Examples of TupleBrowser

jdbm.helper.TupleBrowser
Browser to traverse a collection of tuples. The browser allows for forward and reverse order traversal. @author Alex Boisvert @version $Id: TupleBrowser.java,v 1.2 2001/05/19 14:02:00 boisvert Exp $
org.teiid.common.buffer.TupleBrowser
Implements intelligent browsing over a {@link STree}TODO: this is not as efficient as it should be over partial matches

Examples of jdbm.helper.TupleBrowser

        assertNotNull( bt.find( "8" ) );
        assertNull( bt.find( "9" ) );


        // browse will position us right after "4" and getNext() will return 8
        // since "5", "6", and "7" do not exist
        TupleBrowser browser = bt.browse( "5" );
        assertNotNull( browser );
        Tuple tuple = new Tuple();
        browser.getNext( tuple );
        assertEquals( "8", tuple.getKey() );


        // browse will position us right after "1" and getNext() will return 2
        // since "2" exists.
        browser = bt.browse( "2" );
        assertNotNull( browser );
        tuple = new Tuple();
        browser.getNext( tuple );
        assertEquals( "2", tuple.getKey() );


        // browse will position us right after "8" and getNext() will null
        // since nothing else exists past 8.  We've come to the end.
        browser = bt.browse( "9" );
        assertNotNull( browser );
        tuple = new Tuple();
        browser.getNext( tuple );
        assertNull( tuple.getKey() );


        // browse will position us right before "1" and getPrevious() will
        // null since nothing else exists before 1.  We've come to the end.
        // getNext() will however return "1".
        browser = bt.browse( "0" );
        assertNotNull( browser );
        tuple = new Tuple();
        browser.getPrevious( tuple );
        assertNull( tuple.getKey() );
        browser.getNext( tuple );
        assertEquals( "1", tuple.getKey() );
    }

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Examples of jdbm.helper.TupleBrowser

        bt.insert( 0, 3, true );
        bt.insert( 30, 3, true );
        bt.insert( 25, 3, true );


        Tuple tuple = new Tuple();
        TupleBrowser browser = bt.browse( null );
        assertTrue( browser.getPrevious( tuple ) );
        //noinspection AssertEqualsBetweenInconvertibleTypes
        assertEquals( 30, tuple.getKey() );


        assertTrue( browser.getPrevious( tuple ) );
        //noinspection AssertEqualsBetweenInconvertibleTypes
        assertEquals( 25, tuple.getKey() );


        assertTrue( browser.getNext( tuple ) );
        //noinspection AssertEqualsBetweenInconvertibleTypes
        assertEquals( "If this works the jdbm bug is gone: will start to return " +
            "30 instead as expected for correct operation", 25, tuple.getKey() );
    }

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Examples of jdbm.helper.TupleBrowser

        assertNotNull( bt.find( "8" ) );
        assertNull( bt.find( "9" ) );


        // browse will position us right after "4" and getNext() will return 8
        // since "5", "6", and "7" do not exist
        TupleBrowser browser = bt.browse( "5" );
        assertNotNull( browser );
        Tuple tuple = new Tuple();
        browser.getNext( tuple );
        assertEquals( "8", tuple.getKey() );


        // browse will position us right after "1" and getNext() will return 2
        // since "2" exists.
        browser = bt.browse( "2" );
        assertNotNull( browser );
        tuple = new Tuple();
        browser.getNext( tuple );
        assertEquals( "2", tuple.getKey() );


        // browse will position us right after "8" and getNext() will null
        // since nothing else exists past 8.  We've come to the end.
        browser = bt.browse( "9" );
        assertNotNull( browser );
        tuple = new Tuple();
        browser.getNext( tuple );
        assertNull( tuple.getKey() );


        // browse will position us right before "1" and getPrevious() will
        // null since nothing else exists before 1.  We've come to the end.
        // getNext() will however return "1".
        browser = bt.browse( "0" );
        assertNotNull( browser );
        tuple = new Tuple();
        browser.getPrevious( tuple );
        assertNull( tuple.getKey() );
        browser.getNext( tuple );
        assertEquals( "1", tuple.getKey() );
    }

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Examples of jdbm.helper.TupleBrowser

        {
            return null;
        }


        Tuple tuple = new Tuple( null, null );
        TupleBrowser browser = rootPage.find( _height, key );


        if ( browser.getNext( tuple ) )
        {
            // find returns the matching key or the next ordered key, so we must
            // check if we have an exact match
            if ( _comparator.compare( key, tuple.getKey() ) != 0 )
            {

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Examples of jdbm.helper.TupleBrowser

     *         greater entry was found.
     */
    public synchronized Tuple findGreaterOrEqual( Object key ) throws IOException
    {
        Tuple tuple;
        TupleBrowser browser;


        if ( key == null )
        {
            // there can't be a key greater than or equal to "null"
            // because null is considered an infinite key.
            return null;
        }


        tuple = new Tuple( null, null );
        browser = browse( key );
        if ( browser.getNext( tuple ) )
        {
            return tuple;
        }
        else
        {

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Examples of jdbm.helper.TupleBrowser

        BPage rootPage = getRoot();
        if ( rootPage == null )
        {
            return EmptyBrowser.INSTANCE;
        }
        TupleBrowser browser = rootPage.findFirst();
        return browser;
    }

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Examples of jdbm.helper.TupleBrowser

        BPage rootPage = getRoot();
        if ( rootPage == null )
        {
            return EmptyBrowser.INSTANCE;
        }
        TupleBrowser browser = rootPage.find( _height, key );
        return browser;
    }

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Examples of jdbm.helper.TupleBrowser

             * key argument supplied.  We use this key to advance a browser to
             * that tuple and scan down to lesser Tuples until we hit one
             * that is less than the key argument supplied.  Usually this will
             * be the previous tuple if it exists.
             */
            TupleBrowser browser = bt.browse( tuple.getKey() );
            
            if ( browser.getPrevious( tuple ) )
            {
                return true;
            }
        }

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Examples of jdbm.helper.TupleBrowser

    @SuppressWarnings("unchecked")
    private boolean btreeHas( BTree tree, V key, boolean isGreaterThan ) throws IOException
    {
        jdbm.helper.Tuple tuple = new jdbm.helper.Tuple();
        
        TupleBrowser browser = tree.browse( key );
        if ( isGreaterThan )
        {
            return browser.getNext( tuple );
        }
        else
        {
            if ( browser.getPrevious( tuple ) )
            {
                return true;
            }
            else
            {
                /*
                 * getPrevious() above fails which means the browser has is
                 * before the first Tuple of the btree.  A call to getNext()
                 * should work every time.
                 */
                browser.getNext( tuple );


                /*
                 * Since the browser is positioned now on the Tuple with the
                 * smallest key we just need to check if it equals this key
                 * which is the only chance for returning true.

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Examples of jdbm.helper.TupleBrowser


    @SuppressWarnings("unchecked")
    private ArrayTree<V> convertToArrayTree( BTree bTree ) throws IOException
    {
        ArrayTree<V> avlTree = new ArrayTree<V>( valueComparator );
        TupleBrowser browser = bTree.browse();
        jdbm.helper.Tuple tuple = new jdbm.helper.Tuple();
        
        while ( browser.getNext( tuple ) )
        {
            avlTree.insert( ( V ) tuple.getKey() );
        }


        return avlTree;

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