private void compactMemTableInternal() throws IOException {
Preconditions.checkState(mutex.isHeldByCurrentThread());
if (immutableMemTable == null) {
return;
}
try {
// Save the contents of the memtable as a new Table
VersionEdit edit = new VersionEdit();
Version base = versions.getCurrent();
writeLevel0Table(immutableMemTable, edit, base);
if (shuttingDown.get()) {
throw new DatabaseShutdownException("Database shutdown during memtable compaction");
}
// Replace immutable memtable with the generated Table
edit.setPreviousLogNumber(0);
edit.setLogNumber(log.getFileNumber()); // Earlier logs no longer needed
versions.logAndApply(edit);
immutableMemTable = null;
deleteObsoleteFiles();
} finally {
backgroundCondition.signalAll();
}
}
