gitea/vendor/github.com/pingcap/tidb/model/model.go

199 lines
5.4 KiB

// 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 model
import (
"strings"
"github.com/pingcap/tidb/util/types"
)
// SchemaState is the state for schema elements.
type SchemaState byte
const (
// StateNone means this schema element is absent and can't be used.
StateNone SchemaState = iota
// StateDeleteOnly means we can only delete items for this schema element.
StateDeleteOnly
// StateWriteOnly means we can use any write operation on this schema element,
// but outer can't read the changed data.
StateWriteOnly
// StateWriteReorganization means we are re-organizating whole data after write only state.
StateWriteReorganization
// StateDeleteReorganization means we are re-organizating whole data after delete only state.
StateDeleteReorganization
// StatePublic means this schema element is ok for all write and read operations.
StatePublic
)
// String implements fmt.Stringer interface.
func (s SchemaState) String() string {
switch s {
case StateDeleteOnly:
return "delete only"
case StateWriteOnly:
return "write only"
case StateWriteReorganization:
return "write reorganization"
case StateDeleteReorganization:
return "delete reorganization"
case StatePublic:
return "public"
default:
return "none"
}
}
// ColumnInfo provides meta data describing of a table column.
type ColumnInfo struct {
ID int64 `json:"id"`
Name CIStr `json:"name"`
Offset int `json:"offset"`
DefaultValue interface{} `json:"default"`
types.FieldType `json:"type"`
State SchemaState `json:"state"`
}
// Clone clones ColumnInfo.
func (c *ColumnInfo) Clone() *ColumnInfo {
nc := *c
return &nc
}
// TableInfo provides meta data describing a DB table.
type TableInfo struct {
ID int64 `json:"id"`
Name CIStr `json:"name"`
Charset string `json:"charset"`
Collate string `json:"collate"`
// Columns are listed in the order in which they appear in the schema.
Columns []*ColumnInfo `json:"cols"`
Indices []*IndexInfo `json:"index_info"`
State SchemaState `json:"state"`
PKIsHandle bool `json:"pk_is_handle"`
Comment string `json:"comment"`
}
// Clone clones TableInfo.
func (t *TableInfo) Clone() *TableInfo {
nt := *t
nt.Columns = make([]*ColumnInfo, len(t.Columns))
nt.Indices = make([]*IndexInfo, len(t.Indices))
for i := range t.Columns {
nt.Columns[i] = t.Columns[i].Clone()
}
for i := range t.Indices {
nt.Indices[i] = t.Indices[i].Clone()
}
return &nt
}
// IndexColumn provides index column info.
type IndexColumn struct {
Name CIStr `json:"name"` // Index name
Offset int `json:"offset"` // Index offset
Length int `json:"length"` // Index length
}
// Clone clones IndexColumn.
func (i *IndexColumn) Clone() *IndexColumn {
ni := *i
return &ni
}
// IndexType is the type of index
type IndexType int
// String implements Stringer interface.
func (t IndexType) String() string {
switch t {
case IndexTypeBtree:
return "BTREE"
case IndexTypeHash:
return "HASH"
}
return ""
}
// IndexTypes
const (
IndexTypeBtree IndexType = iota + 1
IndexTypeHash
)
// IndexInfo provides meta data describing a DB index.
// It corresponds to the statement `CREATE INDEX Name ON Table (Column);`
// See: https://dev.mysql.com/doc/refman/5.7/en/create-index.html
type IndexInfo struct {
ID int64 `json:"id"`
Name CIStr `json:"idx_name"` // Index name.
Table CIStr `json:"tbl_name"` // Table name.
Columns []*IndexColumn `json:"idx_cols"` // Index columns.
Unique bool `json:"is_unique"` // Whether the index is unique.
Primary bool `json:"is_primary"` // Whether the index is primary key.
State SchemaState `json:"state"`
Comment string `json:"comment"` // Comment
Tp IndexType `json:"index_type"` // Index type: Btree or Hash
}
// Clone clones IndexInfo.
func (index *IndexInfo) Clone() *IndexInfo {
ni := *index
ni.Columns = make([]*IndexColumn, len(index.Columns))
for i := range index.Columns {
ni.Columns[i] = index.Columns[i].Clone()
}
return &ni
}
// DBInfo provides meta data describing a DB.
type DBInfo struct {
ID int64 `json:"id"` // Database ID
Name CIStr `json:"db_name"` // DB name.
Charset string `json:"charset"`
Collate string `json:"collate"`
Tables []*TableInfo `json:"-"` // Tables in the DB.
State SchemaState `json:"state"`
}
// Clone clones DBInfo.
func (db *DBInfo) Clone() *DBInfo {
newInfo := *db
newInfo.Tables = make([]*TableInfo, len(db.Tables))
for i := range db.Tables {
newInfo.Tables[i] = db.Tables[i].Clone()
}
return &newInfo
}
// CIStr is case insensitve string.
type CIStr struct {
O string `json:"O"` // Original string.
L string `json:"L"` // Lower case string.
}
// String implements fmt.Stringer interface.
func (cis CIStr) String() string {
return cis.O
}
// NewCIStr creates a new CIStr.
func NewCIStr(s string) (cs CIStr) {
cs.O = s
cs.L = strings.ToLower(s)
return
}