blob: 81d37c3bfc8d2115342070477f22c7c7128df429 [file] [log] [blame]
// Copyright 2015 The Bazel Authors. All rights reserved.
//
// 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.google.devtools.build.zip;
import java.io.IOException;
import java.io.InputStream;
import java.util.zip.ZipException;
class Zip64EndOfCentralDirectoryLocator {
static final int SIGNATURE = 0x07064b50;
static final int FIXED_DATA_SIZE = 20;
static final int SIGNATURE_OFFSET = 0;
static final int ZIP64_EOCD_DISK_OFFSET = 4;
static final int ZIP64_EOCD_OFFSET_OFFSET = 8;
static final int DISK_NUMBER_OFFSET = 16;
/**
* Read the Zip64 end of central directory locator from the input stream and parse additional
* {@link ZipFileData} from it.
*/
static ZipFileData read(InputStream in, ZipFileData file) throws IOException {
if (file == null) {
throw new NullPointerException();
}
byte[] fixedSizeData = new byte[FIXED_DATA_SIZE];
if (ZipUtil.readFully(in, fixedSizeData) != FIXED_DATA_SIZE) {
throw new ZipException(
"Unexpected end of file while reading Zip64 End of Central Directory Locator.");
}
if (!ZipUtil.arrayStartsWith(fixedSizeData, ZipUtil.intToLittleEndian(SIGNATURE))) {
throw new ZipException(String.format(
"Malformed Zip64 Central Directory Locator; does not start with %08x", SIGNATURE));
}
file.setZip64(true);
file.setZip64EndOfCentralDirectoryOffset(
ZipUtil.getUnsignedLong(fixedSizeData, ZIP64_EOCD_OFFSET_OFFSET));
return file;
}
/**
* Generates the raw byte data of the Zip64 end of central directory locator for the file.
*/
static byte[] create(ZipFileData file) {
byte[] buf = new byte[FIXED_DATA_SIZE];
ZipUtil.intToLittleEndian(buf, SIGNATURE_OFFSET, SIGNATURE);
ZipUtil.intToLittleEndian(buf, ZIP64_EOCD_DISK_OFFSET, 0);
ZipUtil.longToLittleEndian(buf, ZIP64_EOCD_OFFSET_OFFSET,
file.getZip64EndOfCentralDirectoryOffset());
ZipUtil.intToLittleEndian(buf, DISK_NUMBER_OFFSET, 1);
return buf;
}
}