Examples with SimpleAbstractColumnIterator org.apache.cassandra.db.columniterator.SimpleAbstractColumnIterator used on opensource projects

Example 1 with SimpleAbstractColumnIterator

use of org.apache.cassandra.db.columniterator.SimpleAbstractColumnIterator in project eiger by wlloyd.

the class Memtable method getNamesIterator.

public static IColumnIterator getNamesIterator(final DecoratedKey key, final ColumnFamily cf, final NamesQueryFilter filter) {
    assert cf != null;
    final boolean isStandard = !cf.isSuper();
    return new SimpleAbstractColumnIterator() {

        private Iterator<ByteBuffer> iter = filter.columns.iterator();

        public ColumnFamily getColumnFamily() {
            return cf;
        }

        public DecoratedKey getKey() {
            return key;
        }

        protected IColumn computeNext() {
            while (iter.hasNext()) {
                ByteBuffer current = iter.next();
                IColumn column = cf.getColumn(current);
                if (column != null)
                    // clone supercolumns so caller can freely removeDeleted or otherwise mutate it
                    return isStandard ? column : ((SuperColumn) column).cloneMe();
            }
            return endOfData();
        }
    };
}

Example 2 with SimpleAbstractColumnIterator

use of org.apache.cassandra.db.columniterator.SimpleAbstractColumnIterator in project eiger by wlloyd.

the class CollationController method collectTimeOrderedData.

/**
     * Collects data in order of recency, using the sstable maxtimestamp data.
     * Once we have data for all requests columns that is newer than the newest remaining maxtimestamp,
     * we stop.
     */
private ColumnFamily collectTimeOrderedData() {
    logger.debug("collectTimeOrderedData");
    ISortedColumns.Factory factory = mutableColumns ? AtomicSortedColumns.factory() : TreeMapBackedSortedColumns.factory();
    ColumnFamily container = ColumnFamily.create(cfs.metadata, factory, filter.filter.isReversed());
    List<IColumnIterator> iterators = new ArrayList<IColumnIterator>();
    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());
            }
        }
        // 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;
            }

            public DecoratedKey getKey() {
                return filter.key;
            }
        };
        ColumnFamily returnCF = container.cloneMeShallow();
        filter.collateColumns(returnCF, Collections.singletonList(toCollate), gcBefore);
        // "hoist up" the requested data into a more recent sstable
        if (sstablesIterated > cfs.getMinimumCompactionThreshold() && !cfs.isCompactionDisabled() && cfs.getCompactionStrategy() instanceof SizeTieredCompactionStrategy) {
            RowMutation rm = new RowMutation(cfs.table.name, new Row(filter.key, returnCF.cloneMe()));
            try {
                // skipping commitlog and index updates is fine since we're just de-fragmenting existing data
                Table.open(rm.getTable()).apply(rm, false, false);
            } catch (IOException e) {
                // log and allow the result to be returned
                logger.error("Error re-writing read results", e);
            }
        }
        // Caller is responsible for final removeDeletedCF.  This is important for cacheRow to work correctly:
        return returnCF;
    } finally {
        for (IColumnIterator iter : iterators) FileUtils.closeQuietly(iter);
        SSTableReader.releaseReferences(view.sstables);
    }
}