| /* |
| * 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.io.sstable.keycache; |
| |
| import java.io.IOException; |
| import java.nio.ByteBuffer; |
| import javax.annotation.Nonnull; |
| import javax.annotation.Nullable; |
| |
| import org.apache.cassandra.cache.KeyCacheKey; |
| import org.apache.cassandra.db.ClusteringBound; |
| import org.apache.cassandra.db.DecoratedKey; |
| import org.apache.cassandra.io.sstable.AbstractRowIndexEntry; |
| import org.apache.cassandra.io.sstable.format.SSTableFormat; |
| import org.apache.cassandra.io.sstable.format.SSTableReader; |
| import org.apache.cassandra.io.util.DataInputPlus; |
| |
| public interface KeyCacheSupport<T extends SSTableReader & KeyCacheSupport<T>> |
| { |
| @Nonnull |
| KeyCache getKeyCache(); |
| |
| /** |
| * Should quickly get a lower bound prefix from cache only if everything is already availabe in memory and does not |
| * need to be loaded from disk. |
| */ |
| @Nullable |
| ClusteringBound<?> getLowerBoundPrefixFromCache(DecoratedKey partitionKey, boolean isReversed); |
| |
| default @Nonnull KeyCacheKey getCacheKey(ByteBuffer key) |
| { |
| T reader = (T) this; |
| return new KeyCacheKey(reader.metadata(), reader.descriptor, key); |
| } |
| |
| default @Nonnull KeyCacheKey getCacheKey(DecoratedKey key) |
| { |
| return getCacheKey(key.getKey()); |
| } |
| |
| /** |
| * Will return null if key is not found or cache is not available. |
| */ |
| default @Nullable AbstractRowIndexEntry getCachedPosition(DecoratedKey key, boolean updateStats) |
| { |
| return getCachedPosition(getCacheKey(key), updateStats); |
| } |
| |
| /** |
| * Will return null if key is not found or cache is not available. |
| */ |
| default @Nullable AbstractRowIndexEntry getCachedPosition(KeyCacheKey key, boolean updateStats) |
| { |
| KeyCache keyCache = getKeyCache(); |
| AbstractRowIndexEntry cachedEntry = keyCache.get(key, updateStats); |
| assert cachedEntry == null || cachedEntry.getSSTableFormat() == ((T) this).descriptor.version.format; |
| |
| return cachedEntry; |
| } |
| |
| /** |
| * Caches a key only if cache is available. |
| */ |
| default void cacheKey(@Nonnull DecoratedKey key, @Nonnull AbstractRowIndexEntry info) |
| { |
| T reader = (T) this; |
| assert info.getSSTableFormat() == reader.descriptor.version.format; |
| |
| KeyCacheKey cacheKey = getCacheKey(key); |
| getKeyCache().put(cacheKey, info); |
| } |
| |
| @Nonnull |
| AbstractRowIndexEntry deserializeKeyCacheValue(@Nonnull DataInputPlus input) throws IOException; |
| |
| static boolean isSupportedBy(SSTableFormat<?, ?> format) |
| { |
| return KeyCacheSupport.class.isAssignableFrom(format.getReaderFactory().getReaderClass()); |
| } |
| |
| } |