package com.alibaba.jstorm.metric;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.UnsupportedEncodingException;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.nio.ByteBuffer;

public class Bytes {

    private static final Logger LOG = LoggerFactory.getLogger(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;


    /**
     * 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;
    }

    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;
    }

    /**
     * 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 -> 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 left  left operand
     * @param right right operand
     * @return 0 if equal, < 0 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, < 0 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;
    }

    /**
     * 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;
    }
}