/*
*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*
*/
package org.apache.cassandra.db.filter;
import org.apache.cassandra.db.Cell;
import org.apache.cassandra.db.composites.CellName;
import org.apache.cassandra.db.composites.CellNameType;
import org.apache.cassandra.db.ColumnFamily;
import org.apache.cassandra.db.DeletionInfo;
public class ColumnCounter
{
protected int live;
protected int ignored;
protected final long timestamp;
public ColumnCounter(long timestamp)
{
this.timestamp = timestamp;
}
public void count(Cell cell, DeletionInfo.InOrderTester tester)
{
if (!isLive(cell, tester, timestamp))
ignored++;
else
live++;
}
protected static boolean isLive(Cell cell, DeletionInfo.InOrderTester tester, long timestamp)
{
return cell.isLive(timestamp) && (!tester.isDeleted(cell));
}
public int live()
{
return live;
}
public int ignored()
{
return ignored;
}
public ColumnCounter countAll(ColumnFamily container)
{
if (container == null)
return this;
DeletionInfo.InOrderTester tester = container.inOrderDeletionTester();
for (Cell c : container)
count(c, tester);
return this;
}
public static class GroupByPrefix extends ColumnCounter
{
private final CellNameType type;
private final int toGroup;
private CellName last;
/**
* A column counter that count only 1 for all the columns sharing a
* given prefix of the key.
*
* @param type the type of the column name. This can be null if {@code
* toGroup} is 0, otherwise it should be a composite.
* @param toGroup the number of composite components on which to group
* column. If 0, all columns are grouped, otherwise we group
* those for which the {@code toGroup} first component are equals.
*/
public GroupByPrefix(long timestamp, CellNameType type, int toGroup)
{
super(timestamp);
this.type = type;
this.toGroup = toGroup;
assert toGroup == 0 || type != null;
}
public void count(Cell cell, DeletionInfo.InOrderTester tester)
{
if (!isLive(cell, tester, timestamp))
{
ignored++;
return;
}
if (toGroup == 0)
{
live = 1;
return;
}
CellName current = cell.name();
assert current.size() >= toGroup;
if (last != null)
{
boolean isSameGroup = true;
for (int i = 0; i < toGroup; i++)
{
if (type.subtype(i).compare(last.get(i), current.get(i)) != 0)
{
isSameGroup = false;
break;
}
}
if (isSameGroup)
return;
}
live++;
last = current;
}
}
}