Files
tidb/ddl/placement/utils.go
2021-05-14 17:05:38 +08:00

80 lines
2.4 KiB
Go

// Copyright 2020 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 placement
import (
"encoding/hex"
"strconv"
"strings"
"github.com/pingcap/errors"
"github.com/pingcap/tidb/tablecodec"
"github.com/pingcap/tidb/util/codec"
)
// ObjectIDFromGroupID extracts the db/table/partition ID from the group ID
func ObjectIDFromGroupID(groupID string) (int64, error) {
// If the rule doesn't come from TiDB, skip it.
if !strings.HasPrefix(groupID, BundleIDPrefix) {
return 0, nil
}
id, err := strconv.ParseInt(groupID[len(BundleIDPrefix):], 10, 64)
if err != nil || id <= 0 {
return 0, errors.Errorf("Rule %s doesn't include an id", groupID)
}
return id, nil
}
// BuildPlacementDropBundle builds the bundle to drop placement rules.
func BuildPlacementDropBundle(partitionID int64) *Bundle {
return &Bundle{
ID: GroupID(partitionID),
}
}
// BuildPlacementCopyBundle copies a new bundle from the old, with a new name and a new key range.
func BuildPlacementCopyBundle(oldBundle *Bundle, newID int64) *Bundle {
newBundle := oldBundle.Clone()
newBundle.ID = GroupID(newID)
startKey := hex.EncodeToString(codec.EncodeBytes(nil, tablecodec.GenTableRecordPrefix(newID)))
endKey := hex.EncodeToString(codec.EncodeBytes(nil, tablecodec.GenTableRecordPrefix(newID+1)))
for _, rule := range newBundle.Rules {
rule.GroupID = newBundle.ID
rule.StartKeyHex = startKey
rule.EndKeyHex = endKey
}
return newBundle
}
// GetLeaderDCByBundle returns the leader's DC by Bundle if found
func GetLeaderDCByBundle(bundle *Bundle, dcLabelKey string) (string, bool) {
for _, rule := range bundle.Rules {
if isValidLeaderRule(rule, dcLabelKey) {
return rule.Constraints[0].Values[0], true
}
}
return "", false
}
func isValidLeaderRule(rule *Rule, dcLabelKey string) bool {
if rule.Role == Leader && rule.Count == 1 {
for _, con := range rule.Constraints {
if con.Op == In && con.Key == dcLabelKey && len(con.Values) == 1 {
return true
}
}
}
return false
}