package org.apache.cassandra.db.filter; /* * * 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. * */ import java.io.IOException; import java.util.Comparator; import java.util.Iterator; import java.util.Arrays; import org.apache.cassandra.io.SSTableReader; import org.apache.cassandra.utils.ReducingIterator; import org.apache.cassandra.db.*; import org.apache.cassandra.db.marshal.AbstractType; public abstract class QueryFilter { public final String key; public final QueryPath path; protected QueryFilter(String key, QueryPath path) { this.key = key; this.path = path; } /** * returns an iterator that returns columns from the given memtable * matching the Filter criteria in sorted order. */ public abstract ColumnIterator getMemColumnIterator(Memtable memtable, ColumnFamily cf, AbstractType comparator); public ColumnIterator getMemColumnIterator(Memtable memtable, AbstractType comparator) { return getMemColumnIterator(memtable, memtable.getColumnFamily(key), comparator); } /** * returns an iterator that returns columns from the given SSTable * matching the Filter criteria in sorted order. */ public abstract ColumnIterator getSSTableColumnIterator(SSTableReader sstable) throws IOException; /** * collects columns from reducedColumns into returnCF. Termination is determined * by the filter code, which should have some limit on the number of columns * to avoid running out of memory on large rows. */ public abstract void collectReducedColumns(IColumnContainer container, Iterator<IColumn> reducedColumns, int gcBefore); /** * subcolumns of a supercolumn are unindexed, so to pick out parts of those we operate in-memory. * @param superColumn may be modified by filtering op. */ public abstract SuperColumn filterSuperColumn(SuperColumn superColumn, int gcBefore); public Comparator<IColumn> getColumnComparator(final AbstractType comparator) { return new Comparator<IColumn>() { public int compare(IColumn c1, IColumn c2) { return comparator.compare(c1.name(), c2.name()); } }; } public void collectCollatedColumns(final ColumnFamily returnCF, Iterator<IColumn> collatedColumns, int gcBefore) { // define a 'reduced' iterator that merges columns w/ the same name, which // greatly simplifies computing liveColumns in the presence of tombstones. ReducingIterator<IColumn, IColumn> reduced = new ReducingIterator<IColumn, IColumn>(collatedColumns) { ColumnFamily curCF = returnCF.cloneMeShallow(); protected boolean isEqual(IColumn o1, IColumn o2) { return Arrays.equals(o1.name(), o2.name()); } public void reduce(IColumn current) { curCF.addColumn(current); } protected IColumn getReduced() { IColumn c = curCF.getSortedColumns().iterator().next(); curCF.clear(); return c; } }; collectReducedColumns(returnCF, reduced, gcBefore); } public String getColumnFamilyName() { return path.columnFamilyName; } public static boolean isRelevant(IColumn column, IColumnContainer container, int gcBefore) { // the column itself must be not gc-able (it is live, or a still relevant tombstone, or has live subcolumns), (1) // and if its container is deleted, the column must be changed more recently than the container tombstone (2) // (since otherwise, the only thing repair cares about is the container tombstone) long maxChange = column.mostRecentLiveChangeAt(); return (!column.isMarkedForDelete() || column.getLocalDeletionTime() > gcBefore || maxChange > column.getMarkedForDeleteAt()) // (1) && (!container.isMarkedForDelete() || maxChange > container.getMarkedForDeleteAt()); // (2) } }