private void writeLevel0Table(MemTable mem, VersionEdit edit, Version base) throws IOException {
Preconditions.checkState(mutex.isHeldByCurrentThread());
// skip empty mem table
if (mem.isEmpty()) {
return;
}
// write the memtable to a new sstable
long fileNumber = versions.getNextFileNumber();
pendingOutputs.add(fileNumber);
mutex.unlock();
FileMetaData meta;
try {
meta = buildTable(mem, fileNumber);
} finally {
mutex.lock();
}
pendingOutputs.remove(fileNumber);
// Note that if file size is zero, the file has been deleted and
// should not be added to the manifest.
int level = 0;
if (meta != null && meta.getFileSize() > 0) {
Slice minUserKey = meta.getSmallest().getUserKey();
Slice maxUserKey = meta.getLargest().getUserKey();
if (base != null) {
level = base.pickLevelForMemTableOutput(minUserKey, maxUserKey);
}
edit.addFile(level, meta);
}
}
