From 6fa2ab326a8787f50570aa0861148fe64afd9124 Mon Sep 17 00:00:00 2001
From: crazycs520 <crazycs520@gmail.com>
Date: Wed, 18 Mar 2020 16:08:26 +0800
Subject: [PATCH] ddl: support recover truncate table (#15398)

---
 ddl/serial_test.go | 48 ++++++++++++++++++++++++++++++----------------
 executor/ddl.go    |  6 +++---
 2 files changed, 34 insertions(+), 20 deletions(-)

diff --git a/ddl/serial_test.go b/ddl/serial_test.go
index 0c90f2c94f41e..feecb046f7b2a 100644
--- a/ddl/serial_test.go
+++ b/ddl/serial_test.go
@@ -433,17 +433,23 @@ func (s *testSerialSuite) TestRecoverTableByJobID(c *C) {
 	tk.MustExec("insert into t_recover values (1),(2),(3)")
 	tk.MustExec("drop table t_recover")
 
-	rs, err := tk.Exec("admin show ddl jobs")
-	c.Assert(err, IsNil)
-	rows, err := session.GetRows4Test(context.Background(), tk.Se, rs)
-	c.Assert(err, IsNil)
-	row := rows[0]
-	c.Assert(row.GetString(1), Equals, "test_recover")
-	c.Assert(row.GetString(3), Equals, "drop table")
-	jobID := row.GetInt64(0)
+	getDDLJobID := func(table, tp string) int64 {
+		rs, err := tk.Exec("admin show ddl jobs")
+		c.Assert(err, IsNil)
+		rows, err := session.GetRows4Test(context.Background(), tk.Se, rs)
+		c.Assert(err, IsNil)
+		for _, row := range rows {
+			if row.GetString(1) == table && row.GetString(3) == tp {
+				return row.GetInt64(0)
+			}
+		}
+		c.Errorf("can't find %s table of %s", tp, table)
+		return -1
+	}
+	jobID := getDDLJobID("test_recover", "drop table")
 
 	// if GC safe point is not exists in mysql.tidb
-	_, err = tk.Exec(fmt.Sprintf("recover table by job %d", jobID))
+	_, err := tk.Exec(fmt.Sprintf("recover table by job %d", jobID))
 	c.Assert(err, NotNil)
 	c.Assert(err.Error(), Equals, "can not get 'tikv_gc_safe_point'")
 	// set GC safe point
@@ -492,14 +498,7 @@ func (s *testSerialSuite) TestRecoverTableByJobID(c *C) {
 
 	tk.MustExec("delete from t_recover where a > 1")
 	tk.MustExec("drop table t_recover")
-	rs, err = tk.Exec("admin show ddl jobs")
-	c.Assert(err, IsNil)
-	rows, err = session.GetRows4Test(context.Background(), tk.Se, rs)
-	c.Assert(err, IsNil)
-	row = rows[0]
-	c.Assert(row.GetString(1), Equals, "test_recover")
-	c.Assert(row.GetString(3), Equals, "drop table")
-	jobID = row.GetInt64(0)
+	jobID = getDDLJobID("test_recover", "drop table")
 
 	tk.MustExec(fmt.Sprintf("recover table by job %d", jobID))
 
@@ -509,6 +508,14 @@ func (s *testSerialSuite) TestRecoverTableByJobID(c *C) {
 	tk.MustExec("insert into t_recover values (7),(8),(9)")
 	tk.MustQuery("select * from t_recover;").Check(testkit.Rows("1", "7", "8", "9"))
 
+	// Test for recover truncate table.
+	tk.MustExec("truncate table t_recover")
+	tk.MustExec("rename table t_recover to t_recover_new")
+	jobID = getDDLJobID("test_recover", "truncate table")
+	tk.MustExec(fmt.Sprintf("recover table by job %d", jobID))
+	tk.MustExec("insert into t_recover values (10)")
+	tk.MustQuery("select * from t_recover;").Check(testkit.Rows("1", "7", "8", "9", "10"))
+
 	gcEnable, err := gcutil.CheckGCEnable(tk.Se)
 	c.Assert(err, IsNil)
 	c.Assert(gcEnable, Equals, false)
@@ -608,6 +615,13 @@ func (s *testSerialSuite) TestRecoverTableByTableName(c *C) {
 	tk.MustExec("insert into t_recover values (7),(8),(9)")
 	tk.MustQuery("select * from t_recover;").Check(testkit.Rows("1", "7", "8", "9"))
 
+	// Recover truncate table.
+	tk.MustExec("truncate table t_recover")
+	tk.MustExec("rename table t_recover to t_recover_new1")
+	tk.MustExec("recover table t_recover")
+	tk.MustExec("insert into t_recover values (10)")
+	tk.MustQuery("select * from t_recover;").Check(testkit.Rows("1", "7", "8", "9", "10"))
+
 	gcEnable, err := gcutil.CheckGCEnable(tk.Se)
 	c.Assert(err, IsNil)
 	c.Assert(gcEnable, Equals, false)
diff --git a/executor/ddl.go b/executor/ddl.go
index bb3fae612db45..5116e1e7396cb 100644
--- a/executor/ddl.go
+++ b/executor/ddl.go
@@ -377,8 +377,8 @@ func (e *DDLExec) getRecoverTableByJobID(s *ast.RecoverTableStmt, t *meta.Meta,
 	if job == nil {
 		return nil, nil, admin.ErrDDLJobNotFound.GenWithStackByArgs(s.JobID)
 	}
-	if job.Type != model.ActionDropTable {
-		return nil, nil, errors.Errorf("Job %v type is %v, not drop table", job.ID, job.Type)
+	if job.Type != model.ActionDropTable && job.Type != model.ActionTruncateTable {
+		return nil, nil, errors.Errorf("Job %v type is %v, not dropped/truncated table", job.ID, job.Type)
 	}
 
 	// Check GC safe point for getting snapshot infoSchema.
@@ -424,7 +424,7 @@ func (e *DDLExec) getRecoverTableByTableName(s *ast.RecoverTableStmt, t *meta.Me
 	// TODO: only search recent `e.JobNum` DDL jobs.
 	for i := len(jobs) - 1; i > 0; i-- {
 		job = jobs[i]
-		if job.Type != model.ActionDropTable {
+		if job.Type != model.ActionDropTable && job.Type != model.ActionTruncateTable {
 			continue
 		}
 		// Check GC safe point for getting snapshot infoSchema.