src/java/org/apache/cassandra/io/sstable/format/SSTableWriter.java

/*
 * 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 com.google.common.collect.Sets;
import org.apache.cassandra.config.CFMetaData;
import org.apache.cassandra.config.DatabaseDescriptor;
import org.apache.cassandra.config.Schema;
import org.apache.cassandra.db.ColumnFamily;
import org.apache.cassandra.db.DecoratedKey;
import org.apache.cassandra.db.RowIndexEntry;
import org.apache.cassandra.db.compaction.AbstractCompactedRow;
import org.apache.cassandra.dht.IPartitioner;
import org.apache.cassandra.io.sstable.Component;
import org.apache.cassandra.io.sstable.Descriptor;
import org.apache.cassandra.io.sstable.SSTable;
import org.apache.cassandra.io.sstable.metadata.MetadataCollector;
import org.apache.cassandra.io.sstable.metadata.MetadataComponent;
import org.apache.cassandra.io.sstable.metadata.MetadataType;
import org.apache.cassandra.io.sstable.metadata.StatsMetadata;
import org.apache.cassandra.io.util.FileUtils;
import org.apache.cassandra.utils.concurrent.Transactional;

import java.io.DataInput;
import java.io.IOException;
import java.util.Arrays;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

/**
 * This is the API all table writers must implement.
 *
 * TableWriter.create() is the primary way to create a writer for a particular format.
 * The format information is part of the Descriptor.
 */
public abstract class SSTableWriter extends SSTable implements Transactional
{
    protected long repairedAt;
    protected long maxDataAge = -1;
    protected final long keyCount;
    protected final MetadataCollector metadataCollector;
    protected final RowIndexEntry.IndexSerializer rowIndexEntrySerializer;
    protected final TransactionalProxy txnProxy = txnProxy();

    protected abstract TransactionalProxy txnProxy();

    // due to lack of multiple inheritance, we use an inner class to proxy our Transactional implementation details
    protected abstract class TransactionalProxy extends AbstractTransactional
    {
        // should be set during doPrepare()
        protected SSTableReader finalReader;
        protected boolean openResult;
    }

    protected SSTableWriter(Descriptor descriptor, long keyCount, long repairedAt, CFMetaData metadata, IPartitioner partitioner, MetadataCollector metadataCollector)
    {
        super(descriptor, components(metadata), metadata, partitioner);
        this.keyCount = keyCount;
        this.repairedAt = repairedAt;
        this.metadataCollector = metadataCollector;
        this.rowIndexEntrySerializer = descriptor.version.getSSTableFormat().getIndexSerializer(metadata);
    }

    public static SSTableWriter create(Descriptor descriptor, Long keyCount, Long repairedAt, CFMetaData metadata,  IPartitioner partitioner, MetadataCollector metadataCollector)
    {
        Factory writerFactory = descriptor.getFormat().getWriterFactory();
        return writerFactory.open(descriptor, keyCount, repairedAt, metadata, partitioner, metadataCollector);
    }

    public static SSTableWriter create(Descriptor descriptor, long keyCount, long repairedAt)
    {
        return create(descriptor, keyCount, repairedAt, 0);
    }

    public static SSTableWriter create(Descriptor descriptor, long keyCount, long repairedAt, int sstableLevel)
    {
        CFMetaData metadata = Schema.instance.getCFMetaData(descriptor);
        return create(metadata, descriptor, keyCount, repairedAt, sstableLevel, DatabaseDescriptor.getPartitioner());
    }

    public static SSTableWriter create(CFMetaData metadata,
                                       Descriptor descriptor,
                                       long keyCount,
                                       long repairedAt,
                                       int sstableLevel,
                                       IPartitioner partitioner)
    {
        MetadataCollector collector = new MetadataCollector(metadata.comparator).sstableLevel(sstableLevel);
        return create(descriptor, keyCount, repairedAt, metadata, partitioner, collector);
    }

    public static SSTableWriter create(String filename, long keyCount, long repairedAt, int sstableLevel)
    {
        return create(Descriptor.fromFilename(filename), keyCount, repairedAt, sstableLevel);
    }

    public static SSTableWriter create(String filename, long keyCount, long repairedAt)
    {
        return create(Descriptor.fromFilename(filename), keyCount, repairedAt, 0);
    }

    private static Set<Component> components(CFMetaData metadata)
    {
        Set<Component> components = new HashSet<Component>(Arrays.asList(Component.DATA,
                Component.PRIMARY_INDEX,
                Component.STATS,
                Component.SUMMARY,
                Component.TOC,
                Component.DIGEST));

        if (metadata.getBloomFilterFpChance() < 1.0)
            components.add(Component.FILTER);

        if (metadata.compressionParameters().sstableCompressor != null)
        {
            components.add(Component.COMPRESSION_INFO);
        }
        else
        {
            // it would feel safer to actually add this component later in maybeWriteDigest(),
            // but the components are unmodifiable after construction
            components.add(Component.CRC);
        }
        return components;
    }


    public abstract void mark();


    /**
     * @param row
     * @return null if the row was compacted away entirely; otherwise, the PK index entry for this row
     */
    public abstract RowIndexEntry append(AbstractCompactedRow row);

    public abstract void append(DecoratedKey decoratedKey, ColumnFamily cf);

    public abstract long appendFromStream(DecoratedKey key, CFMetaData metadata, DataInput in, Version version) throws IOException;

    public abstract long getFilePointer();

    public abstract long getOnDiskFilePointer();

    public abstract void resetAndTruncate();

    public SSTableWriter setRepairedAt(long repairedAt)
    {
        if (repairedAt > 0)
            this.repairedAt = repairedAt;
        return this;
    }

    public SSTableWriter setMaxDataAge(long maxDataAge)
    {
        this.maxDataAge = maxDataAge;
        return this;
    }

    public SSTableWriter setOpenResult(boolean openResult)
    {
        txnProxy.openResult = openResult;
        return this;
    }

    /**
     * Open the resultant SSTableReader before it has been fully written
     */
    public abstract SSTableReader openEarly();

    /**
     * Open the resultant SSTableReader once it has been fully written, but before the
     * _set_ of tables that are being written together as one atomic operation are all ready
     */
    public abstract SSTableReader openFinalEarly();

    public SSTableReader finish(long repairedAt, long maxDataAge, boolean openResult)
    {
        if (repairedAt > 0)
            this.repairedAt = repairedAt;
        this.maxDataAge = maxDataAge;
        return finish(openResult);
    }

    public SSTableReader finish(boolean openResult)
    {
        txnProxy.openResult = openResult;
        txnProxy.finish();
        return finished();
    }

    /**
     * Open the resultant SSTableReader once it has been fully written, and all related state
     * is ready to be finalised including other sstables being written involved in the same operation
     */
    public SSTableReader finished()
    {
        return txnProxy.finalReader;
    }

    // finalise our state on disk, including renaming
    public final void prepareToCommit()
    {
        txnProxy.prepareToCommit();
    }

    public final Throwable commit(Throwable accumulate)
    {
        return txnProxy.commit(accumulate);
    }

    public final Throwable abort(Throwable accumulate)
    {
        return txnProxy.abort(accumulate);
    }

    public final void close()
    {
        txnProxy.close();
    }

    public final void abort()
    {
        txnProxy.abort();
    }

    protected Map<MetadataType, MetadataComponent> finalizeMetadata()
    {
        return metadataCollector.finalizeMetadata(partitioner.getClass().getCanonicalName(),
                                                  metadata.getBloomFilterFpChance(), repairedAt);
    }

    protected StatsMetadata statsMetadata()
    {
        return (StatsMetadata) finalizeMetadata().get(MetadataType.STATS);
    }

    public static Descriptor rename(Descriptor tmpdesc, Set<Component> components)
    {
        Descriptor newdesc = tmpdesc.asType(Descriptor.Type.FINAL);
        rename(tmpdesc, newdesc, components);
        return newdesc;
    }

    public static void rename(Descriptor tmpdesc, Descriptor newdesc, Set<Component> components)
    {
        for (Component component : Sets.difference(components, Sets.newHashSet(Component.DATA, Component.SUMMARY)))
        {
            FileUtils.renameWithConfirm(tmpdesc.filenameFor(component), newdesc.filenameFor(component));
        }

        // do -Data last because -Data present should mean the sstable was completely renamed before crash
        FileUtils.renameWithConfirm(tmpdesc.filenameFor(Component.DATA), newdesc.filenameFor(Component.DATA));

        // rename it without confirmation because summary can be available for loadNewSSTables but not for closeAndOpenReader
        FileUtils.renameWithOutConfirm(tmpdesc.filenameFor(Component.SUMMARY), newdesc.filenameFor(Component.SUMMARY));
    }


    public static abstract class Factory
    {
        public abstract SSTableWriter open(Descriptor descriptor, long keyCount, long repairedAt, CFMetaData metadata, IPartitioner partitioner, MetadataCollector metadataCollector);
    }
}