rushlink/db/db.go
2019-11-08 22:17:05 +01:00

125 lines
2.8 KiB
Go

package db
import (
"fmt"
"log"
"time"
"github.com/pkg/errors"
bolt "go.etcd.io/bbolt"
"gitea.hashru.nl/dsprenkels/rushlink/gobmarsh"
)
var DB *bolt.DB
// The current database version
//
// If we alter the database format, we bump this number and write a new
// database migration in migrateDatabase().
const CURRENT_MIGRATE_VERSION = 1
// Bucket storing everything that is not a bulk value. This includes stuff like
// the database version, secret site-wide keys.
const BUCKET_CONF = "conf"
// The main bucket for paste values and URL redirects
const BUCKET_PASTES = "pastes"
// This value stores the current migration version. If this value is less than
// CURRENT_MIGRATE_VERSION, the database has to be migrated.
const KEY_MIGRATE_VERSION = "migrate_version"
// Open the bolt database
func Open(path string) error {
if path == "" {
return errors.New("database not set")
}
var err error
DB, err = bolt.Open(path, 0666, &bolt.Options{Timeout: 1 * time.Second})
if err != nil {
return errors.Wrapf(err, "failed to open database at '%v'", path)
}
return DB.Update(migrateDatabase)
}
// Close the bolt database
func Close() error {
if DB == nil {
panic("no open database")
}
return DB.Close()
}
// Initialize and migrate the database to the current version
func migrateDatabase(tx *bolt.Tx) error {
dbVersion, err := dbVersion(tx)
if err != nil {
return err
}
// Migrate the database to version 1
if dbVersion < 1 {
log.Println("migrating database to version 1")
// Create conf bucket
_, err := tx.CreateBucket([]byte(BUCKET_CONF))
if err != nil {
return err
}
// Create paste bucket
_, err = tx.CreateBucket([]byte(BUCKET_PASTES))
if err != nil {
return err
}
// Update the version number
if err := setDBVersion(tx, 1); err != nil {
return err
}
}
return nil
}
// Get the current migrate version from the database
func dbVersion(tx *bolt.Tx) (int, error) {
conf := tx.Bucket([]byte(BUCKET_CONF))
if conf == nil {
return 0, nil
}
dbVersionBytes := conf.Get([]byte(KEY_MIGRATE_VERSION))
if dbVersionBytes == nil {
return 0, nil
}
// Version was already stored
var dbVersion int
if err := gobmarsh.Unmarshal(dbVersionBytes, &dbVersion); err != nil {
return 0, err
}
if dbVersion == 0 {
return 0, fmt.Errorf("database version is invalid (%v)", dbVersion)
}
if dbVersion > CURRENT_MIGRATE_VERSION {
return 0, fmt.Errorf("database version is too recent (%v > %v)", dbVersion, CURRENT_MIGRATE_VERSION)
}
return dbVersion, nil
}
// Update the current migrate version in the database
func setDBVersion(tx *bolt.Tx, version int) error {
conf, err := tx.CreateBucketIfNotExists([]byte(BUCKET_CONF))
if err != nil {
return err
}
versionBytes, err := gobmarsh.Marshal(version)
if err != nil {
return err
}
return conf.Put([]byte(KEY_MIGRATE_VERSION), versionBytes)
}