From ea4cafa547aab1da02be94a5e7eeedb89a5c0e08 Mon Sep 17 00:00:00 2001
From: CWang <icditwang@163.com>
Date: Tue, 5 Nov 2019 18:59:40 +0800
Subject: [PATCH] implement vectorized evaluation for builtinRightBinarySig 
 (#13144)

---
 expression/builtin_string_vec.go      | 37 +++++++++++++++++++++++++--
 expression/builtin_string_vec_test.go |  9 +++++++
 2 files changed, 44 insertions(+), 2 deletions(-)

diff --git a/expression/builtin_string_vec.go b/expression/builtin_string_vec.go
index c74d2a8e8715d..6e8d7f95c2bec 100644
--- a/expression/builtin_string_vec.go
+++ b/expression/builtin_string_vec.go
@@ -1587,11 +1587,44 @@ func (b *builtinFormatSig) vecEvalString(input *chunk.Chunk, result *chunk.Colum
 }
 
 func (b *builtinRightBinarySig) vectorized() bool {
-	return false
+	return true
 }
 
 func (b *builtinRightBinarySig) vecEvalString(input *chunk.Chunk, result *chunk.Column) error {
-	return errors.Errorf("not implemented")
+	n := input.NumRows()
+	buf, err := b.bufAllocator.get(types.ETString, n)
+	if err != nil {
+		return err
+	}
+	defer b.bufAllocator.put(buf)
+	if err := b.args[0].VecEvalString(b.ctx, input, buf); err != nil {
+		return err
+	}
+	buf2, err := b.bufAllocator.get(types.ETInt, n)
+	if err != nil {
+		return err
+	}
+	defer b.bufAllocator.put(buf2)
+	if err := b.args[1].VecEvalInt(b.ctx, input, buf2); err != nil {
+		return err
+	}
+	right := buf2.Int64s()
+	result.ReserveString(n)
+	for i := 0; i < n; i++ {
+		if buf.IsNull(i) || buf2.IsNull(i) {
+			result.AppendNull()
+			continue
+		}
+		str, rightLength := buf.GetString(i), int(right[i])
+		strLength := len(str)
+		if rightLength > strLength {
+			rightLength = strLength
+		} else if rightLength < 0 {
+			rightLength = 0
+		}
+		result.AppendString(str[strLength-rightLength:])
+	}
+	return nil
 }
 
 func (b *builtinSubstringBinary3ArgsSig) vectorized() bool {
diff --git a/expression/builtin_string_vec_test.go b/expression/builtin_string_vec_test.go
index b1748201ca76d..0aab27ea6b1cd 100644
--- a/expression/builtin_string_vec_test.go
+++ b/expression/builtin_string_vec_test.go
@@ -173,6 +173,15 @@ var vecBuiltinStringCases = map[string][]vecExprBenchCase{
 	},
 	ast.Right: {
 		{retEvalType: types.ETString, childrenTypes: []types.EvalType{types.ETString, types.ETInt}},
+		// need to add BinaryFlag for the Binary func
+		{retEvalType: types.ETString, childrenTypes: []types.EvalType{types.ETString, types.ETInt},
+			childrenFieldTypes: []*types.FieldType{{Tp: mysql.TypeString, Flag: mysql.BinaryFlag, Collate: charset.CollationBin},
+				{Tp: mysql.TypeLonglong}},
+			geners: []dataGenerator{
+				&randLenStrGener{10, 20},
+				&rangeInt64Gener{begin: -10, end: 20},
+			},
+		},
 	},
 	ast.Left: {
 		{retEvalType: types.ETString, childrenTypes: []types.EvalType{types.ETString, types.ETInt}},