Java tutorial
/* * 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.index.sasi.conf.view; import java.nio.ByteBuffer; import java.util.*; import org.apache.cassandra.db.marshal.UUIDType; import org.apache.cassandra.index.sasi.SSTableIndex; import org.apache.cassandra.index.sasi.conf.ColumnIndex; import org.apache.cassandra.index.sasi.plan.Expression; import org.apache.cassandra.db.marshal.AbstractType; import org.apache.cassandra.db.marshal.AsciiType; import org.apache.cassandra.db.marshal.UTF8Type; import org.apache.cassandra.io.sstable.Descriptor; import org.apache.cassandra.io.sstable.format.SSTableReader; import org.apache.cassandra.utils.Interval; import org.apache.cassandra.utils.IntervalTree; import com.google.common.collect.Iterables; import com.google.common.collect.Sets; public class View implements Iterable<SSTableIndex> { private final Map<Descriptor, SSTableIndex> view; private final TermTree termTree; private final AbstractType<?> keyValidator; private final IntervalTree<Key, SSTableIndex, Interval<Key, SSTableIndex>> keyIntervalTree; public View(ColumnIndex index, Set<SSTableIndex> indexes) { this(index, Collections.<SSTableIndex>emptyList(), Collections.<SSTableReader>emptyList(), indexes); } public View(ColumnIndex index, Collection<SSTableIndex> currentView, Collection<SSTableReader> oldSSTables, Set<SSTableIndex> newIndexes) { Map<Descriptor, SSTableIndex> newView = new HashMap<>(); AbstractType<?> validator = index.getValidator(); TermTree.Builder termTreeBuilder = (validator instanceof AsciiType || validator instanceof UTF8Type) ? new PrefixTermTree.Builder(index.getMode().mode, validator) : new RangeTermTree.Builder(index.getMode().mode, validator); List<Interval<Key, SSTableIndex>> keyIntervals = new ArrayList<>(); for (SSTableIndex sstableIndex : Iterables.concat(currentView, newIndexes)) { SSTableReader sstable = sstableIndex.getSSTable(); if (oldSSTables.contains(sstable) || sstable.isMarkedCompacted() || newView.containsKey(sstable.descriptor)) { sstableIndex.release(); continue; } newView.put(sstable.descriptor, sstableIndex); termTreeBuilder.add(sstableIndex); keyIntervals.add(Interval.create(new Key(sstableIndex.minKey(), index.keyValidator()), new Key(sstableIndex.maxKey(), index.keyValidator()), sstableIndex)); } this.view = newView; this.termTree = termTreeBuilder.build(); this.keyValidator = index.keyValidator(); this.keyIntervalTree = IntervalTree.build(keyIntervals); if (keyIntervalTree.intervalCount() != termTree.intervalCount()) throw new IllegalStateException( String.format("mismatched sizes for intervals tree for keys vs terms: %d != %d", keyIntervalTree.intervalCount(), termTree.intervalCount())); } public Set<SSTableIndex> match(Expression expression) { return termTree.search(expression); } public List<SSTableIndex> match(ByteBuffer minKey, ByteBuffer maxKey) { return keyIntervalTree.search( Interval.create(new Key(minKey, keyValidator), new Key(maxKey, keyValidator), (SSTableIndex) null)); } public Iterator<SSTableIndex> iterator() { return view.values().iterator(); } public Collection<SSTableIndex> getIndexes() { return view.values(); } /** * This is required since IntervalTree doesn't support custom Comparator * implementations and relied on items to be comparable which "raw" keys are not. */ private static class Key implements Comparable<Key> { private final ByteBuffer key; private final AbstractType<?> comparator; public Key(ByteBuffer key, AbstractType<?> comparator) { this.key = key; this.comparator = comparator; } public int compareTo(Key o) { return comparator.compare(key, o.key); } } }