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);
}
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);
}
