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 * 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
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package org.apache.cassandra.io.sstable.metadata;

import java.io.*;
import java.util.*;

import com.google.common.collect.Lists;

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.Version;
import org.apache.cassandra.io.util.DataOutputPlus;
import org.apache.cassandra.io.util.DataOutputStreamPlus;
import org.apache.cassandra.io.util.FileDataInput;
import org.apache.cassandra.io.util.FileUtils;
import org.apache.cassandra.io.util.BufferedDataOutputStreamPlus;
import org.apache.cassandra.io.util.RandomAccessReader;
import org.apache.cassandra.utils.FBUtilities;

Metadata serializer for SSTables version >= 'k'.
File format := | number of components (4 bytes) | toc | component1 | component2 | ... |
toc         := | component type (4 bytes) | position of component |
IMetadataComponent.Type's ordinal() defines the order of serialization.
/** * Metadata serializer for SSTables {@code version >= 'k'}. * * <pre> * File format := | number of components (4 bytes) | toc | component1 | component2 | ... | * toc := | component type (4 bytes) | position of component | * </pre> * * IMetadataComponent.Type's ordinal() defines the order of serialization. */
public class MetadataSerializer implements IMetadataSerializer { private static final Logger logger = LoggerFactory.getLogger(MetadataSerializer.class); public void serialize(Map<MetadataType, MetadataComponent> components, DataOutputPlus out, Version version) throws IOException { // sort components by type List<MetadataComponent> sortedComponents = Lists.newArrayList(components.values()); Collections.sort(sortedComponents); // write number of component out.writeInt(components.size()); // build and write toc int lastPosition = 4 + (8 * sortedComponents.size()); for (MetadataComponent component : sortedComponents) { MetadataType type = component.getType(); // serialize type out.writeInt(type.ordinal()); // serialize position out.writeInt(lastPosition); lastPosition += type.serializer.serializedSize(version, component); } // serialize components for (MetadataComponent component : sortedComponents) { component.getType().serializer.serialize(version, component, out); } } public Map<MetadataType, MetadataComponent> deserialize( Descriptor descriptor, EnumSet<MetadataType> types) throws IOException { Map<MetadataType, MetadataComponent> components; logger.trace("Load metadata for {}", descriptor); File statsFile = new File(descriptor.filenameFor(Component.STATS)); if (!statsFile.exists()) { logger.trace("No sstable stats for {}", descriptor); components = new EnumMap<>(MetadataType.class); components.put(MetadataType.STATS, MetadataCollector.defaultStatsMetadata()); } else { try (RandomAccessReader r = RandomAccessReader.open(statsFile)) { components = deserialize(descriptor, r, types); } } return components; } public MetadataComponent deserialize(Descriptor descriptor, MetadataType type) throws IOException { return deserialize(descriptor, EnumSet.of(type)).get(type); } public Map<MetadataType, MetadataComponent> deserialize(Descriptor descriptor, FileDataInput in, EnumSet<MetadataType> types) throws IOException { Map<MetadataType, MetadataComponent> components = new EnumMap<>(MetadataType.class); // read number of components int numComponents = in.readInt(); // read toc Map<MetadataType, Integer> toc = new EnumMap<>(MetadataType.class); MetadataType[] values = MetadataType.values(); for (int i = 0; i < numComponents; i++) { toc.put(values[in.readInt()], in.readInt()); } for (MetadataType type : types) { Integer offset = toc.get(type); if (offset != null) { in.seek(offset); MetadataComponent component = type.serializer.deserialize(descriptor.version, in); components.put(type, component); } } return components; } public void mutateLevel(Descriptor descriptor, int newLevel) throws IOException { logger.trace("Mutating {} to level {}", descriptor.filenameFor(Component.STATS), newLevel); Map<MetadataType, MetadataComponent> currentComponents = deserialize(descriptor, EnumSet.allOf(MetadataType.class)); StatsMetadata stats = (StatsMetadata) currentComponents.remove(MetadataType.STATS); // mutate level currentComponents.put(MetadataType.STATS, stats.mutateLevel(newLevel)); rewriteSSTableMetadata(descriptor, currentComponents); } public void mutateRepairedAt(Descriptor descriptor, long newRepairedAt) throws IOException { logger.trace("Mutating {} to repairedAt time {}", descriptor.filenameFor(Component.STATS), newRepairedAt); Map<MetadataType, MetadataComponent> currentComponents = deserialize(descriptor, EnumSet.allOf(MetadataType.class)); StatsMetadata stats = (StatsMetadata) currentComponents.remove(MetadataType.STATS); // mutate level currentComponents.put(MetadataType.STATS, stats.mutateRepairedAt(newRepairedAt)); rewriteSSTableMetadata(descriptor, currentComponents); } private void rewriteSSTableMetadata(Descriptor descriptor, Map<MetadataType, MetadataComponent> currentComponents) throws IOException { String filePath = descriptor.tmpFilenameFor(Component.STATS); try (DataOutputStreamPlus out = new BufferedDataOutputStreamPlus(new FileOutputStream(filePath))) { serialize(currentComponents, out, descriptor.version); out.flush(); } // we cant move a file on top of another file in windows: if (FBUtilities.isWindows) FileUtils.delete(descriptor.filenameFor(Component.STATS)); FileUtils.renameWithConfirm(filePath, descriptor.filenameFor(Component.STATS)); } }