b6a95a8cb3
* Dropped unused codekit config * Integrated dynamic and static bindata for public * Ignore public bindata * Add a general generate make task * Integrated flexible public assets into web command * Updated vendoring, added all missiong govendor deps * Made the linter happy with the bindata and dynamic code * Moved public bindata definition to modules directory * Ignoring the new bindata path now * Updated to the new public modules import path * Updated public bindata command and drop the new prefix
107 lines
2.8 KiB
Go
107 lines
2.8 KiB
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,
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
package mysql
|
|
|
|
import (
|
|
"fmt"
|
|
"strconv"
|
|
"strings"
|
|
|
|
"github.com/juju/errors"
|
|
)
|
|
|
|
// Bit is for mysql bit type.
|
|
type Bit struct {
|
|
// Value holds the value for bit type.
|
|
Value uint64
|
|
|
|
// Width is the display with for bit value.
|
|
// e.g, with is 8, 0 is for 0b00000000.
|
|
Width int
|
|
}
|
|
|
|
// String implements fmt.Stringer interface.
|
|
func (b Bit) String() string {
|
|
format := fmt.Sprintf("0b%%0%db", b.Width)
|
|
return fmt.Sprintf(format, b.Value)
|
|
}
|
|
|
|
// ToNumber changes bit type to float64 for numeric operation.
|
|
// MySQL treats bit as double type.
|
|
func (b Bit) ToNumber() float64 {
|
|
return float64(b.Value)
|
|
}
|
|
|
|
// ToString returns the binary string for bit type.
|
|
func (b Bit) ToString() string {
|
|
byteSize := (b.Width + 7) / 8
|
|
buf := make([]byte, byteSize)
|
|
for i := byteSize - 1; i >= 0; i-- {
|
|
buf[byteSize-i-1] = byte(b.Value >> uint(i*8))
|
|
}
|
|
return string(buf)
|
|
}
|
|
|
|
// Min and Max bit width.
|
|
const (
|
|
MinBitWidth = 1
|
|
MaxBitWidth = 64
|
|
// UnspecifiedBitWidth is the unspecified with if you want to calculate bit width dynamically.
|
|
UnspecifiedBitWidth = -1
|
|
)
|
|
|
|
// ParseBit parses bit string.
|
|
// The string format can be b'val', B'val' or 0bval, val must be 0 or 1.
|
|
// Width is the display width for bit representation. -1 means calculating
|
|
// width dynamically, using following algorithm: (len("011101") + 7) & ^7,
|
|
// e.g, if bit string is 0b01, the above will return 8 for its bit width.
|
|
func ParseBit(s string, width int) (Bit, error) {
|
|
if len(s) == 0 {
|
|
return Bit{}, errors.Errorf("invalid empty string for parsing bit type")
|
|
}
|
|
|
|
if s[0] == 'b' || s[0] == 'B' {
|
|
// format is b'val' or B'val'
|
|
s = strings.Trim(s[1:], "'")
|
|
} else if strings.HasPrefix(s, "0b") {
|
|
s = s[2:]
|
|
} else {
|
|
// here means format is not b'val', B'val' or 0bval.
|
|
return Bit{}, errors.Errorf("invalid bit type format %s", s)
|
|
}
|
|
|
|
if width == UnspecifiedBitWidth {
|
|
width = (len(s) + 7) & ^7
|
|
}
|
|
|
|
if width == 0 {
|
|
width = MinBitWidth
|
|
}
|
|
|
|
if width < MinBitWidth || width > MaxBitWidth {
|
|
return Bit{}, errors.Errorf("invalid display width for bit type, must in [1, 64], but %d", width)
|
|
}
|
|
|
|
n, err := strconv.ParseUint(s, 2, 64)
|
|
if err != nil {
|
|
return Bit{}, errors.Trace(err)
|
|
}
|
|
|
|
if n > (uint64(1)<<uint64(width))-1 {
|
|
return Bit{}, errors.Errorf("bit %s is too long for width %d", s, width)
|
|
}
|
|
|
|
return Bit{Value: n, Width: width}, nil
|
|
}
|