/**
* Splits this filter into two SliceQueryFilters: one that slices only the static columns, and one
* that slices the remainder of the normal data.
*
* <p>This should only be called when the filter is reversed and the filter is known to cover
* static columns (through hasStaticSlice()).
*
* @return a pair of (static, normal) SliceQueryFilters
*/
public Pair<SliceQueryFilter, SliceQueryFilter> splitOutStaticSlice(CFMetaData cfm) {
assert reversed;
Composite staticSliceEnd = cfm.comparator.staticPrefix().end();
List<ColumnSlice> nonStaticSlices = new ArrayList<>(slices.length);
for (ColumnSlice slice : slices) {
if (sliceIncludesStatics(slice, cfm))
nonStaticSlices.add(new ColumnSlice(slice.start, staticSliceEnd));
else nonStaticSlices.add(slice);
}
return Pair.create(
new SliceQueryFilter(staticSliceEnd, Composites.EMPTY, true, count, compositesToGroup),
new SliceQueryFilter(
nonStaticSlices.toArray(new ColumnSlice[nonStaticSlices.size()]),
true,
count,
compositesToGroup));
}
public SliceQueryFilter withUpdatedStart(Composite newStart, CFMetaData cfm) {
Comparator<Composite> cmp = reversed ? cfm.comparator.reverseComparator() : cfm.comparator;
// Check our slices to see if any fall before the new start (in which case they can be removed)
// or
// if they contain the new start (in which case they should start from the page start).
// However, if the
// slices would include static columns, we need to ensure they are also fetched, and so a
// separate
// slice for the static columns may be required.
// Note that if the query is reversed, we can't handle statics by simply adding a separate slice
// here, so
// the reversed case is handled by SliceFromReadCommand instead. See CASSANDRA-8502 for more
// details.
List<ColumnSlice> newSlices = new ArrayList<>();
boolean pastNewStart = false;
for (ColumnSlice slice : slices) {
if (pastNewStart) {
newSlices.add(slice);
continue;
}
if (slice.isBefore(cmp, newStart)) {
if (!reversed && sliceIncludesStatics(slice, cfm))
newSlices.add(new ColumnSlice(Composites.EMPTY, cfm.comparator.staticPrefix().end()));
continue;
} else if (slice.includes(cmp, newStart)) {
if (!reversed && sliceIncludesStatics(slice, cfm) && !newStart.isEmpty())
newSlices.add(new ColumnSlice(Composites.EMPTY, cfm.comparator.staticPrefix().end()));
newSlices.add(new ColumnSlice(newStart, slice.finish));
} else {
newSlices.add(slice);
}
pastNewStart = true;
}
return withUpdatedSlices(newSlices.toArray(new ColumnSlice[newSlices.size()]));
}
