我正在尝试缩小领域数据库的大小。我的didFinishLaunchingWithOptions中有以下配置：
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
var config = Realm.Configuration(shouldCompactOnLaunch: { totalBytes, usedBytes in
// totalBytes refers to the size of the file on disk in bytes (data + free space)
// usedBytes refers to the number of bytes used by data in the file
// Compact if the file is over 100MB in size and less than 50% 'used'
let oneHundredMB = 100 * 1024 * 1024
return (totalBytes > oneHundredMB) && (Double(usedBytes) / Double(totalBytes)) < 0.5
})
do {
// Realm is compacted on the first open if the configuration block conditions were met.
_ = try Realm(configuration: config)
} catch let err as NSError {
// handle error compacting or opening Realm
print("%%%%%%%%%%%%% in the catch \(err.localizedDescription) !!!! %%%%%%%%%%%%%%")
}
config = checkForMigration(currently: config);
// other stuff
// calling methods which clear out some base64strings to url paths in some realm tables
return true
}
checkForMigration如下所示：
func checkForMigration(currently config: Realm.Configuration) -> Realm.Configuration
{
var configu = config;
var needsMigration: Bool = false;
if util_Migration.schemaVersion != configu.schemaVersion
{
configu.schemaVersion = util_Migration.schemaVersion
configu.migrationBlock = util_Migration.migration
needsMigration = true;
}
Realm.Configuration.defaultConfiguration = configu
if needsMigration {
do { try Realm.performMigration()}
catch let err as NSError
{
print("Realm Migration Error::: \(err.localizedDescription)");
}
}
return configu;
}
1。。如何修改它以同时配置迁移块和启动时的压缩？
现在，如果从以前的版本升级，则我的应用程序可以工作，但全新安装时不可以。重新安装时出现此错误：
Cannot migrate Realms that are already open
当我刚刚传入config = Realm.Configuration（）
时，我的迁移方法始终有效2。。该添加什么？有什么地方可能出问题吗，我们需要在这个问题中加以解决？
3。。有没有理由不使用更严格的规则进行优化？例如如果少于80个使用了？