expression: enable strcmp for tiflash (#30983)

expression/expr_to_pb_test.go

@@ -993,6 +993,11 @@ func TestExprPushDownToFlash(t *testing.T) {
 	require.NoError(t, err)
 	exprs = append(exprs, function)
 
+	// strcmp
+	function, err = NewFunction(mock.NewContext(), ast.Strcmp, types.NewFieldType(mysql.TypeLonglong), stringColumn, stringColumn)
+	require.NoError(t, err)
+	exprs = append(exprs, function)
+
 	pushed, remained = PushDownExprs(sc, exprs, client, kv.TiFlash)
 	require.Len(t, pushed, len(exprs))
 	require.Len(t, remained, 0)

expression/expression.go

@@ -1035,7 +1035,7 @@ func scalarExprSupportedByFlash(function *ScalarFunction) bool {
 		}
 	case
 		ast.LogicOr, ast.LogicAnd, ast.UnaryNot, ast.BitNeg, ast.Xor, ast.And, ast.Or,
-		ast.GE, ast.LE, ast.EQ, ast.NE, ast.LT, ast.GT, ast.In, ast.IsNull, ast.Like,
+		ast.GE, ast.LE, ast.EQ, ast.NE, ast.LT, ast.GT, ast.In, ast.IsNull, ast.Like, ast.Strcmp,
 		ast.Plus, ast.Minus, ast.Div, ast.Mul, ast.Abs, ast.Mod,
 		ast.If, ast.Ifnull, ast.Case,
 		ast.Concat, ast.ConcatWS,

tools/check/ut.go

@@ -15,9 +15,9 @@
 package main
 
 import (
-	"io"
 	"bytes"
 	"fmt"
+	"io"
 	"math/rand"
 	"os"
 	"os/exec"
@@ -354,7 +354,7 @@ func (n *numa) worker(wg *sync.WaitGroup, ch chan task) {
 }
 
 type testResult struct {
-	err error
+	err    error
 	output bytes.Buffer
 }
 
@@ -449,7 +449,7 @@ func numactlExist() bool {
 
 func testFileName(pkg string) string {
 	_, file := path.Split(pkg)
-	return file+".test.bin"
+	return file + ".test.bin"
 }
 
 func testFileFullPath(pkg string) string {