| /* Copyright 2016 Google Inc. All Rights Reserved. |
| |
| Distributed under MIT license. |
| See file LICENSE for detail or copy at https://opensource.org/licenses/MIT |
| */ |
| |
| package org.brotli.integration; |
| |
| import org.brotli.dec.BrotliInputStream; |
| import java.io.FileInputStream; |
| import java.io.FileNotFoundException; |
| import java.io.FilterInputStream; |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.math.BigInteger; |
| import java.util.concurrent.atomic.AtomicInteger; |
| import java.util.zip.ZipEntry; |
| import java.util.zip.ZipInputStream; |
| |
| /** |
| * Decompress files and (optionally) checks their checksums. |
| * |
| * <p> File are read from ZIP archive passed as an array of bytes. Multiple checkers negotiate about |
| * task distribution via shared AtomicInteger counter. |
| * <p> All entries are expected to be valid brotli compressed streams and output CRC64 checksum |
| * is expected to match the checksum hex-encoded in the first part of entry name. |
| */ |
| public class BundleChecker implements Runnable { |
| private final AtomicInteger nextJob; |
| private final InputStream input; |
| private final boolean sanityCheck; |
| |
| /** |
| * @param sanityCheck do not calculate checksum and ignore {@link IOException}. |
| */ |
| public BundleChecker(InputStream input, AtomicInteger nextJob, boolean sanityCheck) { |
| this.input = input; |
| this.nextJob = nextJob; |
| this.sanityCheck = sanityCheck; |
| } |
| |
| /** ECMA CRC64 polynomial. */ |
| private static final long CRC_64_POLY = |
| new BigInteger("C96C5795D7870F42", 16).longValue(); |
| |
| /** |
| * Rolls CRC64 calculation. |
| * |
| * <p> {@code CRC64(data) = -1 ^ updateCrc64((... updateCrc64(-1, firstBlock), ...), lastBlock);} |
| * <p> This simple and reliable checksum is chosen to make is easy to calculate the same value |
| * across the variety of languages (C++, Java, Go, ...). |
| */ |
| private static long updateCrc64(long crc, byte[] data, int offset, int length) { |
| for (int i = offset; i < offset + length; ++i) { |
| long c = (crc ^ (long) (data[i] & 0xFF)) & 0xFF; |
| for (int k = 0; k < 8; k++) { |
| c = ((c & 1) == 1) ? CRC_64_POLY ^ (c >>> 1) : c >>> 1; |
| } |
| crc = c ^ (crc >>> 8); |
| } |
| return crc; |
| } |
| |
| private long decompressAndCalculateCrc(ZipInputStream input) throws IOException { |
| /* Do not allow entry readers to close the whole ZipInputStream. */ |
| FilterInputStream entryStream = new FilterInputStream(input) { |
| @Override |
| public void close() {} |
| }; |
| |
| long crc = -1; |
| byte[] buffer = new byte[65536]; |
| BrotliInputStream decompressedStream = new BrotliInputStream(entryStream); |
| while (true) { |
| int len = decompressedStream.read(buffer); |
| if (len <= 0) { |
| break; |
| } |
| crc = updateCrc64(crc, buffer, 0, len); |
| } |
| decompressedStream.close(); |
| return ~crc; |
| } |
| |
| @Override |
| public void run() { |
| String entryName = ""; |
| ZipInputStream zis = new ZipInputStream(input); |
| try { |
| int entryIndex = 0; |
| ZipEntry entry; |
| int jobIndex = nextJob.getAndIncrement(); |
| while ((entry = zis.getNextEntry()) != null) { |
| if (entry.isDirectory()) { |
| continue; |
| } |
| if (entryIndex++ != jobIndex) { |
| zis.closeEntry(); |
| continue; |
| } |
| entryName = entry.getName(); |
| int dotIndex = entryName.indexOf('.'); |
| String entryCrcString = (dotIndex == -1) ? entryName : entryName.substring(0, dotIndex); |
| long entryCrc = new BigInteger(entryCrcString, 16).longValue(); |
| try { |
| if (entryCrc != decompressAndCalculateCrc(zis) && !sanityCheck) { |
| throw new RuntimeException("CRC mismatch"); |
| } |
| } catch (IOException iox) { |
| if (!sanityCheck) { |
| throw new RuntimeException("Decompression failed", iox); |
| } |
| } |
| zis.closeEntry(); |
| entryName = ""; |
| jobIndex = nextJob.getAndIncrement(); |
| } |
| zis.close(); |
| input.close(); |
| } catch (Throwable ex) { |
| throw new RuntimeException(entryName, ex); |
| } |
| } |
| |
| public static void main(String[] args) throws FileNotFoundException { |
| int argsOffset = 0; |
| boolean sanityCheck = false; |
| if (args.length != 0) { |
| if (args[0].equals("-s")) { |
| sanityCheck = true; |
| argsOffset = 1; |
| } |
| } |
| if (args.length == argsOffset) { |
| throw new RuntimeException("Usage: BundleChecker [-s] <fileX.zip> ..."); |
| } |
| for (int i = argsOffset; i < args.length; ++i) { |
| new BundleChecker(new FileInputStream(args[i]), new AtomicInteger(0), sanityCheck).run(); |
| } |
| } |
| } |