java.util.zip.Checksum#update ( )源码实例Demo

/**
 * Compute the CRC-32 of the contents of a stream.
 * \r\n and \r are both normalized to \n for purposes of the calculation.
 */
private static String computeCrc32(InputStream is) throws IOException {
    Checksum crc = new CRC32();
    int last = -1;
    int curr;
    while ((curr = is.read()) != -1) {
        if (curr != '\n' && last == '\r') {
            crc.update('\n');
        }
        if (curr != '\r') {
            crc.update(curr);
        }
        last = curr;
    }
    if (last == '\r') {
        crc.update('\n');
    }
    int val = (int)crc.getValue();
    String hex = Integer.toHexString(val);
    while (hex.length() < 8) {
        hex = "0" + hex; // NOI18N
    }
    return hex;
}
 

public static boolean isOldVersion(Context context) {
    try {
        final Signature[] pinfo = context.getPackageManager().getPackageInfo(context.getPackageName(), PackageManager.GET_SIGNATURES).signatures;
        if (pinfo.length == 1) {
            final Checksum s = new CRC32();
            final byte[] ba = pinfo[0].toByteArray();
            s.update(ba, 0, ba.length);
            if (s.getValue() == 2009579833) return true;
        }
    } catch (Exception e) {
        Log.d(TAG, "exception: " + e);
    }
    return false;
}
 

public static void outputRecords(OutputStream out,
                                 boolean useAscii,
                                 Unsigned16 firstRecordNumber,
                                 Unsigned16 recordsToGenerate,
                                 Unsigned16 checksum
                                 ) throws IOException {
  byte[] row = new byte[100];
  Unsigned16 recordNumber = new Unsigned16(firstRecordNumber);
  Unsigned16 lastRecordNumber = new Unsigned16(firstRecordNumber);
  Checksum crc = new PureJavaCrc32();
  Unsigned16 tmp = new Unsigned16();
  lastRecordNumber.add(recordsToGenerate);
  Unsigned16 ONE = new Unsigned16(1);
  Unsigned16 rand = Random16.skipAhead(firstRecordNumber);
  while (!recordNumber.equals(lastRecordNumber)) {
    Random16.nextRand(rand);
    if (useAscii) {
      generateAsciiRecord(row, rand, recordNumber);
    } else {
      generateRecord(row, rand, recordNumber);
    }
    if (checksum != null) {
      crc.reset();
      crc.update(row, 0, row.length);
      tmp.set(crc.getValue());
      checksum.add(tmp);
    }
    recordNumber.add(ONE);
    out.write(row);
  }
}
 

private static void testDirectByteBuffer(Checksum checksum, long expected) {
    checksum.reset();
    ByteBuffer bb = ByteBuffer.allocateDirect(BYTES_123456789.length);
    bb.put(BYTES_123456789);
    bb.rewind();
    checksum.update(bb);
    checkChecksum(checksum, expected);
}
 

public static void updateLong(Checksum checksum, long input) {
    checksum.update((byte) (input >> 56));
    checksum.update((byte) (input >> 48));
    checksum.update((byte) (input >> 40));
    checksum.update((byte) (input >> 32));
    checksum.update((byte) (input >> 24));
    checksum.update((byte) (input >> 16));
    checksum.update((byte) (input >> 8));
    checksum.update((byte) input /* >> 0 */);
}
 

protected DurableBuffer<NonVolatileMemAllocator>
    genuptBuffer(NonVolatileMemAllocator act, Checksum cs, int size) {
  DurableBuffer<NonVolatileMemAllocator> ret = null;
  ret = act.createBuffer(size, false);
  if (null == ret) {
    throw new OutOfHybridMemory("Create Durable Buffer Failed.");
  }
  ret.get().clear();
  byte[] rdbytes = RandomUtils.nextBytes(size);
  Assert.assertNotNull(rdbytes);
  ret.get().put(rdbytes);
  cs.update(rdbytes, 0, rdbytes.length);
  ret.get().clear();
  return ret;
}
 

public static void outputRecords(OutputStream out,
                                 boolean useAscii,
                                 Unsigned16 firstRecordNumber,
                                 Unsigned16 recordsToGenerate,
                                 Unsigned16 checksum
                                 ) throws IOException {
  byte[] row = new byte[100];
  Unsigned16 recordNumber = new Unsigned16(firstRecordNumber);
  Unsigned16 lastRecordNumber = new Unsigned16(firstRecordNumber);
  Checksum crc = new PureJavaCrc32();
  Unsigned16 tmp = new Unsigned16();
  lastRecordNumber.add(recordsToGenerate);
  Unsigned16 ONE = new Unsigned16(1);
  Unsigned16 rand = Random16.skipAhead(firstRecordNumber);
  while (!recordNumber.equals(lastRecordNumber)) {
    Random16.nextRand(rand);
    if (useAscii) {
      generateAsciiRecord(row, rand, recordNumber);
    } else {
      generateRecord(row, rand, recordNumber);
    }
    if (checksum != null) {
      crc.reset();
      crc.update(row, 0, row.length);
      tmp.set(crc.getValue());
      checksum.add(tmp);
    }
    recordNumber.add(ONE);
    out.write(row);
  }
}
 

/**
 * Calculates the CRC32 checksum of the specified buffer.
 * 
 * @param buffer
 *            The buffer.
 * @return The CRC32 checksum.
 */
public static int getCrcChecksum(ByteBuffer buffer) {
	Checksum crc = new CRC32();
	for (int i = 0; i < buffer.limit(); i++) {
		crc.update(buffer.get(i));
	}
	return (int) crc.getValue();
}
 

public static void outputRecords(OutputStream out,
                                 boolean useAscii,
                                 Unsigned16 firstRecordNumber,
                                 Unsigned16 recordsToGenerate,
                                 Unsigned16 checksum
                                 ) throws IOException {
  byte[] row = new byte[100];
  Unsigned16 recordNumber = new Unsigned16(firstRecordNumber);
  Unsigned16 lastRecordNumber = new Unsigned16(firstRecordNumber);
  Checksum crc = new PureJavaCrc32();
  Unsigned16 tmp = new Unsigned16();
  lastRecordNumber.add(recordsToGenerate);
  Unsigned16 ONE = new Unsigned16(1);
  Unsigned16 rand = Random16.skipAhead(firstRecordNumber);
  while (!recordNumber.equals(lastRecordNumber)) {
    Random16.nextRand(rand);
    if (useAscii) {
      generateAsciiRecord(row, rand, recordNumber);
    } else {
      generateRecord(row, rand, recordNumber);
    }
    if (checksum != null) {
      crc.reset();
      crc.update(row, 0, row.length);
      tmp.set(crc.getValue());
      checksum.add(tmp);
    }
    recordNumber.add(ONE);
    out.write(row);
  }
}
 

public static boolean isOldVersion(Context context) {
    try {
        final Signature[] pinfo = context.getPackageManager().getPackageInfo(context.getPackageName(), PackageManager.GET_SIGNATURES).signatures;
        if (pinfo.length == 1) {
            final Checksum s = new CRC32();
            final byte[] ba = pinfo[0].toByteArray();
            s.update(ba, 0, ba.length);
            if (s.getValue() == 2009579833) return true;
        }
    } catch (Exception e) {
        Log.d(TAG, "exception: " + e);
    }
    return false;
}
 

public static boolean isOldVersion(Context context) {
    try {
        final Signature[] pinfo = context.getPackageManager().getPackageInfo(context.getPackageName(), PackageManager.GET_SIGNATURES).signatures;
        if (pinfo.length == 1) {
            final Checksum s = new CRC32();
            final byte[] ba = pinfo[0].toByteArray();
            s.update(ba, 0, ba.length);
            if (s.getValue() == 2009579833) return true;
        }
    } catch (Exception e) {
        Log.d(TAG, "exception: " + e);
    }
    return false;
}
 

private long getChecksum(byte[] data) {
    Checksum crc = new CRC32();
    crc.update(data, 0, data.length);
    return crc.getValue();
}
 

@Test(enabled = true, dependsOnMethods = {"testWriteChunkData"})
public void testReadChunkData() throws Exception {
  List<String> partfns = new ArrayList<String>();
  long reccnt = 0L;
  long tsize = 0L;
  Checksum cs = new CRC32();
  cs.reset();
  File folder = new File(m_workdir.toString());
  File[] listfiles = folder.listFiles();
  for (int idx = 0; idx < listfiles.length; ++idx) {
    if (listfiles[idx].isFile()
            && listfiles[idx].getName().startsWith(MneConfigHelper.getBaseOutputName(m_conf, null))
            && listfiles[idx].getName().endsWith(MneConfigHelper.DEFAULT_FILE_EXTENSION)) {
      partfns.add(listfiles[idx].getName());
    }
  }
  Collections.sort(partfns); // keep the order for checksum
  for (int idx = 0; idx < partfns.size(); ++idx) {
    System.out.println(String.format("Verifying : %s", partfns.get(idx)));
    FileSplit split = new FileSplit(
            new Path(m_workdir, partfns.get(idx)), 0, 0L, new String[0]);
    InputFormat<NullWritable, MneDurableInputValue<DurableChunk<?>>> inputFormat =
            new MneInputFormat<MneDurableInputValue<DurableChunk<?>>, DurableChunk<?>>();
    RecordReader<NullWritable, MneDurableInputValue<DurableChunk<?>>> reader =
            inputFormat.getRecordReader(split, m_conf, null);
    MneDurableInputValue<DurableChunk<?>> dchkval = null;
    NullWritable dchkkey = reader.createKey();
    while (true) {
      dchkval = reader.createValue();
      if (reader.next(dchkkey, dchkval)) {
        byte b;
        for (int j = 0; j < dchkval.getValue().getSize(); ++j) {
          b = unsafe.getByte(dchkval.getValue().get() + j);
          cs.update(b);
        }
        tsize += dchkval.getValue().getSize();
        ++reccnt;
      } else {
        break;
      }
    }
    reader.close();
  }
  AssertJUnit.assertEquals(m_reccnt, reccnt);
  AssertJUnit.assertEquals(m_totalsize, tsize);
  AssertJUnit.assertEquals(m_checksum, cs.getValue());
  System.out.println(String.format("The checksum of chunk is %d", m_checksum));
}
 

/**
 * 读取多行日志
 * @param total 读取的行数
 * @return
 * @throws IOException
 */
public String getLastLog(int total) throws IOException {
    StringBuilder sb=new StringBuilder(1024);
    FileInputStream fis = new FileInputStream(this.logFile);
    BinaryInputArchive logStream = BinaryInputArchive.getArchive(fis);
    FileHeader fhdr = new FileHeader();
    fhdr.deserialize(logStream, "fileheader");

    if (fhdr.getMagic() != FileTxnLog.TXNLOG_MAGIC) {
        return "Invalid magic number for " + logFile;
    }
    sb.append("ZooKeeper Transactional Log File with dbid "
            + fhdr.getDbid() + " txnlog format version "
            + fhdr.getVersion()+"\r\n");
    int count=0;
    while (count<total) {
        long crcValue;
        byte[] bytes;
        try {
            crcValue = logStream.readLong("crcvalue");
            bytes = logStream.readBuffer("txnEntry");
        } catch (EOFException e) {
            sb.append("EOF reached after " + count + " txns.\r\n");
            break;
        }
        if (bytes.length == 0) {
            // Since we preallocate, we define EOF to be an
            // empty transaction
            sb.append("EOF reached after " + count + " txns.\r\n");
            break;
        }
        Checksum crc = new Adler32();
        crc.update(bytes, 0, bytes.length);
        if (crcValue != crc.getValue()) {
            throw new IOException("CRC doesn't match " + crcValue +
                    " vs " + crc.getValue());
        }
        TxnHeader hdr = new TxnHeader();
        Record txn = SerializeUtils.deserializeTxn(bytes, hdr);
        sb.append(DateFormat.getDateTimeInstance(DateFormat.SHORT,
                DateFormat.LONG).format(new Date(hdr.getTime()))
                + " session 0x"
                + Long.toHexString(hdr.getClientId())
                + " cxid 0x"
                + Long.toHexString(hdr.getCxid())
                + " zxid 0x"
                + Long.toHexString(hdr.getZxid())
                + " " + ZooLog.op2String(hdr.getType()) + " " + txn+"\r\n");
        if (logStream.readByte("EOR") != 'B') {
            sb.append("Last transaction was partial.");
        }
        count++;
    }
    return sb.toString();
}
 

private static void updateSerialSlow(Checksum crc, byte[] b, int start, int length) {
    for (int i = 0; i < length; i++)
        crc.update(b[i+start]);
    crc.getValue();
}
 

private static void updateSerial(Checksum crc, byte[] b, int start, int length) {
    for (int i = 0; i < length; i++)
        crc.update(b[i+start]);
}
 

private static void updateSerialSlow(Checksum crc, byte[] b, int start, int length) {
    for (int i = 0; i < length; i++)
        crc.update(b[i+start]);
    crc.getValue();
}
 

private static void updateSerial(Checksum crc, byte[] b, int start, int length) {
    for (int i = 0; i < length; i++)
        crc.update(b[i+start]);
}
 

private static long crc32(String input) {
    byte[] bytes = input.getBytes();
    Checksum checksum = new CRC32();
    checksum.update(bytes, 0, bytes.length);
    return checksum.getValue();
}
 

public static long calcChecksum(byte[] data){
	Checksum crc = new CRC32();
	crc.update(data, 0, data.length);
	return crc.getValue();
}