forked from pingcap/tidb
/
domain.go
84 lines (75 loc) · 2.13 KB
/
domain.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 domain
import (
"encoding/json"
"github.com/juju/errors"
"github.com/ngaut/log"
"github.com/pingcap/tidb/ddl"
"github.com/pingcap/tidb/infoschema"
"github.com/pingcap/tidb/kv"
"github.com/pingcap/tidb/meta"
"github.com/pingcap/tidb/model"
"github.com/pingcap/tidb/util"
)
// Domain represents a storage space. Different domains can use the same database name.
// Multiple domains can be used in parallel without synchronization.
type Domain struct {
store kv.Storage
infoHandle *infoschema.Handle
ddl ddl.DDL
}
func (do *Domain) loadInfoSchema(txn kv.Transaction) (err error) {
var schemas []*model.DBInfo
err = util.ScanMetaWithPrefix(txn, meta.SchemaMetaPrefix, func(key []byte, value []byte) bool {
di := &model.DBInfo{}
err := json.Unmarshal(value, di)
if err != nil {
log.Fatal(err)
}
schemas = append(schemas, di)
return true
})
if err != nil {
return errors.Trace(err)
}
do.infoHandle.Set(schemas)
return
}
// InfoSchema gets information schema from domain.
func (do *Domain) InfoSchema() infoschema.InfoSchema {
return do.infoHandle.Get()
}
// DDL gets DDL from domain.
func (do *Domain) DDL() ddl.DDL {
return do.ddl
}
// Store gets KV store from domain.
func (do *Domain) Store() kv.Storage {
return do.store
}
// NewDomain creates a new domain.
func NewDomain(store kv.Storage) (d *Domain, err error) {
infoHandle := infoschema.NewHandle(store)
ddl := ddl.NewDDL(store, infoHandle)
d = &Domain{
store: store,
infoHandle: infoHandle,
ddl: ddl,
}
err = kv.RunInNewTxn(d.store, false, d.loadInfoSchema)
if err != nil {
return nil, errors.Trace(err)
}
return d, nil
}