gitea/vendor/github.com/pingcap/tidb/meta/meta.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 meta
import (
"encoding/binary"
"encoding/json"
"fmt"
"strconv"
"strings"
"sync"
"time"
"github.com/juju/errors"
"github.com/pingcap/tidb/kv"
"github.com/pingcap/tidb/model"
"github.com/pingcap/tidb/structure"
)
var (
globalIDMutex sync.Mutex
)
// Meta structure:
// NextGlobalID -> int64
// SchemaVersion -> int64
// DBs -> {
// DB:1 -> db meta data []byte
// DB:2 -> db meta data []byte
// }
// DB:1 -> {
// Table:1 -> table meta data []byte
// Table:2 -> table meta data []byte
// TID:1 -> int64
// TID:2 -> int64
// }
//
var (
mNextGlobalIDKey = []byte("NextGlobalID")
mSchemaVersionKey = []byte("SchemaVersionKey")
mDBs = []byte("DBs")
mDBPrefix = "DB"
mTablePrefix = "Table"
mTableIDPrefix = "TID"
mBootstrapKey = []byte("BootstrapKey")
)
var (
// ErrDBExists is the error for db exists.
ErrDBExists = errors.New("database already exists")
// ErrDBNotExists is the error for db not exists.
ErrDBNotExists = errors.New("database doesn't exist")
// ErrTableExists is the error for table exists.
ErrTableExists = errors.New("table already exists")
// ErrTableNotExists is the error for table not exists.
ErrTableNotExists = errors.New("table doesn't exist")
)
// Meta is for handling meta information in a transaction.
type Meta struct {
txn *structure.TxStructure
}
// NewMeta creates a Meta in transaction txn.
func NewMeta(txn kv.Transaction) *Meta {
t := structure.NewStructure(txn, []byte{'m'})
return &Meta{txn: t}
}
// GenGlobalID generates next id globally.
func (m *Meta) GenGlobalID() (int64, error) {
globalIDMutex.Lock()
defer globalIDMutex.Unlock()
return m.txn.Inc(mNextGlobalIDKey, 1)
}
// GetGlobalID gets current global id.
func (m *Meta) GetGlobalID() (int64, error) {
return m.txn.GetInt64(mNextGlobalIDKey)
}
func (m *Meta) dbKey(dbID int64) []byte {
return []byte(fmt.Sprintf("%s:%d", mDBPrefix, dbID))
}
func (m *Meta) parseDatabaseID(key string) (int64, error) {
seps := strings.Split(key, ":")
if len(seps) != 2 {
return 0, errors.Errorf("invalid db key %s", key)
}
n, err := strconv.ParseInt(seps[1], 10, 64)
return n, errors.Trace(err)
}
func (m *Meta) autoTalbeIDKey(tableID int64) []byte {
return []byte(fmt.Sprintf("%s:%d", mTableIDPrefix, tableID))
}
func (m *Meta) tableKey(tableID int64) []byte {
return []byte(fmt.Sprintf("%s:%d", mTablePrefix, tableID))
}
func (m *Meta) parseTableID(key string) (int64, error) {
seps := strings.Split(key, ":")
if len(seps) != 2 {
return 0, errors.Errorf("invalid table meta key %s", key)
}
n, err := strconv.ParseInt(seps[1], 10, 64)
return n, errors.Trace(err)
}
// GenAutoTableID adds step to the auto id of the table and returns the sum.
func (m *Meta) GenAutoTableID(dbID int64, tableID int64, step int64) (int64, error) {
// Check if db exists.
dbKey := m.dbKey(dbID)
if err := m.checkDBExists(dbKey); err != nil {
return 0, errors.Trace(err)
}
// Check if table exists.
tableKey := m.tableKey(tableID)
if err := m.checkTableExists(dbKey, tableKey); err != nil {
return 0, errors.Trace(err)
}
return m.txn.HInc(dbKey, m.autoTalbeIDKey(tableID), step)
}
// GetAutoTableID gets current auto id with table id.
func (m *Meta) GetAutoTableID(dbID int64, tableID int64) (int64, error) {
return m.txn.HGetInt64(m.dbKey(dbID), m.autoTalbeIDKey(tableID))
}
// GetSchemaVersion gets current global schema version.
func (m *Meta) GetSchemaVersion() (int64, error) {
return m.txn.GetInt64(mSchemaVersionKey)
}
// GenSchemaVersion generates next schema version.
func (m *Meta) GenSchemaVersion() (int64, error) {
return m.txn.Inc(mSchemaVersionKey, 1)
}
func (m *Meta) checkDBExists(dbKey []byte) error {
v, err := m.txn.HGet(mDBs, dbKey)
if err != nil {
return errors.Trace(err)
} else if v == nil {
return ErrDBNotExists
}
return nil
}
func (m *Meta) checkDBNotExists(dbKey []byte) error {
v, err := m.txn.HGet(mDBs, dbKey)
if err != nil {
return errors.Trace(err)
}
if v != nil {
return ErrDBExists
}
return nil
}
func (m *Meta) checkTableExists(dbKey []byte, tableKey []byte) error {
v, err := m.txn.HGet(dbKey, tableKey)
if err != nil {
return errors.Trace(err)
}
if v == nil {
return ErrTableNotExists
}
return nil
}
func (m *Meta) checkTableNotExists(dbKey []byte, tableKey []byte) error {
v, err := m.txn.HGet(dbKey, tableKey)
if err != nil {
return errors.Trace(err)
}
if v != nil {
return ErrTableExists
}
return nil
}
// CreateDatabase creates a database with db info.
func (m *Meta) CreateDatabase(dbInfo *model.DBInfo) error {
dbKey := m.dbKey(dbInfo.ID)
if err := m.checkDBNotExists(dbKey); err != nil {
return errors.Trace(err)
}
data, err := json.Marshal(dbInfo)
if err != nil {
return errors.Trace(err)
}
return m.txn.HSet(mDBs, dbKey, data)
}
// UpdateDatabase updates a database with db info.
func (m *Meta) UpdateDatabase(dbInfo *model.DBInfo) error {
dbKey := m.dbKey(dbInfo.ID)
if err := m.checkDBExists(dbKey); err != nil {
return errors.Trace(err)
}
data, err := json.Marshal(dbInfo)
if err != nil {
return errors.Trace(err)
}
return m.txn.HSet(mDBs, dbKey, data)
}
// CreateTable creates a table with tableInfo in database.
func (m *Meta) CreateTable(dbID int64, tableInfo *model.TableInfo) error {
// Check if db exists.
dbKey := m.dbKey(dbID)
if err := m.checkDBExists(dbKey); err != nil {
return errors.Trace(err)
}
// Check if table exists.
tableKey := m.tableKey(tableInfo.ID)
if err := m.checkTableNotExists(dbKey, tableKey); err != nil {
return errors.Trace(err)
}
data, err := json.Marshal(tableInfo)
if err != nil {
return errors.Trace(err)
}
return m.txn.HSet(dbKey, tableKey, data)
}
// DropDatabase drops whole database.
func (m *Meta) DropDatabase(dbID int64) error {
// Check if db exists.
dbKey := m.dbKey(dbID)
if err := m.txn.HClear(dbKey); err != nil {
return errors.Trace(err)
}
if err := m.txn.HDel(mDBs, dbKey); err != nil {
return errors.Trace(err)
}
return nil
}
// DropTable drops table in database.
func (m *Meta) DropTable(dbID int64, tableID int64) error {
// Check if db exists.
dbKey := m.dbKey(dbID)
if err := m.checkDBExists(dbKey); err != nil {
return errors.Trace(err)
}
// Check if table exists.
tableKey := m.tableKey(tableID)
if err := m.checkTableExists(dbKey, tableKey); err != nil {
return errors.Trace(err)
}
if err := m.txn.HDel(dbKey, tableKey); err != nil {
return errors.Trace(err)
}
if err := m.txn.HDel(dbKey, m.autoTalbeIDKey(tableID)); err != nil {
return errors.Trace(err)
}
return nil
}
// UpdateTable updates the table with table info.
func (m *Meta) UpdateTable(dbID int64, tableInfo *model.TableInfo) error {
// Check if db exists.
dbKey := m.dbKey(dbID)
if err := m.checkDBExists(dbKey); err != nil {
return errors.Trace(err)
}
// Check if table exists.
tableKey := m.tableKey(tableInfo.ID)
if err := m.checkTableExists(dbKey, tableKey); err != nil {
return errors.Trace(err)
}
data, err := json.Marshal(tableInfo)
if err != nil {
return errors.Trace(err)
}
err = m.txn.HSet(dbKey, tableKey, data)
return errors.Trace(err)
}
// ListTables shows all tables in database.
func (m *Meta) ListTables(dbID int64) ([]*model.TableInfo, error) {
dbKey := m.dbKey(dbID)
if err := m.checkDBExists(dbKey); err != nil {
return nil, errors.Trace(err)
}
res, err := m.txn.HGetAll(dbKey)
if err != nil {
return nil, errors.Trace(err)
}
tables := make([]*model.TableInfo, 0, len(res)/2)
for _, r := range res {
// only handle table meta
tableKey := string(r.Field)
if !strings.HasPrefix(tableKey, mTablePrefix) {
continue
}
tbInfo := &model.TableInfo{}
err = json.Unmarshal(r.Value, tbInfo)
if err != nil {
return nil, errors.Trace(err)
}
tables = append(tables, tbInfo)
}
return tables, nil
}
// ListDatabases shows all databases.
func (m *Meta) ListDatabases() ([]*model.DBInfo, error) {
res, err := m.txn.HGetAll(mDBs)
if err != nil {
return nil, errors.Trace(err)
}
dbs := make([]*model.DBInfo, 0, len(res))
for _, r := range res {
dbInfo := &model.DBInfo{}
err = json.Unmarshal(r.Value, dbInfo)
if err != nil {
return nil, errors.Trace(err)
}
dbs = append(dbs, dbInfo)
}
return dbs, nil
}
// GetDatabase gets the database value with ID.
func (m *Meta) GetDatabase(dbID int64) (*model.DBInfo, error) {
dbKey := m.dbKey(dbID)
value, err := m.txn.HGet(mDBs, dbKey)
if err != nil || value == nil {
return nil, errors.Trace(err)
}
dbInfo := &model.DBInfo{}
err = json.Unmarshal(value, dbInfo)
return dbInfo, errors.Trace(err)
}
// GetTable gets the table value in database with tableID.
func (m *Meta) GetTable(dbID int64, tableID int64) (*model.TableInfo, error) {
// Check if db exists.
dbKey := m.dbKey(dbID)
if err := m.checkDBExists(dbKey); err != nil {
return nil, errors.Trace(err)
}
tableKey := m.tableKey(tableID)
value, err := m.txn.HGet(dbKey, tableKey)
if err != nil || value == nil {
return nil, errors.Trace(err)
}
tableInfo := &model.TableInfo{}
err = json.Unmarshal(value, tableInfo)
return tableInfo, errors.Trace(err)
}
// DDL job structure
// DDLOnwer: []byte
// DDLJobList: list jobs
// DDLJobHistory: hash
// DDLJobReorg: hash
//
// for multi DDL workers, only one can become the owner
// to operate DDL jobs, and dispatch them to MR Jobs.
var (
mDDLJobOwnerKey = []byte("DDLJobOwner")
mDDLJobListKey = []byte("DDLJobList")
mDDLJobHistoryKey = []byte("DDLJobHistory")
mDDLJobReorgKey = []byte("DDLJobReorg")
)
func (m *Meta) getJobOwner(key []byte) (*model.Owner, error) {
value, err := m.txn.Get(key)
if err != nil || value == nil {
return nil, errors.Trace(err)
}
owner := &model.Owner{}
err = json.Unmarshal(value, owner)
return owner, errors.Trace(err)
}
// GetDDLJobOwner gets the current owner for DDL.
func (m *Meta) GetDDLJobOwner() (*model.Owner, error) {
return m.getJobOwner(mDDLJobOwnerKey)
}
func (m *Meta) setJobOwner(key []byte, o *model.Owner) error {
b, err := json.Marshal(o)
if err != nil {
return errors.Trace(err)
}
return m.txn.Set(key, b)
}
// SetDDLJobOwner sets the current owner for DDL.
func (m *Meta) SetDDLJobOwner(o *model.Owner) error {
return m.setJobOwner(mDDLJobOwnerKey, o)
}
func (m *Meta) enQueueDDLJob(key []byte, job *model.Job) error {
b, err := job.Encode()
if err != nil {
return errors.Trace(err)
}
return m.txn.RPush(key, b)
}
// EnQueueDDLJob adds a DDL job to the list.
func (m *Meta) EnQueueDDLJob(job *model.Job) error {
return m.enQueueDDLJob(mDDLJobListKey, job)
}
func (m *Meta) deQueueDDLJob(key []byte) (*model.Job, error) {
value, err := m.txn.LPop(key)
if err != nil || value == nil {
return nil, errors.Trace(err)
}
job := &model.Job{}
err = job.Decode(value)
return job, errors.Trace(err)
}
// DeQueueDDLJob pops a DDL job from the list.
func (m *Meta) DeQueueDDLJob() (*model.Job, error) {
return m.deQueueDDLJob(mDDLJobListKey)
}
func (m *Meta) getDDLJob(key []byte, index int64) (*model.Job, error) {
value, err := m.txn.LIndex(key, index)
if err != nil || value == nil {
return nil, errors.Trace(err)
}
job := &model.Job{}
err = job.Decode(value)
return job, errors.Trace(err)
}
// GetDDLJob returns the DDL job with index.
func (m *Meta) GetDDLJob(index int64) (*model.Job, error) {
job, err := m.getDDLJob(mDDLJobListKey, index)
return job, errors.Trace(err)
}
func (m *Meta) updateDDLJob(index int64, job *model.Job, key []byte) error {
// TODO: use timestamp allocated by TSO
job.LastUpdateTS = time.Now().UnixNano()
b, err := job.Encode()
if err != nil {
return errors.Trace(err)
}
return m.txn.LSet(key, index, b)
}
// UpdateDDLJob updates the DDL job with index.
func (m *Meta) UpdateDDLJob(index int64, job *model.Job) error {
return m.updateDDLJob(index, job, mDDLJobListKey)
}
// DDLJobQueueLen returns the DDL job queue length.
func (m *Meta) DDLJobQueueLen() (int64, error) {
return m.txn.LLen(mDDLJobListKey)
}
func (m *Meta) jobIDKey(id int64) []byte {
b := make([]byte, 8)
binary.BigEndian.PutUint64(b, uint64(id))
return b
}
func (m *Meta) addHistoryDDLJob(key []byte, job *model.Job) error {
b, err := job.Encode()
if err != nil {
return errors.Trace(err)
}
return m.txn.HSet(key, m.jobIDKey(job.ID), b)
}
// AddHistoryDDLJob adds DDL job to history.
func (m *Meta) AddHistoryDDLJob(job *model.Job) error {
return m.addHistoryDDLJob(mDDLJobHistoryKey, job)
}
func (m *Meta) getHistoryDDLJob(key []byte, id int64) (*model.Job, error) {
value, err := m.txn.HGet(key, m.jobIDKey(id))
if err != nil || value == nil {
return nil, errors.Trace(err)
}
job := &model.Job{}
err = job.Decode(value)
return job, errors.Trace(err)
}
// GetHistoryDDLJob gets a history DDL job.
func (m *Meta) GetHistoryDDLJob(id int64) (*model.Job, error) {
return m.getHistoryDDLJob(mDDLJobHistoryKey, id)
}
// IsBootstrapped returns whether we have already run bootstrap or not.
// return true means we don't need doing any other bootstrap.
func (m *Meta) IsBootstrapped() (bool, error) {
value, err := m.txn.GetInt64(mBootstrapKey)
if err != nil {
return false, errors.Trace(err)
}
return value == 1, nil
}
// FinishBootstrap finishes bootstrap.
func (m *Meta) FinishBootstrap() error {
err := m.txn.Set(mBootstrapKey, []byte("1"))
return errors.Trace(err)
}
// UpdateDDLReorgHandle saves the job reorganization latest processed handle for later resuming.
func (m *Meta) UpdateDDLReorgHandle(job *model.Job, handle int64) error {
err := m.txn.HSet(mDDLJobReorgKey, m.jobIDKey(job.ID), []byte(strconv.FormatInt(handle, 10)))
return errors.Trace(err)
}
// RemoveDDLReorgHandle removes the job reorganization handle.
func (m *Meta) RemoveDDLReorgHandle(job *model.Job) error {
err := m.txn.HDel(mDDLJobReorgKey, m.jobIDKey(job.ID))
return errors.Trace(err)
}
// GetDDLReorgHandle gets the latest processed handle.
func (m *Meta) GetDDLReorgHandle(job *model.Job) (int64, error) {
value, err := m.txn.HGetInt64(mDDLJobReorgKey, m.jobIDKey(job.ID))
return value, errors.Trace(err)
}
// DDL background job structure
// BgJobOnwer: []byte
// BgJobList: list jobs
// BgJobHistory: hash
// BgJobReorg: hash
//
// for multi background worker, only one can become the owner
// to operate background job, and dispatch them to MR background job.
var (
mBgJobOwnerKey = []byte("BgJobOwner")
mBgJobListKey = []byte("BgJobList")
mBgJobHistoryKey = []byte("BgJobHistory")
)
// UpdateBgJob updates the background job with index.
func (m *Meta) UpdateBgJob(index int64, job *model.Job) error {
return m.updateDDLJob(index, job, mBgJobListKey)
}
// GetBgJob returns the background job with index.
func (m *Meta) GetBgJob(index int64) (*model.Job, error) {
job, err := m.getDDLJob(mBgJobListKey, index)
return job, errors.Trace(err)
}
// EnQueueBgJob adds a background job to the list.
func (m *Meta) EnQueueBgJob(job *model.Job) error {
return m.enQueueDDLJob(mBgJobListKey, job)
}
// BgJobQueueLen returns the background job queue length.
func (m *Meta) BgJobQueueLen() (int64, error) {
return m.txn.LLen(mBgJobListKey)
}
// AddHistoryBgJob adds background job to history.
func (m *Meta) AddHistoryBgJob(job *model.Job) error {
return m.addHistoryDDLJob(mBgJobHistoryKey, job)
}
// GetHistoryBgJob gets a history background job.
func (m *Meta) GetHistoryBgJob(id int64) (*model.Job, error) {
return m.getHistoryDDLJob(mBgJobHistoryKey, id)
}
// DeQueueBgJob pops a background job from the list.
func (m *Meta) DeQueueBgJob() (*model.Job, error) {
return m.deQueueDDLJob(mBgJobListKey)
}
// GetBgJobOwner gets the current background job owner.
func (m *Meta) GetBgJobOwner() (*model.Owner, error) {
return m.getJobOwner(mBgJobOwnerKey)
}
// SetBgJobOwner sets the current background job owner.
func (m *Meta) SetBgJobOwner(o *model.Owner) error {
return m.setJobOwner(mBgJobOwnerKey, o)
}