cassandra/test/unit/org/apache/cassandra/io/SSTableTest.java

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* to you under the Apache License, Version 2.0 (the
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package org.apache.cassandra.io;

import java.io.File;
import java.io.IOException;
import java.util.*;

import org.junit.Test;
import static org.junit.Assert.*;

import org.apache.cassandra.CleanupHelper;
import org.apache.cassandra.db.DecoratedKey;
import org.apache.cassandra.dht.OrderPreservingPartitioner;

import com.google.common.base.Predicate;
import com.google.common.base.Predicates;

public class SSTableTest extends CleanupHelper
{
    @Test
    public void testSingleWrite() throws IOException {
        // write test data
        String key = Integer.toString(1);
        byte[] bytes = new byte[1024];
        new Random().nextBytes(bytes);

        TreeMap<String, byte[]> map = new TreeMap<String,byte[]>();
        map.put(key, bytes);
        SSTableReader ssTable = SSTableUtils.writeSSTable("singlewrite", map, 1,
                                                          new OrderPreservingPartitioner(), 0.01);

        // verify
        verifySingle(ssTable, bytes, key);
        SSTableReader.reopenUnsafe(); // force reloading the index
        verifySingle(ssTable, bytes, key);
    }

    private void verifySingle(SSTableReader sstable, byte[] bytes, String key) throws IOException
    {
        BufferedRandomAccessFile file = new BufferedRandomAccessFile(sstable.path, "r");
        file.seek(sstable.getPosition(sstable.partitioner.decorateKey(key)));
        assert key.equals(file.readUTF());
        int size = file.readInt();
        byte[] bytes2 = new byte[size];
        file.readFully(bytes2);
        assert Arrays.equals(bytes2, bytes);
    }

    @Test
    public void testManyWrites() throws IOException {
        TreeMap<String, byte[]> map = new TreeMap<String,byte[]>();
        for ( int i = 100; i < 1000; ++i )
        {
            map.put(Integer.toString(i), ("Avinash Lakshman is a good man: " + i).getBytes());
        }

        // write
        SSTableReader ssTable = SSTableUtils.writeSSTable("manywrites", map, 1000,
                                                          new OrderPreservingPartitioner(), 0.01);

        // verify
        verifyMany(ssTable, map);
        SSTableReader.reopenUnsafe(); // force reloading the index
        verifyMany(ssTable, map);
    }

    private void verifyMany(SSTableReader sstable, TreeMap<String, byte[]> map) throws IOException
    {
        List<String> keys = new ArrayList<String>(map.keySet());
        Collections.shuffle(keys);
        BufferedRandomAccessFile file = new BufferedRandomAccessFile(sstable.path, "r");
        for (String key : keys)
        {
            file.seek(sstable.getPosition(sstable.partitioner.decorateKey(key)));
            assert key.equals(file.readUTF());
            int size = file.readInt();
            byte[] bytes2 = new byte[size];
            file.readFully(bytes2);
            assert Arrays.equals(bytes2, map.get(key));
        }
    }

    @Test
    public void testGetIndexedDecoratedKeysFor() throws IOException {
        final String ssname = "indexedkeys";

        int numkeys = 1000;
        TreeMap<String, byte[]> map = new TreeMap<String,byte[]>();
        for ( int i = 0; i < numkeys; i++ )
        {
            map.put(Integer.toString(i), "blah".getBytes());
        }

        // write
        SSTableReader ssTable = SSTableUtils.writeSSTable(ssname, map, 1000,
                                                          new OrderPreservingPartitioner(), 0.01);


        // verify
        Predicate<SSTable> cfpred;
        Predicate<DecoratedKey> dkpred;

        cfpred = new Predicate<SSTable>() {
            public boolean apply(SSTable ss)
            {
                return ss.getColumnFamilyName().equals(ssname);
            }
            };
        dkpred = Predicates.alwaysTrue();
        int actual = SSTableReader.getIndexedDecoratedKeysFor(cfpred, dkpred).size();
        assert 0 < actual;
        assert actual <= Math.ceil((double)numkeys/SSTableReader.indexInterval());
    }
}