expression: implement vectorized evaluation for builtinLocate2ArgsSig

expression/builtin_string_vec.go

@@ -732,11 +732,52 @@ func (b *builtinLengthSig) vecEvalInt(input *chunk.Chunk, result *chunk.Column)
 }
 
 func (b *builtinLocate2ArgsSig) vectorized() bool {
-	return false
+	return true
 }
 
+// vecEvalInt evals LOCATE(substr,str), non case-sensitive.
+// See https://dev.mysql.com/doc/refman/5.7/en/string-functions.html#function_locate
 func (b *builtinLocate2ArgsSig) vecEvalInt(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
+	}
+	buf1, err := b.bufAllocator.get(types.ETString, n)
+	if err != nil {
+		return err
+	}
+	defer b.bufAllocator.put(buf1)
+	if err := b.args[1].VecEvalString(b.ctx, input, buf1); err != nil {
+		return err
+	}
+
+	result.ResizeInt64(n, false)
+	result.MergeNulls(buf, buf1)
+	i64s := result.Int64s()
+	for i := 0; i < n; i++ {
+		if result.IsNull(i) {
+			continue
+		}
+		subStr := buf.GetString(i)
+		str := buf1.GetString(i)
+
+		if int64(len([]rune(subStr))) == 0 {
+			i64s[i] = 1
+			continue
+		}
+		slice := string([]rune(strings.ToLower(str)))
+		ret, idx := 0, strings.Index(slice, strings.ToLower(subStr))
+		if idx != -1 {
+			ret = utf8.RuneCountInString(slice[:idx]) + 1
+		}
+		i64s[i] = int64(ret)
+	}
+	return nil
 }
 
 func (b *builtinBitLengthSig) vectorized() bool {

expression/builtin_string_vec_test.go

@@ -29,8 +29,14 @@ var vecBuiltinStringCases = map[string][]vecExprBenchCase{
 	ast.Convert:        {},
 	ast.Substring:      {},
 	ast.SubstringIndex: {},
-	ast.Locate:         {},
-	ast.Hex:            {},
+	ast.Locate: {
+		{
+			retEvalType:   types.ETInt,
+			childrenTypes: []types.EvalType{types.ETString, types.ETString},
+			geners:        []dataGenerator{&randLenStrGener{0, 10}, &randLenStrGener{0, 20}},
+		},
+	},
+	ast.Hex: {},
 	ast.Unhex: {
 		{retEvalType: types.ETString, childrenTypes: []types.EvalType{types.ETString}, geners: []dataGenerator{&randHexStrGener{10, 100}}},
 	},