forgejo-federation/vendor/github.com/pingcap/tidb/infoschema/infoschema.go

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// 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 infoschema
import (
"strings"
"sync/atomic"
"github.com/juju/errors"
"github.com/pingcap/tidb/kv"
"github.com/pingcap/tidb/meta"
"github.com/pingcap/tidb/meta/autoid"
"github.com/pingcap/tidb/model"
"github.com/pingcap/tidb/mysql"
"github.com/pingcap/tidb/perfschema"
"github.com/pingcap/tidb/table"
"github.com/pingcap/tidb/terror"
// import table implementation to init table.TableFromMeta
_ "github.com/pingcap/tidb/table/tables"
"github.com/pingcap/tidb/util/types"
)
// InfoSchema is the interface used to retrieve the schema information.
// It works as a in memory cache and doesn't handle any schema change.
// InfoSchema is read-only, and the returned value is a copy.
// TODO: add more methods to retrieve tables and columns.
type InfoSchema interface {
SchemaByName(schema model.CIStr) (*model.DBInfo, bool)
SchemaExists(schema model.CIStr) bool
TableByName(schema, table model.CIStr) (table.Table, error)
TableExists(schema, table model.CIStr) bool
ColumnByName(schema, table, column model.CIStr) (*model.ColumnInfo, bool)
ColumnExists(schema, table, column model.CIStr) bool
IndexByName(schema, table, index model.CIStr) (*model.IndexInfo, bool)
SchemaByID(id int64) (*model.DBInfo, bool)
TableByID(id int64) (table.Table, bool)
AllocByID(id int64) (autoid.Allocator, bool)
ColumnByID(id int64) (*model.ColumnInfo, bool)
ColumnIndicesByID(id int64) ([]*model.IndexInfo, bool)
AllSchemaNames() []string
AllSchemas() []*model.DBInfo
Clone() (result []*model.DBInfo)
SchemaTables(schema model.CIStr) []table.Table
SchemaMetaVersion() int64
}
// Infomation Schema Name.
const (
Name = "INFORMATION_SCHEMA"
)
type infoSchema struct {
schemaNameToID map[string]int64
tableNameToID map[tableName]int64
columnNameToID map[columnName]int64
schemas map[int64]*model.DBInfo
tables map[int64]table.Table
tableAllocators map[int64]autoid.Allocator
columns map[int64]*model.ColumnInfo
indices map[indexName]*model.IndexInfo
columnIndices map[int64][]*model.IndexInfo
// We should check version when change schema.
schemaMetaVersion int64
}
var _ InfoSchema = (*infoSchema)(nil)
type tableName struct {
schema string
table string
}
type columnName struct {
tableName
name string
}
type indexName struct {
tableName
name string
}
func (is *infoSchema) SchemaByName(schema model.CIStr) (val *model.DBInfo, ok bool) {
id, ok := is.schemaNameToID[schema.L]
if !ok {
return
}
val, ok = is.schemas[id]
return
}
func (is *infoSchema) SchemaMetaVersion() int64 {
return is.schemaMetaVersion
}
func (is *infoSchema) SchemaExists(schema model.CIStr) bool {
_, ok := is.schemaNameToID[schema.L]
return ok
}
func (is *infoSchema) TableByName(schema, table model.CIStr) (t table.Table, err error) {
id, ok := is.tableNameToID[tableName{schema: schema.L, table: table.L}]
if !ok {
return nil, TableNotExists.Gen("table %s.%s does not exist", schema, table)
}
t = is.tables[id]
return
}
func (is *infoSchema) TableExists(schema, table model.CIStr) bool {
_, ok := is.tableNameToID[tableName{schema: schema.L, table: table.L}]
return ok
}
func (is *infoSchema) ColumnByName(schema, table, column model.CIStr) (val *model.ColumnInfo, ok bool) {
id, ok := is.columnNameToID[columnName{tableName: tableName{schema: schema.L, table: table.L}, name: column.L}]
if !ok {
return
}
val, ok = is.columns[id]
return
}
func (is *infoSchema) ColumnExists(schema, table, column model.CIStr) bool {
_, ok := is.columnNameToID[columnName{tableName: tableName{schema: schema.L, table: table.L}, name: column.L}]
return ok
}
func (is *infoSchema) IndexByName(schema, table, index model.CIStr) (val *model.IndexInfo, ok bool) {
val, ok = is.indices[indexName{tableName: tableName{schema: schema.L, table: table.L}, name: index.L}]
return
}
func (is *infoSchema) SchemaByID(id int64) (val *model.DBInfo, ok bool) {
val, ok = is.schemas[id]
return
}
func (is *infoSchema) TableByID(id int64) (val table.Table, ok bool) {
val, ok = is.tables[id]
return
}
func (is *infoSchema) AllocByID(id int64) (val autoid.Allocator, ok bool) {
val, ok = is.tableAllocators[id]
return
}
func (is *infoSchema) ColumnByID(id int64) (val *model.ColumnInfo, ok bool) {
val, ok = is.columns[id]
return
}
func (is *infoSchema) ColumnIndicesByID(id int64) (indices []*model.IndexInfo, ok bool) {
indices, ok = is.columnIndices[id]
return
}
func (is *infoSchema) AllSchemaNames() (names []string) {
for _, v := range is.schemas {
names = append(names, v.Name.O)
}
return
}
func (is *infoSchema) AllSchemas() (schemas []*model.DBInfo) {
for _, v := range is.schemas {
schemas = append(schemas, v)
}
return
}
func (is *infoSchema) SchemaTables(schema model.CIStr) (tables []table.Table) {
di, ok := is.SchemaByName(schema)
if !ok {
return
}
for _, ti := range di.Tables {
tables = append(tables, is.tables[ti.ID])
}
return
}
func (is *infoSchema) Clone() (result []*model.DBInfo) {
for _, v := range is.schemas {
result = append(result, v.Clone())
}
return
}
// Handle handles information schema, including getting and setting.
type Handle struct {
value atomic.Value
store kv.Storage
}
// NewHandle creates a new Handle.
func NewHandle(store kv.Storage) *Handle {
h := &Handle{
store: store,
}
// init memory tables
initMemoryTables(store)
initPerfSchema(store)
return h
}
func initPerfSchema(store kv.Storage) {
perfHandle = perfschema.NewPerfHandle(store)
}
func genGlobalID(store kv.Storage) (int64, error) {
var globalID int64
err := kv.RunInNewTxn(store, true, func(txn kv.Transaction) error {
var err error
globalID, err = meta.NewMeta(txn).GenGlobalID()
return errors.Trace(err)
})
return globalID, errors.Trace(err)
}
var (
// Information_Schema
isDB *model.DBInfo
schemataTbl table.Table
tablesTbl table.Table
columnsTbl table.Table
statisticsTbl table.Table
charsetTbl table.Table
collationsTbl table.Table
filesTbl table.Table
defTbl table.Table
profilingTbl table.Table
nameToTable map[string]table.Table
perfHandle perfschema.PerfSchema
)
func setColumnID(meta *model.TableInfo, store kv.Storage) error {
var err error
for _, c := range meta.Columns {
c.ID, err = genGlobalID(store)
if err != nil {
return errors.Trace(err)
}
}
return nil
}
func initMemoryTables(store kv.Storage) error {
// Init Information_Schema
var (
err error
tbl table.Table
)
dbID, err := genGlobalID(store)
if err != nil {
return errors.Trace(err)
}
nameToTable = make(map[string]table.Table)
isTables := make([]*model.TableInfo, 0, len(tableNameToColumns))
for name, cols := range tableNameToColumns {
meta := buildTableMeta(name, cols)
isTables = append(isTables, meta)
meta.ID, err = genGlobalID(store)
if err != nil {
return errors.Trace(err)
}
err = setColumnID(meta, store)
if err != nil {
return errors.Trace(err)
}
alloc := autoid.NewMemoryAllocator(dbID)
tbl, err = createMemoryTable(meta, alloc)
if err != nil {
return errors.Trace(err)
}
nameToTable[meta.Name.L] = tbl
}
schemataTbl = nameToTable[strings.ToLower(tableSchemata)]
tablesTbl = nameToTable[strings.ToLower(tableTables)]
columnsTbl = nameToTable[strings.ToLower(tableColumns)]
statisticsTbl = nameToTable[strings.ToLower(tableStatistics)]
charsetTbl = nameToTable[strings.ToLower(tableCharacterSets)]
collationsTbl = nameToTable[strings.ToLower(tableCollations)]
// CharacterSets/Collations contain static data. Init them now.
err = insertData(charsetTbl, dataForCharacterSets())
if err != nil {
return errors.Trace(err)
}
err = insertData(collationsTbl, dataForColltions())
if err != nil {
return errors.Trace(err)
}
// create db
isDB = &model.DBInfo{
ID: dbID,
Name: model.NewCIStr(Name),
Charset: mysql.DefaultCharset,
Collate: mysql.DefaultCollationName,
Tables: isTables,
}
return nil
}
func insertData(tbl table.Table, rows [][]types.Datum) error {
for _, r := range rows {
_, err := tbl.AddRecord(nil, r)
if err != nil {
return errors.Trace(err)
}
}
return nil
}
func refillTable(tbl table.Table, rows [][]types.Datum) error {
err := tbl.Truncate(nil)
if err != nil {
return errors.Trace(err)
}
return insertData(tbl, rows)
}
// Set sets DBInfo to information schema.
func (h *Handle) Set(newInfo []*model.DBInfo, schemaMetaVersion int64) error {
info := &infoSchema{
schemaNameToID: map[string]int64{},
tableNameToID: map[tableName]int64{},
columnNameToID: map[columnName]int64{},
schemas: map[int64]*model.DBInfo{},
tables: map[int64]table.Table{},
tableAllocators: map[int64]autoid.Allocator{},
columns: map[int64]*model.ColumnInfo{},
indices: map[indexName]*model.IndexInfo{},
columnIndices: map[int64][]*model.IndexInfo{},
schemaMetaVersion: schemaMetaVersion,
}
var err error
var hasOldInfo bool
infoschema := h.Get()
if infoschema != nil {
hasOldInfo = true
}
for _, di := range newInfo {
info.schemas[di.ID] = di
info.schemaNameToID[di.Name.L] = di.ID
for _, t := range di.Tables {
alloc := autoid.NewAllocator(h.store, di.ID)
if hasOldInfo {
val, ok := infoschema.AllocByID(t.ID)
if ok {
alloc = val
}
}
info.tableAllocators[t.ID] = alloc
info.tables[t.ID], err = table.TableFromMeta(alloc, t)
if err != nil {
return errors.Trace(err)
}
tname := tableName{di.Name.L, t.Name.L}
info.tableNameToID[tname] = t.ID
for _, c := range t.Columns {
info.columns[c.ID] = c
info.columnNameToID[columnName{tname, c.Name.L}] = c.ID
}
for _, idx := range t.Indices {
info.indices[indexName{tname, idx.Name.L}] = idx
for _, idxCol := range idx.Columns {
columnID := t.Columns[idxCol.Offset].ID
columnIndices := info.columnIndices[columnID]
info.columnIndices[columnID] = append(columnIndices, idx)
}
}
}
}
// Build Information_Schema
info.schemaNameToID[isDB.Name.L] = isDB.ID
info.schemas[isDB.ID] = isDB
for _, t := range isDB.Tables {
tbl, ok := nameToTable[t.Name.L]
if !ok {
return errors.Errorf("table `%s` is missing.", t.Name)
}
info.tables[t.ID] = tbl
tname := tableName{isDB.Name.L, t.Name.L}
info.tableNameToID[tname] = t.ID
for _, c := range t.Columns {
info.columns[c.ID] = c
info.columnNameToID[columnName{tname, c.Name.L}] = c.ID
}
}
// Add Performance_Schema
psDB := perfHandle.GetDBMeta()
info.schemaNameToID[psDB.Name.L] = psDB.ID
info.schemas[psDB.ID] = psDB
for _, t := range psDB.Tables {
tbl, ok := perfHandle.GetTable(t.Name.O)
if !ok {
return errors.Errorf("table `%s` is missing.", t.Name)
}
info.tables[t.ID] = tbl
tname := tableName{psDB.Name.L, t.Name.L}
info.tableNameToID[tname] = t.ID
for _, c := range t.Columns {
info.columns[c.ID] = c
info.columnNameToID[columnName{tname, c.Name.L}] = c.ID
}
}
// Should refill some tables in Information_Schema.
// schemata/tables/columns/statistics
dbNames := make([]string, 0, len(info.schemas))
dbInfos := make([]*model.DBInfo, 0, len(info.schemas))
for _, v := range info.schemas {
dbNames = append(dbNames, v.Name.L)
dbInfos = append(dbInfos, v)
}
err = refillTable(schemataTbl, dataForSchemata(dbNames))
if err != nil {
return errors.Trace(err)
}
err = refillTable(tablesTbl, dataForTables(dbInfos))
if err != nil {
return errors.Trace(err)
}
err = refillTable(columnsTbl, dataForColumns(dbInfos))
if err != nil {
return errors.Trace(err)
}
err = refillTable(statisticsTbl, dataForStatistics(dbInfos))
if err != nil {
return errors.Trace(err)
}
h.value.Store(info)
return nil
}
// Get gets information schema from Handle.
func (h *Handle) Get() InfoSchema {
v := h.value.Load()
schema, _ := v.(InfoSchema)
return schema
}
// Schema error codes.
const (
CodeDbDropExists terror.ErrCode = 1008
CodeDatabaseNotExists = 1049
CodeTableNotExists = 1146
CodeColumnNotExists = 1054
CodeDatabaseExists = 1007
CodeTableExists = 1050
CodeBadTable = 1051
)
var (
// DatabaseDropExists returns for drop an unexist database.
DatabaseDropExists = terror.ClassSchema.New(CodeDbDropExists, "database doesn't exist")
// DatabaseNotExists returns for database not exists.
DatabaseNotExists = terror.ClassSchema.New(CodeDatabaseNotExists, "database not exists")
// TableNotExists returns for table not exists.
TableNotExists = terror.ClassSchema.New(CodeTableNotExists, "table not exists")
// ColumnNotExists returns for column not exists.
ColumnNotExists = terror.ClassSchema.New(CodeColumnNotExists, "field not exists")
// DatabaseExists returns for database already exists.
DatabaseExists = terror.ClassSchema.New(CodeDatabaseExists, "database already exists")
// TableExists returns for table already exists.
TableExists = terror.ClassSchema.New(CodeTableExists, "table already exists")
// TableDropExists returns for drop an unexist table.
TableDropExists = terror.ClassSchema.New(CodeBadTable, "unknown table")
)
func init() {
schemaMySQLErrCodes := map[terror.ErrCode]uint16{
CodeDbDropExists: mysql.ErrDbDropExists,
CodeDatabaseNotExists: mysql.ErrBadDb,
CodeTableNotExists: mysql.ErrNoSuchTable,
CodeColumnNotExists: mysql.ErrBadField,
CodeDatabaseExists: mysql.ErrDbCreateExists,
CodeTableExists: mysql.ErrTableExists,
CodeBadTable: mysql.ErrBadTable,
}
terror.ErrClassToMySQLCodes[terror.ClassSchema] = schemaMySQLErrCodes
}