| /* |
| * 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.format; |
| |
| import java.io.IOException; |
| import java.util.Set; |
| |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| import org.apache.cassandra.io.sstable.Component; |
| import org.apache.cassandra.io.sstable.Descriptor; |
| import org.apache.cassandra.io.sstable.format.SSTableFormat.Components; |
| import org.apache.cassandra.io.sstable.metadata.ValidationMetadata; |
| import org.apache.cassandra.io.util.File; |
| import org.apache.cassandra.io.util.FileInputStreamPlus; |
| import org.apache.cassandra.io.util.FileOutputStreamPlus; |
| import org.apache.cassandra.schema.TableMetadata; |
| import org.apache.cassandra.utils.BloomFilterSerializer; |
| import org.apache.cassandra.utils.FilterFactory; |
| import org.apache.cassandra.utils.IFilter; |
| |
| public class FilterComponent |
| { |
| private static final Logger logger = LoggerFactory.getLogger(FilterComponent.class); |
| |
| final static boolean rebuildFilterOnFPChanceChange = false; |
| final static double filterFPChanceTolerance = 0d; |
| |
| private FilterComponent() |
| { |
| } |
| |
| /** |
| * Load bloom filter from Filter.db file. |
| */ |
| public static IFilter load(Descriptor descriptor) throws IOException |
| { |
| File filterFile = descriptor.fileFor(Components.FILTER); |
| |
| if (!filterFile.exists()) |
| return null; |
| |
| if (filterFile.length() == 0) |
| return FilterFactory.AlwaysPresent; |
| |
| try (FileInputStreamPlus stream = descriptor.fileFor(Components.FILTER).newInputStream()) |
| { |
| return BloomFilterSerializer.forVersion(descriptor.version.hasOldBfFormat()).deserialize(stream); |
| } |
| catch (IOException ex) |
| { |
| throw new IOException("Failed to load Bloom filter for SSTable: " + descriptor.baseFile(), ex); |
| } |
| } |
| |
| public static void save(IFilter filter, Descriptor descriptor, boolean deleteOnFailure) throws IOException |
| { |
| File filterFile = descriptor.fileFor(Components.FILTER); |
| try (FileOutputStreamPlus stream = filterFile.newOutputStream(File.WriteMode.OVERWRITE)) |
| { |
| filter.serialize(stream, descriptor.version.hasOldBfFormat()); |
| stream.flush(); |
| stream.sync(); |
| } |
| catch (IOException ex) |
| { |
| if (deleteOnFailure) |
| descriptor.fileFor(Components.FILTER).deleteIfExists(); |
| throw new IOException("Failed to save Bloom filter for SSTable: " + descriptor.baseFile(), ex); |
| } |
| } |
| |
| /** |
| * Optionally loads a Bloom filter. |
| * If the filter is not needed (FP chance is neglectable), it returns {@link FilterFactory#AlwaysPresent}. |
| * If the filter is expected to be recreated for various reasons the method returns {@code null}. |
| * Otherwise, an attempt to load the filter is made and if it succeeds, the loaded filter is returned. |
| * If loading fails, the method returns {@code null}. |
| * |
| * @return {@link FilterFactory#AlwaysPresent}, loaded filter or {@code null} (which means that the filter should be rebuilt) |
| */ |
| public static IFilter maybeLoadBloomFilter(Descriptor descriptor, Set<Component> components, TableMetadata metadata, ValidationMetadata validationMetadata) |
| { |
| double currentFPChance = validationMetadata != null ? validationMetadata.bloomFilterFPChance : Double.NaN; |
| double desiredFPChance = metadata.params.bloomFilterFpChance; |
| |
| IFilter filter = null; |
| if (!shouldUseBloomFilter(desiredFPChance)) |
| { |
| if (logger.isTraceEnabled()) |
| logger.trace("Bloom filter for {} will not be loaded because fpChance={} is negligible", descriptor, desiredFPChance); |
| |
| return FilterFactory.AlwaysPresent; |
| } |
| else if (!components.contains(Components.FILTER) || Double.isNaN(currentFPChance)) |
| { |
| if (logger.isTraceEnabled()) |
| logger.trace("Bloom filter for {} will not be loaded because the filter component is missing or sstable lacks validation metadata", descriptor); |
| |
| return null; |
| } |
| else if (!isFPChanceDiffNegligible(desiredFPChance, currentFPChance) && rebuildFilterOnFPChanceChange) |
| { |
| if (logger.isTraceEnabled()) |
| logger.trace("Bloom filter for {} will not be loaded because fpChance has changed from {} to {} and the filter should be recreated", descriptor, currentFPChance, desiredFPChance); |
| |
| return null; |
| } |
| |
| try |
| { |
| filter = load(descriptor); |
| if (filter == null || !filter.isInformative()) |
| logger.info("Bloom filter for {} is missing or invalid", descriptor); |
| } |
| catch (IOException ex) |
| { |
| logger.info("Bloom filter for " + descriptor + " could not be deserialized", ex); |
| } |
| |
| return filter; |
| } |
| |
| static boolean shouldUseBloomFilter(double fpChance) |
| { |
| return !(Math.abs(1 - fpChance) <= filterFPChanceTolerance); |
| } |
| |
| static boolean isFPChanceDiffNegligible(double fpChance1, double fpChance2) |
| { |
| return Math.abs(fpChance1 - fpChance2) <= filterFPChanceTolerance; |
| } |
| } |