100 lines
2.4 KiB
Go
100 lines
2.4 KiB
Go
// Copyright 2015 PingCAP, Inc.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package domain
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import (
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"encoding/json"
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"github.com/juju/errors"
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"github.com/ngaut/log"
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"github.com/pingcap/tidb/ddl"
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"github.com/pingcap/tidb/infoschema"
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"github.com/pingcap/tidb/kv"
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"github.com/pingcap/tidb/meta"
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"github.com/pingcap/tidb/model"
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"github.com/pingcap/tidb/util"
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)
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// Domain represents a storage space. Different domains can use the same database name.
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// Multiple domains can be used in parallel without synchronization.
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type Domain struct {
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store kv.Storage
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infoHandle *infoschema.Handle
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ddl ddl.DDL
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}
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func (do *Domain) loadInfoSchema(txn kv.Transaction) (err error) {
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var schemas []*model.DBInfo
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err = util.ScanMetaWithPrefix(txn, meta.SchemaMetaPrefix, func(key []byte, value []byte) bool {
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di := &model.DBInfo{}
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err := json.Unmarshal(value, di)
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if err != nil {
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log.Fatal(err)
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}
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schemas = append(schemas, di)
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return true
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})
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if err != nil {
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return errors.Trace(err)
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}
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schemaMetaVersion, err := txn.GetInt64(meta.SchemaMetaVersionKey)
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if err != nil {
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return
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}
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log.Infof("loadInfoSchema %d", schemaMetaVersion)
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do.infoHandle.Set(schemas, schemaMetaVersion)
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return
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}
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// InfoSchema gets information schema from domain.
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func (do *Domain) InfoSchema() infoschema.InfoSchema {
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return do.infoHandle.Get()
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}
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// DDL gets DDL from domain.
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func (do *Domain) DDL() ddl.DDL {
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return do.ddl
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}
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// Store gets KV store from domain.
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func (do *Domain) Store() kv.Storage {
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return do.store
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}
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func (do *Domain) onDDLChange(err error) error {
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if err != nil {
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return err
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}
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log.Warnf("on DDL change")
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return do.reload()
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}
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func (do *Domain) reload() error {
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err := kv.RunInNewTxn(do.store, false, do.loadInfoSchema)
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return errors.Trace(err)
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}
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// NewDomain creates a new domain.
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func NewDomain(store kv.Storage) (d *Domain, err error) {
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d = &Domain{
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store: store,
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}
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d.infoHandle = infoschema.NewHandle(d.store)
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d.ddl = ddl.NewDDL(d.store, d.infoHandle, d.onDDLChange)
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err = d.reload()
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return d, errors.Trace(err)
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}
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