go-sample-webpage/vendor/github.com/golang-migrate/migrate/v4/database/util.go

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2021-11-08 01:25:36 +00:00
package database
import (
"fmt"
"go.uber.org/atomic"
"hash/crc32"
"strings"
)
const advisoryLockIDSalt uint = 1486364155
// GenerateAdvisoryLockId inspired by rails migrations, see https://goo.gl/8o9bCT
func GenerateAdvisoryLockId(databaseName string, additionalNames ...string) (string, error) { // nolint: golint
if len(additionalNames) > 0 {
databaseName = strings.Join(append(additionalNames, databaseName), "\x00")
}
sum := crc32.ChecksumIEEE([]byte(databaseName))
sum = sum * uint32(advisoryLockIDSalt)
return fmt.Sprint(sum), nil
}
// CasRestoreOnErr CAS wrapper to automatically restore the lock state on error
func CasRestoreOnErr(lock *atomic.Bool, o, n bool, casErr error, f func() error) error {
if !lock.CAS(o, n) {
return casErr
}
if err := f(); err != nil {
// Automatically unlock/lock on error
lock.Store(o)
return err
}
return nil
}