How to use

minimalBufferFor

method

in

org.apache.cassandra.utils.ByteBufferUtil

private static ByteBuffer maybeMinimize(ByteBuffer buffer)
{
  // ByteBuffer.minimalBufferFor doesn't handle null, but we can get it in this case since it's possible
  // for some clustering values to be null
  return buffer == null ? null : ByteBufferUtil.minimalBufferFor(buffer);
}

private static ByteBuffer maybeMinimize(ByteBuffer buffer)
{
  // ByteBuffer.minimalBufferFor doesn't handle null, but we can get it in this case since it's possible
  // for some clustering values to be null
  return buffer == null ? null : ByteBufferUtil.minimalBufferFor(buffer);
}

private static ByteBuffer maybeMinimize(ByteBuffer buffer)
{
  // ByteBuffer.minimalBufferFor doesn't handle null, but we can get it in this case since it's possible
  // for some clustering values to be null
  return buffer == null ? null : ByteBufferUtil.minimalBufferFor(buffer);
}

private static ByteBuffer maybeMinimize(ByteBuffer buffer)
{
  // ByteBuffer.minimalBufferFor doesn't handle null, but we can get it in this case since it's possible
  // for some clustering values to be null
  return buffer == null ? null : ByteBufferUtil.minimalBufferFor(buffer);
}

private static List<ByteBuffer> minimalBuffersFor(List<ByteBuffer> candidates)
{
  List<ByteBuffer> minimalBuffers = new ArrayList<ByteBuffer>(candidates.size());
  for (ByteBuffer byteBuffer : candidates)
    minimalBuffers.add(minimalBufferFor(byteBuffer));
  return minimalBuffers;
}

public static ColumnIdentifier getInterned(AbstractType<?> type, ByteBuffer bytes, String text)
{
  bytes = ByteBufferUtil.minimalBufferFor(bytes);
  InternedKey key = new InternedKey(type, bytes);
  ColumnIdentifier id = internedInstances.get(key);
  if (id != null)
    return id;
  ColumnIdentifier created = new ColumnIdentifier(bytes, text, true);
  ColumnIdentifier previous = internedInstances.putIfAbsent(key, created);
  return previous == null ? created : previous;
}

public static ColumnIdentifier getInterned(AbstractType<?> type, ByteBuffer bytes, String text)
{
  bytes = ByteBufferUtil.minimalBufferFor(bytes);
  InternedKey key = new InternedKey(type, bytes);
  ColumnIdentifier id = internedInstances.get(key);
  if (id != null)
    return id;
  ColumnIdentifier created = new ColumnIdentifier(bytes, text, true);
  ColumnIdentifier previous = internedInstances.putIfAbsent(key, created);
  return previous == null ? created : previous;
}

public static ColumnIdentifier getInterned(AbstractType<?> type, ByteBuffer bytes, String text)
{
  bytes = ByteBufferUtil.minimalBufferFor(bytes);
  InternedKey key = new InternedKey(type, bytes);
  ColumnIdentifier id = internedInstances.get(key);
  if (id != null)
    return id;
  ColumnIdentifier created = new ColumnIdentifier(bytes, text, true);
  ColumnIdentifier previous = internedInstances.putIfAbsent(key, created);
  return previous == null ? created : previous;
}

/**
 * Merge 2 lists of min cell name components.
 *
 * @param minColumnNames lhs
 * @param candidates rhs
 * @param comparator comparator to use
 * @return a list with smallest column names according to (sub)comparator
 */
public static List<ByteBuffer> mergeMin(List<ByteBuffer> minColumnNames, List<ByteBuffer> candidates, CellNameType comparator)
{
  if (minColumnNames.isEmpty())
    return minimalBuffersFor(candidates);
  if (candidates.isEmpty())
    return minColumnNames;
  List<ByteBuffer> biggest = minColumnNames.size() > candidates.size() ? minColumnNames : candidates;
  List<ByteBuffer> smallest = minColumnNames.size() > candidates.size() ? candidates : minColumnNames;
  // We want to always copy the smallest list, and maybeGrow does it only if it's actually smaller
  List<ByteBuffer> retList = smallest.size() == biggest.size()
               ? new ArrayList<>(smallest)
               : maybeGrow(smallest, biggest.size());
  for (int i = 0; i < biggest.size(); i++)
    retList.set(i, minimalBufferFor(min(retList.get(i), biggest.get(i), comparator.subtype(i))));
  return retList;
}

/**
 * Merge 2 lists of max cell name components.
 *
 * @param maxColumnNames lhs
 * @param candidates rhs
 * @param comparator comparator to use
 * @return a list with biggest column names according to (sub)comparator
 */
public static List<ByteBuffer> mergeMax(List<ByteBuffer> maxColumnNames, List<ByteBuffer> candidates, CellNameType comparator)
{
  if (maxColumnNames.isEmpty())
    return minimalBuffersFor(candidates);
  if (candidates.isEmpty())
    return maxColumnNames;
  List<ByteBuffer> biggest = maxColumnNames.size() > candidates.size() ? maxColumnNames : candidates;
  List<ByteBuffer> smallest = maxColumnNames.size() > candidates.size() ? candidates : maxColumnNames;
  // We want to always copy the smallest list, and maybeGrow does it only if it's actually smaller
  List<ByteBuffer> retList = smallest.size() == biggest.size()
               ? new ArrayList<>(smallest)
               : maybeGrow(smallest, biggest.size());
  for (int i = 0; i < biggest.size(); i++)
    retList.set(i, minimalBufferFor(max(retList.get(i), biggest.get(i), comparator.subtype(i))));
  return retList;
}