private void internalReadFromLedger(LedgerHandle ledger, OpReadEntry opReadEntry) {
// Perform the read
long firstEntry = opReadEntry.readPosition.getEntryId();
if (firstEntry > ledger.getLastAddConfirmed()) {
log.debug(
"[{}] No more messages to read from ledger={} lastEntry={} readEntry={}",
va(name, ledger.getId(), ledger.getLastAddConfirmed(), firstEntry));
if (ledger.getId() != currentLedger.getId()) {
// Cursor was placed past the end of one ledger, move it to the
// beginning of the next ledger
Long nextLedgerId = ledgers.ceilingKey(ledger.getId() + 1);
opReadEntry.nextReadPosition = new Position(nextLedgerId, 0);
}
opReadEntry.emptyResponse();
return;
}
long lastEntry = min(firstEntry + opReadEntry.count - 1, ledger.getLastAddConfirmed());
long expectedEntries = lastEntry - firstEntry + 1;
opReadEntry.entries = Lists.newArrayListWithExpectedSize((int) expectedEntries);
log.debug(
"[{}] Reading entries from ledger {} - first={} last={}",
va(name, ledger.getId(), firstEntry, lastEntry));
ledger.asyncReadEntries(firstEntry, lastEntry, this, opReadEntry);
}
/*
* (non-Javadoc)
*
* @see
* org.apache.bookkeeper.client.AsyncCallback.OpenCallback#openComplete(int,
* org.apache.bookkeeper.client.LedgerHandle, java.lang.Object)
*/
@Override
public void openComplete(int rc, LedgerHandle ledger, Object ctx) {
OpReadEntry opReadEntry = (OpReadEntry) ctx;
if (rc != BKException.Code.OK) {
opReadEntry.failed(new ManagedLedgerException(BKException.create(rc)));
return;
}
log.debug("[{}] Successfully opened ledger {} for reading", name, ledger.getId());
internalReadFromLedger(ledger, opReadEntry);
}
protected synchronized void asyncReadEntries(OpReadEntry opReadEntry) {
if (state == State.Fenced) {
opReadEntry.failed(new ManagedLedgerFencedException());
return;
}
LedgerHandle ledger = null;
if (opReadEntry.readPosition.getLedgerId() == -1) {
if (ledgers.isEmpty()) {
// The ManagedLedger is completely empty
opReadEntry.emptyResponse();
return;
}
// Initialize the position on the first entry for the first ledger
// in the set
opReadEntry.readPosition = new Position(ledgers.firstKey(), 0);
}
long id = opReadEntry.readPosition.getLedgerId();
if (id == currentLedger.getId()) {
// Current writing ledger is not in the cache (since we don't want
// it to be automatically evicted), and we cannot use 2 different
// ledger handles (read & write)for the same ledger.
ledger = currentLedger;
} else {
ledger = ledgerCache.getIfPresent(id);
if (ledger == null) {
// Open the ledger and cache the handle
log.debug("[{}] Asynchronously opening ledger {} for read", name, id);
bookKeeper.asyncOpenLedger(
id, config.getDigestType(), config.getPassword(), this, opReadEntry);
return;
}
}
internalReadFromLedger(ledger, opReadEntry);
}
/*
* (non-Javadoc)
*
* @see
* org.apache.bookkeeper.client.AsyncCallback.ReadCallback#readComplete(int,
* org.apache.bookkeeper.client.LedgerHandle, java.util.Enumeration,
* java.lang.Object)
*/
@Override
public void readComplete(
int rc, LedgerHandle lh, Enumeration<LedgerEntry> entriesEnum, Object ctx) {
OpReadEntry opReadEntry = (OpReadEntry) ctx;
if (rc != BKException.Code.OK) {
log.warn(
"[{}] read failed from ledger {} at position:{}",
va(name, lh.getId(), opReadEntry.readPosition));
opReadEntry.failed(new ManagedLedgerException(BKException.create(rc)));
return;
}
List<Entry> entries = opReadEntry.entries;
while (entriesEnum.hasMoreElements()) entries.add(new EntryImpl(entriesEnum.nextElement()));
long lastEntry = entries.get(entries.size() - 1).getPosition().getEntryId();
// Get the "next read position", we need to advance the position taking
// care of ledgers boundaries
Position nextReadPosition;
if (lastEntry < lh.getLastAddConfirmed()) {
nextReadPosition = new Position(lh.getId(), lastEntry + 1);
} else {
// Move to next ledger
Long nextLedgerId = ledgers.ceilingKey(lh.getId() + 1);
if (nextLedgerId == null) {
// We are already in the last ledger
nextReadPosition = new Position(lh.getId(), lastEntry + 1);
} else {
nextReadPosition = new Position(nextLedgerId, 0);
}
}
opReadEntry.nextReadPosition = nextReadPosition;
opReadEntry.succeeded();
}