1a06baeb23
This commit changes the way that consensus.Clean() works. Before it deleted the whole data folder. Now it renames it as <name>.old.0 and leaves it. When Clean() is called again, it renames <name>.old.0 as <name>.old.1, and the actual data becomes <name>.old.0. Higher number means older. The number of backups is fixed to 5. When 5 backups exists and a new one comes up again, the last one is discarded. License: MIT Signed-off-by: Hector Sanjuan <hector@protocol.ai>
70 lines
1.7 KiB
Go
70 lines
1.7 KiB
Go
package raft
|
|
|
|
import (
|
|
"fmt"
|
|
"os"
|
|
"path/filepath"
|
|
)
|
|
|
|
// RaftDataBackupKeep indicates the number of data folders we keep around
|
|
// after consensus.Clean() has been called.
|
|
var RaftDataBackupKeep = 5
|
|
|
|
// dataBackupHelper helps making and rotating backups from a folder.
|
|
// it will name them <folderName>.old.0, .old.1... and so on.
|
|
// when a new backup is made, the old.0 is renamed to old.1 and so on.
|
|
// when the RaftDataBackupKeep number is reached, the last is always
|
|
// discarded.
|
|
type dataBackupHelper struct {
|
|
baseDir string
|
|
folderName string
|
|
}
|
|
|
|
func newDataBackupHelper(dataFolder string) *dataBackupHelper {
|
|
return &dataBackupHelper{
|
|
baseDir: filepath.Dir(dataFolder),
|
|
folderName: filepath.Base(dataFolder),
|
|
}
|
|
}
|
|
|
|
func (dbh *dataBackupHelper) makeName(i int) string {
|
|
return filepath.Join(dbh.baseDir, fmt.Sprintf("%s.old.%d", dbh.folderName, i))
|
|
}
|
|
|
|
func (dbh *dataBackupHelper) listBackups() []string {
|
|
backups := []string{}
|
|
for i := 0; i < RaftDataBackupKeep; i++ {
|
|
name := dbh.makeName(i)
|
|
if _, err := os.Stat(name); os.IsNotExist(err) {
|
|
return backups
|
|
}
|
|
backups = append(backups, name)
|
|
}
|
|
return backups
|
|
}
|
|
|
|
func (dbh *dataBackupHelper) makeBackup() error {
|
|
err := os.MkdirAll(dbh.baseDir, 0700)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
backups := dbh.listBackups()
|
|
// remove last / oldest
|
|
if len(backups) >= RaftDataBackupKeep {
|
|
os.RemoveAll(backups[len(backups)-1])
|
|
} else {
|
|
backups = append(backups, dbh.makeName(len(backups)))
|
|
}
|
|
|
|
// increase number for all backups folders
|
|
for i := len(backups) - 1; i > 0; i-- {
|
|
err := os.Rename(backups[i-1], backups[i])
|
|
if err != nil {
|
|
return err
|
|
}
|
|
}
|
|
|
|
// save new as name.old.0
|
|
return os.Rename(filepath.Join(dbh.baseDir, dbh.folderName), dbh.makeName(0))
|
|
}
|