// IsAutocommit checks if it is in the auto-commit mode.
func (s *session) isAutocommit(ctx context.Context) bool {
if ctx.Value(&sqlexec.RestrictedSQLExecutorKeyType{}) != nil {
return false
}
autocommit, ok := variable.GetSessionVars(ctx).Systems["autocommit"]
if !ok {
if s.initing {
return false
}
var err error
autocommit, err = s.GetGlobalSysVar(ctx, "autocommit")
if err != nil {
log.Errorf("Get global sys var error: %v", err)
return false
}
variable.GetSessionVars(ctx).Systems["autocommit"] = autocommit
ok = true
}
if ok && (autocommit == "ON" || autocommit == "on" || autocommit == "1") {
variable.GetSessionVars(ctx).SetStatusFlag(mysql.ServerStatusAutocommit, true)
return true
}
variable.GetSessionVars(ctx).SetStatusFlag(mysql.ServerStatusAutocommit, false)
return false
}
// GetSessionVars gets the session vars from context.
func GetSessionVars(ctx context.Context) *SessionVars {
v, ok := ctx.Value(sessionVarsKey).(*SessionVars)
if !ok {
return nil
}
return v
}
// GetCurrentSchema gets current schema name from context.
func GetCurrentSchema(ctx context.Context) string {
v, ok := ctx.Value(currentDBKey).(string)
if !ok {
return ""
}
return v
}
// GetGlobalVarAccessor gets accessor from ctx.
func GetGlobalVarAccessor(ctx context.Context) GlobalVarAccessor {
v, ok := ctx.Value(accessorKey).(GlobalVarAccessor)
if !ok {
panic("Miss global sysvar accessor")
}
return v
}
// GetExecArgs gets executive args from context.
func GetExecArgs(ctx context.Context) []interface{} {
v, ok := ctx.Value(execArgsKey).([]interface{})
if !ok {
return nil
}
return v
}
// IsAutocommit checks if it is in the auto-commit mode.
func (s *session) isAutocommit(ctx context.Context) (bool, error) {
sessionVar := variable.GetSessionVars(ctx)
autocommit := sessionVar.GetSystemVar("autocommit")
if autocommit.IsNull() {
if ctx.Value(context.Initing) != nil {
return false, nil
}
autocommitStr, err := s.GetGlobalSysVar(ctx, "autocommit")
if err != nil {
return false, errors.Trace(err)
}
autocommit.SetString(autocommitStr)
err = sessionVar.SetSystemVar("autocommit", autocommit)
if err != nil {
return false, errors.Trace(err)
}
}
autocommitStr := autocommit.GetString()
if autocommitStr == "ON" || autocommitStr == "on" || autocommitStr == "1" {
variable.GetSessionVars(ctx).SetStatusFlag(mysql.ServerStatusAutocommit, true)
return true, nil
}
variable.GetSessionVars(ctx).SetStatusFlag(mysql.ServerStatusAutocommit, false)
return false, nil
}
// ExecRestrictedSQL implements SQLHelper interface.
// This is used for executing some restricted sql statements.
func (s *session) ExecRestrictedSQL(ctx context.Context, sql string) (rset.Recordset, error) {
if ctx.Value(&sqlexec.RestrictedSQLExecutorKeyType{}) != nil {
// We do not support run this function concurrently.
// TODO: Maybe we should remove this restriction latter.
return nil, errors.New("Should not call ExecRestrictedSQL concurrently.")
}
statements, err := Compile(ctx, sql)
if err != nil {
log.Errorf("Compile %s with error: %v", sql, err)
return nil, errors.Trace(err)
}
if len(statements) != 1 {
log.Errorf("ExecRestrictedSQL only executes one statement. Too many/few statement in %s", sql)
return nil, errors.New("Wrong number of statement.")
}
st := statements[0]
// Check statement for some restriction
// For example only support DML on system meta table.
// TODO: Add more restrictions.
log.Debugf("Executing %s [%s]", st.OriginText(), sql)
ctx.SetValue(&sqlexec.RestrictedSQLExecutorKeyType{}, true)
defer ctx.ClearValue(&sqlexec.RestrictedSQLExecutorKeyType{})
rs, err := st.Exec(ctx)
return rs, errors.Trace(err)
}
// GetSchemaVersion gets schema version in the context.
func GetSchemaVersion(ctx context.Context) int64 {
v, ok := ctx.Value(schemaVersionKey).(int64)
if !ok {
log.Error("get schema version failed")
}
return v
}
// GetTiDBSystemVar get variable value for name.
// The variable should be a TiDB specific system variable (The vars in tidbSysVars map).
// If the session scope variable is not set, it will get global scope value and fill session scope value.
func (s *SessionVars) GetTiDBSystemVar(ctx context.Context, name string) (string, error) {
key := strings.ToLower(name)
_, ok := tidbSysVars[key]
if !ok {
return "", errors.Errorf("%s is not a TiDB specific system variable.", name)
}
sVal, ok := s.systems[key]
if ok {
return sVal, nil
}
if ctx.Value(context.Initing) != nil {
// When running bootstrap or upgrade job, we should not access global storage.
return SysVars[key].Value, nil
}
if key == DistSQLScanConcurrencyVar {
// Get global variable need to scan table which depends on DistSQLScanConcurrencyVar.
// So we should add it here to break the dependency loop.
s.systems[DistSQLScanConcurrencyVar] = SysVars[key].Value
}
globalVars := GetGlobalVarAccessor(ctx)
globalVal, err := globalVars.GetGlobalSysVar(ctx, key)
if err != nil {
if key == DistSQLScanConcurrencyVar {
// Clean up.
delete(s.systems, DistSQLScanConcurrencyVar)
}
return "", errors.Trace(err)
}
s.systems[key] = globalVal
return globalVal, nil
}
// ShouldAutocommit gets checker from ctx and checks if it should autocommit.
func ShouldAutocommit(ctx context.Context) (bool, error) {
v, ok := ctx.Value(key).(Checker)
if !ok {
panic("Miss autocommit checker")
}
return v.ShouldAutocommit(ctx)
}
// GetDomain gets domain from context.
func GetDomain(ctx context.Context) *domain.Domain {
v, ok := ctx.Value(domainKey).(*domain.Domain)
if !ok {
return nil
}
return v
}
func getRowStack(ctx context.Context) *RowStack {
v := ctx.Value(rowStackKey)
if v == nil {
return nil
}
// must be RowStack
t := v.(*RowStack)
return t
}
// GetPrewriteValue gets binlog prewrite value in the context.
func GetPrewriteValue(ctx context.Context, createIfNotExists bool) *binlog.PrewriteValue {
v, ok := ctx.Value(binlogKey).(*binlog.PrewriteValue)
if !ok && createIfNotExists {
schemaVer := GetSchemaVersion(ctx)
v = &binlog.PrewriteValue{SchemaVersion: schemaVer}
ctx.SetValue(binlogKey, v)
}
return v
}
func (s *session) ShouldAutocommit(ctx context.Context) bool {
if ctx.Value(&sqlexec.RestrictedSQLExecutorKeyType{}) != nil {
return false
}
// With START TRANSACTION, autocommit remains disabled until you end
// the transaction with COMMIT or ROLLBACK.
if variable.GetSessionVars(ctx).Status&mysql.ServerStatusInTrans == 0 && s.isAutocommit(ctx) {
return true
}
return false
}
func getDirtyDB(ctx context.Context) *dirtyDB {
var udb *dirtyDB
x := ctx.Value(DirtyDBKey)
if x == nil {
udb = &dirtyDB{tables: make(map[int64]*dirtyTable)}
ctx.SetValue(DirtyDBKey, udb)
} else {
udb = x.(*dirtyDB)
}
return udb
}
func (sq *SubQuery) push(ctx context.Context) {
var st []*SubQuery
v := ctx.Value(subQueryStackKey)
if v == nil {
st = []*SubQuery{}
} else {
// must ok
st = v.([]*SubQuery)
}
st = append(st, sq)
ctx.SetValue(subQueryStackKey, st)
}
// SetOuterQueryUsed is called when current running subquery uses outer query.
func SetOuterQueryUsed(ctx context.Context) {
v := ctx.Value(subQueryStackKey)
if v == nil {
return
}
st := v.([]*SubQuery)
// if current sub query uses outer query, the select result can not be cached,
// at the same time, all the upper sub query must not cache the result too.
for i := len(st) - 1; i >= 0; i-- {
st[i].UseOuterQuery = true
}
}
// addDDLJob gets a global job ID and puts the DDL job in the DDL queue.
func (d *ddl) addDDLJob(ctx context.Context, job *model.Job) error {
job.Query, _ = ctx.Value(context.QueryString).(string)
return kv.RunInNewTxn(d.store, true, func(txn kv.Transaction) error {
t := meta.NewMeta(txn)
var err error
job.ID, err = t.GenGlobalID()
if err != nil {
return errors.Trace(err)
}
err = t.EnQueueDDLJob(job)
return errors.Trace(err)
})
}
// GetGlobalSysVar implements GlobalVarAccessor.GetGlobalSysVar interface.
func (s *session) GetGlobalSysVar(ctx context.Context, name string) (string, error) {
if ctx.Value(context.Initing) != nil {
// When running bootstrap or upgrade, we should not access global storage.
return "", nil
}
sql := fmt.Sprintf(`SELECT VARIABLE_VALUE FROM %s.%s WHERE VARIABLE_NAME="%s";`,
mysql.SystemDB, mysql.GlobalVariablesTable, name)
sysVar, err := s.getExecRet(ctx, sql)
if err != nil {
if terror.ExecResultIsEmpty.Equal(err) {
return "", variable.UnknownSystemVar.Gen("unknown sys variable:%s", name)
}
return "", errors.Trace(err)
}
return sysVar, nil
}
func (sq *SubQuery) pop(ctx context.Context) error {
v := ctx.Value(subQueryStackKey)
if v == nil {
return errors.Errorf("pop empty sub query stack")
}
st := v.([]*SubQuery)
// can not empty
n := len(st) - 1
if st[n] != sq {
return errors.Errorf("pop invalid top sub query in stack, want %v, but top is %v", sq, st[n])
}
st[n] = nil
st = st[0:n]
if len(st) == 0 {
ctx.ClearValue(subQueryStackKey)
return nil
}
ctx.SetValue(subQueryStackKey, st)
return nil
}
func (d *ddl) doDDLJob(ctx context.Context, job *model.Job) error {
// for every DDL, we must commit current transaction.
if err := ctx.CommitTxn(); err != nil {
return errors.Trace(err)
}
var startTS uint64
err := kv.RunInNewTxn(d.store, true, func(txn kv.Transaction) error {
t := meta.NewMeta(txn)
var err error
job.ID, err = t.GenGlobalID()
startTS = txn.StartTS()
return errors.Trace(err)
})
if err != nil {
return errors.Trace(err)
}
ddlQuery, _ := ctx.Value(context.QueryString).(string)
job.Query = ddlQuery
// Create a new job and queue it.
err = kv.RunInNewTxn(d.store, true, func(txn kv.Transaction) error {
t := meta.NewMeta(txn)
err1 := t.EnQueueDDLJob(job)
return errors.Trace(err1)
})
if err != nil {
return errors.Trace(err)
}
// notice worker that we push a new job and wait the job done.
asyncNotify(d.ddlJobCh)
log.Warnf("[ddl] start DDL job %v", job)
var historyJob *model.Job
jobID := job.ID
// for a job from start to end, the state of it will be none -> delete only -> write only -> reorganization -> public
// for every state changes, we will wait as lease 2 * lease time, so here the ticker check is 10 * lease.
ticker := time.NewTicker(chooseLeaseTime(10*d.lease, 10*time.Second))
startTime := time.Now()
jobsGauge.WithLabelValues(JobType(ddlJobFlag).String(), job.Type.String()).Inc()
defer func() {
ticker.Stop()
jobsGauge.WithLabelValues(JobType(ddlJobFlag).String(), job.Type.String()).Dec()
retLabel := handleJobSucc
if err != nil {
retLabel = handleJobFailed
}
handleJobHistogram.WithLabelValues(JobType(ddlJobFlag).String(), job.Type.String(),
retLabel).Observe(time.Since(startTime).Seconds())
}()
for {
select {
case <-d.ddlJobDoneCh:
case <-ticker.C:
}
historyJob, err = d.getHistoryDDLJob(jobID)
if err != nil {
log.Errorf("[ddl] get history DDL job err %v, check again", err)
continue
} else if historyJob == nil {
log.Warnf("[ddl] DDL job %d is not in history, maybe not run", jobID)
continue
}
// if a job is a history table, the state must be JobDone or JobCancel.
if historyJob.State == model.JobDone {
return nil
}
return errors.Trace(historyJob.Error)
}
}
// GetPrivilegeChecker gets Checker from context.
func GetPrivilegeChecker(ctx context.Context) Checker {
if v, ok := ctx.Value(key).(Checker); ok {
return v
}
return nil
}