com.bigdata.dastor.io.CompactionIterator.java Source code

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Here is the source code for com.bigdata.dastor.io.CompactionIterator.java

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package com.bigdata.dastor.io;
/*
 * 
 * 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.
 * 
 */

import java.io.Closeable;
import java.io.IOException;
import java.io.IOError;
import java.util.List;
import java.util.ArrayList;
import java.util.Set;
import java.util.HashSet;
import java.util.Iterator;

import org.apache.log4j.Logger;
import org.apache.commons.collections.iterators.CollatingIterator;

import com.bigdata.dastor.config.DatabaseDescriptor;
import com.bigdata.dastor.db.ColumnFamily;
import com.bigdata.dastor.db.ColumnFamilyStore;
import com.bigdata.dastor.db.DecoratedKey;
import com.bigdata.dastor.io.util.DataOutputBuffer;
import com.bigdata.dastor.utils.FBUtilities;
import com.bigdata.dastor.utils.ReducingIterator;

public class CompactionIterator extends ReducingIterator<IteratingRow, CompactionIterator.CompactedRow>
        implements Closeable {
    private static Logger logger = Logger.getLogger(CompactionIterator.class);

    protected static final int FILE_BUFFER_SIZE = 1024 * 1024;

    private final List<IteratingRow> rows = new ArrayList<IteratingRow>();
    private final ColumnFamilyStore cfs;
    private final int gcBefore;
    private final boolean major;

    private long totalBytes;
    private long bytesRead;
    private long row;

    public CompactionIterator(ColumnFamilyStore cfs, Iterable<SSTableReader> sstables, int gcBefore, boolean major)
            throws IOException {
        this(cfs, getCollatingIterator(sstables), gcBefore, major);
    }

    @SuppressWarnings("unchecked")
    protected CompactionIterator(ColumnFamilyStore cfs, Iterator iter, int gcBefore, boolean major) {
        super(iter);
        row = 0;
        totalBytes = bytesRead = 0;
        for (SSTableScanner scanner : getScanners()) {
            totalBytes += scanner.getFileLength();
        }
        this.cfs = cfs;
        this.gcBefore = gcBefore;
        this.major = major;
    }

    @SuppressWarnings("unchecked")
    protected static CollatingIterator getCollatingIterator(Iterable<SSTableReader> sstables) throws IOException {
        CollatingIterator iter = FBUtilities.<IteratingRow>getCollatingIterator();
        for (SSTableReader sstable : sstables) {
            iter.addIterator(sstable.getScanner(FILE_BUFFER_SIZE));
        }
        return iter;
    }

    @Override
    protected boolean isEqual(IteratingRow o1, IteratingRow o2) {
        return o1.getKey().equals(o2.getKey());
    }

    public void reduce(IteratingRow current) {
        rows.add(current);
    }

    protected CompactedRow getReduced() {
        assert rows.size() > 0;

        DataOutputBuffer headerBuffer = new DataOutputBuffer(); // BIGDATA
        DataOutputBuffer buffer = new DataOutputBuffer();
        DecoratedKey key = rows.get(0).getKey();

        Set<SSTable> sstables = new HashSet<SSTable>();
        for (IteratingRow row : rows)
            sstables.add(row.sstable);
        boolean shouldPurge = major || !cfs.isKeyInRemainingSSTables(key, sstables);

        try {
            if (rows.size() > 1 || shouldPurge) {
                ColumnFamily cf = null;
                for (IteratingRow row : rows) {
                    ColumnFamily thisCF;
                    try {
                        thisCF = row.getColumnFamily();
                    } catch (IOException e) {
                        logger.error("Skipping row " + key + " in " + row.getPath(), e);
                        continue;
                    }
                    if (cf == null) {
                        cf = thisCF;
                    } else {
                        cf.addAll(thisCF);
                    }
                }
                ColumnFamily cfPurged = shouldPurge ? ColumnFamilyStore.removeDeleted(cf, gcBefore) : cf;
                if (cfPurged == null)
                    return null;
                ColumnFamily.serializer().serializeWithIndexes(cfPurged, headerBuffer, buffer,
                        cfs.getCFMetaData().compressAlgo); // BIGDATA
            } else {
                assert rows.size() == 1;
                try {
                    rows.get(0).echoData(buffer);
                } catch (IOException e) {
                    throw new IOError(e);
                }
            }
        } finally {
            rows.clear();
            if ((row++ % 1000) == 0) {
                bytesRead = 0;
                for (SSTableScanner scanner : getScanners()) {
                    bytesRead += scanner.getFilePointer();
                }
            }
        }
        return new CompactedRow(key, headerBuffer, buffer);
    }

    public void close() throws IOException {
        for (SSTableScanner scanner : getScanners()) {
            scanner.close();
        }
    }

    protected Iterable<SSTableScanner> getScanners() {
        return ((CollatingIterator) source).getIterators();
    }

    public long getTotalBytes() {
        return totalBytes;
    }

    public long getBytesRead() {
        return bytesRead;
    }

    public static class CompactedRow {
        public final DecoratedKey key;
        public final DataOutputBuffer headerBuffer; // BIGDATA: add headerBuffer
        public final DataOutputBuffer buffer;

        public CompactedRow(DecoratedKey key, DataOutputBuffer headerBuffer, DataOutputBuffer buffer) // BIGDATA: add headerBuffer
        {
            this.key = key;
            this.headerBuffer = headerBuffer; // BIGDATA: add headerBuffer
            this.buffer = buffer;
        }
    }
}