We should pass around db.Instance instead of leveldb.DB

We're going to need the db.Instance to keep some state, and for that to
work we need the same one passed around everywhere. Hence this moves the
leveldb-specific file opening stuff into the db package and exports the
dbInstance type.

lib/model/model.go

@@ -33,7 +33,6 @@ import (
 	"github.com/syncthing/syncthing/lib/symlinks"
 	"github.com/syncthing/syncthing/lib/sync"
 	"github.com/syncthing/syncthing/lib/versioner"
-	"github.com/syndtr/goleveldb/leveldb"
 	"github.com/thejerf/suture"
 )
 
@@ -64,7 +63,7 @@ type Model struct {
 	*suture.Supervisor
 
 	cfg               *config.Wrapper
-	db                *leveldb.DB
+	db                *db.Instance
 	finder            *db.BlockFinder
 	progressEmitter   *ProgressEmitter
 	id                protocol.DeviceID
@@ -99,7 +98,7 @@ var (
 // NewModel creates and starts a new model. The model starts in read-only mode,
 // where it sends index information to connected peers and responds to requests
 // for file data without altering the local folder in any way.
-func NewModel(cfg *config.Wrapper, id protocol.DeviceID, deviceName, clientName, clientVersion string, ldb *leveldb.DB, protectedFiles []string) *Model {
+func NewModel(cfg *config.Wrapper, id protocol.DeviceID, deviceName, clientName, clientVersion string, ldb *db.Instance, protectedFiles []string) *Model {
 	m := &Model{
 		Supervisor: suture.New("model", suture.Spec{
 			Log: func(line string) {

lib/model/model_test.go

@@ -22,8 +22,6 @@ import (
 	"github.com/syncthing/syncthing/lib/config"
 	"github.com/syncthing/syncthing/lib/db"
 	"github.com/syncthing/syncthing/lib/protocol"
-	"github.com/syndtr/goleveldb/leveldb"
-	"github.com/syndtr/goleveldb/leveldb/storage"
 )
 
 var device1, device2 protocol.DeviceID
@@ -90,7 +88,7 @@ func init() {
 }
 
 func TestRequest(t *testing.T) {
-	db, _ := leveldb.Open(storage.NewMemStorage(), nil)
+	db := db.OpenMemory()
 
 	m := NewModel(defaultConfig, protocol.LocalDeviceID, "device", "syncthing", "dev", db, nil)
 
@@ -167,7 +165,7 @@ func BenchmarkIndex_100(b *testing.B) {
 }
 
 func benchmarkIndex(b *testing.B, nfiles int) {
-	db, _ := leveldb.Open(storage.NewMemStorage(), nil)
+	db := db.OpenMemory()
 	m := NewModel(defaultConfig, protocol.LocalDeviceID, "device", "syncthing", "dev", db, nil)
 	m.AddFolder(defaultFolderConfig)
 	m.StartFolderRO("default")
@@ -196,7 +194,7 @@ func BenchmarkIndexUpdate_10000_1(b *testing.B) {
 }
 
 func benchmarkIndexUpdate(b *testing.B, nfiles, nufiles int) {
-	db, _ := leveldb.Open(storage.NewMemStorage(), nil)
+	db := db.OpenMemory()
 	m := NewModel(defaultConfig, protocol.LocalDeviceID, "device", "syncthing", "dev", db, nil)
 	m.AddFolder(defaultFolderConfig)
 	m.StartFolderRO("default")
@@ -261,7 +259,7 @@ func (FakeConnection) Statistics() protocol.Statistics {
 }
 
 func BenchmarkRequest(b *testing.B) {
-	db, _ := leveldb.Open(storage.NewMemStorage(), nil)
+	db := db.OpenMemory()
 	m := NewModel(defaultConfig, protocol.LocalDeviceID, "device", "syncthing", "dev", db, nil)
 	m.AddFolder(defaultFolderConfig)
 	m.ServeBackground()
@@ -317,7 +315,7 @@ func TestDeviceRename(t *testing.T) {
 	}
 	cfg := config.Wrap("tmpconfig.xml", rawCfg)
 
-	db, _ := leveldb.Open(storage.NewMemStorage(), nil)
+	db := db.OpenMemory()
 	m := NewModel(cfg, protocol.LocalDeviceID, "device", "syncthing", "dev", db, nil)
 
 	fc := FakeConnection{
@@ -391,7 +389,7 @@ func TestClusterConfig(t *testing.T) {
 		},
 	}
 
-	db, _ := leveldb.Open(storage.NewMemStorage(), nil)
+	db := db.OpenMemory()
 
 	m := NewModel(config.Wrap("/tmp/test", cfg), protocol.LocalDeviceID, "device", "syncthing", "dev", db, nil)
 	m.AddFolder(cfg.Folders[0])
@@ -463,7 +461,7 @@ func TestIgnores(t *testing.T) {
 	ioutil.WriteFile("testdata/.stfolder", nil, 0644)
 	ioutil.WriteFile("testdata/.stignore", []byte(".*\nquux\n"), 0644)
 
-	db, _ := leveldb.Open(storage.NewMemStorage(), nil)
+	db := db.OpenMemory()
 	m := NewModel(defaultConfig, protocol.LocalDeviceID, "device", "syncthing", "dev", db, nil)
 	m.AddFolder(defaultFolderConfig)
 	m.StartFolderRO("default")
@@ -538,7 +536,7 @@ func TestIgnores(t *testing.T) {
 }
 
 func TestRefuseUnknownBits(t *testing.T) {
-	db, _ := leveldb.Open(storage.NewMemStorage(), nil)
+	db := db.OpenMemory()
 	m := NewModel(defaultConfig, protocol.LocalDeviceID, "device", "syncthing", "dev", db, nil)
 	m.AddFolder(defaultFolderConfig)
 	m.ServeBackground()
@@ -576,7 +574,7 @@ func TestRefuseUnknownBits(t *testing.T) {
 }
 
 func TestROScanRecovery(t *testing.T) {
-	ldb, _ := leveldb.Open(storage.NewMemStorage(), nil)
+	ldb := db.OpenMemory()
 	set := db.NewFileSet("default", ldb)
 	set.Update(protocol.LocalDeviceID, []protocol.FileInfo{
 		{Name: "dummyfile"},
@@ -660,7 +658,7 @@ func TestROScanRecovery(t *testing.T) {
 }
 
 func TestRWScanRecovery(t *testing.T) {
-	ldb, _ := leveldb.Open(storage.NewMemStorage(), nil)
+	ldb := db.OpenMemory()
 	set := db.NewFileSet("default", ldb)
 	set.Update(protocol.LocalDeviceID, []protocol.FileInfo{
 		{Name: "dummyfile"},
@@ -744,7 +742,7 @@ func TestRWScanRecovery(t *testing.T) {
 }
 
 func TestGlobalDirectoryTree(t *testing.T) {
-	db, _ := leveldb.Open(storage.NewMemStorage(), nil)
+	db := db.OpenMemory()
 	m := NewModel(defaultConfig, protocol.LocalDeviceID, "device", "syncthing", "dev", db, nil)
 	m.AddFolder(defaultFolderConfig)
 	m.ServeBackground()
@@ -994,7 +992,7 @@ func TestGlobalDirectoryTree(t *testing.T) {
 }
 
 func TestGlobalDirectorySelfFixing(t *testing.T) {
-	db, _ := leveldb.Open(storage.NewMemStorage(), nil)
+	db := db.OpenMemory()
 	m := NewModel(defaultConfig, protocol.LocalDeviceID, "device", "syncthing", "dev", db, nil)
 	m.AddFolder(defaultFolderConfig)
 	m.ServeBackground()
@@ -1168,7 +1166,7 @@ func BenchmarkTree_100_10(b *testing.B) {
 }
 
 func benchmarkTree(b *testing.B, n1, n2 int) {
-	db, _ := leveldb.Open(storage.NewMemStorage(), nil)
+	db := db.OpenMemory()
 	m := NewModel(defaultConfig, protocol.LocalDeviceID, "device", "syncthing", "dev", db, nil)
 	m.AddFolder(defaultFolderConfig)
 	m.ServeBackground()
@@ -1186,7 +1184,7 @@ func benchmarkTree(b *testing.B, n1, n2 int) {
 }
 
 func TestIgnoreDelete(t *testing.T) {
-	db, _ := leveldb.Open(storage.NewMemStorage(), nil)
+	db := db.OpenMemory()
 	m := NewModel(defaultConfig, protocol.LocalDeviceID, "device", "syncthing", "dev", db, nil)
 
 	// This folder should ignore external deletes

lib/model/rwfolder_test.go

@@ -12,12 +12,10 @@ import (
 	"testing"
 	"time"
 
+	"github.com/syncthing/syncthing/lib/db"
 	"github.com/syncthing/syncthing/lib/protocol"
 	"github.com/syncthing/syncthing/lib/scanner"
 	"github.com/syncthing/syncthing/lib/sync"
-
-	"github.com/syndtr/goleveldb/leveldb"
-	"github.com/syndtr/goleveldb/leveldb/storage"
 )
 
 func init() {
@@ -69,7 +67,7 @@ func TestHandleFile(t *testing.T) {
 	requiredFile := existingFile
 	requiredFile.Blocks = blocks[1:]
 
-	db, _ := leveldb.Open(storage.NewMemStorage(), nil)
+	db := db.OpenMemory()
 	m := NewModel(defaultConfig, protocol.LocalDeviceID, "device", "syncthing", "dev", db, nil)
 	m.AddFolder(defaultFolderConfig)
 	// Update index
@@ -125,7 +123,7 @@ func TestHandleFileWithTemp(t *testing.T) {
 	requiredFile := existingFile
 	requiredFile.Blocks = blocks[1:]
 
-	db, _ := leveldb.Open(storage.NewMemStorage(), nil)
+	db := db.OpenMemory()
 	m := NewModel(defaultConfig, protocol.LocalDeviceID, "device", "syncthing", "dev", db, nil)
 	m.AddFolder(defaultFolderConfig)
 	// Update index
@@ -187,7 +185,7 @@ func TestCopierFinder(t *testing.T) {
 	requiredFile.Blocks = blocks[1:]
 	requiredFile.Name = "file2"
 
-	db, _ := leveldb.Open(storage.NewMemStorage(), nil)
+	db := db.OpenMemory()
 	m := NewModel(defaultConfig, protocol.LocalDeviceID, "device", "syncthing", "dev", db, nil)
 	m.AddFolder(defaultFolderConfig)
 	// Update index
@@ -264,7 +262,7 @@ func TestCopierCleanup(t *testing.T) {
 		return true
 	}
 
-	db, _ := leveldb.Open(storage.NewMemStorage(), nil)
+	db := db.OpenMemory()
 	m := NewModel(defaultConfig, protocol.LocalDeviceID, "device", "syncthing", "dev", db, nil)
 	m.AddFolder(defaultFolderConfig)
 
@@ -313,7 +311,7 @@ func TestCopierCleanup(t *testing.T) {
 // Make sure that the copier routine hashes the content when asked, and pulls
 // if it fails to find the block.
 func TestLastResortPulling(t *testing.T) {
-	db, _ := leveldb.Open(storage.NewMemStorage(), nil)
+	db := db.OpenMemory()
 	m := NewModel(defaultConfig, protocol.LocalDeviceID, "device", "syncthing", "dev", db, nil)
 	m.AddFolder(defaultFolderConfig)
 
@@ -387,7 +385,7 @@ func TestDeregisterOnFailInCopy(t *testing.T) {
 	}
 	defer os.Remove("testdata/" + defTempNamer.TempName("filex"))
 
-	db, _ := leveldb.Open(storage.NewMemStorage(), nil)
+	db := db.OpenMemory()
 
 	m := NewModel(defaultConfig, protocol.LocalDeviceID, "device", "syncthing", "dev", db, nil)
 	m.AddFolder(defaultFolderConfig)
@@ -480,7 +478,7 @@ func TestDeregisterOnFailInPull(t *testing.T) {
 	}
 	defer os.Remove("testdata/" + defTempNamer.TempName("filex"))
 
-	db, _ := leveldb.Open(storage.NewMemStorage(), nil)
+	db := db.OpenMemory()
 	m := NewModel(defaultConfig, protocol.LocalDeviceID, "device", "syncthing", "dev", db, nil)
 	m.AddFolder(defaultFolderConfig)