}
// there is a little bit of excess here- we iterate all the non-indexed kvs for this check first
// and then do it again later when getting out the index updates. This should be pretty minor
// though, compared to the rest of the runtime
IndexedKeyValue ikv = getFirstIndexedKeyValue(edit);
/*
* early exit - we have nothing to write, so we don't need to do anything else. NOTE: we don't
* release the WAL Rolling lock (INDEX_UPDATE_LOCK) since we never take it in doPre if there are
* no index updates.
*/
if (ikv == null) {
return;
}
/*
* only write the update if we haven't already seen this batch. We only want to write the batch
* once (this hook gets called with the same WALEdit for each Put/Delete in a batch, which can
* lead to writing all the index updates for each Put/Delete).
*/
if (!ikv.getBatchFinished()) {
Collection<Pair<Mutation, byte[]>> indexUpdates = extractIndexUpdate(edit);
// the WAL edit is kept in memory and we already specified the factory when we created the
// references originally - therefore, we just pass in a null factory here and use the ones
// already specified on each reference
try {
writer.writeAndKillYourselfOnFailure(indexUpdates);
} finally {
// With a custom kill policy, we may throw instead of kill the server.
// Without doing this in a finally block (at least with the mini cluster),
// the region server never goes down.
// mark the batch as having been written. In the single-update case, this never gets check
// again, but in the batch case, we will check it again (see above).
ikv.markBatchFinished();
// release the lock on the index, we wrote everything properly
// we took the lock for each Put/Delete, so we have to release it a matching number of times
// batch cases only take the lock once, so we need to make sure we don't over-release the
// lock.