Examples with VectorOffset org.apache.druid.segment.vector.VectorOffset used on opensource projects

Example 1 with VectorOffset

use of org.apache.druid.segment.vector.VectorOffset in project druid by druid-io.

the class QueryableIndexCursorSequenceBuilder method buildVectorized.

public VectorCursor buildVectorized(final int vectorSize) {
    // Sanity check - matches QueryableIndexStorageAdapter.canVectorize
    Preconditions.checkState(!descending, "!descending");
    final Map<String, BaseColumn> columnCache = new HashMap<>();
    final Closer closer = Closer.create();
    NumericColumn timestamps = null;
    final int startOffset;
    final int endOffset;
    if (interval.getStartMillis() > minDataTimestamp) {
        timestamps = (NumericColumn) index.getColumnHolder(ColumnHolder.TIME_COLUMN_NAME).getColumn();
        closer.register(timestamps);
        startOffset = timeSearch(timestamps, interval.getStartMillis(), 0, index.getNumRows());
    } else {
        startOffset = 0;
    }
    if (interval.getEndMillis() <= maxDataTimestamp) {
        if (timestamps == null) {
            timestamps = (NumericColumn) index.getColumnHolder(ColumnHolder.TIME_COLUMN_NAME).getColumn();
            closer.register(timestamps);
        }
        endOffset = timeSearch(timestamps, interval.getEndMillis(), startOffset, index.getNumRows());
    } else {
        endOffset = index.getNumRows();
    }
    final VectorOffset baseOffset = filterBitmap == null ? new NoFilterVectorOffset(vectorSize, startOffset, endOffset) : new BitmapVectorOffset(vectorSize, filterBitmap, startOffset, endOffset);
    // baseColumnSelectorFactory using baseOffset is the column selector for filtering.
    final VectorColumnSelectorFactory baseColumnSelectorFactory = makeVectorColumnSelectorFactoryForOffset(columnCache, baseOffset, closer);
    if (postFilter == null) {
        return new QueryableIndexVectorCursor(baseColumnSelectorFactory, baseOffset, vectorSize, closer);
    } else {
        final VectorOffset filteredOffset = FilteredVectorOffset.create(baseOffset, baseColumnSelectorFactory, postFilter);
        // Now create the cursor and column selector that will be returned to the caller.
        // 
        // There is an inefficiency with how we do things here: this cursor (the one that will be provided to the
        // caller) does share a columnCache with "baseColumnSelectorFactory", but it *doesn't* share vector data. This
        // means that if the caller wants to read from a column that is also used for filtering, the underlying column
        // object will get hit twice for some of the values (anything that matched the filter). This is probably most
        // noticeable if it causes thrashing of decompression buffers due to out-of-order reads. I haven't observed
        // this directly but it seems possible in principle.
        // baseColumnSelectorFactory using baseOffset is the column selector for filtering.
        final VectorColumnSelectorFactory filteredColumnSelectorFactory = makeVectorColumnSelectorFactoryForOffset(columnCache, filteredOffset, closer);
        return new QueryableIndexVectorCursor(filteredColumnSelectorFactory, filteredOffset, vectorSize, closer);
    }
}