Stream

package server.net.packet;

import server.Config;
import server.util.ISAACRandomGen;

public class Stream {

    public Stream() {
    }

    public Stream(byte abyte0[]) {
    buffer = abyte0;
    currentOffset = 0;
    }

    public byte readSignedByteA() {
    return (byte) (buffer[currentOffset++] - 128);
    }

    public byte readSignedByteC() {
    return (byte) (-buffer[currentOffset++]);
    }

    public byte readSignedByteS() {
    return (byte) (128 - buffer[currentOffset++]);
    }

    public int readUnsignedByteA() {
    return buffer[currentOffset++] - 128 & 0xff;
    }

    public int readUnsignedByteC() {
    return -buffer[currentOffset++] & 0xff;
    }

    public int readUnsignedByteS() {
    return 128 - buffer[currentOffset++] & 0xff;
    }

    public void writeByteA(int i) {
    ensureCapacity(1);
    buffer[currentOffset++] = (byte) (i + 128);
    }

    public void writeByteS(int i) {
    ensureCapacity(1);
    buffer[currentOffset++] = (byte) (128 - i);
    }

    public void writeByteC(int i) {
    ensureCapacity(1);
    buffer[currentOffset++] = (byte) (-i);
    }

    public int readSignedWordBigEndian() {
    currentOffset += 2;
    int i = ((buffer[currentOffset - 1] & 0xff) << 8) + (buffer[currentOffset - 2] & 0xff);
    if (i > 32767)
        i -= 0x10000;
    return i;
    }

    public int readSignedWordA() {
    currentOffset += 2;
    int i = ((buffer[currentOffset - 2] & 0xff) << 8) + (buffer[currentOffset - 1] - 128 & 0xff);
    if (i > 32767)
        i -= 0x10000;
    return i;
    }

    public int readSignedWordBigEndianA() {
    currentOffset += 2;
    int i = ((buffer[currentOffset - 1] & 0xff) << 8) + (buffer[currentOffset - 2] - 128 & 0xff);
    if (i > 32767)
        i -= 0x10000;
    return i;
    }

    public int readUnsignedWordBigEndian() {
    currentOffset += 2;
    return ((buffer[currentOffset - 1] & 0xff) << 8) + (buffer[currentOffset - 2] & 0xff);
    }

    public int readUnsignedWordA() {
    currentOffset += 2;
    return ((buffer[currentOffset - 2] & 0xff) << 8) + (buffer[currentOffset - 1] - 128 & 0xff);
    }

    public int readUnsignedWordBigEndianA() {
    currentOffset += 2;
    return ((buffer[currentOffset - 1] & 0xff) << 8) + (buffer[currentOffset - 2] - 128 & 0xff);
    }

    public void writeWordBigEndianA(int i) {
    ensureCapacity(2);
    buffer[currentOffset++] = (byte) (i + 128);
    buffer[currentOffset++] = (byte) (i >> 8);
    }

    public void writeWordA(int i) {
    ensureCapacity(2);
    buffer[currentOffset++] = (byte) (i >> 8);
    buffer[currentOffset++] = (byte) (i + 128);
    }

    public void writeWordBigEndian_dup(int i) {
    ensureCapacity(2);
    buffer[currentOffset++] = (byte) i;
    buffer[currentOffset++] = (byte) (i >> 8);
    }

    public int readDWord_v1() {
    currentOffset += 4;
    return ((buffer[currentOffset - 2] & 0xff) << 24) + ((buffer[currentOffset - 1] & 0xff) << 16)
        + ((buffer[currentOffset - 4] & 0xff) << 8) + (buffer[currentOffset - 3] & 0xff);
    }

    public int readDWord_v2() {
    currentOffset += 4;
    return ((buffer[currentOffset - 3] & 0xff) << 24) + ((buffer[currentOffset - 4] & 0xff) << 16)
        + ((buffer[currentOffset - 1] & 0xff) << 8) + (buffer[currentOffset - 2] & 0xff);
    }

    public void writeDWord_v1(int i) {
    ensureCapacity(4);
    buffer[currentOffset++] = (byte) (i >> 8);
    buffer[currentOffset++] = (byte) i;
    buffer[currentOffset++] = (byte) (i >> 24);
    buffer[currentOffset++] = (byte) (i >> 16);
    }

    public void writeDWord_v2(int i) {
    ensureCapacity(4);
    buffer[currentOffset++] = (byte) (i >> 16);
    buffer[currentOffset++] = (byte) (i >> 24);
    buffer[currentOffset++] = (byte) i;
    buffer[currentOffset++] = (byte) (i >> 8);
    }

    public void readBytes_reverse(byte abyte0[], int i, int j) {
    for (int k = (j + i) - 1; k >= j; k--)
        abyte0[k] = buffer[currentOffset++];

    }

    public void writeBytes_reverse(byte abyte0[], int i, int j) {
    ensureCapacity(i);
    for (int k = (j + i) - 1; k >= j; k--)
        buffer[currentOffset++] = abyte0[k];

    }

    public void readBytes_reverseA(byte abyte0[], int i, int j) {
    ensureCapacity(i);
    for (int k = (j + i) - 1; k >= j; k--)
        abyte0[k] = (byte) (buffer[currentOffset++] - 128);

    }

    public void writeBytes_reverseA(byte abyte0[], int i, int j) {
    ensureCapacity(i);
    for (int k = (j + i) - 1; k >= j; k--)
        buffer[currentOffset++] = (byte) (abyte0[k] + 128);

    }

    public void createFrame(int id) {
    ensureCapacity(1);
    buffer[currentOffset++] = (byte) (id + packetEncryption.getNextKey());
    }

    private static final int frameStackSize = 10;
    private int frameStackPtr = -1;
    private int frameStack[] = new int[frameStackSize];

    public void createFrameVarSize(int id) {
    ensureCapacity(3);
    buffer[currentOffset++] = (byte) (id + packetEncryption.getNextKey());
    buffer[currentOffset++] = 0;

    if (frameStackPtr >= frameStackSize - 1) {
        throw new RuntimeException("Stack overflow");
    } else {
        frameStack[++frameStackPtr] = currentOffset;
    }
    }

    public void createFrameVarSizeWord(int id) {
    ensureCapacity(2);
    buffer[currentOffset++] = (byte) (id + packetEncryption.getNextKey());
    writeWord(0);
    if (frameStackPtr >= frameStackSize - 1) {
        throw new RuntimeException("Stack overflow");
    } else
        frameStack[++frameStackPtr] = currentOffset;
    }

    public void endFrameVarSize() {
    if (frameStackPtr < 0) {
        throw new RuntimeException("Stack empty");
    } else {
        writeFrameSize(currentOffset - frameStack[frameStackPtr--]);
    }
    }

    public void endFrameVarSizeWord() {
    if (frameStackPtr < 0)
        throw new RuntimeException("Stack empty");
    else
        writeFrameSizeWord(currentOffset - frameStack[frameStackPtr--]);
    }

    public void writeByte(int i) {
    ensureCapacity(1);
    buffer[currentOffset++] = (byte) i;
    }

    public void writeWord(int i) {
    ensureCapacity(2);
    buffer[currentOffset++] = (byte) (i >> 8);
    buffer[currentOffset++] = (byte) i;
    }

    public void writeWordBigEndian(int i) {
    ensureCapacity(2);
    buffer[currentOffset++] = (byte) i;
    buffer[currentOffset++] = (byte) (i >> 8);
    }

    public void write3Byte(int i) {
    ensureCapacity(3);
    buffer[currentOffset++] = (byte) (i >> 16);
    buffer[currentOffset++] = (byte) (i >> 8);
    buffer[currentOffset++] = (byte) i;
    }

    public void writeDWord(int i) {
    ensureCapacity(4);
    buffer[currentOffset++] = (byte) (i >> 24);
    buffer[currentOffset++] = (byte) (i >> 16);
    buffer[currentOffset++] = (byte) (i >> 8);
    buffer[currentOffset++] = (byte) i;
    }

    public void writeDWordBigEndian(int i) {
    ensureCapacity(4);
    buffer[currentOffset++] = (byte) i;
    buffer[currentOffset++] = (byte) (i >> 8);
    buffer[currentOffset++] = (byte) (i >> 16);
    buffer[currentOffset++] = (byte) (i >> 24);
    }

    public void writeQWord(long l) {
    ensureCapacity(8);
    buffer[currentOffset++] = (byte) (int) (l >> 56);
    buffer[currentOffset++] = (byte) (int) (l >> 48);
    buffer[currentOffset++] = (byte) (int) (l >> 40);
    buffer[currentOffset++] = (byte) (int) (l >> 32);
    buffer[currentOffset++] = (byte) (int) (l >> 24);
    buffer[currentOffset++] = (byte) (int) (l >> 16);
    buffer[currentOffset++] = (byte) (int) (l >> 8);
    buffer[currentOffset++] = (byte) (int) l;
    }

    public void writeString(java.lang.String s) {
    ensureCapacity(s.length());
    System.arraycopy(s.getBytes(), 0, buffer, currentOffset, s.length());
    currentOffset += s.length();
    buffer[currentOffset++] = 10;
    }

    public void writeBytes(byte abyte0[], int i, int j) {
    ensureCapacity(i);
    for (int k = j; k < j + i; k++)
        buffer[currentOffset++] = abyte0[k];
    }

    public void writeFrameSize(int i) {
    buffer[currentOffset - i - 1] = (byte) i;
    }

    public void writeFrameSizeWord(int i) {
    buffer[currentOffset - i - 2] = (byte) (i >> 8);
    buffer[currentOffset - i - 1] = (byte) i;
    }

    public int readUnsignedByte() {
    return buffer[currentOffset++] & 0xff;
    }

    public byte readSignedByte() {
    return buffer[currentOffset++];
    }

    public int readUnsignedWord() {
    currentOffset += 2;
    return ((buffer[currentOffset - 2] & 0xff) << 8) + (buffer[currentOffset - 1] & 0xff);
    }

    public int readSignedWord() {
    currentOffset += 2;
    int i = ((buffer[currentOffset - 2] & 0xff) << 8) + (buffer[currentOffset - 1] & 0xff);
    if (i > 32767)
        i -= 0x10000;
    return i;
    }

    public int readDWord() {
    currentOffset += 4;
    return ((buffer[currentOffset - 4] & 0xff) << 24) + ((buffer[currentOffset - 3] & 0xff) << 16)
        + ((buffer[currentOffset - 2] & 0xff) << 8) + (buffer[currentOffset - 1] & 0xff);
    }

    public long readQWord() {
    long l = (long) readDWord() & 0xffffffffL;
    long l1 = (long) readDWord() & 0xffffffffL;
    return (l << 32) + l1;
    }

    public long readQWord2() {
    final long l = readDWord() & 0xffffffffL;
    final long l1 = readDWord() & 0xffffffffL;
    return (l << 32) + l1;
    }

    public java.lang.String readString() {
    int i = currentOffset;
    while (buffer[currentOffset++] != 10)
        ;
    return new String(buffer, i, currentOffset - i - 1);
    }

    public void readBytes(byte abyte0[], int i, int j) {
    for (int k = j; k < j + i; k++)
        abyte0[k] = buffer[currentOffset++];

    }

    public void initBitAccess() {
    bitPosition = currentOffset * 8;
    }

    public void writeBits(int numBits, int value) {
    ensureCapacity(((int) Math.ceil(numBits * 8)) * 4);
    int bytePos = bitPosition >> 3;
    int bitOffset = 8 - (bitPosition & 7);
    bitPosition += numBits;

    for (; numBits > bitOffset; bitOffset = 8) {
        buffer[bytePos] &= ~bitMaskOut[bitOffset];
        buffer[bytePos++] |= (value >> (numBits - bitOffset)) & bitMaskOut[bitOffset];

        numBits -= bitOffset;
    }
    if (numBits == bitOffset) {
        buffer[bytePos] &= ~bitMaskOut[bitOffset];
        buffer[bytePos] |= value & bitMaskOut[bitOffset];
    } else {
        buffer[bytePos] &= ~(bitMaskOut[numBits] << (bitOffset - numBits));
        buffer[bytePos] |= (value & bitMaskOut[numBits]) << (bitOffset - numBits);
    }
    }

    public void finishBitAccess() {
    currentOffset = (bitPosition + 7) / 8;
    }

    public byte buffer[] = null;
    public int currentOffset = 0;
    public int bitPosition = 0;

    public static int bitMaskOut[] = new int[32];
    static {
    for (int i = 0; i < 32; i++)
        bitMaskOut[i] = (1 << i) - 1;
    }

    public void ensureCapacity(int len) {
    if ((currentOffset + len + 1) >= buffer.length) {
        byte[] oldBuffer = buffer;
        int newLength = (buffer.length * 2);
        buffer = new byte[newLength];
        System.arraycopy(oldBuffer, 0, buffer, 0, oldBuffer.length);
        ensureCapacity(len);
    }
    }

    public void reset() {
    if (!(currentOffset > Config.BUFFER_SIZE)) {
        byte[] oldBuffer = buffer;
        buffer = new byte[Config.BUFFER_SIZE];
        for (int i = 0; i < currentOffset; i++) {
        buffer[i] = oldBuffer[i];
        }
    }
    }

    public ISAACRandomGen packetEncryption = null;

}