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field.go
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/
field.go
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// Copyright 2015 The kingshard Authors. All rights reserved.
//
// 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 mysql
import (
"encoding/binary"
)
type FieldData []byte
type Field struct {
Data FieldData
Schema []byte
Table []byte
OrgTable []byte
Name []byte
OrgName []byte
Charset uint16
ColumnLength uint32
Type uint8
Flag uint16
Decimal uint8
DefaultValueLength uint64
DefaultValue []byte
}
func (p FieldData) Parse() (f *Field, err error) {
f = new(Field)
f.Data = p
var n int
pos := 0
//skip catelog, always def
n, err = SkipLengthEnodedString(p)
if err != nil {
return
}
pos += n
//schema
f.Schema, _, n, err = LengthEnodedString(p[pos:])
if err != nil {
return
}
pos += n
//table
f.Table, _, n, err = LengthEnodedString(p[pos:])
if err != nil {
return
}
pos += n
//org_table
f.OrgTable, _, n, err = LengthEnodedString(p[pos:])
if err != nil {
return
}
pos += n
//name
f.Name, _, n, err = LengthEnodedString(p[pos:])
if err != nil {
return
}
pos += n
//org_name
f.OrgName, _, n, err = LengthEnodedString(p[pos:])
if err != nil {
return
}
pos += n
//skip oc
pos += 1
//charset
f.Charset = binary.LittleEndian.Uint16(p[pos:])
pos += 2
//column length
f.ColumnLength = binary.LittleEndian.Uint32(p[pos:])
pos += 4
//type
f.Type = p[pos]
pos++
//flag
f.Flag = binary.LittleEndian.Uint16(p[pos:])
pos += 2
//decimals 1
f.Decimal = p[pos]
pos++
//filter [0x00][0x00]
pos += 2
f.DefaultValue = nil
//if more data, command was field list
if len(p) > pos {
//length of default value lenenc-int
f.DefaultValueLength, _, n = LengthEncodedInt(p[pos:])
pos += n
if pos+int(f.DefaultValueLength) > len(p) {
err = ErrMalformPacket
return
}
//default value string[$len]
f.DefaultValue = p[pos:(pos + int(f.DefaultValueLength))]
}
return
}
func (f *Field) Dump() []byte {
if f.Data != nil {
return []byte(f.Data)
}
l := len(f.Schema) + len(f.Table) + len(f.OrgTable) + len(f.Name) + len(f.OrgName) + len(f.DefaultValue) + 48
data := make([]byte, 0, l)
data = append(data, PutLengthEncodedString([]byte("def"))...)
data = append(data, PutLengthEncodedString(f.Schema)...)
data = append(data, PutLengthEncodedString(f.Table)...)
data = append(data, PutLengthEncodedString(f.OrgTable)...)
data = append(data, PutLengthEncodedString(f.Name)...)
data = append(data, PutLengthEncodedString(f.OrgName)...)
data = append(data, 0x0c)
data = append(data, Uint16ToBytes(f.Charset)...)
data = append(data, Uint32ToBytes(f.ColumnLength)...)
data = append(data, f.Type)
data = append(data, Uint16ToBytes(f.Flag)...)
data = append(data, f.Decimal)
data = append(data, 0, 0)
if f.DefaultValue != nil {
data = append(data, Uint64ToBytes(f.DefaultValueLength)...)
data = append(data, f.DefaultValue...)
}
return data
}