long maxSequence = 0;
MemTable memTable = null;
for (Slice record = logReader.readRecord(); record != null; record = logReader.readRecord()) {
SliceInput sliceInput = record.input();
// read header
if (sliceInput.available() < 12) {
logMonitor.corruption(sliceInput.available(), "log record too small");
continue;
}
long sequenceBegin = sliceInput.readLong();
int updateSize = sliceInput.readInt();