parser, executor: truncate info field for show processlist and show f…

…ull processlist support (#4739)

executor/show.go

@@ -177,6 +177,14 @@ func (e *ShowExec) fetchShowProcessList() error {
 		if len(pi.Info) != 0 {
 			t = uint64(time.Since(pi.Time) / time.Second)
 		}
+
+		var info string
+		if e.Full {
+			info = pi.Info
+		} else {
+			info = fmt.Sprintf("%.100v", pi.Info)
+		}
+
 		row := []types.Datum{
 			types.NewUintDatum(pi.ID),
 			types.NewStringDatum(pi.User),
@@ -185,10 +193,11 @@ func (e *ShowExec) fetchShowProcessList() error {
 			types.NewStringDatum(pi.Command),
 			types.NewUintDatum(t),
 			types.NewStringDatum(fmt.Sprintf("%d", pi.State)),
-			types.NewStringDatum(pi.Info),
+			types.NewStringDatum(info),
 		}
 		e.rows = append(e.rows, row)
 	}
+
 	return nil
 }
 

executor/show_test.go

@@ -22,6 +22,7 @@ import (
 	"github.com/pingcap/tidb/plan"
 	"github.com/pingcap/tidb/privilege/privileges"
 	"github.com/pingcap/tidb/sessionctx/variable"
+	"github.com/pingcap/tidb/util"
 	"github.com/pingcap/tidb/util/auth"
 	"github.com/pingcap/tidb/util/testkit"
 	"github.com/pingcap/tidb/util/testutil"
@@ -138,6 +139,7 @@ func (s *testSuite) TestShow(c *C) {
 	tk.MustQuery("SHOW PROCEDURE STATUS WHERE Db='test'").Check(testkit.Rows())
 	tk.MustQuery("SHOW TRIGGERS WHERE `Trigger` ='test'").Check(testkit.Rows())
 	tk.MustQuery("SHOW PROCESSLIST;").Check(testkit.Rows())
+	tk.MustQuery("SHOW FULL PROCESSLIST;").Check(testkit.Rows())
 	tk.MustQuery("SHOW EVENTS WHERE Db = 'test'").Check(testkit.Rows())
 	tk.MustQuery("SHOW PLUGINS").Check(testkit.Rows())
 	tk.MustQuery("SHOW PROFILES").Check(testkit.Rows())
@@ -307,6 +309,37 @@ func (s *testSuite) TestShowVisibility(c *C) {
 	tk.MustExec("drop database showdatabase")
 }
 
+// mockSessionManager is a mocked session manager that wraps one session
+// it returns only this session's current proccess info as processlist for test.
+type mockSessionManager struct {
+	tidb.Session
+}
+
+// ShowProcessList implements the SessionManager.ShowProcessList interface.
+func (msm *mockSessionManager) ShowProcessList() []util.ProcessInfo {
+	return []util.ProcessInfo{msm.ShowProcess()}
+}
+
+// Kill implements the SessionManager.Kill interface.
+func (msm *mockSessionManager) Kill(cid uint64, query bool) {
+}
+
+func (s *testSuite) TestShowFullProcessList(c *C) {
+	tk := testkit.NewTestKit(c, s.store)
+	tk.MustExec("select 1") // for tk.Se init
+
+	se := tk.Se
+	se.SetSessionManager(&mockSessionManager{se})
+
+	fullSQL := "show                                                                                        full processlist"
+	simpSQL := "show                                                                                        processlist"
+
+	tk.MustQuery(fullSQL).Check(testutil.RowsWithSep("|", "218|   Query|0|2|"+fullSQL))
+	tk.MustQuery(simpSQL).Check(testutil.RowsWithSep("|", "218|   Query|0|2|"+simpSQL[:100]))
+
+	se.SetSessionManager(nil) // reset sm so other tests won't use this
+}
+
 type stats struct {
 }
 

parser/parser.y

@@ -4524,10 +4524,11 @@ ShowStmt:
 			User:	$4.(*auth.UserIdentity),
 		}
 	}
-|	"SHOW" "PROCESSLIST"
+|	"SHOW" OptFull "PROCESSLIST"
 	{
 		$$ = &ast.ShowStmt{
 			Tp: ast.ShowProcessList,
+			Full:	$2.(bool),
 		}
 	}
 |	"SHOW" "STATS_META" ShowLikeOrWhereOpt

parser/parser_test.go

@@ -1914,6 +1914,7 @@ func (s *testParserSuite) TestSessionManage(c *C) {
 		{"kill tidb connection 23123", true},
 		{"kill tidb query 23123", true},
 		{"show processlist", true},
+		{"show full processlist", true},
 	}
 	s.RunTest(c, table)
 }