| /* |
| * Copyright (C) 2020 The Android Open Source Project |
| * |
| * Licensed 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 com.android.zipflinger; |
| |
| import com.android.annotations.NonNull; |
| import java.io.IOException; |
| import java.nio.ByteBuffer; |
| import java.nio.ByteOrder; |
| import java.nio.channels.FileChannel; |
| |
| public class Zip64Eocd { |
| private static final int SIGNATURE = 0x06064b50; |
| static final int SIZE = 56; |
| |
| private long numEntries; |
| private Location cdLocation; |
| |
| public Zip64Eocd(long numEntries, @NonNull Location cdLocation) { |
| this.numEntries = numEntries; |
| this.cdLocation = cdLocation; |
| } |
| |
| private Zip64Eocd() { |
| this(0, Location.INVALID); |
| } |
| |
| @NonNull |
| public Location write(@NonNull ZipWriter writer) throws IOException { |
| ByteBuffer eocd = ByteBuffer.allocate(SIZE).order(ByteOrder.LITTLE_ENDIAN); |
| eocd.putInt(SIGNATURE); |
| eocd.putLong(SIZE - 12); // Peculiar specs mandate not to include 12 bytes already written. |
| eocd.putShort((short) 0); // Version made by |
| eocd.putShort(Zip64.VERSION_NEEDED); // Version needed to extract |
| eocd.putInt(0); // disk # |
| eocd.putInt(0); // total # of disks |
| eocd.putLong(numEntries); // # entries in cd on this disk |
| eocd.putLong(numEntries); // total # entries in cd |
| eocd.putLong(cdLocation.size()); // CD offset. |
| eocd.putLong(cdLocation.first); // size of CD. |
| eocd.rewind(); |
| |
| long position = writer.position(); |
| writer.write(eocd); |
| |
| return new Location(position, SIZE); |
| } |
| |
| @NonNull |
| Location getCdLocation() { |
| return cdLocation; |
| } |
| |
| @NonNull |
| static Zip64Eocd parse(@NonNull FileChannel channel, long eocdOffset) throws IOException { |
| Zip64Eocd zip64Eocd = new Zip64Eocd(); |
| long fileSize = channel.size(); |
| if (eocdOffset < 0 || eocdOffset + SIZE > fileSize) { |
| return zip64Eocd; |
| } |
| |
| ByteBuffer buffer = ByteBuffer.allocate(SIZE).order(ByteOrder.LITTLE_ENDIAN); |
| channel.read(buffer, eocdOffset); |
| buffer.rewind(); |
| |
| int signature = buffer.getInt(); // signature |
| if (signature != SIGNATURE) { |
| return zip64Eocd; |
| } |
| |
| // Skip uninteresting fields |
| buffer.position(buffer.position() + 28); |
| // eocd.getLong(); 8 // size of zip64EOCD |
| // eocd.getShort(); 2 // Version made by |
| // eocd.getShort(); 2 // Version needed to extract |
| // eocd.getInt(); 4 // disk # |
| // eocd.getInt(); 4 // total # of disks |
| // eocd.getLong(); 8 // # entries in cd on this disk |
| long numEntries = buffer.getLong(); // total # entries in cd |
| long size = Ints.ulongToLong(buffer.getLong()); // size of CD. |
| long offset = Ints.ulongToLong(buffer.getLong()); // CD offset. |
| |
| zip64Eocd.numEntries = numEntries; |
| zip64Eocd.cdLocation = new Location(offset, size); |
| return zip64Eocd; |
| } |
| } |