org.tukaani.xz.XZ Java Examples

public static Check getInstance(int checkType)
        throws UnsupportedOptionsException {
    switch (checkType) {
        case XZ.CHECK_NONE:
            return new None();

        case XZ.CHECK_CRC32:
            return new CRC32();

        case XZ.CHECK_CRC64:
            return new CRC64();

        case XZ.CHECK_SHA256:
            try {
                return new SHA256();
            } catch (java.security.NoSuchAlgorithmException e) {}

            break;
    }

    throw new UnsupportedOptionsException(
            "Unsupported Check ID " + checkType);
}
 

public static StreamFlags decodeStreamHeader(byte[] buf)
        throws IOException {
    for (int i = 0; i < XZ.HEADER_MAGIC.length; ++i)
        if (buf[i] != XZ.HEADER_MAGIC[i])
            throw new XZFormatException();

    if (!isCRC32Valid(buf, XZ.HEADER_MAGIC.length, 2,
                      XZ.HEADER_MAGIC.length + 2))
        throw new CorruptedInputException("XZ Stream Header is corrupt");

    try {
        return decodeStreamFlags(buf, XZ.HEADER_MAGIC.length);
    } catch (UnsupportedOptionsException e) {
        throw new UnsupportedOptionsException(
                "Unsupported options in XZ Stream Header");
    }
}
 

public static Check getInstance(int checkType)
        throws UnsupportedOptionsException {
    switch (checkType) {
        case XZ.CHECK_NONE:
            return new None();

        case XZ.CHECK_CRC32:
            return new CRC32();

        case XZ.CHECK_CRC64:
            return new CRC64();

        case XZ.CHECK_SHA256:
            try {
                return new SHA256();
            } catch (java.security.NoSuchAlgorithmException e) {}

            break;
    }

    throw new UnsupportedOptionsException(
            "Unsupported Check ID " + checkType);
}
 

public static StreamFlags decodeStreamHeader(byte[] buf)
        throws IOException {
    for (int i = 0; i < XZ.HEADER_MAGIC.length; ++i)
        if (buf[i] != XZ.HEADER_MAGIC[i])
            throw new XZFormatException();

    if (!isCRC32Valid(buf, XZ.HEADER_MAGIC.length, 2,
                      XZ.HEADER_MAGIC.length + 2))
        throw new CorruptedInputException("XZ Stream Header is corrupt");

    try {
        return decodeStreamFlags(buf, XZ.HEADER_MAGIC.length);
    } catch (UnsupportedOptionsException e) {
        throw new UnsupportedOptionsException(
                "Unsupported options in XZ Stream Header");
    }
}
 

public static StreamFlags decodeStreamFooter(byte[] buf)
        throws IOException {
    if (buf[10] != XZ.FOOTER_MAGIC[0] || buf[11] != XZ.FOOTER_MAGIC[1]) {
        // NOTE: The exception could be XZFormatException too.
        // It depends on the situation which one is better.
        throw new CorruptedInputException("XZ Stream Footer is corrupt");
    }

    if (!isCRC32Valid(buf, 4, 6, 0))
        throw new CorruptedInputException("XZ Stream Footer is corrupt");

    StreamFlags streamFlags;
    try {
        streamFlags = decodeStreamFlags(buf, 8);
    } catch (UnsupportedOptionsException e) {
        throw new UnsupportedOptionsException(
                "Unsupported options in XZ Stream Footer");
    }

    streamFlags.backwardSize = 0;
    for (int i = 0; i < 4; ++i)
        streamFlags.backwardSize |= (buf[i + 4] & 0xFF) << (i * 8);

    streamFlags.backwardSize = (streamFlags.backwardSize + 1) * 4;

    return streamFlags;
}
 

public static StreamFlags decodeStreamFooter(byte[] buf)
        throws IOException {
    if (buf[10] != XZ.FOOTER_MAGIC[0] || buf[11] != XZ.FOOTER_MAGIC[1]) {
        // NOTE: The exception could be XZFormatException too.
        // It depends on the situation which one is better.
        throw new CorruptedInputException("XZ Stream Footer is corrupt");
    }

    if (!isCRC32Valid(buf, 4, 6, 0))
        throw new CorruptedInputException("XZ Stream Footer is corrupt");

    StreamFlags streamFlags;
    try {
        streamFlags = decodeStreamFlags(buf, 8);
    } catch (UnsupportedOptionsException e) {
        throw new UnsupportedOptionsException(
                "Unsupported options in XZ Stream Footer");
    }

    streamFlags.backwardSize = 0;
    for (int i = 0; i < 4; ++i)
        streamFlags.backwardSize |= (buf[i + 4] & 0xFF) << (i * 8);

    streamFlags.backwardSize = (streamFlags.backwardSize + 1) * 4;

    return streamFlags;
}
 

@Test
public void testXzStep() throws IOException {
  Path sourceFile =
      TestDataHelper.getTestDataScenario(this, "compression_test").resolve("step.data");
  File destinationFile = tmp.newFile("step.data.xz");

  XzStep step =
      new XzStep(
          TestProjectFilesystems.createProjectFilesystem(tmp.getRoot().toPath()),
          sourceFile,
          destinationFile.toPath(),
          /* compressionLevel -- for faster testing */ 1,
          /* keep */ true,
          XZ.CHECK_CRC32);

  ExecutionContext context = TestExecutionContext.newInstance();

  assertEquals(0, step.execute(context).getExitCode());

  ByteSource original = PathByteSource.asByteSource(sourceFile);
  ByteSource decompressed =
      new ByteSource() {
        @Override
        public InputStream openStream() throws IOException {
          return new XZInputStream(new FileInputStream(destinationFile));
        }
      };

  assertTrue(Files.exists(sourceFile));
  assertTrue(
      "Decompressed file must be identical to original.", original.contentEquals(decompressed));
}
 

@Test
public void testXzStepDeletesOriginal() throws IOException {
  Path sourceFileOriginal =
      TestDataHelper.getTestDataScenario(this, "compression_test").resolve("step.data");
  Path sourceFile = tmp.newFile("step.data").toPath();
  Files.copy(sourceFileOriginal, sourceFile, StandardCopyOption.REPLACE_EXISTING);
  File destinationFile = tmp.newFile("step.data.xz");

  XzStep step =
      new XzStep(
          TestProjectFilesystems.createProjectFilesystem(tmp.getRoot().toPath()),
          sourceFile,
          destinationFile.toPath(),
          /* compressionLevel -- for faster testing */ 1,
          /* keep */ false,
          XZ.CHECK_CRC32);

  ExecutionContext context = TestExecutionContext.newInstance();

  assertEquals(0, step.execute(context).getExitCode());

  ByteSource original = PathByteSource.asByteSource(sourceFileOriginal);
  ByteSource decompressed =
      new ByteSource() {
        @Override
        public InputStream openStream() throws IOException {
          return new XZInputStream(new FileInputStream(destinationFile));
        }
      };

  assertFalse(Files.exists(sourceFile));
  assertTrue(
      "Decompressed file must be identical to original.", original.contentEquals(decompressed));
}
 

/**
 * Creates an XzStep to compress a file with XZ at a user supplied compression level .
 *
 * <p>The destination file will be {@code sourceFile} with the added {@code .xz} extension.
 *
 * <p>Decompression will require up to 64MiB of RAM.
 *
 * @param sourceFile file to compress
 * @param compressionLevel value from 0 to 9. Higher values result in better compression, but also
 *     need more time to compress and will need more RAM to decompress.
 */
public XzStep(ProjectFilesystem filesystem, Path sourceFile, int compressionLevel) {
  this(
      filesystem,
      sourceFile,
      Paths.get(sourceFile + ".xz"),
      compressionLevel,
      /* keep */ false,
      XZ.CHECK_CRC32);
}
 

/**
 * Creates an XzStep to compress a file with the given XZ compression level and output path.
 *
 * <p>Decompression will require up to 64MiB of RAM.
 *
 * @param sourceFile file to compress
 * @param outputPath the desired output path.
 * @param compressionLevel level of compression (from 0-9)
 */
public XzStep(
    ProjectFilesystem filesystem, Path sourceFile, Path outputPath, int compressionLevel) {
  this(filesystem, sourceFile, outputPath, compressionLevel, /* keep */ false, XZ.CHECK_CRC32);
}