import org.apache.cassandra.db.compaction.ICompactionScanner; //导入依赖的package包/类
/** see CASSANDRA-5407 */
@Test
public void testGetScannerForNoIntersectingRanges()
{
    Keyspace keyspace = Keyspace.open("Keyspace1");
    ColumnFamilyStore store = keyspace.getColumnFamilyStore("Standard1");
    ByteBuffer key = ByteBufferUtil.bytes(String.valueOf("k1"));
    RowMutation rm = new RowMutation("Keyspace1", key);
    rm.add("Standard1", ByteBufferUtil.bytes("xyz"), ByteBufferUtil.bytes("abc"), 0);
    rm.apply();
    store.forceBlockingFlush();
    boolean foundScanner = false;
    for (SSTableReader s : store.getSSTables())
    {
        ICompactionScanner scanner = s.getScanner(new Range<Token>(t(0), t(1), s.partitioner), null);
        scanner.next(); // throws exception pre 5407
        foundScanner = true;
    }
    assertTrue(foundScanner);
}
 

import org.apache.cassandra.db.compaction.ICompactionScanner; //导入依赖的package包/类
private static void assertScanContainsRanges(ICompactionScanner scanner, int ... rangePairs)
{
    assert rangePairs.length % 2 == 0;

    for (int pairIdx = 0; pairIdx < rangePairs.length; pairIdx += 2)
    {
        int rangeStart = rangePairs[pairIdx];
        int rangeEnd = rangePairs[pairIdx + 1];

        for (int expected = rangeStart; expected <= rangeEnd; expected++)
        {
            assertTrue(String.format("Expected to see key %03d", expected), scanner.hasNext());
            assertEquals(toKey(expected), new String(scanner.next().getKey().key.array()));
        }
    }
    assertFalse(scanner.hasNext());
}
 

import org.apache.cassandra.db.compaction.ICompactionScanner; //导入依赖的package包/类
/** see CASSANDRA-5407 */
@Test
public void testGetScannerForNoIntersectingRanges()
{
    Keyspace keyspace = Keyspace.open(KEYSPACE1);
    ColumnFamilyStore store = keyspace.getColumnFamilyStore("Standard1");
    ByteBuffer key = ByteBufferUtil.bytes(String.valueOf("k1"));
    Mutation rm = new Mutation(KEYSPACE1, key);
    rm.add("Standard1", cellname("xyz"), ByteBufferUtil.bytes("abc"), 0);
    rm.applyUnsafe();
    store.forceBlockingFlush();
    boolean foundScanner = false;
    for (SSTableReader s : store.getSSTables())
    {
        ICompactionScanner scanner = s.getScanner(new Range<Token>(t(0), t(1), s.partitioner), null);
        scanner.next(); // throws exception pre 5407
        foundScanner = true;
    }
    assertTrue(foundScanner);
}
 

import org.apache.cassandra.db.compaction.ICompactionScanner; //导入依赖的package包/类
private static void assertScanContainsRanges(ICompactionScanner scanner, int ... rangePairs)
{
    assert rangePairs.length % 2 == 0;

    for (int pairIdx = 0; pairIdx < rangePairs.length; pairIdx += 2)
    {
        int rangeStart = rangePairs[pairIdx];
        int rangeEnd = rangePairs[pairIdx + 1];

        for (int expected = rangeStart; expected <= rangeEnd; expected++)
        {
            assertTrue(String.format("Expected to see key %03d", expected), scanner.hasNext());
            assertEquals(toKey(expected), new String(scanner.next().getKey().getKey().array()));
        }
    }
    assertFalse(scanner.hasNext());
}
 

import org.apache.cassandra.db.compaction.ICompactionScanner; //导入依赖的package包/类
/** see CASSANDRA-5407 */
@Test
public void testGetScannerForNoIntersectingRanges()
{
    Keyspace keyspace = Keyspace.open("Keyspace1");
    ColumnFamilyStore store = keyspace.getColumnFamilyStore("Standard1");
    ByteBuffer key = ByteBufferUtil.bytes(String.valueOf("k1"));
    Mutation rm = new Mutation("Keyspace1", key);
    rm.add("Standard1", cellname("xyz"), ByteBufferUtil.bytes("abc"), 0);
    rm.apply();
    store.forceBlockingFlush();
    boolean foundScanner = false;
    for (SSTableReader s : store.getSSTables())
    {
        ICompactionScanner scanner = s.getScanner(new Range<Token>(t(0), t(1), s.partitioner), null);
        scanner.next(); // throws exception pre 5407
        foundScanner = true;
    }
    assertTrue(foundScanner);
}
 

import org.apache.cassandra.db.compaction.ICompactionScanner; //导入依赖的package包/类
/**
 * Direct I/O SSTableScanner over a defined range of tokens.
 *
 * @param range the range of keys to cover
 * @return A Scanner for seeking over the rows of the SSTable.
 */
public ICompactionScanner getScanner(Range<Token> range, RateLimiter limiter)
{
    if (range == null)
        return getScanner(limiter);
    return getScanner(Collections.singletonList(range), limiter);
}
 

import org.apache.cassandra.db.compaction.ICompactionScanner; //导入依赖的package包/类
@Test
public void testSingleKeyMultipleRanges()
{
    Keyspace keyspace = Keyspace.open(KEYSPACE);
    ColumnFamilyStore store = keyspace.getColumnFamilyStore(TABLE);
    store.clearUnsafe();

    // disable compaction while flushing
    store.disableAutoCompaction();

    insertRowWithKey(205);
    store.forceBlockingFlush();

    assertEquals(1, store.getSSTables().size());
    SSTableReader sstable = store.getSSTables().iterator().next();

    // full range scan
    SSTableScanner fullScanner = sstable.getScanner();
    assertScanContainsRanges(fullScanner, 205, 205);

    // scan three ranges separately
    ICompactionScanner scanner = sstable.getScanner(makeRanges(101, 109,
                                                               201, 209), null);

    // this will currently fail
    assertScanContainsRanges(scanner, 205, 205);
}
 

import org.apache.cassandra.db.compaction.ICompactionScanner; //导入依赖的package包/类
/**
* Direct I/O SSTableScanner over a defined range of tokens.
*
* @param range the range of keys to cover
* @return A Scanner for seeking over the rows of the SSTable.
*/
public ICompactionScanner getDirectScanner(Range<Token> range, RateLimiter limiter)
{
    if (range == null)
        return getDirectScanner(limiter);

    Iterator<Pair<Long, Long>> rangeIterator = getPositionsForRanges(Collections.singletonList(range)).iterator();
    return rangeIterator.hasNext()
           ? new SSTableBoundedScanner(this, true, rangeIterator, limiter)
           : new EmptyCompactionScanner(getFilename());
}