Reduce TiDB dependencies

cmd/backup.go

@@ -15,7 +15,7 @@ func runBackupCommand(command *cobra.Command, cmdName string) error {
 	if err := cfg.ParseFromFlags(command.Flags()); err != nil {
 		return err
 	}
-	return task.RunBackup(GetDefaultContext(), cmdName, &cfg)
+	return task.RunBackup(GetDefaultContext(), tidbGlue, cmdName, &cfg)
 }
 
 // NewBackupCommand return a full backup subcommand.

cmd/cmd.go

@@ -13,6 +13,7 @@ import (
 	"github.com/spf13/cobra"
 	"go.uber.org/zap"
 
+	"github.com/pingcap/br/pkg/gluetidb"
 	"github.com/pingcap/br/pkg/task"
 	"github.com/pingcap/br/pkg/utils"
 )
@@ -21,6 +22,7 @@ var (
 	initOnce       = sync.Once{}
 	defaultContext context.Context
 	hasLogFile     uint64
+	tidbGlue       = gluetidb.Glue{}
 )
 
 const (

cmd/restore.go

@@ -14,7 +14,7 @@ func runRestoreCommand(command *cobra.Command, cmdName string) error {
 	if err := cfg.ParseFromFlags(command.Flags()); err != nil {
 		return err
 	}
-	return task.RunRestore(GetDefaultContext(), cmdName, &cfg)
+	return task.RunRestore(GetDefaultContext(), tidbGlue, cmdName, &cfg)
 }
 
 // NewRestoreCommand returns a restore subcommand

pkg/backup/safe_point_test.go

@@ -8,18 +8,18 @@ import (
 	pd "github.com/pingcap/pd/client"
 	"github.com/pingcap/tidb/util/testleak"
 
-	"github.com/pingcap/br/pkg/utils"
+	"github.com/pingcap/br/pkg/mock"
 )
 
 var _ = Suite(&testSaftPointSuite{})
 
 type testSaftPointSuite struct {
-	mock *utils.MockCluster
+	mock *mock.Cluster
 }
 
 func (s *testSaftPointSuite) SetUpSuite(c *C) {
 	var err error
-	s.mock, err = utils.NewMockCluster()
+	s.mock, err = mock.NewCluster()
 	c.Assert(err, IsNil)
 }
 

pkg/backup/schema_test.go

@@ -9,18 +9,18 @@ import (
 	"github.com/pingcap/tidb/util/testkit"
 	"github.com/pingcap/tidb/util/testleak"
 
-	"github.com/pingcap/br/pkg/utils"
+	"github.com/pingcap/br/pkg/mock"
 )
 
 var _ = Suite(&testBackupSchemaSuite{})
 
 type testBackupSchemaSuite struct {
-	mock *utils.MockCluster
+	mock *mock.Cluster
 }
 
 func (s *testBackupSchemaSuite) SetUpSuite(c *C) {
 	var err error
-	s.mock, err = utils.NewMockCluster()
+	s.mock, err = mock.NewCluster()
 	c.Assert(err, IsNil)
 }
 
@@ -77,7 +77,7 @@ func (s *testBackupSchemaSuite) TestBuildBackupRangeAndSchema(c *C) {
 	<-updateCh
 	c.Assert(err, IsNil)
 	c.Assert(len(schemas), Equals, 1)
-	// MockCluster returns a dummy checksum (all fields are 1).
+	// Cluster returns a dummy checksum (all fields are 1).
 	c.Assert(schemas[0].Crc64Xor, Not(Equals), 0, Commentf("%v", schemas[0]))
 	c.Assert(schemas[0].TotalKvs, Not(Equals), 0, Commentf("%v", schemas[0]))
 	c.Assert(schemas[0].TotalBytes, Not(Equals), 0, Commentf("%v", schemas[0]))
@@ -97,7 +97,7 @@ func (s *testBackupSchemaSuite) TestBuildBackupRangeAndSchema(c *C) {
 	<-updateCh
 	c.Assert(err, IsNil)
 	c.Assert(len(schemas), Equals, 2)
-	// MockCluster returns a dummy checksum (all fields are 1).
+	// Cluster returns a dummy checksum (all fields are 1).
 	c.Assert(schemas[0].Crc64Xor, Not(Equals), 0, Commentf("%v", schemas[0]))
 	c.Assert(schemas[0].TotalKvs, Not(Equals), 0, Commentf("%v", schemas[0]))
 	c.Assert(schemas[0].TotalBytes, Not(Equals), 0, Commentf("%v", schemas[0]))

pkg/checksum/executor_test.go

@@ -12,6 +12,7 @@ import (
 	"github.com/pingcap/tidb/util/testleak"
 	"github.com/pingcap/tipb/go-tipb"
 
+	"github.com/pingcap/br/pkg/mock"
 	"github.com/pingcap/br/pkg/utils"
 )
 
@@ -22,12 +23,12 @@ func TestT(t *testing.T) {
 var _ = Suite(&testChecksumSuite{})
 
 type testChecksumSuite struct {
-	mock *utils.MockCluster
+	mock *mock.Cluster
 }
 
 func (s *testChecksumSuite) SetUpSuite(c *C) {
 	var err error
-	s.mock, err = utils.NewMockCluster()
+	s.mock, err = mock.NewCluster()
 	c.Assert(err, IsNil)
 }
 
@@ -61,7 +62,7 @@ func (s *testChecksumSuite) TestChecksum(c *C) {
 	c.Assert(len(exe1.reqs), Equals, 1)
 	resp, err := exe1.Execute(context.TODO(), s.mock.Storage.GetClient(), func() {})
 	c.Assert(err, IsNil)
-	// MockCluster returns a dummy checksum (all fields are 1).
+	// Cluster returns a dummy checksum (all fields are 1).
 	c.Assert(resp.Checksum, Equals, uint64(1), Commentf("%v", resp))
 	c.Assert(resp.TotalKvs, Equals, uint64(1), Commentf("%v", resp))
 	c.Assert(resp.TotalBytes, Equals, uint64(1), Commentf("%v", resp))

pkg/conn/conn.go

@@ -20,13 +20,14 @@ import (
 	"github.com/pingcap/log"
 	pd "github.com/pingcap/pd/client"
 	"github.com/pingcap/tidb/domain"
-	"github.com/pingcap/tidb/session"
 	"github.com/pingcap/tidb/store/tikv"
 	"github.com/pingcap/tidb/util/codec"
 	"go.uber.org/zap"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/backoff"
 	"google.golang.org/grpc/keepalive"
+
+	"github.com/pingcap/br/pkg/glue"
 )
 
 const (
@@ -87,7 +88,7 @@ func pdRequest(
 }
 
 // NewMgr creates a new Mgr.
-func NewMgr(ctx context.Context, pdAddrs string, storage tikv.Storage) (*Mgr, error) {
+func NewMgr(ctx context.Context, g glue.Glue, pdAddrs string, storage tikv.Storage) (*Mgr, error) {
 	addrs := strings.Split(pdAddrs, ",")
 
 	failure := errors.Errorf("pd address (%s) has wrong format", pdAddrs)
@@ -130,7 +131,7 @@ func NewMgr(ctx context.Context, pdAddrs string, storage tikv.Storage) (*Mgr, er
 		return nil, errors.Errorf("tikv cluster not health %+v", stores)
 	}
 
-	dom, err := session.BootstrapSession(storage)
+	dom, err := g.BootstrapSession(storage)
 	if err != nil {
 		return nil, errors.Trace(err)
 	}

pkg/glue/glue.go

@@ -0,0 +1,24 @@
+package glue
+
+import (
+	"context"
+
+	"github.com/pingcap/parser/model"
+	"github.com/pingcap/tidb/domain"
+	"github.com/pingcap/tidb/kv"
+	"github.com/pingcap/tidb/meta/autoid"
+)
+
+// Glue is an abstraction of TiDB function calls used in BR.
+type Glue interface {
+	BootstrapSession(store kv.Storage) (*domain.Domain, error)
+	CreateSession(store kv.Storage) (Session, error)
+}
+
+// Session is an abstraction of the session.Session interface.
+type Session interface {
+	Execute(ctx context.Context, sql string) error
+	ShowCreateDatabase(schema *model.DBInfo) (string, error)
+	ShowCreateTable(table *model.TableInfo, allocator autoid.Allocator) (string, error)
+	Close()
+}

pkg/gluetidb/glue.go

@@ -0,0 +1,65 @@
+package gluetidb
+
+import (
+	"bytes"
+	"context"
+
+	"github.com/pingcap/parser/model"
+	"github.com/pingcap/tidb/domain"
+	"github.com/pingcap/tidb/executor"
+	"github.com/pingcap/tidb/kv"
+	"github.com/pingcap/tidb/meta/autoid"
+	"github.com/pingcap/tidb/session"
+
+	"github.com/pingcap/br/pkg/glue"
+)
+
+// Glue is an implementation of glue.Glue using a new TiDB session.
+type Glue struct{}
+
+type tidbSession struct {
+	se session.Session
+}
+
+// BootstrapSession implements glue.Glue
+func (Glue) BootstrapSession(store kv.Storage) (*domain.Domain, error) {
+	return session.BootstrapSession(store)
+}
+
+// CreateSession implements glue.Glue
+func (Glue) CreateSession(store kv.Storage) (glue.Session, error) {
+	se, err := session.CreateSession(store)
+	if err != nil {
+		return nil, err
+	}
+	return &tidbSession{se: se}, nil
+}
+
+// Execute implements glue.Session
+func (gs *tidbSession) Execute(ctx context.Context, sql string) error {
+	_, err := gs.se.Execute(ctx, sql)
+	return err
+}
+
+// ShowCreateDatabase implements glue.Session
+func (gs *tidbSession) ShowCreateDatabase(schema *model.DBInfo) (string, error) {
+	var buf bytes.Buffer
+	if err := executor.ConstructResultOfShowCreateDatabase(gs.se, schema, true, &buf); err != nil {
+		return "", err
+	}
+	return buf.String(), nil
+}
+
+// ShowCreateTable implements glue.Session
+func (gs *tidbSession) ShowCreateTable(table *model.TableInfo, allocator autoid.Allocator) (string, error) {
+	var buf bytes.Buffer
+	if err := executor.ConstructResultOfShowCreateTable(gs.se, table, allocator, &buf); err != nil {
+		return "", err
+	}
+	return buf.String(), nil
+}
+
+// Close implements glue.Session
+func (gs *tidbSession) Close() {
+	gs.se.Close()
+}

pkg/utils/mock_cluster.go → pkg/mock/mock_cluster.go

@@ -1,4 +1,4 @@
-package utils
+package mock
 
 import (
 	"database/sql"
@@ -28,8 +28,8 @@ import (
 
 var pprofOnce sync.Once
 
-// MockCluster is mock tidb cluster, includes tikv and pd.
-type MockCluster struct {
+// Cluster is mock tidb cluster, includes tikv and pd.
+type Cluster struct {
 	*server.Server
 	*mocktikv.Cluster
 	mocktikv.MVCCStore
@@ -40,8 +40,8 @@ type MockCluster struct {
 	PDClient pd.Client
 }
 
-// NewMockCluster create a new mock cluster.
-func NewMockCluster() (*MockCluster, error) {
+// NewCluster create a new mock cluster.
+func NewCluster() (*Cluster, error) {
 	pprofOnce.Do(func() {
 		go func() {
 			// Make sure pprof is registered.
@@ -72,7 +72,7 @@ func NewMockCluster() (*MockCluster, error) {
 	if err != nil {
 		return nil, err
 	}
-	return &MockCluster{
+	return &Cluster{
 		Cluster:   cluster,
 		MVCCStore: mvccStore,
 		Storage:   storage,
@@ -82,7 +82,7 @@ func NewMockCluster() (*MockCluster, error) {
 }
 
 // Start runs a mock cluster
-func (mock *MockCluster) Start() error {
+func (mock *Cluster) Start() error {
 	statusURL, err := url.Parse(tempurl.Alloc())
 	if err != nil {
 		return err
@@ -124,7 +124,7 @@ func (mock *MockCluster) Start() error {
 }
 
 // Stop stops a mock cluster
-func (mock *MockCluster) Stop() {
+func (mock *Cluster) Stop() {
 	if mock.Domain != nil {
 		mock.Domain.Close()
 	}

pkg/mock/mock_cluster_test.go

@@ -0,0 +1,27 @@
+package mock
+
+import (
+	. "github.com/pingcap/check"
+	"github.com/pingcap/tidb/util/testleak"
+)
+
+var _ = Suite(&testClusterSuite{})
+
+type testClusterSuite struct {
+	mock *Cluster
+}
+
+func (s *testClusterSuite) SetUpSuite(c *C) {
+	var err error
+	s.mock, err = NewCluster()
+	c.Assert(err, IsNil)
+}
+
+func (s *testClusterSuite) TearDownSuite(c *C) {
+	testleak.AfterTest(c)()
+}
+
+func (s *testClusterSuite) TestSmoke(c *C) {
+	c.Assert(s.mock.Start(), IsNil)
+	s.mock.Stop()
+}

pkg/restore/backoff_test.go

@@ -7,18 +7,19 @@ import (
 	. "github.com/pingcap/check"
 	"github.com/pingcap/tidb/util/testleak"
 
+	"github.com/pingcap/br/pkg/mock"
 	"github.com/pingcap/br/pkg/utils"
 )
 
 var _ = Suite(&testBackofferSuite{})
 
 type testBackofferSuite struct {
-	mock *utils.MockCluster
+	mock *mock.Cluster
 }
 
 func (s *testBackofferSuite) SetUpSuite(c *C) {
 	var err error
-	s.mock, err = utils.NewMockCluster()
+	s.mock, err = mock.NewCluster()
 	c.Assert(err, IsNil)
 }
 

pkg/restore/client.go

@@ -23,6 +23,7 @@ import (
 	"google.golang.org/grpc/keepalive"
 
 	"github.com/pingcap/br/pkg/checksum"
+	"github.com/pingcap/br/pkg/glue"
 	"github.com/pingcap/br/pkg/summary"
 	"github.com/pingcap/br/pkg/utils"
 )
@@ -53,11 +54,12 @@ type Client struct {
 // NewRestoreClient returns a new RestoreClient
 func NewRestoreClient(
 	ctx context.Context,
+	g glue.Glue,
 	pdClient pd.Client,
 	store kv.Storage,
 ) (*Client, error) {
 	ctx, cancel := context.WithCancel(ctx)
-	db, err := NewDB(store)
+	db, err := NewDB(g, store)
 	if err != nil {
 		cancel()
 		return nil, errors.Trace(err)