gowiki/pkg/db/migration.go

72 lines
1.5 KiB
Go

package db
import (
"git.giftfish.de/ston1th/gowiki/pkg/core"
"git.giftfish.de/ston1th/gowiki/pkg/log"
)
const (
versionKey = "version/version"
currentVersion = 2
)
type migrator func(*DB) (int, error)
var migrators = []migrator{
func(db *DB) (int, error) {
return 0, nil
},
func(db *DB) (version int, err error) {
version = 1
return
},
func(db *DB) (version int, err error) {
version = 2
// recreate all pages with new format
var pages []string
db.store.ForEach(func(k string, _ []byte) error {
if trim, ok := hasTrimPrefix(k, pagePrefix); ok {
pages = append(pages, trim)
}
return nil
})
var p core.Page
for _, v := range pages {
k := pagePrefix + v
err := db.store.Get(k, &p)
if err != nil {
log.Printf("db: migrator[%d]: pageGet %s: %s", version, k, err)
continue
}
err = db.store.Set(k, &p)
if err != nil {
log.Printf("db: migrator[%d]: pageSet %s: %s", version, k, err)
continue
}
}
return
},
}
func (db *DB) RunMigrations() (err error) {
var version int
err = db.store.Get(versionKey, &version)
if err == ErrKeyNotFound {
err = db.store.Set(versionKey, 0)
if err != nil {
return
}
}
log.Printf("db: detected database version %d", version)
for version < currentVersion {
log.Printf("db: running migration %d", version)
version, err = migrators[version](db)
if err != nil {
return
}
err = db.store.Set(versionKey, version)
if err != nil {
return
}
}
}