content: package com.bj58.argo.thirdparty.jetty;
  
  import java.io.IOException;
  import java.nio.ByteBuffer;
  
  /* ------------------------------------------------------------ */
  /**
   * Utf8 Appendable abstract base class
   *
   * This abstract class wraps a standard {@link java.lang.Appendable} and provides methods to append UTF-8 encoded bytes, that are converted into characters.
   *
   * This class is stateful and up to 4 calls to {@link #append(byte)} may be needed before state a character is appended to the string buffer.
   *
   * The UTF-8 decoding is done by this class and no additional buffers or Readers are used. The UTF-8 code was inspired by
   * http://bjoern.hoehrmann.de/utf-8/decoder/dfa/
   *
   * License information for Bjoern Hoehrmann's code:
   *
   * Copyright (c) 2008-2009 Bjoern Hoehrmann <bjoern@hoehrmann.de>
   * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal
   * in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   * copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
   * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
   * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
   **/
  public abstract class Utf8Appendable
  {
  //    protected static final Logger LOG = Log.getLogger(Utf8Appendable.class);
      public static final char REPLACEMENT = '\ufffd';
      private static final int UTF8_ACCEPT = 0;
      private static final int UTF8_REJECT = 12;
  
      protected final Appendable _appendable;
      protected int _state = UTF8_ACCEPT;
  
      private static final byte[] BYTE_TABLE =
      {
          // The first part of the table maps bytes to character classes that
          // to reduce the size of the transition table and create bitmasks.
           0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
           0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
           0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
           0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
           1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,  9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,
           7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,  7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
           8,8,2,2,2,2,2,2,2,2,2,2,2,2,2,2,  2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
          10,3,3,3,3,3,3,3,3,3,3,3,3,4,3,3, 11,6,6,6,5,8,8,8,8,8,8,8,8,8,8,8
      };
  
      private static final byte[] TRANS_TABLE =
      {
          // The second part is a transition table that maps a combination
          // of a state of the automaton and a character class to a state.
           0,12,24,36,60,96,84,12,12,12,48,72, 12,12,12,12,12,12,12,12,12,12,12,12,
          12, 0,12,12,12,12,12, 0,12, 0,12,12, 12,24,12,12,12,12,12,24,12,24,12,12,
          12,12,12,12,12,12,12,24,12,12,12,12, 12,24,12,12,12,12,12,12,12,24,12,12,
          12,12,12,12,12,12,12,36,12,36,12,12, 12,36,12,12,12,12,12,36,12,36,12,12,
          12,36,12,12,12,12,12,12,12,12,12,12
      };
  
      private int _codep;
  
      public Utf8Appendable(Appendable appendable)
      {
          _appendable = appendable;
      }
  
      public abstract int length();
  
      protected void reset()
      {
          _state = UTF8_ACCEPT;
      }
  
      public void append(byte b)
      {
          try
          {
              appendByte(b);
          }
          catch (IOException e)
          {
              throw new RuntimeException(e);
          }
      }
      
      public void append(ByteBuffer buf)
      {
          try
          {
              while (buf.remaining() > 0)
              {
                  appendByte(buf.get());
              }
          }
          catch (IOException e)
          {
              throw new RuntimeException(e);
          }
      }
  
      public void append(byte[] b, int offset, int length)
      {
          try
          {
              int end = offset + length;
              for (int i = offset; i < end; i++)
                  appendByte(b[i]);
          }
          catch (IOException e)
          {
              throw new RuntimeException(e);
          }
      }
  
      public boolean append(byte[] b, int offset, int length, int maxChars)
      {
          try
          {
              int end = offset + length;
              for (int i = offset; i < end; i++)
              {
                  if (length() > maxChars)
                      return false;
                  appendByte(b[i]);
              }
              return true;
          }
          catch (IOException e)
          {
              throw new RuntimeException(e);
          }
      }
  
      protected void appendByte(byte b) throws IOException
      {
  
          if (b > 0 && _state == UTF8_ACCEPT)
          {
              _appendable.append((char)(b & 0xFF));
          }
          else
          {
              int i = b & 0xFF;
              int type = BYTE_TABLE[i];
              _codep = _state == UTF8_ACCEPT ? (0xFF >> type) & i : (i & 0x3F) | (_codep << 6);
              int next = TRANS_TABLE[_state + type];
  
              switch(next)
              {
                  case UTF8_ACCEPT:
                      _state=next;
                      if (_codep < Character.MIN_HIGH_SURROGATE)
                      {
                          _appendable.append((char)_codep);
                      }
                      else
                      {
                          for (char c : Character.toChars(_codep))
                              _appendable.append(c);
                      }
                      break;
                      
                  case UTF8_REJECT:
                      String reason = "byte "+TypeUtil.toHexString(b)+" in state "+(_state/12);
                      _codep=0;
                      _state = UTF8_ACCEPT;
                      _appendable.append(REPLACEMENT);
                      throw new NotUtf8Exception(reason);
                      
                  default:
                      _state=next;
                      
              }
          }
      }
  
      public boolean isUtf8SequenceComplete()
      {
          return _state == UTF8_ACCEPT;
      }
  
      @SuppressWarnings("serial")
      public static class NotUtf8Exception extends IllegalArgumentException
      {
          public NotUtf8Exception(String reason)
          {
              super("Not valid UTF8! "+reason);
          }
      }
  
      protected void checkState()
      {
          if (!isUtf8SequenceComplete())
          {
              _codep=0;
              _state = UTF8_ACCEPT;
              try
              {
                  _appendable.append(REPLACEMENT);
              }
              catch(IOException e)
              {
                  throw new RuntimeException(e);
              }
              throw new NotUtf8Exception("incomplete UTF8 sequence");
          }
      }
      
      public String toReplacedString()
      {
          if (!isUtf8SequenceComplete())
          {
              _codep=0;
              _state = UTF8_ACCEPT;
              try
              {
                  _appendable.append(REPLACEMENT);
              }
              catch(IOException e)
              {
                  throw new RuntimeException(e);
              }
  //            Throwable th= new NotUtf8Exception("incomplete UTF8 sequence");
  //            LOG.warn(th.toString());
  //            LOG.debug(th);
          }
          return _appendable.toString();
      }
  }
  