refactoring: transaction manager PR #12203

pkg/bus/bus.go

@@ -12,8 +12,8 @@ type Msg interface{}
 
 var ErrHandlerNotFound = errors.New("handler not found")
 
-type TransactionWrapper interface {
-	Wrap(ctx context.Context, fn func(ctx context.Context) error) error
+type TransactionManager interface {
+	InTransaction(ctx context.Context, fn func(ctx context.Context) error) error
 }
 
 type Bus interface {
@@ -35,19 +35,18 @@ type Bus interface {
 	// SetTransactionManager allows the user to replace the internal
 	// noop TransactionManager that is responsible for manageing
 	// transactions in `InTransaction`
-	SetTransactionManager(tm TransactionWrapper)
+	SetTransactionManager(tm TransactionManager)
 }
 
 func (b *InProcBus) InTransaction(ctx context.Context, fn func(ctx context.Context) error) error {
-	return b.transactionWrapper.Wrap(ctx, fn)
+	return b.txMng.InTransaction(ctx, fn)
 }
 
 type InProcBus struct {
 	handlers          map[string]HandlerFunc
 	listeners         map[string][]HandlerFunc
 	wildcardListeners []HandlerFunc
-
-	transactionWrapper TransactionWrapper
+	txMng             TransactionManager
 }
 
 // temp stuff, not sure how to handle bus instance, and init yet
@@ -58,8 +57,7 @@ func New() Bus {
 	bus.handlers = make(map[string]HandlerFunc)
 	bus.listeners = make(map[string][]HandlerFunc)
 	bus.wildcardListeners = make([]HandlerFunc, 0)
-
-	bus.transactionWrapper = &noopTransactionManager{}
+	bus.txMng = &noopTransactionManager{}
 
 	return bus
 }
@@ -69,12 +67,8 @@ func GetBus() Bus {
 	return globalBus
 }
 
-func SetTransactionManager(tm TransactionWrapper) {
-	globalBus.SetTransactionManager(tm)
-}
-
-func (b *InProcBus) SetTransactionManager(tm TransactionWrapper) {
-	b.transactionWrapper = tm
+func (b *InProcBus) SetTransactionManager(tm TransactionManager) {
+	b.txMng = tm
 }
 
 func (b *InProcBus) DispatchCtx(ctx context.Context, msg Msg) error {
@@ -213,6 +207,6 @@ func ClearBusHandlers() {
 
 type noopTransactionManager struct{}
 
-func (*noopTransactionManager) Wrap(ctx context.Context, fn func(ctx context.Context) error) error {
+func (*noopTransactionManager) InTransaction(ctx context.Context, fn func(ctx context.Context) error) error {
 	return nil
 }

pkg/models/transaction.go

@@ -0,0 +1,7 @@
+package models
+
+import "context"
+
+type TransactionManager interface {
+	InTransaction(ctx context.Context, fn func(ctx context.Context) error) error
+}

pkg/services/sqlstore/session.go

@@ -0,0 +1,63 @@
+package sqlstore
+
+import (
+	"context"
+	"reflect"
+
+	"github.com/go-xorm/xorm"
+)
+
+type DBSession struct {
+	*xorm.Session
+	events []interface{}
+}
+
+type dbTransactionFunc func(sess *DBSession) error
+
+func (sess *DBSession) publishAfterCommit(msg interface{}) {
+	sess.events = append(sess.events, msg)
+}
+
+func newSession() *DBSession {
+	return &DBSession{Session: x.NewSession()}
+}
+
+func startSession(ctx context.Context) *DBSession {
+	value := ctx.Value(ContextSessionName)
+	var sess *DBSession
+	sess, ok := value.(*DBSession)
+
+	if !ok {
+		newSess := newSession()
+		newSess.Begin()
+		return newSess
+	}
+
+	return sess
+}
+
+func withDbSession(ctx context.Context, callback dbTransactionFunc) error {
+	sess := startSession(ctx)
+
+	return callback(sess)
+}
+
+func (sess *DBSession) InsertId(bean interface{}) (int64, error) {
+	table := sess.DB().Mapper.Obj2Table(getTypeName(bean))
+
+	dialect.PreInsertId(table, sess.Session)
+
+	id, err := sess.Session.InsertOne(bean)
+
+	dialect.PostInsertId(table, sess.Session)
+
+	return id, err
+}
+
+func getTypeName(bean interface{}) (res string) {
+	t := reflect.TypeOf(bean)
+	for t.Kind() == reflect.Ptr {
+		t = t.Elem()
+	}
+	return t.Name()
+}

pkg/services/sqlstore/sqlstore.go

@@ -23,11 +23,10 @@ import (
 
 	"github.com/go-sql-driver/mysql"
 	"github.com/go-xorm/xorm"
-	_ "github.com/lib/pq"
-	_ "github.com/mattn/go-sqlite3"
-	sqlite3 "github.com/mattn/go-sqlite3"
 
 	_ "github.com/grafana/grafana/pkg/tsdb/mssql"
+	_ "github.com/lib/pq"
+	_ "github.com/mattn/go-sqlite3"
 )
 
 var (
@@ -82,9 +81,7 @@ func (ss *SqlStore) Init() error {
 	// Init repo instances
 	annotations.SetRepository(&SqlAnnotationRepo{})
 
-	ss.Bus.SetTransactionManager(&SQLTransactionManager{
-		engine: ss.engine,
-	})
+	ss.Bus.SetTransactionManager(ss)
 
 	// ensure admin user
 	if ss.skipEnsureAdmin {
@@ -94,57 +91,10 @@ func (ss *SqlStore) Init() error {
 	return ss.ensureAdminUser()
 }
 
-// SQLTransactionManager begin/end transaction
-type SQLTransactionManager struct {
-	engine *xorm.Engine
-}
-
-func (stm *SQLTransactionManager) Wrap(ctx context.Context, fn func(ctx context.Context) error) error {
-	return stm.wrapInternal(ctx, fn, 0)
-}
-
-func (stm *SQLTransactionManager) wrapInternal(ctx context.Context, fn func(ctx context.Context) error, retry int) error {
-	sess := startSession(ctx)
-	defer sess.Close()
-
-	withValue := context.WithValue(ctx, ContextSessionName, sess)
-
-	err := fn(withValue)
-
-	// special handling of database locked errors for sqlite, then we can retry 3 times
-	if sqlError, ok := err.(sqlite3.Error); ok && retry < 5 {
-		if sqlError.Code == sqlite3.ErrLocked {
-			sess.Rollback()
-			time.Sleep(time.Millisecond * time.Duration(10))
-			sqlog.Info("Database table locked, sleeping then retrying", "retry", retry)
-			return stm.wrapInternal(ctx, fn, retry+1)
-		}
-	}
-
-	if err != nil {
-		sess.Rollback()
-		return err
-	}
-
-	if err = sess.Commit(); err != nil {
-		return err
-	}
-
-	if len(sess.events) > 0 {
-		for _, e := range sess.events {
-			if err = bus.Publish(e); err != nil {
-				log.Error(3, "Failed to publish event after commit", err)
-			}
-		}
-	}
-
-	return nil
-}
-
 func (ss *SqlStore) ensureAdminUser() error {
 	systemUserCountQuery := m.GetSystemUserCountStatsQuery{}
 
-	err := bus.InTransaction(context.Background(), func(ctx context.Context) error {
+	err := ss.InTransaction(context.Background(), func(ctx context.Context) error {
 
 		err := bus.DispatchCtx(ctx, &systemUserCountQuery)
 		if err != nil {

pkg/services/sqlstore/shared.go → pkg/services/sqlstore/transactions.go

@@ -2,52 +2,53 @@ package sqlstore
 
 import (
 	"context"
-	"reflect"
 	"time"
 
-	"github.com/go-xorm/xorm"
 	"github.com/grafana/grafana/pkg/bus"
 	"github.com/grafana/grafana/pkg/log"
 	sqlite3 "github.com/mattn/go-sqlite3"
 )
 
-type DBSession struct {
-	*xorm.Session
-	events []interface{}
+func (ss *SqlStore) InTransaction(ctx context.Context, fn func(ctx context.Context) error) error {
+	return ss.inTransactionWithRetry(ctx, fn, 0)
 }
 
-type dbTransactionFunc func(sess *DBSession) error
-
-func (sess *DBSession) publishAfterCommit(msg interface{}) {
-	sess.events = append(sess.events, msg)
-}
+func (ss *SqlStore) inTransactionWithRetry(ctx context.Context, fn func(ctx context.Context) error, retry int) error {
+	sess := startSession(ctx)
+	defer sess.Close()
 
-func newSession() *DBSession {
-	return &DBSession{Session: x.NewSession()}
-}
+	withValue := context.WithValue(ctx, ContextSessionName, sess)
 
-func inTransaction(callback dbTransactionFunc) error {
-	return inTransactionWithRetry(callback, 0)
-}
+	err := fn(withValue)
 
-func startSession(ctx context.Context) *DBSession {
-	value := ctx.Value(ContextSessionName)
-	var sess *DBSession
-	sess, ok := value.(*DBSession)
+	// special handling of database locked errors for sqlite, then we can retry 3 times
+	if sqlError, ok := err.(sqlite3.Error); ok && retry < 5 {
+		if sqlError.Code == sqlite3.ErrLocked {
+			sess.Rollback()
+			time.Sleep(time.Millisecond * time.Duration(10))
+			ss.log.Info("Database table locked, sleeping then retrying", "retry", retry)
+			return ss.inTransactionWithRetry(ctx, fn, retry+1)
+		}
+	}
 
-	if !ok {
-		newSess := newSession()
-		newSess.Begin()
-		return newSess
+	if err != nil {
+		sess.Rollback()
+		return err
 	}
 
-	return sess
-}
+	if err = sess.Commit(); err != nil {
+		return err
+	}
 
-func withDbSession(ctx context.Context, callback dbTransactionFunc) error {
-	sess := startSession(ctx)
+	if len(sess.events) > 0 {
+		for _, e := range sess.events {
+			if err = bus.Publish(e); err != nil {
+				ss.log.Error("Failed to publish event after commit", err)
+			}
+		}
+	}
 
-	return callback(sess)
+	return nil
 }
 
 func inTransactionWithRetry(callback dbTransactionFunc, retry int) error {
@@ -94,22 +95,6 @@ func inTransactionWithRetryCtx(ctx context.Context, callback dbTransactionFunc,
 	return nil
 }
 
-func (sess *DBSession) InsertId(bean interface{}) (int64, error) {
-	table := sess.DB().Mapper.Obj2Table(getTypeName(bean))
-
-	dialect.PreInsertId(table, sess.Session)
-
-	id, err := sess.Session.InsertOne(bean)
-
-	dialect.PostInsertId(table, sess.Session)
-
-	return id, err
-}
-
-func getTypeName(bean interface{}) (res string) {
-	t := reflect.TypeOf(bean)
-	for t.Kind() == reflect.Ptr {
-		t = t.Elem()
-	}
-	return t.Name()
+func inTransaction(callback dbTransactionFunc) error {
+	return inTransactionWithRetry(callback, 0)
 }

pkg/services/sqlstore/user.go

@@ -31,7 +31,6 @@ func init() {
 	bus.AddHandler("sql", DeleteUser)
 	bus.AddHandler("sql", UpdateUserPermissions)
 	bus.AddHandler("sql", SetUserHelpFlag)
-
 	bus.AddCtxHandler("sql", CreateUserCtx)
 }