async UniTask <bool> ReadFileAsync(IAltoStorageData data)
{
string path = $"{ DataPath() }/{ SlotPrefix() }{ data.SaveFileName() }";
Log($"Read file : {path}");
if (!File.Exists(path))
{
Log($"File not exists, so set initial data : { data.GetType() }");
data.OnCreateNewData();
return(false);
}
try
{
byte[] dataBytes;
byte[] ivSeedBytes = new byte[IvSeedLength];
using (var fileStream = new FileStream(path, FileMode.OpenOrCreate, FileAccess.Read))
{
dataBytes = new byte[fileStream.Length - IvSeedLength];
await fileStream.ReadAsync(ivSeedBytes, 0, IvSeedLength);
await fileStream.ReadAsync(dataBytes, 0, dataBytes.Length);
}
string ivSeed = Encoding.UTF8.GetString(ivSeedBytes);
dataBytes = AltoCrypto.Decrypt(dataBytes, CryptoKey(), ivSeed);
string json = Encoding.UTF8.GetString(dataBytes);
data.OnDeserialize(json);
data.ClearDirty();
MigrateIfNeeded(data);
return(true);
}
catch (Exception e)
{
Debug.LogException(e);
return(false);
}
}
void MigrateIfNeeded(IAltoStorageData data)
{
if (data.savedSchemaVersion >= data.schemaVersion)
{
return;
}
Log($"Migration { data.GetType() } : {data.savedSchemaVersion} -> {data.schemaVersion}");
if (data.savedSchemaVersion + 1000 < data.schemaVersion)
{
LogError("Data shcema version is too big! / Migration is canceled.");
return;
}
int versionHead = data.savedSchemaVersion;
while (versionHead < data.schemaVersion)
{
data.OnMigrateData(versionHead + 1);
++versionHead;
}
}
