import org.tukaani.xz.UnsupportedOptionsException; //导入依赖的package包/类
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);
}
 

import org.tukaani.xz.UnsupportedOptionsException; //导入依赖的package包/类
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");
    }
}
 

import org.tukaani.xz.UnsupportedOptionsException; //导入依赖的package包/类
@Override // ClientProtocol
public boolean delete(String src, boolean recursive) throws IOException {
  if (stateChangeLog.isDebugEnabled()) {
    stateChangeLog.debug(
        "*DIR* Namenode.delete: src=" + src + ", recursive=" + recursive);
  }

  boolean ret;
  if (namesystem.isLegacyDeleteEnabled()) {
    //ret = namesystem.incrementalDelete(src, recursive);
    throw new UnsupportedOptionsException("Old single transaction delete "
            + "is not supported ");
  } else {
    ret = namesystem.multiTransactionalDelete(src, recursive);
  }

  if (ret) {
    metrics.incrDeleteFileOps();
  }
  return ret;
}
 

import org.tukaani.xz.UnsupportedOptionsException; //导入依赖的package包/类
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);
}
 

import org.tukaani.xz.UnsupportedOptionsException; //导入依赖的package包/类
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");
	}
}
 

import org.tukaani.xz.UnsupportedOptionsException; //导入依赖的package包/类
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;
}
 

import org.tukaani.xz.UnsupportedOptionsException; //导入依赖的package包/类
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;
}
 

import org.tukaani.xz.UnsupportedOptionsException; //导入依赖的package包/类
private static StreamFlags decodeStreamFlags(byte[] buf, int off)
        throws UnsupportedOptionsException {
    if (buf[off] != 0x00 || (buf[off + 1] & 0xFF) >= 0x10)
        throw new UnsupportedOptionsException();

    StreamFlags streamFlags = new StreamFlags();
    streamFlags.checkType = buf[off + 1];

    return streamFlags;
}
 

import org.tukaani.xz.UnsupportedOptionsException; //导入依赖的package包/类
private static StreamFlags decodeStreamFlags(byte[] buf, int off)
		throws UnsupportedOptionsException {
	if (buf[off] != 0x00 || (buf[off + 1] & 0xFF) >= 0x10)
		throw new UnsupportedOptionsException();

	StreamFlags streamFlags = new StreamFlags();
	streamFlags.checkType = buf[off + 1];

	return streamFlags;
}