/** Commits the transaction to the log file. */
void commit() throws IOException {
Serialization.writeObject(oos, txns[curTxn]);
sync();
// set clean flag to indicate blocks have been written to log
setClean(txns[curTxn]);
// open a new ObjectOutputStream in order to store
// newer states of BlockIo
oos = new DataOutputStream(new BufferedOutputStream(fos));
}
/** Startup recovery on all files */
private void recover() throws IOException {
String logName = makeLogName();
File logFile = new File(logName);
if (!logFile.exists()) return;
if (logFile.length() == 0) {
logFile.delete();
return;
}
FileInputStream fis = new FileInputStream(logFile);
DataInputStream ois = new DataInputStream(new BufferedInputStream(fis));
try {
if (ois.readShort() != Magic.LOGFILE_HEADER) throw new Error("Bad magic on log file");
} catch (IOException e) {
// corrupted/empty logfile
logFile.delete();
return;
}
while (true) {
ArrayList<BlockIo> blocks = null;
try {
blocks = (ArrayList<BlockIo>) Serialization.readObject(ois);
} catch (ClassNotFoundException e) {
throw new Error("Unexcepted exception: " + e);
} catch (IOException e) {
// corrupted logfile, ignore rest of transactions
break;
}
synchronizeBlocks(blocks, false);
// ObjectInputStream must match exactly each
// ObjectOutputStream created during writes
// try {
ois = new DataInputStream(fis);
// } catch (IOException e) {
// // corrupted logfile, ignore rest of transactions
// break;
// }
}
owner.sync();
fis.close();
logFile.delete();
}