PointerV5.java

/* ====================================================================
   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.
==================================================================== */

package org.apache.poi.hdgf.pointers;

import org.apache.poi.util.LittleEndian;

/**
 * A Pointer from v5
 */
public final class PointerV5 extends Pointer {
    // TODO Are these getters correct?
    public boolean destinationHasStrings() {
        return isFormatBetween(0x40, 0x50);
    }
    
    public boolean destinationHasPointers() {
        return switch (getType()) {
            case 20 -> true;
            case 22 -> false;
            default -> isFormatBetween(0x1d, 0x1f) || isFormatBetween(0x50, 0x60);
        };
    }
 
    public boolean destinationHasChunks() {
        return switch (getType()) {
            case 21 -> true;
            case 24 -> true;
            default -> isFormatBetween(0xd0, 0xdf);
        };
    }

    public boolean destinationCompressed() {
        // Apparently, it's the second least significant bit
        return (getFormat() & 2) > 0;
    }

    /**
     * With v6 pointers, the on-disk size is 16 bytes
     */
    public int getSizeInBytes() { return 16; }

    /**
     * Depends on the type only, not stored
     */
    public int getNumPointersOffset(byte[] data) {
        return switch (getType()) {
            case 0x1d, 0x4e -> 30;
            case 0x1e -> 54;
            case 0x14 -> 130;
            default -> 10;
        };
    }
    /**
     * 16 bit int at the given offset
     */
    public int getNumPointers(int offset, byte[] data) {
        // V5 stores it as a 16 bit number at the offset
        return LittleEndian.getShort(data, offset);
    }
    /**
     * Just the 2 bytes of the number of pointers
     */
    public int getPostNumPointersSkip() {
        return 2;
    }
}