@Override
public synchronized <E> void insert(String key, E value) {
assertInit();
final ObjectEntity<E> objectEntity = new ObjectEntity<>(value);
objectEntity.removeReferences();
final File originalFile = getOriginalFile(key);
final File backupFile = makeBackupFile(originalFile);
// Rename the current file so it may be used as a backup during the next read
if (originalFile.exists()) {
// Rename original to backup
if (!backupFile.exists()) {
if (!originalFile.renameTo(backupFile)) {
throw new PaperDbException(
"Couldn't rename file " + originalFile + " to backup file " + backupFile);
}
} else {
// Backup exist -> original file is broken and must be deleted
//noinspection ResultOfMethodCallIgnored
originalFile.delete();
}
}
writeTableFile(key, objectEntity, originalFile, backupFile);
objectEntity.restoreReferences();
}
private <E> E readTableFile(String key, File originalFile) {
try {
final Input i = new Input(new FileInputStream(originalFile));
final Kryo kryo = getKryo();
//noinspection unchecked
final ObjectEntity<E> objectEntity = kryo.readObject(i, ObjectEntity.class);
objectEntity.restoreReferences();
i.close();
return objectEntity.getContent();
} catch (FileNotFoundException | KryoException e) {
// Clean up an unsuccessfully written file
if (originalFile.exists()) {
if (!originalFile.delete()) {
throw new PaperDbException(
"Couldn't clean up broken/unserializable file " + originalFile, e);
}
}
throw new PaperDbException(
"Couldn't read/deserialize file " + originalFile + " for table " + key, e);
}
}
