*: remove Next function for RecordSet (pingcap#6040)

ast/ast.go

@@ -137,9 +137,6 @@ type RecordSet interface {
 	// Fields gets result fields.
 	Fields() []*ResultField
 
-	// Next returns the next row, nil row means there is no more to return.
-	Next(ctx context.Context) (row types.Row, err error)
-
 	// NextChunk reads records into chunk.
 	NextChunk(ctx context.Context, chk *chunk.Chunk) error
 

bench_test.go

@@ -82,15 +82,16 @@ func prepareJoinBenchData(se Session, colType string, valueFormat string, valueC
 }
 
 func readResult(ctx context.Context, rs ast.RecordSet, count int) {
+	chk := rs.NewChunk()
 	for count > 0 {
-		x, err := rs.Next(ctx)
+		err := rs.NextChunk(ctx, chk)
 		if err != nil {
 			log.Fatal(err)
 		}
-		if x == nil {
+		if chk.NumRows() == 0 {
 			log.Fatal(count)
 		}
-		count--
+		count -= chk.NumRows()
 	}
 	rs.Close()
 }

bootstrap.go

@@ -32,6 +32,7 @@ import (
 	"github.com/pingcap/tidb/sessionctx/variable"
 	"github.com/pingcap/tidb/terror"
 	"github.com/pingcap/tidb/util/auth"
+	"github.com/pingcap/tidb/util/chunk"
 	log "github.com/sirupsen/logrus"
 	"golang.org/x/net/context"
 )
@@ -270,10 +271,12 @@ func getTiDBVar(s Session, name string) (sVal string, isNull bool, e error) {
 	}
 	r := rs[0]
 	defer terror.Call(r.Close)
-	row, err := r.Next(ctx)
-	if err != nil || row == nil {
+	chk := r.NewChunk()
+	err = r.NextChunk(ctx, chk)
+	if err != nil || chk.NumRows() == 0 {
 		return "", true, errors.Trace(err)
 	}
+	row := chk.GetRow(0)
 	if row.IsNull(0) {
 		return "", true, nil
 	}
@@ -473,17 +476,21 @@ func upgradeToVer12(s Session) {
 	r := rs[0]
 	sqls := make([]string, 0, 1)
 	defer terror.Call(r.Close)
-	row, err := r.Next(ctx)
-	for err == nil && row != nil {
-		user := row.GetString(0)
-		host := row.GetString(1)
-		pass := row.GetString(2)
-		var newPass string
-		newPass, err = oldPasswordUpgrade(pass)
-		terror.MustNil(err)
-		updateSQL := fmt.Sprintf(`UPDATE mysql.user set password = "%s" where user="%s" and host="%s"`, newPass, user, host)
-		sqls = append(sqls, updateSQL)
-		row, err = r.Next(ctx)
+	chk := r.NewChunk()
+	it := chunk.NewIterator4Chunk(chk)
+	err = r.NextChunk(ctx, chk)
+	for err == nil && chk.NumRows() != 0 {
+		for row := it.Begin(); row != it.End(); row = it.Next() {
+			user := row.GetString(0)
+			host := row.GetString(1)
+			pass := row.GetString(2)
+			var newPass string
+			newPass, err = oldPasswordUpgrade(pass)
+			terror.MustNil(err)
+			updateSQL := fmt.Sprintf(`UPDATE mysql.user set password = "%s" where user="%s" and host="%s"`, newPass, user, host)
+			sqls = append(sqls, updateSQL)
+		}
+		err = r.NextChunk(ctx, chk)
 	}
 	terror.MustNil(err)
 

bootstrap_test.go

@@ -50,10 +50,11 @@ func (s *testBootstrapSuite) TestBootstrap(c *C) {
 	r := mustExecSQL(c, se, `select * from user;`)
 	c.Assert(r, NotNil)
 	ctx := context.Background()
-	row, err := r.Next(ctx)
+	chk := r.NewChunk()
+	err := r.NextChunk(ctx, chk)
 	c.Assert(err, IsNil)
-	c.Assert(row, NotNil)
-	datums := ast.RowToDatums(row, r.Fields())
+	c.Assert(chk.NumRows() == 0, IsFalse)
+	datums := ast.RowToDatums(chk.GetRow(0), r.Fields())
 	match(c, datums, []byte("%"), []byte("root"), []byte(""), "Y", "Y", "Y", "Y", "Y", "Y", "Y", "Y", "Y", "Y", "Y", "Y", "Y", "Y", "Y", "Y", "Y", "Y", "Y", "Y", "Y", "Y", "Y")
 
 	c.Assert(se.Auth(&auth.UserIdentity{Username: "root", Hostname: "anyhost"}, []byte(""), []byte("")), IsTrue)
@@ -65,9 +66,10 @@ func (s *testBootstrapSuite) TestBootstrap(c *C) {
 	// Check privilege tables.
 	r = mustExecSQL(c, se, "SELECT COUNT(*) from mysql.global_variables;")
 	c.Assert(r, NotNil)
-	v, err := r.Next(ctx)
+	chk = r.NewChunk()
+	err = r.NextChunk(ctx, chk)
 	c.Assert(err, IsNil)
-	c.Assert(v.GetInt64(0), Equals, globalVarsCount())
+	c.Assert(chk.GetRow(0).GetInt64(0), Equals, globalVarsCount())
 
 	// Check a storage operations are default autocommit after the second start.
 	mustExecSQL(c, se, "USE test;")
@@ -84,9 +86,11 @@ func (s *testBootstrapSuite) TestBootstrap(c *C) {
 	mustExecSQL(c, se, "USE test;")
 	r = mustExecSQL(c, se, "select * from t")
 	c.Assert(r, NotNil)
-	v, err = r.Next(ctx)
+
+	chk = r.NewChunk()
+	err = r.NextChunk(ctx, chk)
 	c.Assert(err, IsNil)
-	datums = ast.RowToDatums(v, r.Fields())
+	datums = ast.RowToDatums(chk.GetRow(0), r.Fields())
 	match(c, datums, 3)
 	mustExecSQL(c, se, "drop table if exists t")
 	se.Close()
@@ -143,9 +147,11 @@ func (s *testBootstrapSuite) testBootstrapWithError(c *C) {
 	se := newSession(c, store, s.dbNameBootstrap)
 	mustExecSQL(c, se, "USE mysql;")
 	r := mustExecSQL(c, se, `select * from user;`)
-	row, err := r.Next(ctx)
+	chk := r.NewChunk()
+	err := r.NextChunk(ctx, chk)
 	c.Assert(err, IsNil)
-	c.Assert(row, NotNil)
+	c.Assert(chk.NumRows() == 0, IsFalse)
+	row := chk.GetRow(0)
 	datums := ast.RowToDatums(row, r.Fields())
 	match(c, datums, []byte("%"), []byte("root"), []byte(""), "Y", "Y", "Y", "Y", "Y", "Y", "Y", "Y", "Y", "Y", "Y", "Y", "Y", "Y", "Y", "Y", "Y", "Y", "Y", "Y")
 	mustExecSQL(c, se, "USE test;")
@@ -155,14 +161,18 @@ func (s *testBootstrapSuite) testBootstrapWithError(c *C) {
 	mustExecSQL(c, se, "SELECT * from mysql.columns_priv;")
 	// Check global variables.
 	r = mustExecSQL(c, se, "SELECT COUNT(*) from mysql.global_variables;")
-	v, err := r.Next(ctx)
+	chk = r.NewChunk()
+	err = r.NextChunk(ctx, chk)
 	c.Assert(err, IsNil)
+	v := chk.GetRow(0)
 	c.Assert(v.GetInt64(0), Equals, globalVarsCount())
 
 	r = mustExecSQL(c, se, `SELECT VARIABLE_VALUE from mysql.TiDB where VARIABLE_NAME="bootstrapped";`)
-	row, err = r.Next(ctx)
+	chk = r.NewChunk()
+	err = r.NextChunk(ctx, chk)
 	c.Assert(err, IsNil)
-	c.Assert(row, NotNil)
+	c.Assert(chk.NumRows() == 0, IsFalse)
+	row = chk.GetRow(0)
 	c.Assert(row.Len(), Equals, 1)
 	c.Assert(row.GetBytes(0), BytesEquals, []byte("True"))
 
@@ -181,9 +191,11 @@ func (s *testBootstrapSuite) TestUpgrade(c *C) {
 
 	// bootstrap with currentBootstrapVersion
 	r := mustExecSQL(c, se, `SELECT VARIABLE_VALUE from mysql.TiDB where VARIABLE_NAME="tidb_server_version";`)
-	row, err := r.Next(ctx)
+	chk := r.NewChunk()
+	err := r.NextChunk(ctx, chk)
+	row := chk.GetRow(0)
 	c.Assert(err, IsNil)
-	c.Assert(row, NotNil)
+	c.Assert(chk.NumRows() == 0, IsFalse)
 	c.Assert(row.Len(), Equals, 1)
 	c.Assert(row.GetBytes(0), BytesEquals, []byte(fmt.Sprintf("%d", currentBootstrapVersion)))
 
@@ -208,9 +220,10 @@ func (s *testBootstrapSuite) TestUpgrade(c *C) {
 	delete(storeBootstrapped, store.UUID())
 	// Make sure the version is downgraded.
 	r = mustExecSQL(c, se1, `SELECT VARIABLE_VALUE from mysql.TiDB where VARIABLE_NAME="tidb_server_version";`)
-	row, err = r.Next(ctx)
+	chk = r.NewChunk()
+	err = r.NextChunk(ctx, chk)
 	c.Assert(err, IsNil)
-	c.Assert(row, IsNil)
+	c.Assert(chk.NumRows() == 0, IsTrue)
 
 	ver, err = getBootstrapVersion(se1)
 	c.Assert(err, IsNil)
@@ -222,9 +235,11 @@ func (s *testBootstrapSuite) TestUpgrade(c *C) {
 	defer dom1.Close()
 	se2 := newSession(c, store, s.dbName)
 	r = mustExecSQL(c, se2, `SELECT VARIABLE_VALUE from mysql.TiDB where VARIABLE_NAME="tidb_server_version";`)
-	row, err = r.Next(ctx)
+	chk = r.NewChunk()
+	err = r.NextChunk(ctx, chk)
 	c.Assert(err, IsNil)
-	c.Assert(row, NotNil)
+	c.Assert(chk.NumRows() == 0, IsFalse)
+	row = chk.GetRow(0)
 	c.Assert(row.Len(), Equals, 1)
 	c.Assert(row.GetBytes(0), BytesEquals, []byte(fmt.Sprintf("%d", currentBootstrapVersion)))
 

cmd/benchdb/main.go

@@ -117,12 +117,13 @@ func (ut *benchDB) mustExec(sql string) {
 	if len(rss) > 0 {
 		ctx := context.Background()
 		rs := rss[0]
+		chk := rs.NewChunk()
 		for {
-			row, err1 := rs.Next(ctx)
-			if err1 != nil {
-				log.Fatal(err1)
+			err := rs.NextChunk(ctx, chk)
+			if err != nil {
+				log.Fatal(err)
 			}
-			if row == nil {
+			if chk.NumRows() == 0 {
 				break
 			}
 		}

ddl/util/util.go

@@ -21,6 +21,7 @@ import (
 	"github.com/pingcap/tidb/kv"
 	"github.com/pingcap/tidb/sessionctx"
 	"github.com/pingcap/tidb/terror"
+	"github.com/pingcap/tidb/util/chunk"
 	"github.com/pingcap/tidb/util/sqlexec"
 	"golang.org/x/net/context"
 )
@@ -54,28 +55,33 @@ func LoadDeleteRanges(ctx sessionctx.Context, safePoint uint64) (ranges []DelRan
 	}
 
 	rs := rss[0]
+	chk := rs.NewChunk()
+	it := chunk.NewIterator4Chunk(chk)
 	for {
-		row, err := rs.Next(context.TODO())
+		err = rs.NextChunk(context.TODO(), chk)
 		if err != nil {
 			return nil, errors.Trace(err)
 		}
-		if row == nil {
+		if chk.NumRows() == 0 {
 			break
 		}
-		startKey, err := hex.DecodeString(row.GetString(2))
-		if err != nil {
-			return nil, errors.Trace(err)
-		}
-		endKey, err := hex.DecodeString(row.GetString(3))
-		if err != nil {
-			return nil, errors.Trace(err)
+
+		for row := it.Begin(); row != it.End(); row = it.Next() {
+			startKey, err := hex.DecodeString(row.GetString(2))
+			if err != nil {
+				return nil, errors.Trace(err)
+			}
+			endKey, err := hex.DecodeString(row.GetString(3))
+			if err != nil {
+				return nil, errors.Trace(err)
+			}
+			ranges = append(ranges, DelRangeTask{
+				JobID:     row.GetInt64(0),
+				ElementID: row.GetInt64(1),
+				StartKey:  startKey,
+				EndKey:    endKey,
+			})
 		}
-		ranges = append(ranges, DelRangeTask{
-			JobID:     row.GetInt64(0),
-			ElementID: row.GetInt64(1),
-			StartKey:  startKey,
-			EndKey:    endKey,
-		})
 	}
 	return ranges, nil
 }

executor/ddl_test.go

@@ -25,6 +25,7 @@ import (
 	"github.com/pingcap/tidb/plan"
 	"github.com/pingcap/tidb/table"
 	"github.com/pingcap/tidb/types"
+	"github.com/pingcap/tidb/util/chunk"
 	"github.com/pingcap/tidb/util/testkit"
 	"golang.org/x/net/context"
 )
@@ -64,23 +65,31 @@ func (s *testSuite) TestCreateTable(c *C) {
 	rs, err := tk.Exec(`desc issue312_1`)
 	c.Assert(err, IsNil)
 	ctx := context.Background()
+	chk := rs.NewChunk()
+	it := chunk.NewIterator4Chunk(chk)
 	for {
-		row, err1 := rs.Next(ctx)
+		err1 := rs.NextChunk(ctx, chk)
 		c.Assert(err1, IsNil)
-		if row == nil {
+		if chk.NumRows() == 0 {
 			break
 		}
-		c.Assert(row.GetString(1), Equals, "float")
+		for row := it.Begin(); row != it.End(); row = it.Next() {
+			c.Assert(row.GetString(1), Equals, "float")
+		}
 	}
 	rs, err = tk.Exec(`desc issue312_2`)
 	c.Assert(err, IsNil)
+	chk = rs.NewChunk()
+	it = chunk.NewIterator4Chunk(chk)
 	for {
-		row, err1 := rs.Next(ctx)
+		err1 := rs.NextChunk(ctx, chk)
 		c.Assert(err1, IsNil)
-		if row == nil {
+		if chk.NumRows() == 0 {
 			break
 		}
-		c.Assert(row.GetString(1), Equals, "double")
+		for row := it.Begin(); row != it.End(); row = it.Next() {
+			c.Assert(chk.GetRow(0).GetString(1), Equals, "double")
+		}
 	}
 
 	// table option is auto-increment
@@ -146,8 +155,10 @@ func (s *testSuite) TestAlterTableAddColumn(c *C) {
 	now := time.Now().Add(-time.Duration(1 * time.Second)).Format(types.TimeFormat)
 	r, err := tk.Exec("select c2 from alter_test")
 	c.Assert(err, IsNil)
-	row, err := r.Next(context.Background())
+	chk := r.NewChunk()
+	err = r.NextChunk(context.Background(), chk)
 	c.Assert(err, IsNil)
+	row := chk.GetRow(0)
 	c.Assert(row.Len(), Equals, 1)
 	c.Assert(now, GreaterEqual, row.GetTime(0).String())
 	tk.MustExec("alter table alter_test add column c3 varchar(50) default 'CURRENT_TIMESTAMP'")

executor/distsql_test.go

@@ -54,7 +54,9 @@ func (s *testSuite) TestIndexDoubleReadClose(c *C) {
 
 	rs, err := tk.Exec("select * from dist where c_idx between 0 and 100")
 	c.Assert(err, IsNil)
-	_, err = rs.Next(context.Background())
+	chk := rs.NewChunk()
+	err = rs.NextChunk(context.Background(), chk)
+	c.Assert(err, IsNil)
 	c.Assert(err, IsNil)
 	keyword := "pickAndExecTask"
 	rs.Close()
@@ -103,9 +105,10 @@ func (s *testSuite) TestCopClientSend(c *C) {
 	rs, err := tk.Exec("select sum(id) from copclient")
 	c.Assert(err, IsNil)
 	defer rs.Close()
-	row, err := rs.Next(ctx)
+	chk := rs.NewChunk()
+	err = rs.NextChunk(ctx, chk)
 	c.Assert(err, IsNil)
-	c.Assert(row.GetMyDecimal(0).String(), Equals, "499500")
+	c.Assert(chk.GetRow(0).GetMyDecimal(0).String(), Equals, "499500")
 
 	// Split one region.
 	key := tablecodec.EncodeRowKeyWithHandle(tblID, 500)
@@ -116,15 +119,17 @@ func (s *testSuite) TestCopClientSend(c *C) {
 	// Check again.
 	rs, err = tk.Exec("select sum(id) from copclient")
 	c.Assert(err, IsNil)
-	row, err = rs.Next(ctx)
+	chk = rs.NewChunk()
+	err = rs.NextChunk(ctx, chk)
 	c.Assert(err, IsNil)
-	c.Assert(row.GetMyDecimal(0).String(), Equals, "499500")
+	c.Assert(chk.GetRow(0).GetMyDecimal(0).String(), Equals, "499500")
 	rs.Close()
 
 	// Check there is no goroutine leak.
 	rs, err = tk.Exec("select * from copclient order by id")
 	c.Assert(err, IsNil)
-	_, err = rs.Next(ctx)
+	chk = rs.NewChunk()
+	err = rs.NextChunk(ctx, chk)
 	c.Assert(err, IsNil)
 	rs.Close()
 	keyword := "(*copIterator).work"

executor/executor.go

@@ -226,7 +226,7 @@ func (e *CancelDDLJobsExec) NextChunk(ctx context.Context, chk *chunk.Chunk) err
 	}
 	numCurBatch := mathutil.Min(e.maxChunkSize, len(e.jobIDs)-e.cursor)
 	for i := e.cursor; i < e.cursor+numCurBatch; i++ {
-		chk.AppendInt64(0, e.jobIDs[i])
+		chk.AppendString(0, fmt.Sprintf("%d", e.jobIDs[i]))
 		if e.errs[i] != nil {
 			chk.AppendString(1, fmt.Sprintf("error: %v", e.errs[i]))
 		} else {