/**
* Find the best editlog input stream to read from txid. If a journal throws an
* CorruptionException while reading from a txn id, it means that it has more transactions, but
* can't find any from fromTxId. If this is the case and no other journal has transactions, we
* should throw an exception as it means more transactions exist, we just can't load them.
*
* @param fromTxnId Transaction id to start from.
* @return A edit log input stream with tranactions fromTxId or null if no more exist
*/
@Override
public EditLogInputStream getInputStream(long fromTxnId) throws IOException {
JournalManager bestjm = null;
long bestjmNumTxns = 0;
CorruptionException corruption = null;
for (JournalAndStream jas : journals) {
JournalManager candidate = jas.getManager();
long candidateNumTxns = 0;
try {
candidateNumTxns = candidate.getNumberOfTransactions(fromTxnId);
} catch (CorruptionException ce) {
corruption = ce;
} catch (IOException ioe) {
continue; // error reading disk, just skip
}
if (candidateNumTxns > bestjmNumTxns) {
bestjm = candidate;
bestjmNumTxns = candidateNumTxns;
}
}
if (bestjm == null) {
if (corruption != null) {
throw new IOException("No non-corrupt logs for txid " + fromTxnId, corruption);
} else {
return null;
}
}
return bestjm.getInputStream(fromTxnId);
}
List<JournalManager> getJournalManagers() {
List<JournalManager> jList = new ArrayList<JournalManager>();
for (JournalAndStream j : journals) {
jList.add(j.getManager());
}
return jList;
}
/**
* Returns true if there are no journals or all are disabled.
*
* @return True if no journals or all are disabled.
*/
public boolean isEmpty() {
for (JournalAndStream jas : journals) {
if (!jas.isDisabled()) {
return false;
}
}
return true;
}
/**
* Return a manifest of what finalized edit logs are available. All available edit logs are
* returned starting from the transaction id passed.
*
* @param fromTxId Starting transaction id to read the logs.
* @return RemoteEditLogManifest object.
*/
public synchronized RemoteEditLogManifest getEditLogManifest(long fromTxId) {
// Collect RemoteEditLogs available from each FileJournalManager
List<RemoteEditLog> allLogs = Lists.newArrayList();
for (JournalAndStream j : journals) {
if (j.getManager() instanceof FileJournalManager) {
FileJournalManager fjm = (FileJournalManager) j.getManager();
try {
allLogs.addAll(fjm.getRemoteEditLogs(fromTxId));
} catch (Throwable t) {
LOG.warn("Cannot list edit logs in " + fjm, t);
}
}
}
// Group logs by their starting txid
ImmutableListMultimap<Long, RemoteEditLog> logsByStartTxId =
Multimaps.index(allLogs, RemoteEditLog.GET_START_TXID);
long curStartTxId = fromTxId;
List<RemoteEditLog> logs = Lists.newArrayList();
while (true) {
ImmutableList<RemoteEditLog> logGroup = logsByStartTxId.get(curStartTxId);
if (logGroup.isEmpty()) {
// we have a gap in logs - for example because we recovered some old
// storage directory with ancient logs. Clear out any logs we've
// accumulated so far, and then skip to the next segment of logs
// after the gap.
SortedSet<Long> startTxIds = Sets.newTreeSet(logsByStartTxId.keySet());
startTxIds = startTxIds.tailSet(curStartTxId);
if (startTxIds.isEmpty()) {
break;
} else {
if (LOG.isDebugEnabled()) {
LOG.debug(
"Found gap in logs at "
+ curStartTxId
+ ": "
+ "not returning previous logs in manifest.");
}
logs.clear();
curStartTxId = startTxIds.first();
continue;
}
}
// Find the one that extends the farthest forward
RemoteEditLog bestLog = Collections.max(logGroup);
logs.add(bestLog);
// And then start looking from after that point
curStartTxId = bestLog.getEndTxId() + 1;
}
RemoteEditLogManifest ret = new RemoteEditLogManifest(logs);
if (LOG.isDebugEnabled()) {
LOG.debug("Generated manifest for logs since " + fromTxId + ":" + ret);
}
return ret;
}
@Override
protected long getNumSync() {
for (JournalAndStream jas : journals) {
if (jas.isActive()) {
return jas.getCurrentStream().getNumSync();
}
}
return 0;
}
@Override
public boolean shouldForceSync() {
for (JournalAndStream js : journals) {
if (js.isActive() && js.getCurrentStream().shouldForceSync()) {
return true;
}
}
return false;
}
/** Add sync times to the buffer. */
String getSyncTimes() {
StringBuilder buf = new StringBuilder();
for (JournalAndStream jas : journals) {
if (jas.isActive()) {
buf.append(jas.getCurrentStream().getTotalSyncTime());
buf.append(" ");
}
}
return buf.toString();
}
/** Called when some journals experience an error in some operation. */
private void disableAndReportErrorOnJournals(List<JournalAndStream> badJournals) {
if (badJournals == null || badJournals.isEmpty()) {
return; // nothing to do
}
for (JournalAndStream j : badJournals) {
LOG.error("Disabling journal " + j);
j.abort();
j.setDisabled(true);
}
}
void remove(JournalManager j) {
JournalAndStream jasToRemove = null;
for (JournalAndStream jas : journals) {
if (jas.getManager().equals(j)) {
jasToRemove = jas;
break;
}
}
if (jasToRemove != null) {
jasToRemove.abort();
journals.remove(jasToRemove);
}
}
@Override
public long getNumberOfTransactions(long fromTxnId) throws IOException {
long num = 0;
for (JournalAndStream jas : journals) {
if (jas.isActive()) {
long newNum = jas.getManager().getNumberOfTransactions(fromTxnId);
if (newNum > num) {
num = newNum;
}
}
}
return num;
}