ColumnFamilyStore.ViewFragment view = cfs.markReferenced(filter.key);
try
{
for (Memtable memtable : view.memtables)
{
IColumnIterator iter = filter.getMemtableColumnIterator(memtable);
if (iter != null)
{
iterators.add(iter);
container.delete(iter.getColumnFamily());
while (iter.hasNext())
container.addColumn(iter.next());
}
}
// avoid changing the filter columns of the original filter
// (reduceNameFilter removes columns that are known to be irrelevant)
TreeSet<ByteBuffer> filterColumns = new TreeSet<ByteBuffer>(((NamesQueryFilter) filter.filter).columns);
QueryFilter reducedFilter = new QueryFilter(filter.key, filter.path, new NamesQueryFilter(filterColumns));
/* add the SSTables on disk */
Collections.sort(view.sstables, SSTable.maxTimestampComparator);
// read sorted sstables
for (SSTableReader sstable : view.sstables)
{
long currentMaxTs = sstable.getMaxTimestamp();
reduceNameFilter(reducedFilter, container, currentMaxTs);
if (((NamesQueryFilter) reducedFilter.filter).columns.isEmpty())
break;
IColumnIterator iter = reducedFilter.getSSTableColumnIterator(sstable);
iterators.add(iter);
if (iter.getColumnFamily() != null)
{
container.delete(iter.getColumnFamily());
sstablesIterated++;
while (iter.hasNext())
container.addColumn(iter.next());
}
}
// we need to distinguish between "there is no data at all for this row" (BF will let us rebuild that efficiently)
// and "there used to be data, but it's gone now" (we should cache the empty CF so we don't need to rebuild that slower)
if (iterators.isEmpty())
return null;
// do a final collate. toCollate is boilerplate required to provide a CloseableIterator
final ColumnFamily c2 = container;
CloseableIterator<IColumn> toCollate = new SimpleAbstractColumnIterator()
{
final Iterator<IColumn> iter = c2.iterator();
protected IColumn computeNext()
{
return iter.hasNext() ? iter.next() : endOfData();
}
public ColumnFamily getColumnFamily()
{
return c2;