void loadBtree()

in mavibot/src/main/java/org/apache/directory/mavibot/btree/RecordManager.java [1005:1106]
58 lines of code
3 McCabe index (conditional complexity)

    /* no qualifier */<K, V> void loadBtree( PageIO[] pageIos, BTree btree, BTree<K, V> parentBTree )
        throws EndOfFileExceededException,
        IOException, ClassNotFoundException, IllegalAccessException, InstantiationException, IllegalArgumentException,
        SecurityException, NoSuchFieldException
    {
        long dataPos = 0L;

        // Process the B-tree header
        BTreeHeader<K, V> btreeHeader = new BTreeHeader<K, V>();
        btreeHeader.setBtree( btree );

        // The BtreeHeader offset
        btreeHeader.setBTreeHeaderOffset( pageIos[0].getOffset() );

        // The B-tree current revision
        long revision = readLong( pageIos, dataPos );
        btreeHeader.setRevision( revision );
        dataPos += LONG_SIZE;

        // The nb elems in the tree
        long nbElems = readLong( pageIos, dataPos );
        btreeHeader.setNbElems( nbElems );
        dataPos += LONG_SIZE;

        // The B-tree rootPage offset
        long rootPageOffset = readLong( pageIos, dataPos );
        btreeHeader.setRootPageOffset( rootPageOffset );
        dataPos += LONG_SIZE;

        // The B-tree information offset
        long btreeInfoOffset = readLong( pageIos, dataPos );

        // Now, process the common informations
        PageIO[] infoPageIos = readPageIOs( btreeInfoOffset, Long.MAX_VALUE );
        ( ( PersistedBTree<K, V> ) btree ).setBtreeInfoOffset( infoPageIos[0].getOffset() );
        dataPos = 0L;

        // The B-tree page size
        int btreePageSize = readInt( infoPageIos, dataPos );
        BTreeFactory.setPageSize( btree, btreePageSize );
        dataPos += INT_SIZE;

        // The tree name
        ByteBuffer btreeNameBytes = readBytes( infoPageIos, dataPos );
        dataPos += INT_SIZE + btreeNameBytes.limit();
        String btreeName = Strings.utf8ToString( btreeNameBytes );
        BTreeFactory.setName( btree, btreeName );

        // The keySerializer FQCN
        ByteBuffer keySerializerBytes = readBytes( infoPageIos, dataPos );
        dataPos += INT_SIZE + keySerializerBytes.limit();

        String keySerializerFqcn = "";

        if ( keySerializerBytes != null )
        {
            keySerializerFqcn = Strings.utf8ToString( keySerializerBytes );
        }

        BTreeFactory.setKeySerializer( btree, keySerializerFqcn );

        // The valueSerialier FQCN
        ByteBuffer valueSerializerBytes = readBytes( infoPageIos, dataPos );

        String valueSerializerFqcn = "";
        dataPos += INT_SIZE + valueSerializerBytes.limit();

        if ( valueSerializerBytes != null )
        {
            valueSerializerFqcn = Strings.utf8ToString( valueSerializerBytes );
        }

        BTreeFactory.setValueSerializer( btree, valueSerializerFqcn );

        // The B-tree allowDuplicates flag
        int allowDuplicates = readInt( infoPageIos, dataPos );
        ( ( PersistedBTree<K, V> ) btree ).setAllowDuplicates( allowDuplicates != 0 );
        dataPos += INT_SIZE;

        // Set the recordManager in the btree
        ( ( PersistedBTree<K, V> ) btree ).setRecordManager( this );

        // Set the current revision to the one stored in the B-tree header
        // Here, we have to tell the BTree to keep this revision in the
        // btreeRevisions Map, thus the 'true' parameter at the end.
        ( ( PersistedBTree<K, V> ) btree ).storeRevision( btreeHeader, true );

        // Now, init the B-tree
        ( ( PersistedBTree<K, V> ) btree ).init( parentBTree );

        // Update the BtreeHeaders Maps
        currentBTreeHeaders.put( btree.getName(), ( ( PersistedBTree<K, V> ) btree ).getBtreeHeader() );
        newBTreeHeaders.put( btree.getName(), ( ( PersistedBTree<K, V> ) btree ).getBtreeHeader() );

        // Read the rootPage pages on disk
        PageIO[] rootPageIos = readPageIOs( rootPageOffset, Long.MAX_VALUE );

        Page<K, V> btreeRoot = readPage( btree, rootPageIos );
        BTreeFactory.setRecordManager( btree, this );

        BTreeFactory.setRootPage( btree, btreeRoot );
    }