Built-in string functions implementation: ASCII, BIN, BIT_LENGTH

go/vt/vtgate/evalengine/func.go

@@ -30,12 +30,15 @@ import (
 )
 
 var builtinFunctions = map[string]builtin{
-	"coalesce":  builtinCoalesce{},
-	"greatest":  &builtinMultiComparison{name: "GREATEST", cmp: 1},
-	"least":     &builtinMultiComparison{name: "LEAST", cmp: -1},
-	"collation": builtinCollation{},
-	"bit_count": builtinBitCount{},
-	"hex":       builtinHex{},
+	"coalesce":   builtinCoalesce{},
+	"greatest":   &builtinMultiComparison{name: "GREATEST", cmp: 1},
+	"least":      &builtinMultiComparison{name: "LEAST", cmp: -1},
+	"collation":  builtinCollation{},
+	"bit_count":  builtinBitCount{},
+	"hex":        builtinHex{},
+	"ascii":      builtinAscii{},
+	"bin":        builtinBin{},
+	"bit_length": builtinBitLength{},
 }
 
 var builtinFunctionsRewrite = map[string]builtinRewrite{

go/vt/vtgate/evalengine/integration/string_func_test.go

@@ -0,0 +1,119 @@
+/*
+Copyright 2021 The Vitess Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package integration
+
+import (
+	"fmt"
+	"testing"
+)
+
+func TestBuiltinAscii(t *testing.T) {
+	var elems = []string{
+		"NULL",
+		"\"\"",
+		"\"a\"",
+		"\"abc\"",
+		"1",
+		"-1",
+		"0123",
+		"0xAACC",
+		"3.1415926",
+		"\"中文测试\"",
+		"\"日本語テスト\"",
+		"\"한국어 시험\"",
+		"\"😊😂🤢\"",
+		"9223372036854775807",
+		"-9223372036854775808",
+		"999999999999999999999999",
+		"-999999999999999999999999",
+	}
+
+	var conn = mysqlconn(t)
+	defer conn.Close()
+
+	t.Run("ASCII", func(t *testing.T) {
+		for i := 0; i < len(elems); i++ {
+			query := fmt.Sprintf("SELECT ASCII(%s)", elems[i])
+			compareRemoteQuery(t, conn, query)
+		}
+	})
+}
+
+func TestBuiltinBin(t *testing.T) {
+	var elems = []string{
+		"NULL",
+		"\"\"",
+		"\"a\"",
+		"\"101\"",
+		"\"-101\"",
+		"1",
+		"-1",
+		"20",
+		"-100",
+		"\"10abc\"",
+		"\"10a1b2c3\"",
+		"\"中文测试\"",
+		"\"日本語テスト\"",
+		"\"한국어 시험\"",
+		"\"😊😂🤢\"",
+		"3.1415926",
+		"9223372036854775807",
+		"-9223372036854775808",
+	}
+
+	var conn = mysqlconn(t)
+	defer conn.Close()
+
+	t.Run("BIN", func(t *testing.T) {
+		for i := 0; i < len(elems); i++ {
+			query := fmt.Sprintf("SELECT BIN(%s)", elems[i])
+			compareRemoteQuery(t, conn, query)
+		}
+	})
+}
+
+func TestBuiltinBitLength(t *testing.T) {
+	var elems = []string{
+		"NULL",
+		"\"\"",
+		"\"a\"",
+		"\"abc\"",
+		"1",
+		"-1",
+		"20",
+		"-100",
+		"\"中文测试\"",
+		"\"日本語テスト\"",
+		"\"한국어 시험\"",
+		"\"😊😂🤢\"",
+		"3.1415926",
+		"9223372036854775807",
+		"-9223372036854775808",
+		"999999999999999999999999",
+		"-999999999999999999999999",
+	}
+
+	var conn = mysqlconn(t)
+	defer conn.Close()
+
+	t.Run("BIT_LENGTH", func(t *testing.T) {
+		for i := 0; i < len(elems); i++ {
+			query := fmt.Sprintf("SELECT BIT_LENGTH(%s)", elems[i])
+			compareRemoteQuery(t, conn, query)
+		}
+	})
+}

go/vt/vtgate/evalengine/string.go

@@ -0,0 +1,111 @@
+/*
+Copyright 2022 The Vitess Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package evalengine
+
+import (
+	"strconv"
+	"vitess.io/vitess/go/mysql/collations"
+	"vitess.io/vitess/go/sqltypes"
+	vtrpcpb "vitess.io/vitess/go/vt/proto/vtrpc"
+	"vitess.io/vitess/go/vt/vterrors"
+)
+
+type (
+	builtinAscii     struct{}
+	builtinBin       struct{}
+	builtinBitLength struct{}
+)
+
+func (builtinAscii) call(_ *ExpressionEnv, args []EvalResult, result *EvalResult) {
+	toascii := &args[0]
+	if toascii.isNull() {
+		result.setNull()
+		return
+	}
+
+	toascii.makeBinary()
+	bs := toascii.bytes()
+	if len(bs) > 0 {
+		result.setInt64(int64(bs[0]))
+	} else {
+		result.setInt64(0)
+	}
+}
+
+func (builtinAscii) typeof(env *ExpressionEnv, args []Expr) (sqltypes.Type, flag) {
+	if len(args) != 1 {
+		throwArgError("ASCII")
+	}
+	_, f := args[0].typeof(env)
+	return sqltypes.Int64, f
+}
+
+func (builtinBin) call(env *ExpressionEnv, args []EvalResult, result *EvalResult) {
+	tobin := &args[0]
+	if tobin.isNull() {
+		result.setNull()
+		return
+	}
+
+	var raw []byte
+	switch t := tobin.typeof(); {
+	case sqltypes.IsNumber(t):
+		tobin.makeUnsignedIntegral()
+		raw = strconv.AppendUint(raw, tobin.uint64(), 2)
+	case sqltypes.IsText(t):
+		if len(tobin.bytes()) == 0 {
+			return
+		}
+		tobin.makeFloat()
+		float, _ := tobin.coerceToFloat()
+		raw = strconv.AppendUint(raw, uint64(float), 2)
+	default:
+		throwEvalError(vterrors.Errorf(vtrpcpb.Code_UNIMPLEMENTED, "Unsupported BIN argument: %s", t.String()))
+	}
+
+	result.setRaw(sqltypes.VarChar, raw, collations.TypedCollation{
+		Collation:    env.DefaultCollation,
+		Coercibility: collations.CoerceCoercible,
+		Repertoire:   collations.RepertoireASCII,
+	})
+}
+
+func (builtinBin) typeof(env *ExpressionEnv, args []Expr) (sqltypes.Type, flag) {
+	if len(args) != 1 {
+		throwArgError("BIN")
+	}
+	_, f := args[0].typeof(env)
+	return sqltypes.VarChar, f
+}
+
+func (builtinBitLength) call(_ *ExpressionEnv, args []EvalResult, result *EvalResult) {
+	arg1 := &args[0]
+	if arg1.isNull() {
+		result.setNull()
+		return
+	}
+
+	result.setInt64(int64(8 * len(arg1.toRawBytes())))
+}
+
+func (builtinBitLength) typeof(env *ExpressionEnv, args []Expr) (sqltypes.Type, flag) {
+	if len(args) != 1 {
+		throwArgError("BIT_LENGTH")
+	}
+	_, f := args[0].typeof(env)
+	return sqltypes.Int64, f
+}