content: package com.alicloud.openservices.tablestore.core.utils;
  
  import com.alicloud.openservices.tablestore.core.Constants;
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  
  import java.io.DataInput;
  import java.io.DataOutput;
  import java.io.IOException;
  import java.io.UnsupportedEncodingException;
  import java.math.BigDecimal;
  import java.math.BigInteger;
  import java.nio.ByteBuffer;
  
  public class Bytes {
  
      private static final Log LOG = LogFactory.getLog(Bytes.class);
  
      /**
       * Size of boolean in bytes
       */
      public static final int SIZEOF_BOOLEAN = Byte.SIZE / Byte.SIZE;
  
      /**
       * Size of byte in bytes
       */
      public static final int SIZEOF_BYTE = SIZEOF_BOOLEAN;
  
      /**
       * Size of char in bytes
       */
      public static final int SIZEOF_CHAR = Character.SIZE / Byte.SIZE;
  
      /**
       * Size of double in bytes
       */
      public static final int SIZEOF_DOUBLE = Double.SIZE / Byte.SIZE;
  
      /**
       * Size of float in bytes
       */
      public static final int SIZEOF_FLOAT = Float.SIZE / Byte.SIZE;
  
      /**
       * Size of int in bytes
       */
      public static final int SIZEOF_INT = Integer.SIZE / Byte.SIZE;
  
      /**
       * Size of long in bytes
       */
      public static final int SIZEOF_LONG = Long.SIZE / Byte.SIZE;
  
      /**
       * Size of short in bytes
       */
      public static final int SIZEOF_SHORT = Short.SIZE / Byte.SIZE;
  
  
      /**
       * Estimate of size cost to pay beyond payload in jvm for instance of byte [].
       * Estimate based on study of jhat and jprofiler numbers.
       */
      // JHat says BU is 56 bytes.
      // SizeOf which uses java.lang.instrument says 24 bytes. (3 longs?)
      public static final int ESTIMATED_HEAP_TAX = 16;
  
      public static class WritableUtils {
          public static int readVInt(DataInput stream) throws IOException {
              return (int) readVLong(stream);
          }
  
          public static long readVLong(DataInput stream) throws IOException {
              byte firstByte = stream.readByte();
              int len = decodeVIntSize(firstByte);
              if (len == 1) {
                  return firstByte;
              }
              long i = 0;
              for (int idx = 0; idx < len - 1; idx++) {
                  byte b = stream.readByte();
                  i = i << 8;
                  i = i | (b & 0xFF);
              }
              return (isNegativeVInt(firstByte) ? (i ^ -1L) : i);
          }
  
          public static int decodeVIntSize(byte value) {
              if (value >= -112) {
                  return 1;
              } else if (value < -120) {
                  return -119 - value;
              }
              return -111 - value;
          }
  
          public static boolean isNegativeVInt(byte value) {
              return value < -120 || (value >= -112 && value < 0);
          }
  
          public static boolean writeVInt(byte value) {
              return value < -120 || (value >= -112 && value < 0);
          }
  
          public static void writeVInt(DataOutput stream, int i) throws IOException {
              writeVLong(stream, i);
          }
  
          public static void writeVLong(DataOutput stream, long i) throws IOException {
              if (i >= -112 && i <= 127) {
                  stream.writeByte((byte) i);
                  return;
              }
  
              int len = -112;
              if (i < 0) {
                  i ^= -1L; // take one's complement'
                  len = -120;
              }
  
              long tmp = i;
              while (tmp != 0) {
                  tmp = tmp >> 8;
                  len--;
              }
  
              stream.writeByte((byte) len);
  
              len = (len < -120) ? -(len + 120) : -(len + 112);
  
              for (int idx = len; idx != 0; idx--) {
                  int shiftbits = (idx - 1) * 8;
                  long mask = 0xFFL << shiftbits;
                  stream.writeByte((byte) ((i & mask) >> shiftbits));
              }
          }
  
          public static int getVIntSize(long i) {
              if (i >= -112 && i <= 127) {
                  return 1;
              }
  
              if (i < 0) {
                  i ^= -1L; // take one's complement'
              }
              // find the number of bytes with non-leading zeros
              int dataBits = Long.SIZE - Long.numberOfLeadingZeros(i);
              // find the number of data bytes + length byte
              return (dataBits + 7) / 8 + 1;
          }
      }
  
      /**
       * Read byte-array written with a WritableableUtils.vint prefix.
       *
       * @param in Input to read from.
       * @return byte array read off <code>in</code>
       * @throws IOException e
       */
      public static byte[] readByteArray(final DataInput in)
              throws IOException {
          int len = WritableUtils.readVInt(in);
          if (len < 0) {
              throw new NegativeArraySizeException(Integer.toString(len));
          }
          byte[] result = new byte[len];
          in.readFully(result, 0, len);
          return result;
      }
  
      /**
       * Read byte-array written with a WritableableUtils.vint prefix.
       * IOException is converted to a RuntimeException.
       *
       * @param in Input to read from.
       * @return byte array read off <code>in</code>
       */
      public static byte[] readByteArrayThrowsRuntime(final DataInput in) {
          try {
              return readByteArray(in);
          } catch (Exception e) {
              throw new RuntimeException(e);
          }
      }
  
      /**
       * Write byte-array with a WritableableUtils.vint prefix.
       *
       * @param out output stream to be written to
       * @param b   array to write
       * @throws IOException e
       */
      public static void writeByteArray(final DataOutput out, final byte[] b)
              throws IOException {
          if (b == null) {
              WritableUtils.writeVInt(out, 0);
          } else {
              writeByteArray(out, b, 0, b.length);
          }
      }
  
      /**
       * Write byte-array to out with a vint length prefix.
       *
       * @param out    output stream
       * @param b      array
       * @param offset offset into array
       * @param length length past offset
       * @throws IOException e
       */
      public static void writeByteArray(final DataOutput out, final byte[] b,
                                        final int offset, final int length)
              throws IOException {
          WritableUtils.writeVInt(out, length);
          out.write(b, offset, length);
      }
  
      /**
       * Write byte-array from src to tgt with a vint length prefix.
       *
       * @param tgt       target array
       * @param tgtOffset offset into target array
       * @param src       source array
       * @param srcOffset source offset
       * @param srcLength source length
       * @return New offset in src array.
       */
      public static int writeByteArray(final byte[] tgt, final int tgtOffset,
                                       final byte[] src, final int srcOffset, final int srcLength) {
          byte[] vint = vintToBytes(srcLength);
          System.arraycopy(vint, 0, tgt, tgtOffset, vint.length);
          int offset = tgtOffset + vint.length;
          System.arraycopy(src, srcOffset, tgt, offset, srcLength);
          return offset + srcLength;
      }
  
      /**
       * Put bytes at the specified byte array position.
       *
       * @param tgtBytes  the byte array
       * @param tgtOffset position in the array
       * @param srcBytes  array to write out
       * @param srcOffset source offset
       * @param srcLength source length
       * @return incremented offset
       */
      public static int putBytes(byte[] tgtBytes, int tgtOffset, byte[] srcBytes,
                                 int srcOffset, int srcLength) {
          System.arraycopy(srcBytes, srcOffset, tgtBytes, tgtOffset, srcLength);
          return tgtOffset + srcLength;
      }
  
      /**
       * Write a single byte out to the specified byte array position.
       *
       * @param bytes  the byte array
       * @param offset position in the array
       * @param b      byte to write out
       * @return incremented offset
       */
      public static int putByte(byte[] bytes, int offset, byte b) {
          bytes[offset] = b;
          return offset + 1;
      }
  
      /**
       * Returns a new byte array, copied from the passed ByteBuffer.
       *
       * @param bb A ByteBuffer
       * @return the byte array
       */
      public static byte[] toBytes(ByteBuffer bb) {
          int length = bb.limit();
          byte[] result = new byte[length];
          System.arraycopy(bb.array(), bb.arrayOffset(), result, 0, length);
          return result;
      }
  
      /**
       * @param b Presumed UTF-8 encoded byte array.
       * @return String made from <code>b</code>
       */
      public static String toString(final byte[] b) {
          if (b == null) {
              return null;
          }
          return toString(b, 0, b.length);
      }
  
      /**
       * Joins two byte arrays together using a separator.
       *
       * @param b1  The first byte array.
       * @param sep The separator to use.
       * @param b2  The second byte array.
       */
      public static String toString(final byte[] b1,
                                    String sep,
                                    final byte[] b2) {
          return toString(b1, 0, b1.length) + sep + toString(b2, 0, b2.length);
      }
  
      /**
       * This method will convert utf8 encoded bytes into a string. If
       * an UnsupportedEncodingException occurs, this method will eat it
       * and return null instead.
       *
       * @param b   Presumed UTF-8 encoded byte array.
       * @param off offset into array
       * @param len length of utf-8 sequence
       * @return String made from <code>b</code> or null
       */
      public static String toString(final byte[] b, int off, int len) {
          if (b == null) {
              return null;
          }
          if (len == 0) {
              return "";
          }
          try {
              return new String(b, off, len, Constants.UTF8_ENCODING);
          } catch (UnsupportedEncodingException e) {
              LOG.error("UTF-8 not supported?", e);
              return null;
          }
      }
  
      public static byte[] copyBytes(final byte[] bytes, int offset, int length) {
          if (offset + length > bytes.length) {
              throw explainWrongLengthOrOffset(bytes, offset, length, length);
          }
          byte[] result = new byte[length];
          System.arraycopy(bytes, offset, result, 0, length);
          return result;
      }
  
      /**
       * Write a printable representation of a byte array.
       *
       * @param b byte array
       * @return string
       * @see #toStringBinary(byte[], int, int)
       */
      public static String toStringBinary(final byte[] b) {
          if (b == null)
              return "null";
          return toStringBinary(b, 0, b.length);
      }
  
      /**
       * Converts the given byte buffer, from its array offset to its limit, to
       * a string. The position and the mark are ignored.
       *
       * @param buf a byte buffer
       * @return a string representation of the buffer's binary contents
       */
      public static String toStringBinary(ByteBuffer buf) {
          if (buf == null)
              return "null";
          return toStringBinary(buf.array(), buf.arrayOffset(), buf.limit());
      }
  
      /**
       * Write a printable representation of a byte array. Non-printable
       * characters are hex escaped in the format \\x%02X, eg:
       * \x00 \x05 etc
       *
       * @param b   array to write out
       * @param off offset to start at
       * @param len length to write
       * @return string output
       */
      public static String toStringBinary(final byte[] b, int off, int len) {
          StringBuilder result = new StringBuilder();
          try {
              String first = new String(b, off, len, "ISO-8859-1");
              for (int i = 0; i < first.length(); ++i) {
                  int ch = first.charAt(i) & 0xFF;
                  if ((ch >= '0' && ch <= '9')
                          || (ch >= 'A' && ch <= 'Z')
                          || (ch >= 'a' && ch <= 'z')
                          || " `~!@#$%^&*()-_=+[]{}\\|;:'\",.<>/?".indexOf(ch) >= 0) {
                      result.append(first.charAt(i));
                  } else {
                      result.append(String.format("\\x%02X", ch));
                  }
              }
          } catch (UnsupportedEncodingException e) {
              LOG.error("ISO-8859-1 not supported?", e);
          }
          return result.toString();
      }
  
      private static boolean isHexDigit(char c) {
          return
                  (c >= 'A' && c <= 'F') ||
                          (c >= '0' && c <= '9');
      }
  
      /**
       * Takes a ASCII digit in the range A-F0-9 and returns
       * the corresponding integer/ordinal value.
       *
       * @param ch The hex digit.
       * @return The converted hex value as a byte.
       */
      public static byte toBinaryFromHex(byte ch) {
          if (ch >= 'A' && ch <= 'F')
              return (byte) ((byte) 10 + (byte) (ch - 'A'));
          // else
          return (byte) (ch - '0');
      }
  
      public static byte[] toBytesBinary(String in) {
          // this may be bigger than we need, but lets be safe.
          byte[] b = new byte[in.length()];
          int size = 0;
          for (int i = 0; i < in.length(); ++i) {
              char ch = in.charAt(i);
              if (ch == '\\' && in.length() > i + 1 && in.charAt(i + 1) == 'x') {
                  // ok, take next 2 hex digits.
                  char hd1 = in.charAt(i + 2);
                  char hd2 = in.charAt(i + 3);
  
                  // they need to be A-F0-9:
                  if (!isHexDigit(hd1) ||
                          !isHexDigit(hd2)) {
                      // bogus escape code, ignore:
                      continue;
                  }
                  // turn hex ASCII digit -> number
                  byte d = (byte) ((toBinaryFromHex((byte) hd1) << 4) + toBinaryFromHex((byte) hd2));
  
                  b[size++] = d;
                  i += 3; // skip 3
              } else {
                  b[size++] = (byte) ch;
              }
          }
          // resize:
          byte[] b2 = new byte[size];
          System.arraycopy(b, 0, b2, 0, size);
          return b2;
      }
  
      /**
       * Converts a string to a UTF-8 byte array.
       *
       * @param s string
       * @return the byte array
       */
      public static byte[] toBytes(String s) {
          try {
              return s.getBytes(Constants.UTF8_ENCODING);
          } catch (UnsupportedEncodingException e) {
              LOG.error("UTF-8 not supported?", e);
              return null;
          }
      }
  
      /**
       * Convert a boolean to a byte array. True becomes -1
       * and false becomes 0.
       *
       * @param b value
       * @return <code>b</code> encoded in a byte array.
       */
      public static byte[] toBytes(final boolean b) {
          return new byte[]{b ? (byte) -1 : (byte) 0};
      }
  
      /**
       * Reverses {@link #toBytes(boolean)}
       *
       * @param b array
       * @return True or false.
       */
      public static boolean toBoolean(final byte[] b) {
          if (b.length != 1) {
              throw new IllegalArgumentException("Array has wrong size: " + b.length);
          }
          return b[0] != (byte) 0;
      }
  
      public static boolean toBoolean(final byte[] bytes, int offset, int length) {
          if (length != SIZEOF_BOOLEAN || offset + length > bytes.length) {
              throw explainWrongLengthOrOffset(bytes, offset, length, SIZEOF_BOOLEAN);
          }
          return bytes[offset] != (byte) 0;
      }
  
      /**
       * Convert a long value to a byte array using big-endian.
       *
       * @param val value to convert
       * @return the byte array
       */
      public static byte[] toBytes(long val) {
          byte[] b = new byte[8];
          for (int i = 7; i > 0; i--) {
              b[i] = (byte) val;
              val >>>= 8;
          }
          b[0] = (byte) val;
          return b;
      }
  
      /**
       * Converts a byte array to a long value. Reverses
       * {@link #toBytes(long)}
       *
       * @param bytes array
       * @return the long value
       */
      public static long toLong(byte[] bytes) {
          return toLong(bytes, 0, SIZEOF_LONG);
      }
  
      /**
       * Converts a byte array to a long value. Assumes there will be
       * {@link #SIZEOF_LONG} bytes available.
       *
       * @param bytes  bytes
       * @param offset offset
       * @return the long value
       */
      public static long toLong(byte[] bytes, int offset) {
          return toLong(bytes, offset, SIZEOF_LONG);
      }
  
      /**
       * Converts a byte array to a long value.
       *
       * @param bytes  array of bytes
       * @param offset offset into array
       * @param length length of data (must be {@link #SIZEOF_LONG})
       * @return the long value
       * @throws IllegalArgumentException if length is not {@link #SIZEOF_LONG} or
       *                                  if there's not enough room in the array at the offset indicated.
       */
      public static long toLong(byte[] bytes, int offset, final int length) {
          if (length != SIZEOF_LONG || offset + length > bytes.length) {
              throw explainWrongLengthOrOffset(bytes, offset, length, SIZEOF_LONG);
          }
          long l = 0;
          for (int i = offset; i < offset + length; i++) {
              l <<= 8;
              l ^= bytes[i] & 0xFF;
          }
          return l;
      }
  
      private static IllegalArgumentException
      explainWrongLengthOrOffset(final byte[] bytes,
                                 final int offset,
                                 final int length,
                                 final int expectedLength) {
          String reason;
          if (length != expectedLength) {
              reason = "Wrong length: " + length + ", expected " + expectedLength;
          } else {
              reason = "offset (" + offset + ") + length (" + length + ") exceed the"
                      + " capacity of the array: " + bytes.length;
          }
          return new IllegalArgumentException(reason);
      }
  
      /**
       * Put a long value out to the specified byte array position.
       *
       * @param bytes  the byte array
       * @param offset position in the array
       * @param val    long to write out
       * @return incremented offset
       * @throws IllegalArgumentException if the byte array given doesn't have
       *                                  enough room at the offset specified.
       */
      public static int putLong(byte[] bytes, int offset, long val) {
          if (bytes.length - offset < SIZEOF_LONG) {
              throw new IllegalArgumentException("Not enough room to put a long at"
                      + " offset " + offset + " in a " + bytes.length + " byte array");
          }
          for (int i = offset + 7; i > offset; i--) {
              bytes[i] = (byte) val;
              val >>>= 8;
          }
          bytes[offset] = (byte) val;
          return offset + SIZEOF_LONG;
      }
  
      /**
       * Presumes float encoded as IEEE 754 floating-point "single format"
       *
       * @param bytes byte array
       * @return Float made from passed byte array.
       */
      public static float toFloat(byte[] bytes) {
          return toFloat(bytes, 0);
      }
  
      /**
       * Presumes float encoded as IEEE 754 floating-point "single format"
       *
       * @param bytes  array to convert
       * @param offset offset into array
       * @return Float made from passed byte array.
       */
      public static float toFloat(byte[] bytes, int offset) {
          return Float.intBitsToFloat(toInt(bytes, offset, SIZEOF_INT));
      }
  
      /**
       * @param bytes  byte array
       * @param offset offset to write to
       * @param f      float value
       * @return New offset in <code>bytes</code>
       */
      public static int putFloat(byte[] bytes, int offset, float f) {
          return putInt(bytes, offset, Float.floatToRawIntBits(f));
      }
  
      /**
       * @param f float value
       * @return the float represented as byte []
       */
      public static byte[] toBytes(final float f) {
          // Encode it as int
          return Bytes.toBytes(Float.floatToRawIntBits(f));
      }
  
      /**
       * @param bytes byte array
       * @return Return double made from passed bytes.
       */
      public static double toDouble(final byte[] bytes) {
          return toDouble(bytes, 0);
      }
  
      /**
       * @param bytes  byte array
       * @param offset offset where double is
       * @return Return double made from passed bytes.
       */
      public static double toDouble(final byte[] bytes, final int offset) {
          return Double.longBitsToDouble(toLong(bytes, offset, SIZEOF_LONG));
      }
  
      /**
       * @param bytes  byte array
       * @param offset offset to write to
       * @param d      value
       * @return New offset into array <code>bytes</code>
       */
      public static int putDouble(byte[] bytes, int offset, double d) {
          return putLong(bytes, offset, Double.doubleToLongBits(d));
      }
  
      /**
       * Serialize a double as the IEEE 754 double format output. The resultant
       * array will be 8 bytes long.
       *
       * @param d value
       * @return the double represented as byte []
       */
      public static byte[] toBytes(final double d) {
          // Encode it as a long
          return Bytes.toBytes(Double.doubleToRawLongBits(d));
      }
  
      /**
       * Convert an int value to a byte array
       *
       * @param val value
       * @return the byte array
       */
      public static byte[] toBytes(int val) {
          byte[] b = new byte[4];
          for (int i = 3; i > 0; i--) {
              b[i] = (byte) val;
              val >>>= 8;
          }
          b[0] = (byte) val;
          return b;
      }
  
      /**
       * Converts a byte array to an int value
       *
       * @param bytes byte array
       * @return the int value
       */
      public static int toInt(byte[] bytes) {
          return toInt(bytes, 0, SIZEOF_INT);
      }
  
      /**
       * Converts a byte array to an int value
       *
       * @param bytes  byte array
       * @param offset offset into array
       * @return the int value
       */
      public static int toInt(byte[] bytes, int offset) {
          return toInt(bytes, offset, SIZEOF_INT);
      }
  
      /**
       * Converts a byte array to an int value
       *
       * @param bytes  byte array
       * @param offset offset into array
       * @param length length of int (has to be {@link #SIZEOF_INT})
       * @return the int value
       * @throws IllegalArgumentException if length is not {@link #SIZEOF_INT} or
       *                                  if there's not enough room in the array at the offset indicated.
       */
      public static int toInt(byte[] bytes, int offset, final int length) {
          if (length != SIZEOF_INT || offset + length > bytes.length) {
              throw explainWrongLengthOrOffset(bytes, offset, length, SIZEOF_INT);
          }
          int n = 0;
          for (int i = offset; i < (offset + length); i++) {
              n <<= 8;
              n ^= bytes[i] & 0xFF;
          }
          return n;
      }
  
      /**
       * Put an int value out to the specified byte array position.
       *
       * @param bytes  the byte array
       * @param offset position in the array
       * @param val    int to write out
       * @return incremented offset
       * @throws IllegalArgumentException if the byte array given doesn't have
       *                                  enough room at the offset specified.
       */
      public static int putInt(byte[] bytes, int offset, int val) {
          if (bytes.length - offset < SIZEOF_INT) {
              throw new IllegalArgumentException("Not enough room to put an int at"
                      + " offset " + offset + " in a " + bytes.length + " byte array");
          }
          for (int i = offset + 3; i > offset; i--) {
              bytes[i] = (byte) val;
              val >>>= 8;
          }
          bytes[offset] = (byte) val;
          return offset + SIZEOF_INT;
      }
  
      /**
       * Convert a short value to a byte array of {@link #SIZEOF_SHORT} bytes long.
       *
       * @param val value
       * @return the byte array
       */
      public static byte[] toBytes(short val) {
          byte[] b = new byte[SIZEOF_SHORT];
          b[1] = (byte) val;
          val >>= 8;
          b[0] = (byte) val;
          return b;
      }
  
      /**
       * Converts a byte array to a short value
       *
       * @param bytes byte array
       * @return the short value
       */
      public static short toShort(byte[] bytes) {
          return toShort(bytes, 0, SIZEOF_SHORT);
      }
  
      /**
       * Converts a byte array to a short value
       *
       * @param bytes  byte array
       * @param offset offset into array
       * @return the short value
       */
      public static short toShort(byte[] bytes, int offset) {
          return toShort(bytes, offset, SIZEOF_SHORT);
      }
  
      /**
       * Converts a byte array to a short value
       *
       * @param bytes  byte array
       * @param offset offset into array
       * @param length length, has to be {@link #SIZEOF_SHORT}
       * @return the short value
       * @throws IllegalArgumentException if length is not {@link #SIZEOF_SHORT}
       *                                  or if there's not enough room in the array at the offset indicated.
       */
      public static short toShort(byte[] bytes, int offset, final int length) {
          if (length != SIZEOF_SHORT || offset + length > bytes.length) {
              throw explainWrongLengthOrOffset(bytes, offset, length, SIZEOF_SHORT);
          }
          short n = 0;
          n ^= bytes[offset] & 0xFF;
          n <<= 8;
          n ^= bytes[offset + 1] & 0xFF;
          return n;
      }
  
      /**
       * This method will get a sequence of bytes from pos to limit,
       * but will restore pos after.
       *
       * @param buf
       * @return byte array
       */
      public static byte[] getBytes(ByteBuffer buf) {
          int savedPos = buf.position();
          byte[] newBytes = new byte[buf.remaining()];
          buf.get(newBytes);
          buf.position(savedPos);
          return newBytes;
      }
  
      /**
       * Put a short value out to the specified byte array position.
       *
       * @param bytes  the byte array
       * @param offset position in the array
       * @param val    short to write out
       * @return incremented offset
       * @throws IllegalArgumentException if the byte array given doesn't have
       *                                  enough room at the offset specified.
       */
      public static int putShort(byte[] bytes, int offset, short val) {
          if (bytes.length - offset < SIZEOF_SHORT) {
              throw new IllegalArgumentException("Not enough room to put a short at"
                      + " offset " + offset + " in a " + bytes.length + " byte array");
          }
          bytes[offset + 1] = (byte) val;
          val >>= 8;
          bytes[offset] = (byte) val;
          return offset + SIZEOF_SHORT;
      }
  
      public static byte toByte(byte[] bytes, int offset, int length) {
          if (length != SIZEOF_BYTE || offset + length > bytes.length) {
              throw explainWrongLengthOrOffset(bytes, offset, length, SIZEOF_BYTE);
          }
          return bytes[offset];
      }
  
  
      /**
       * Convert a BigDecimal value to a byte array
       *
       * @param val
       * @return the byte array
       */
      public static byte[] toBytes(BigDecimal val) {
          byte[] valueBytes = val.unscaledValue().toByteArray();
          byte[] result = new byte[valueBytes.length + SIZEOF_INT];
          int offset = putInt(result, 0, val.scale());
          putBytes(result, offset, valueBytes, 0, valueBytes.length);
          return result;
      }
  
  
      /**
       * Converts a byte array to a BigDecimal
       *
       * @param bytes
       * @return the char value
       */
      public static BigDecimal toBigDecimal(byte[] bytes) {
          return toBigDecimal(bytes, 0, bytes.length);
      }
  
      /**
       * Converts a byte array to a BigDecimal value
       *
       * @param bytes
       * @param offset
       * @param length
       * @return the char value
       */
      public static BigDecimal toBigDecimal(byte[] bytes, int offset, final int length) {
          if (bytes == null || length < SIZEOF_INT + 1 ||
                  (offset + length > bytes.length)) {
              return null;
          }
  
          int scale = toInt(bytes, offset);
          byte[] tcBytes = new byte[length - SIZEOF_INT];
          System.arraycopy(bytes, offset + SIZEOF_INT, tcBytes, 0, length - SIZEOF_INT);
          return new BigDecimal(new BigInteger(tcBytes), scale);
      }
  
      /**
       * Put a BigDecimal value out to the specified byte array position.
       *
       * @param bytes  the byte array
       * @param offset position in the array
       * @param val    BigDecimal to write out
       * @return incremented offset
       */
      public static int putBigDecimal(byte[] bytes, int offset, BigDecimal val) {
          if (bytes == null) {
              return offset;
          }
  
          byte[] valueBytes = val.unscaledValue().toByteArray();
          byte[] result = new byte[valueBytes.length + SIZEOF_INT];
          offset = putInt(result, offset, val.scale());
          return putBytes(result, offset, valueBytes, 0, valueBytes.length);
      }
  
      /**
       * @param vint Integer to make a vint of.
       * @return Vint as bytes array.
       */
      public static byte[] vintToBytes(final long vint) {
          long i = vint;
          int size = WritableUtils.getVIntSize(i);
          byte[] result = new byte[size];
          int offset = 0;
          if (i >= -112 && i <= 127) {
              result[offset] = (byte) i;
              return result;
          }
  
          int len = -112;
          if (i < 0) {
              i ^= -1L; // take one's complement'
              len = -120;
          }
  
          long tmp = i;
          while (tmp != 0) {
              tmp = tmp >> 8;
              len--;
          }
  
          result[offset++] = (byte) len;
  
          len = (len < -120) ? -(len + 120) : -(len + 112);
  
          for (int idx = len; idx != 0; idx--) {
              int shiftbits = (idx - 1) * 8;
              long mask = 0xFFL << shiftbits;
              result[offset++] = (byte) ((i & mask) >> shiftbits);
          }
          return result;
      }
  
      /**
       * @param buffer buffer to convert
       * @return vint bytes as an integer.
       */
      public static long bytesToVint(final byte[] buffer) {
          int offset = 0;
          byte firstByte = buffer[offset++];
          int len = WritableUtils.decodeVIntSize(firstByte);
          if (len == 1) {
              return firstByte;
          }
          long i = 0;
          for (int idx = 0; idx < len - 1; idx++) {
              byte b = buffer[offset++];
              i = i << 8;
              i = i | (b & 0xFF);
          }
          return (WritableUtils.isNegativeVInt(firstByte) ? ~i : i);
      }
  
      /**
       * Reads a zero-compressed encoded long from input stream and returns it.
       *
       * @param buffer Binary array
       * @param offset Offset into array at which vint begins.
       * @return deserialized long from stream.
       * @throws java.io.IOException e
       */
      public static long readVLong(final byte[] buffer, final int offset)
              throws IOException {
          byte firstByte = buffer[offset];
          int len = WritableUtils.decodeVIntSize(firstByte);
          if (len == 1) {
              return firstByte;
          }
          long i = 0;
          for (int idx = 0; idx < len - 1; idx++) {
              byte b = buffer[offset + 1 + idx];
              i = i << 8;
              i = i | (b & 0xFF);
          }
          return (WritableUtils.isNegativeVInt(firstByte) ? ~i : i);
      }
  
      /**
       * @param left  left operand
       * @param right right operand
       * @return 0 if equal, negative value if left is less than right, etc.
       */
      public static int compareTo(final byte[] left, final byte[] right) {
          return compareByteArrayInLexOrder(left, 0, left.length, right, 0, right.length);
      }
  
      /**
       * Lexicographically compare two arrays.
       *
       * @param buffer1 left operand
       * @param buffer2 right operand
       * @param offset1 Where to start comparing in the left buffer
       * @param offset2 Where to start comparing in the right buffer
       * @param length1 How much to compare from the left buffer
       * @param length2 How much to compare from the right buffer
       * @return 0 if equal, negative value if left is less than right, etc.
       */
      public static int compareTo(byte[] buffer1, int offset1, int length1,
                                  byte[] buffer2, int offset2, int length2) {
          return compareByteArrayInLexOrder(buffer1, offset1, length1, buffer2, offset2, length2);
      }
  
      public static int compareByteArrayInLexOrder(byte[] buffer1, int offset1, int length1,
                                                   byte[] buffer2, int offset2, int length2) {
          // Short circuit equal case
          if (buffer1 == buffer2 &&
                  offset1 == offset2 &&
                  length1 == length2) {
              return 0;
          }
          // Bring WritableComparator code local
          int end1 = offset1 + length1;
          int end2 = offset2 + length2;
          for (int i = offset1, j = offset2; i < end1 && j < end2; i++, j++) {
              int a = (buffer1[i] & 0xff);
              int b = (buffer2[j] & 0xff);
              if (a != b) {
                  return a - b;
              }
          }
          return length1 - length2;
      }
  
      /**
       * @param left  left operand
       * @param right right operand
       * @return True if equal
       */
      public static boolean equals(final byte[] left, final byte[] right) {
          // Could use Arrays.equals?
          //noinspection SimplifiableConditionalExpression
          if (left == right) return true;
          if (left == null || right == null) return false;
          if (left.length != right.length) return false;
          if (left.length == 0) return true;
  
          // Since we're often comparing adjacent sorted data,
          // it's usual to have equal arrays except for the very last byte
          // so check that first
          if (left[left.length - 1] != right[right.length - 1]) return false;
  
          return compareTo(left, right) == 0;
      }
  
      public static boolean equals(final byte[] left, int leftOffset, int leftLen,
                                   final byte[] right, int rightOffset, int rightLen) {
          // short circuit case
          if (left == right &&
                  leftOffset == rightOffset &&
                  leftLen == rightLen) {
              return true;
          }
          // different lengths fast check
          if (leftLen != rightLen) {
              return false;
          }
          if (leftLen == 0) {
              return true;
          }
  
          // Since we're often comparing adjacent sorted data,
          // it's usual to have equal arrays except for the very last byte
          // so check that first
          if (left[leftOffset + leftLen - 1] != right[rightOffset + rightLen - 1]) return false;
  
          return compareByteArrayInLexOrder(left, leftOffset, leftLen, right, rightOffset, rightLen) == 0;
      }
  
  
      /**
       * Return true if the byte array on the right is a prefix of the byte
       * array on the left.
       */
      public static boolean startsWith(byte[] bytes, byte[] prefix) {
          return bytes != null && prefix != null &&
                  bytes.length >= prefix.length &&
                  compareByteArrayInLexOrder(bytes, 0, prefix.length, prefix, 0, prefix.length) == 0;
      }
  
      public static int hashCode(final byte[] b) {
          return hashCode(b, b.length);
      }
  
      public static int hashCode(final byte[] b, final int length) {
          return hashBytes(b, length);
      }
  
      /**
       * Compute hash for binary data.
       */
      public static int hashBytes(byte[] bytes, int offset, int length) {
          int hash = 1;
          for (int i = offset; i < offset + length; i++)
              hash = (31 * hash) + (int) bytes[i];
          return hash;
      }
  
      /**
       * Compute hash for binary data.
       */
      public static int hashBytes(byte[] bytes, int length) {
          return hashBytes(bytes, 0, length);
      }
  
      /**
       * @param bytes  array to hash
       * @param offset offset to start from
       * @param length length to hash
       */
      public static int hashCode(byte[] bytes, int offset, int length) {
          int hash = 1;
          for (int i = offset; i < offset + length; i++)
              hash = (31 * hash) + (int) bytes[i];
          return hash;
      }
  
      /**
       * Reference standard: http://tools.ietf.org/html/rfc3629
       */
      public static int stringtoUTF8Bytes(String str, byte[] buffer) {
          int index = 0;
          for (int i = 0; i < str.length(); i++) {
              char strChar = str.charAt(i);
              if ((strChar & 0xFF80) == 0) {
                  // (00000000 00000000 - 00000000 01111111) -> 0xxxxxxx
                  buffer[index++] = (byte) (strChar & 0x00FF);
              } else if ((strChar & 0xF800) == 0) {
                  // (00000000 10000000 - 00000111 11111111) -> 110xxxxx 10xxxxxx
                  buffer[index++] = (byte) ((strChar >> 6) | 0x00c0);
                  buffer[index++] = (byte) ((strChar & 0x003F) | 0x0080);
              } else {
                  // (00001000 00000000 - 11111111 11111111) -> 1110xxxx 10xxxxxx 10xxxxxx
                  buffer[index++] = (byte) ((strChar >> 12) | 0x00e0);
                  buffer[index++] = (byte) (((strChar >> 6) & 0x003F) | 0x0080);
                  buffer[index++] = (byte) ((strChar & 0x003F) | 0x0080);
              }
          }
          return index;
      }
  }
  