tidb etc 代码
文件路径：/types/etc.go
/ Copyright 2015 PingCAP, Inc.
/
/ 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.
/ Copyright 2014 The ql Authors. All rights reserved.
/ Use of this source code is governed by a BSD-style
/ license that can be found in the LICENSES/QL-LICENSE file.
package types
import (
"io"
"github.com/pingcap/errors"
"github.com/pingcap/tidb/parser/charset"
"github.com/pingcap/tidb/parser/mysql"
"github.com/pingcap/tidb/parser/opcode"
"github.com/pingcap/tidb/parser/terror"
ast "github.com/pingcap/tidb/parser/types"
"github.com/pingcap/tidb/util/collate"
)
/ IsTypeBlob returns a boolean indicating whether the tp is a blob type.
var IsTypeBlob = ast.IsTypeBlob
/ IsTypeChar returns a boolean indicating
/ whether the tp is the char type like a string type or a varchar type.
var IsTypeChar = ast.IsTypeChar
/ IsTypeVarchar returns a boolean indicating
/ whether the tp is the varchar type like a varstring type or a varchar type.
func IsTypeVarchar(tp byte) bool {
return tp == mysql.TypeVarString || tp == mysql.TypeVarchar
}
/ IsTypeUnspecified returns a boolean indicating whether the tp is the Unspecified type.
func IsTypeUnspecified(tp byte) bool {
return tp == mysql.TypeUnspecified
}
/ IsTypePrefixable returns a boolean indicating
/ whether an index on a column with the tp can be defined with a prefix.
func IsTypePrefixable(tp byte) bool {
return IsTypeBlob(tp) || IsTypeChar(tp)
}
/ IsTypeFractionable returns a boolean indicating
/ whether the tp can has time fraction.
func IsTypeFractionable(tp byte) bool {
return tp == mysql.TypeDatetime || tp == mysql.TypeDuration || tp == mysql.TypeTimestamp
}
/ IsTypeTime returns a boolean indicating
/ whether the tp is time type like datetime, date or timestamp.
func IsTypeTime(tp byte) bool {
return tp == mysql.TypeDatetime || tp == mysql.TypeDate || tp == mysql.TypeTimestamp
}
/ IsTypeFloat indicates whether the type is TypeFloat
func IsTypeFloat(tp byte) bool {
return tp == mysql.TypeFloat
}
/ IsTypeInteger returns a boolean indicating whether the tp is integer type.
func IsTypeInteger(tp byte) bool {
switch tp {
case mysql.TypeTiny, mysql.TypeShort, mysql.TypeInt24, mysql.TypeLong, mysql.TypeLonglong, mysql.TypeYear:
return true
}
return false
}
/ IsTypeNumeric returns a boolean indicating whether the tp is numeric type.
func IsTypeNumeric(tp byte) bool {
switch tp {
case mysql.TypeBit, mysql.TypeTiny, mysql.TypeInt24, mysql.TypeLong, mysql.TypeLonglong, mysql.TypeNewDecimal,
mysql.TypeFloat, mysql.TypeDouble, mysql.TypeShort:
return true
}
return false
}
/ IsTemporalWithDate returns a boolean indicating
/ whether the tp is time type with date.
func IsTemporalWithDate(tp byte) bool {
return IsTypeTime(tp)
}
/ IsBinaryStr returns a boolean indicating
/ whether the field type is a binary string type.
func IsBinaryStr(ft *FieldType) bool {
return ft.GetCollate() == charset.CollationBin && IsString(ft.GetType())
}
/ IsNonBinaryStr returns a boolean indicating
/ whether the field type is a non-binary string type.
func IsNonBinaryStr(ft *FieldType) bool {
if ft.GetCollate() != charset.CollationBin && IsString(ft.GetType()) {
return true
}
return false
}
/ NeedRestoredData returns if a type needs restored data.
/ If the type is char and the collation is _bin, NeedRestoredData() returns false.
func NeedRestoredData(ft *FieldType) bool {
if collate.NewCollationEnabled() &&
IsNonBinaryStr(ft) &&
!(collate.IsBinCollation(ft.GetCollate()) && !IsTypeVarchar(ft.GetType())) {
return true
}
return false
}
/ IsString returns a boolean indicating
/ whether the field type is a string type.
func IsString(tp byte) bool {
return IsTypeChar(tp) || IsTypeBlob(tp) || IsTypeVarchar(tp) || IsTypeUnspecified(tp)
}
var kind2Str = map[byte]string{
KindNull: "null",
KindInt64: "bigint",
KindUint64: "unsigned bigint",
KindFloat32: "float",
KindFloat64: "double",
KindString: "char",
KindBytes: "bytes",
KindBinaryLiteral: "bit/hex literal",
KindMysqlDecimal: "decimal",
KindMysqlDuration: "time",
KindMysqlEnum: "enum",
KindMysqlBit: "bit",
KindMysqlSet: "set",
KindMysqlTime: "datetime",
KindInterface: "interface",
KindMinNotNull: "min_not_null",
KindMaxValue: "max_value",
KindRaw: "raw",
KindMysqlJSON: "json",
}
/ TypeStr converts tp to a string.
var TypeStr = ast.TypeStr
/ KindStr converts kind to a string.
func KindStr(kind byte) (r string) {
return kind2Str[kind]
}
/ TypeToStr converts a field to a string.
/ It is used for converting Text to Blob,
/ or converting Char to Binary.
/ Args:
/
/ tp: type enum
/ cs: charset
var TypeToStr = ast.TypeToStr
/ EOFAsNil filtrates errors,
/ If err is equal to io.EOF returns nil.
func EOFAsNil(err error) error {
if terror.ErrorEqual(err, io.EOF) {
return nil
}
return errors.Trace(err)
}
/ InvOp2 returns an invalid operation error.
func InvOp2(x, y interface{}, o opcode.Op) (interface{}, error) {
return nil, errors.Errorf("Invalid operation: %v %v %v (mismatched types %T and %T)", x, o, y, x, y)
}
/ overflow returns an overflowed error.
func overflow(v interface{}, tp byte) error {
return ErrOverflow.GenWithStack("constant %v overflows %s", v, TypeStr(tp))
}
/ IsTypeTemporal checks if a type is a temporal type.
func IsTypeTemporal(tp byte) bool {
switch tp {
case mysql.TypeDuration, mysql.TypeDatetime, mysql.TypeTimestamp,
mysql.TypeDate, mysql.TypeNewDate:
return true
}
return false
}