
+	}
+	file = genFile("foo3", 1, 44)
+	if err := sdb.Update(folderID, protocol.DeviceID{44}, []protocol.FileInfo{file}); err != nil {
+		t.Fatal()
+	}
+
+	// Verify remote sequences
+	seqs, err := sdb.RemoteSequences(folderID)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(seqs) != 3 || seqs[protocol.DeviceID{42}] != 42 ||
+		seqs[protocol.DeviceID{43}] != 43 ||
+		seqs[protocol.DeviceID{44}] != 44 {
+		t.Log(seqs)
+		t.Error("bad seqs")
+	}
+}