/** Synchs in-core transactions to data file and opens a fresh log */
private void synchronizeLogFromMemory() throws IOException {
close();
TreeSet<BlockIo> blockList = new TreeSet<BlockIo>(new BlockIoComparator());
int numBlocks = 0;
int writtenBlocks = 0;
for (int i = 0; i < _maxTxns; i++) {
if (txns[i] == null) continue;
// Add each block to the blockList, replacing the old copy of this
// block if necessary, thus avoiding writing the same block twice
for (Iterator<BlockIo> k = txns[i].iterator(); k.hasNext(); ) {
BlockIo block = k.next();
if (blockList.contains(block)) {
block.decrementTransactionCount();
} else {
writtenBlocks++;
boolean result = blockList.add(block);
}
numBlocks++;
}
txns[i] = null;
}
// Write the blocks from the blockList to disk
synchronizeBlocks(blockList, true);
owner.sync();
open();
}
/** 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();
}