//
//  ========================================================================
//  Copyright (c) 1995-2016 Mort Bay Consulting Pty. Ltd.
//  ------------------------------------------------------------------------
//  All rights reserved. This program and the accompanying materials
//  are made available under the terms of the Eclipse Public License v1.0
//  and Apache License v2.0 which accompanies this distribution.
//
//      The Eclipse Public License is available at
//      http://www.eclipse.org/legal/epl-v10.html
//
//      The Apache License v2.0 is available at
//      http://www.opensource.org/licenses/apache2.0.php
//
//  You may elect to redistribute this code under either of these licenses.
//  ========================================================================
//

package org.eclipse.jetty.http;

import static org.eclipse.jetty.http.HttpTokens.CARRIAGE_RETURN;
import static org.eclipse.jetty.http.HttpTokens.LINE_FEED;
import static org.eclipse.jetty.http.HttpTokens.SPACE;
import static org.eclipse.jetty.http.HttpTokens.TAB;

import java.nio.ByteBuffer;
import java.nio.charset.StandardCharsets;
import java.util.Arrays;
import java.util.EnumSet;

import org.eclipse.jetty.http.HttpTokens.EndOfContent;
import org.eclipse.jetty.util.ArrayTernaryTrie;
import org.eclipse.jetty.util.ArrayTrie;
import org.eclipse.jetty.util.BufferUtil;
import org.eclipse.jetty.util.Trie;
import org.eclipse.jetty.util.TypeUtil;
import org.eclipse.jetty.util.Utf8StringBuilder;
import org.eclipse.jetty.util.log.Log;
import org.eclipse.jetty.util.log.Logger;


/* ------------------------------------------------------------ */
/** A Parser for 1.0 and 1.1 as defined by RFC7230
 * <p>
 * This parser parses HTTP client and server messages from buffers
 * passed in the {@link #parseNext(ByteBuffer)} method.  The parsed
 * elements of the HTTP message are passed as event calls to the 
 * {@link HttpHandler} instance the parser is constructed with.
 * If the passed handler is a {@link RequestHandler} then server side
 * parsing is performed and if it is a {@link ResponseHandler}, then 
 * client side parsing is done.
 * </p>
 * <p>
 * The contract of the {@link HttpHandler} API is that if a call returns 
 * true then the call to {@link #parseNext(ByteBuffer)} will return as 
 * soon as possible also with a true response.  Typically this indicates
 * that the parsing has reached a stage where the caller should process 
 * the events accumulated by the handler.    It is the preferred calling
 * style that handling such as calling a servlet to process a request, 
 * should be done after a true return from {@link #parseNext(ByteBuffer)}
 * rather than from within the scope of a call like 
 * {@link RequestHandler#messageComplete()}
 * </p>
 * <p>
 * For performance, the parse is heavily dependent on the 
 * {@link Trie#getBest(ByteBuffer, int, int)} method to look ahead in a
 * single pass for both the structure ( : and CRLF ) and semantic (which
 * header and value) of a header.  Specifically the static {@link HttpHeader#CACHE}
 * is used to lookup common combinations of headers and values 
 * (eg. "Connection: close"), or just header names (eg. "Connection:" ).
 * For headers who's value is not known statically (eg. Host, COOKIE) then a
 * per parser dynamic Trie of {@link HttpFields} from previous parsed messages
 * is used to help the parsing of subsequent messages.
 * </p>
 * <p>
 * If the system property "org.eclipse.jetty.http.HttpParser.STRICT" is set to true,
 * then the parser will strictly pass on the exact strings received for methods and header
 * fields.  Otherwise a fast case insensitive string lookup is used that may alter the
 * case of the method and/or headers
 * </p>
 * <p>
 * @see <a href="http://tools.ietf.org/html/rfc7230">RFC 7230</a>
 */
public class HttpParser
{
    public static final Logger LOG = Log.getLogger(HttpParser.class);
    public final static boolean __STRICT=Boolean.getBoolean("org.eclipse.jetty.http.HttpParser.STRICT"); 
    public final static int INITIAL_URI_LENGTH=256;

    /**
     * Cache of common {@link HttpField}s including: <UL>
     * <LI>Common static combinations such as:<UL>
     *   <li>Connection: close
     *   <li>Accept-Encoding: gzip
     *   <li>Content-Length: 0
     * </ul>
     * <li>Combinations of Content-Type header for common mime types by common charsets
     * <li>Most common headers with null values so that a lookup will at least
     * determine the header name even if the name:value combination is not cached
     * </ul>
     */
    public final static Trie<HttpField> CACHE = new ArrayTrie<>(2048);
    
    // States
    public enum State
    {
        START,
        METHOD,
        RESPONSE_VERSION,
        SPACE1,
        STATUS,
        URI,
        SPACE2,
        REQUEST_VERSION,
        REASON,
        PROXY,
        HEADER,
        HEADER_IN_NAME,
        HEADER_VALUE,
        HEADER_IN_VALUE,
        CONTENT,
        EOF_CONTENT,
        CHUNKED_CONTENT,
        CHUNK_SIZE,
        CHUNK_PARAMS,
        CHUNK,
        CHUNK_END,
        END,
        CLOSE,  // The associated stream/endpoint should be closed
        CLOSED  // The associated stream/endpoint is at EOF
    }

    private final static EnumSet<State> __idleStates = EnumSet.of(State.START,State.END,State.CLOSE,State.CLOSED);
    private final static EnumSet<State> __completeStates = EnumSet.of(State.END,State.CLOSE,State.CLOSED);
    
    private final boolean DEBUG=LOG.isDebugEnabled(); // Cache debug to help branch prediction
    private final HttpHandler _handler;
    private final RequestHandler _requestHandler;
    private final ResponseHandler _responseHandler;
    private final int _maxHeaderBytes;
    private final boolean _strict;
    private HttpField _field;
    private HttpHeader _header;
    private String _headerString;
    private HttpHeaderValue _value;
    private String _valueString;
    private int _responseStatus;
    private int _headerBytes;
    private boolean _host;

    /* ------------------------------------------------------------------------------- */
    private volatile State _state=State.START;
    private volatile boolean _eof;
    private HttpMethod _method;
    private String _methodString;
    private HttpVersion _version;
    private Utf8StringBuilder _uri=new Utf8StringBuilder(INITIAL_URI_LENGTH); // Tune?
    private EndOfContent _endOfContent;
    private long _contentLength;
    private long _contentPosition;
    private int _chunkLength;
    private int _chunkPosition;
    private boolean _headResponse;
    private boolean _cr;
    private ByteBuffer _contentChunk;
    private Trie<HttpField> _connectionFields;

    private int _length;
    private final StringBuilder _string=new StringBuilder();

    static
    {
        CACHE.put(new HttpField(HttpHeader.CONNECTION,HttpHeaderValue.CLOSE));
        CACHE.put(new HttpField(HttpHeader.CONNECTION,HttpHeaderValue.KEEP_ALIVE));
        CACHE.put(new HttpField(HttpHeader.CONNECTION,HttpHeaderValue.UPGRADE));
        CACHE.put(new HttpField(HttpHeader.ACCEPT_ENCODING,"gzip"));
        CACHE.put(new HttpField(HttpHeader.ACCEPT_ENCODING,"gzip, deflate"));
        CACHE.put(new HttpField(HttpHeader.ACCEPT_ENCODING,"gzip,deflate,sdch"));
        CACHE.put(new HttpField(HttpHeader.ACCEPT_LANGUAGE,"en-US,en;q=0.5"));
        CACHE.put(new HttpField(HttpHeader.ACCEPT_LANGUAGE,"en-GB,en-US;q=0.8,en;q=0.6"));
        CACHE.put(new HttpField(HttpHeader.ACCEPT_CHARSET,"ISO-8859-1,utf-8;q=0.7,*;q=0.3"));
        CACHE.put(new HttpField(HttpHeader.ACCEPT,"*/*"));
        CACHE.put(new HttpField(HttpHeader.ACCEPT,"image/png,image/*;q=0.8,*/*;q=0.5"));
        CACHE.put(new HttpField(HttpHeader.ACCEPT,"text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8"));
        CACHE.put(new HttpField(HttpHeader.PRAGMA,"no-cache"));
        CACHE.put(new HttpField(HttpHeader.CACHE_CONTROL,"private, no-cache, no-cache=Set-Cookie, proxy-revalidate"));
        CACHE.put(new HttpField(HttpHeader.CACHE_CONTROL,"no-cache"));
        CACHE.put(new HttpField(HttpHeader.CONTENT_LENGTH,"0"));
        CACHE.put(new HttpField(HttpHeader.CONTENT_ENCODING,"gzip"));
        CACHE.put(new HttpField(HttpHeader.CONTENT_ENCODING,"deflate"));
        CACHE.put(new HttpField(HttpHeader.TRANSFER_ENCODING,"chunked"));
        CACHE.put(new HttpField(HttpHeader.EXPIRES,"Fri, 01 Jan 1990 00:00:00 GMT"));
        
        // Add common Content types as fields
        for (String type : new String[]{"text/plain","text/html","text/xml","text/json","application/json","application/x-www-form-urlencoded"})
        {
            HttpField field=new PreEncodedHttpField(HttpHeader.CONTENT_TYPE,type);
            CACHE.put(field);
            
            for (String charset : new String[]{"utf-8","iso-8859-1"})
            {
                CACHE.put(new PreEncodedHttpField(HttpHeader.CONTENT_TYPE,type+";charset="+charset));
                CACHE.put(new PreEncodedHttpField(HttpHeader.CONTENT_TYPE,type+"; charset="+charset));
                CACHE.put(new PreEncodedHttpField(HttpHeader.CONTENT_TYPE,type+";charset="+charset.toUpperCase()));
                CACHE.put(new PreEncodedHttpField(HttpHeader.CONTENT_TYPE,type+"; charset="+charset.toUpperCase()));
            }
        }
    
        // Add headers with null values so HttpParser can avoid looking up name again for unknown values
        for (HttpHeader h:HttpHeader.values())
            if (!CACHE.put(new HttpField(h,(String)null)))
                throw new IllegalStateException("CACHE FULL");
        // Add some more common headers
        CACHE.put(new HttpField(HttpHeader.REFERER,(String)null));
        CACHE.put(new HttpField(HttpHeader.IF_MODIFIED_SINCE,(String)null));
        CACHE.put(new HttpField(HttpHeader.IF_NONE_MATCH,(String)null));
        CACHE.put(new HttpField(HttpHeader.AUTHORIZATION,(String)null));
        CACHE.put(new HttpField(HttpHeader.COOKIE,(String)null));
    }

    /* ------------------------------------------------------------------------------- */
    public HttpParser(RequestHandler handler)
    {
        this(handler,-1,__STRICT);
    }

    /* ------------------------------------------------------------------------------- */
    public HttpParser(ResponseHandler handler)
    {
        this(handler,-1,__STRICT);
    }

    /* ------------------------------------------------------------------------------- */
    public HttpParser(RequestHandler handler,int maxHeaderBytes)
    {
        this(handler,maxHeaderBytes,__STRICT);
    }

    /* ------------------------------------------------------------------------------- */
    public HttpParser(ResponseHandler handler,int maxHeaderBytes)
    {
        this(handler,maxHeaderBytes,__STRICT);
    }
    
    /* ------------------------------------------------------------------------------- */
    public HttpParser(RequestHandler handler,int maxHeaderBytes,boolean strict)
    {
        _handler=handler;
        _requestHandler=handler;
        _responseHandler=null;
        _maxHeaderBytes=maxHeaderBytes;
        _strict=strict;
    }

    /* ------------------------------------------------------------------------------- */
    public HttpParser(ResponseHandler handler,int maxHeaderBytes,boolean strict)
    {
        _handler=handler;
        _requestHandler=null;
        _responseHandler=handler;
        _maxHeaderBytes=maxHeaderBytes;
        _strict=strict;
    }

    /* ------------------------------------------------------------------------------- */
    public long getContentLength()
    {
        return _contentLength;
    }

    /* ------------------------------------------------------------ */
    public long getContentRead()
    {
        return _contentPosition;
    }

    /* ------------------------------------------------------------ */
    /** Set if a HEAD response is expected
     * @param head true if head response is expected
     */
    public void setHeadResponse(boolean head)
    {
        _headResponse=head;
    }

    /* ------------------------------------------------------------------------------- */
    protected void setResponseStatus(int status)
    {
        _responseStatus=status;
    }

    /* ------------------------------------------------------------------------------- */
    public State getState()
    {
        return _state;
    }

    /* ------------------------------------------------------------------------------- */
    public boolean inContentState()
    {
        return _state.ordinal()>=State.CONTENT.ordinal() && _state.ordinal()<State.END.ordinal();
    }

    /* ------------------------------------------------------------------------------- */
    public boolean inHeaderState()
    {
        return _state.ordinal() < State.CONTENT.ordinal();
    }

    /* ------------------------------------------------------------------------------- */
    public boolean isChunking()
    {
        return _endOfContent==EndOfContent.CHUNKED_CONTENT;
    }

    /* ------------------------------------------------------------ */
    public boolean isStart()
    {
        return isState(State.START);
    }

    /* ------------------------------------------------------------ */
    public boolean isClose()
    {
        return isState(State.CLOSE);
    }

    /* ------------------------------------------------------------ */
    public boolean isClosed()
    {
        return isState(State.CLOSED);
    }

    /* ------------------------------------------------------------ */
    public boolean isIdle()
    {
        return __idleStates.contains(_state);
    }

    /* ------------------------------------------------------------ */
    public boolean isComplete()
    {
        return __completeStates.contains(_state);
    }

    /* ------------------------------------------------------------------------------- */
    public boolean isState(State state)
    {
        return _state == state;
    }

    /* ------------------------------------------------------------------------------- */
    enum CharState { ILLEGAL, CR, LF, LEGAL }
    private final static CharState[] __charState;
    static
    {
        // token          = 1*tchar
        // tchar          = "!" / "#" / "$" / "%" / "&" / "'" / "*"
        //                / "+" / "-" / "." / "^" / "_" / "`" / "|" / "~"
        //                / DIGIT / ALPHA
        //                ; any VCHAR, except delimiters
        // quoted-string  = DQUOTE *( qdtext / quoted-pair ) DQUOTE
        // qdtext         = HTAB / SP /%x21 / %x23-5B / %x5D-7E / obs-text
        // obs-text       = %x80-FF
        // comment        = "(" *( ctext / quoted-pair / comment ) ")"
        // ctext          = HTAB / SP / %x21-27 / %x2A-5B / %x5D-7E / obs-text
        // quoted-pair    = "\" ( HTAB / SP / VCHAR / obs-text )
   
        __charState=new CharState[256];
        Arrays.fill(__charState,CharState.ILLEGAL);
        __charState[LINE_FEED]=CharState.LF;
        __charState[CARRIAGE_RETURN]=CharState.CR;
        __charState[TAB]=CharState.LEGAL;
        __charState[SPACE]=CharState.LEGAL;
        
        __charState['!']=CharState.LEGAL;
        __charState['#']=CharState.LEGAL;
        __charState['$']=CharState.LEGAL;
        __charState['%']=CharState.LEGAL;
        __charState['&']=CharState.LEGAL;
        __charState['\'']=CharState.LEGAL;
        __charState['*']=CharState.LEGAL;
        __charState['+']=CharState.LEGAL;
        __charState['-']=CharState.LEGAL;
        __charState['.']=CharState.LEGAL;
        __charState['^']=CharState.LEGAL;
        __charState['_']=CharState.LEGAL;
        __charState['`']=CharState.LEGAL;
        __charState['|']=CharState.LEGAL;
        __charState['~']=CharState.LEGAL;
        
        __charState['"']=CharState.LEGAL;
        
        __charState['\\']=CharState.LEGAL;
        __charState['(']=CharState.LEGAL;
        __charState[')']=CharState.LEGAL;
        Arrays.fill(__charState,0x21,0x27+1,CharState.LEGAL);
        Arrays.fill(__charState,0x2A,0x5B+1,CharState.LEGAL);
        Arrays.fill(__charState,0x5D,0x7E+1,CharState.LEGAL);
        Arrays.fill(__charState,0x80,0xFF+1,CharState.LEGAL);
        
    }
    
    /* ------------------------------------------------------------------------------- */
    private byte next(ByteBuffer buffer)
    {
        byte ch = buffer.get();
        
        CharState s = __charState[0xff & ch];
        switch(s)
        {
            case ILLEGAL:
                throw new IllegalCharacterException(_state,ch,buffer);
                
            case LF:
                _cr=false;
                break;
                
            case CR:
                if (_cr)
                    throw new BadMessageException("Bad EOL");

                _cr=true;
                if (buffer.hasRemaining())
                {
                    if(_maxHeaderBytes>0 && _state.ordinal()<State.END.ordinal())
                        _headerBytes++;
                    return next(buffer);
                }
                
                // Can return 0 here to indicate the need for more characters, 
                // because a real 0 in the buffer would cause a BadMessage below 
                return 0;
                
            case LEGAL:
                if (_cr)
                    throw new BadMessageException("Bad EOL");
                
        }
        
        return ch;
    }
    
    /* ------------------------------------------------------------------------------- */
    /* Quick lookahead for the start state looking for a request method or a HTTP version,
     * otherwise skip white space until something else to parse.
     */
    private boolean quickStart(ByteBuffer buffer)
    {    	
        if (_requestHandler!=null)
        {
            _method = HttpMethod.lookAheadGet(buffer);
            if (_method!=null)
            {
                _methodString = _method.asString();
                buffer.position(buffer.position()+_methodString.length()+1);
                
                setState(State.SPACE1);
                return false;
            }
        }
        else if (_responseHandler!=null)
        {
            _version = HttpVersion.lookAheadGet(buffer);
            if (_version!=null)
            {
                buffer.position(buffer.position()+_version.asString().length()+1);
                setState(State.SPACE1);
                return false;
            }
        }
        
        // Quick start look
        while (_state==State.START && buffer.hasRemaining())
        {
            int ch=next(buffer);

            if (ch > SPACE)
            {
                _string.setLength(0);
                _string.append((char)ch);
                setState(_requestHandler!=null?State.METHOD:State.RESPONSE_VERSION);
                return false;
            }
            else if (ch==0)
                break;
            else if (ch<0)
                throw new BadMessageException();
            
            // count this white space as a header byte to avoid DOS
            if (_maxHeaderBytes>0 && ++_headerBytes>_maxHeaderBytes)
            {
                LOG.warn("padding is too large >"+_maxHeaderBytes);
                throw new BadMessageException(HttpStatus.BAD_REQUEST_400);
            }
        }
        return false;
    }

    /* ------------------------------------------------------------------------------- */
    private void setString(String s)
    {
        _string.setLength(0);
        _string.append(s);
        _length=s.length();
    }
    
    /* ------------------------------------------------------------------------------- */
    private String takeString()
    {
        _string.setLength(_length);
        String s =_string.toString();
        _string.setLength(0);
        _length=-1;
        return s;
    }

    /* ------------------------------------------------------------------------------- */
    /* Parse a request or response line
     */
    private boolean parseLine(ByteBuffer buffer)
    {
        boolean handle=false;

        // Process headers
        while (_state.ordinal()<State.HEADER.ordinal() && buffer.hasRemaining() && !handle)
        {
            // process each character
            byte ch=next(buffer);
            if (ch==0)
                break;

            if (_maxHeaderBytes>0 && ++_headerBytes>_maxHeaderBytes)
            {
                if (_state==State.URI)
                {
                    LOG.warn("URI is too large >"+_maxHeaderBytes);
                    throw new BadMessageException(HttpStatus.REQUEST_URI_TOO_LONG_414);
                }
                else
                {
                    if (_requestHandler!=null)
                        LOG.warn("request is too large >"+_maxHeaderBytes);
                    else
                        LOG.warn("response is too large >"+_maxHeaderBytes);
                    throw new BadMessageException(HttpStatus.REQUEST_ENTITY_TOO_LARGE_413);
                }
            }

            switch (_state)
            {
                case METHOD:
                    if (ch == SPACE)
                    {
                        _length=_string.length();
                        _methodString=takeString();
                        HttpMethod method=HttpMethod.CACHE.get(_methodString);
                        if (method!=null && !_strict)
                            _methodString=method.asString();
                        setState(State.SPACE1);
                    }
                    else if (ch < SPACE)
                    {
                        if (ch==LINE_FEED)
                            throw new BadMessageException("No URI");
                        else
                            throw new IllegalCharacterException(_state,ch,buffer);
                    }
                    else
                        _string.append((char)ch);
                    break;

                case RESPONSE_VERSION:
                    if (ch == HttpTokens.SPACE)
                    {
                        _length=_string.length();
                        String version=takeString();
                        _version=HttpVersion.CACHE.get(version);
                        if (_version==null)
                            throw new BadMessageException(HttpStatus.BAD_REQUEST_400,"Unknown Version");
                        setState(State.SPACE1);
                    }
                    else if (ch < HttpTokens.SPACE)
                        throw new IllegalCharacterException(_state,ch,buffer);
                    else
                        _string.append((char)ch);
                    break;

                case SPACE1:
                    if (ch > HttpTokens.SPACE || ch<0)
                    {
                        if (_responseHandler!=null)
                        {
                            setState(State.STATUS);
                            setResponseStatus(ch-'0');
                        }
                        else
                        {
                            _uri.reset();
                            setState(State.URI);
                            // quick scan for space or EoBuffer
                            if (buffer.hasArray())
                            {
                                byte[] array=buffer.array();
                                int p=buffer.arrayOffset()+buffer.position();
                                int l=buffer.arrayOffset()+buffer.limit();
                                int i=p;
                                while (i<l && array[i]>HttpTokens.SPACE)
                                    i++;

                                int len=i-p;
                                _headerBytes+=len;
                                
                                if (_maxHeaderBytes>0 && ++_headerBytes>_maxHeaderBytes)
                                {
                                    LOG.warn("URI is too large >"+_maxHeaderBytes);
                                    throw new BadMessageException(HttpStatus.REQUEST_URI_TOO_LONG_414);
                                }
                                _uri.append(array,p-1,len+1);
                                buffer.position(i-buffer.arrayOffset());
                            }
                            else
                                _uri.append(ch);
                        }
                    }
                    else if (ch < HttpTokens.SPACE)
                    {
                        throw new BadMessageException(HttpStatus.BAD_REQUEST_400,_requestHandler!=null?"No URI":"No Status");
                    }
                    break;

                case STATUS:
                    if (ch == HttpTokens.SPACE)
                    {
                        setState(State.SPACE2);
                    }
                    else if (ch>='0' && ch<='9')
                    {
                        _responseStatus=_responseStatus*10+(ch-'0');
                    }
                    else if (ch < HttpTokens.SPACE && ch>=0)
                    {
                        handle=_responseHandler.startResponse(_version, _responseStatus, null)||handle;
                        setState(State.HEADER);
                    }
                    else
                    {
                        throw new BadMessageException();
                    }
                    break;

                case URI:
                    if (ch == HttpTokens.SPACE)
                    {
                        setState(State.SPACE2);
                    }
                    else if (ch < HttpTokens.SPACE && ch>=0)
                    {
                        // HTTP/0.9
                        throw new BadMessageException("HTTP/0.9 not supported");
                    }
                    else
                    {
                        _uri.append(ch);
                    }
                    break;

                case SPACE2:
                    if (ch > HttpTokens.SPACE)
                    {
                        _string.setLength(0);
                        _string.append((char)ch);
                        if (_responseHandler!=null)
                        {
                            _length=1;
                            setState(State.REASON);
                        }
                        else
                        {
                            setState(State.REQUEST_VERSION);

                            // try quick look ahead for HTTP Version
                            HttpVersion version;
                            if (buffer.position()>0 && buffer.hasArray())
                                version=HttpVersion.lookAheadGet(buffer.array(),buffer.arrayOffset()+buffer.position()-1,buffer.arrayOffset()+buffer.limit());
                            else
                                version=HttpVersion.CACHE.getBest(buffer,0,buffer.remaining());
                            
                            if (version!=null)
                            {
                                int pos = buffer.position()+version.asString().length()-1;
                                if (pos<buffer.limit())
                                {
                                    byte n=buffer.get(pos);
                                    if (n==HttpTokens.CARRIAGE_RETURN)
                                    {
                                        _cr=true;
                                        _version=version;
                                        _string.setLength(0);
                                        buffer.position(pos+1);
                                    }
                                    else if (n==HttpTokens.LINE_FEED)
                                    {
                                        _version=version;
                                        _string.setLength(0);
                                        buffer.position(pos);
                                    }
                                }
                            }
                        }
                    }
                    else if (ch == HttpTokens.LINE_FEED)
                    {
                        if (_responseHandler!=null)
                        {
                            handle=_responseHandler.startResponse(_version, _responseStatus, null)||handle;
                            setState(State.HEADER);
                        }
                        else
                        {
                            // HTTP/0.9
                            throw new BadMessageException("HTTP/0.9 not supported");
                        }
                    }
                    else if (ch<0)
                        throw new BadMessageException();
                    break;

                case REQUEST_VERSION:
                    if (ch == HttpTokens.LINE_FEED)
                    {
                        if (_version==null)
                        {
                            _length=_string.length();
                            _version=HttpVersion.CACHE.get(takeString());
                        }
                        if (_version==null)
                            throw new BadMessageException(HttpStatus.BAD_REQUEST_400,"Unknown Version");
                        
                        // Should we try to cache header fields?
                        if (_connectionFields==null && _version.getVersion()>=HttpVersion.HTTP_1_1.getVersion() && _handler.getHeaderCacheSize()>0)
                        {
                            int header_cache = _handler.getHeaderCacheSize();
                            _connectionFields=new ArrayTernaryTrie<>(header_cache);                            
                        }

                        setState(State.HEADER);
                        
                        handle=_requestHandler.startRequest(_methodString,_uri.toString(), _version)||handle;
                        continue;
                    }
                    else if (ch>=HttpTokens.SPACE)
                        _string.append((char)ch);
                    else
                        throw new BadMessageException();

                    break;

                case REASON:
                    if (ch == HttpTokens.LINE_FEED)
                    {
                        String reason=takeString();

                        setState(State.HEADER);
                        handle=_responseHandler.startResponse(_version, _responseStatus, reason)||handle;
                        continue;
                    }
                    else if (ch>=HttpTokens.SPACE)
                    {
                        _string.append((char)ch);
                        if (ch!=' '&&ch!='\t')
                            _length=_string.length();
                    } 
                    else
                        throw new BadMessageException();
                    break;

                default:
                    throw new IllegalStateException(_state.toString());

            }
        }

        return handle;
    }

    private void parsedHeader()
    {
        // handler last header if any.  Delayed to here just in case there was a continuation line (above)
        if (_headerString!=null || _valueString!=null)
        {
            // Handle known headers
            if (_header!=null)
            {
                boolean add_to_connection_trie=false;
                switch (_header)
                {
                    case CONTENT_LENGTH:
                        if (_endOfContent != EndOfContent.CHUNKED_CONTENT)
                        {
                            try
                            {
                                _contentLength=Long.parseLong(_valueString);
                            }
                            catch(NumberFormatException e)
                            {
                                LOG.ignore(e);
                                throw new BadMessageException(HttpStatus.BAD_REQUEST_400,"Bad Content-Length");
                            }
                            if (_contentLength <= 0)
                                _endOfContent=EndOfContent.NO_CONTENT;
                            else
                                _endOfContent=EndOfContent.CONTENT_LENGTH;
                        }
                        break;

                    case TRANSFER_ENCODING:
                        if (_value==HttpHeaderValue.CHUNKED)
                            _endOfContent=EndOfContent.CHUNKED_CONTENT;
                        else
                        {
                            if (_valueString.endsWith(HttpHeaderValue.CHUNKED.toString()))
                                _endOfContent=EndOfContent.CHUNKED_CONTENT;
                            else if (_valueString.contains(HttpHeaderValue.CHUNKED.toString()))
                            {
                                throw new BadMessageException(HttpStatus.BAD_REQUEST_400,"Bad chunking");
                            }
                        }
                        break;

                    case HOST:
                        _host=true;
                        if (!(_field instanceof HostPortHttpField))
                        {
                            _field=new HostPortHttpField(_header,_strict?_headerString:_header.asString(),_valueString);
                            add_to_connection_trie=_connectionFields!=null;
                        }
                      break;
                      
                    case CONNECTION:
                        // Don't cache if not persistent
                        if (_valueString!=null && _valueString.contains("close"))
                            _connectionFields=null;
                        
                        break;

                    case AUTHORIZATION:
                    case ACCEPT:
                    case ACCEPT_CHARSET:
                    case ACCEPT_ENCODING:
                    case ACCEPT_LANGUAGE:
                    case COOKIE:
                    case CACHE_CONTROL:
                    case USER_AGENT:
                        add_to_connection_trie=_connectionFields!=null && _field==null;
                        break;
                        
                    default: break;
                }
            
                if (add_to_connection_trie && !_connectionFields.isFull() && _header!=null && _valueString!=null)
                {
                    if (_field==null)
                        _field=new HttpField(_header,_strict?_headerString:_header.asString(),_valueString);
                    _connectionFields.put(_field);
                }
            }
            _handler.parsedHeader(_field!=null?_field:new HttpField(_header,_headerString,_valueString));
        }
        
        _headerString=_valueString=null;
        _header=null;
        _value=null;
        _field=null;
    }
    
    
    /* ------------------------------------------------------------------------------- */
    /*
     * Parse the message headers and return true if the handler has signaled for a return
     */
    protected boolean parseHeaders(ByteBuffer buffer)
    {
        boolean handle=false;

        // Process headers
        while (_state.ordinal()<State.CONTENT.ordinal() && buffer.hasRemaining() && !handle)
        {
            // process each character
            byte ch=next(buffer);
            if (ch==0)
                break;
            
            if (_maxHeaderBytes>0 && ++_headerBytes>_maxHeaderBytes)
            {
                LOG.warn("Header is too large >"+_maxHeaderBytes);
                throw new BadMessageException(HttpStatus.REQUEST_ENTITY_TOO_LARGE_413);
            }

            switch (_state)
            {
                case HEADER:
                    switch(ch)
                    {
                        case HttpTokens.COLON:
                        case HttpTokens.SPACE:
                        case HttpTokens.TAB:
                            throw new BadMessageException(HttpStatus.BAD_REQUEST_400,"Bad Continuation");

                        case HttpTokens.LINE_FEED:
                        {
                            _contentPosition=0;

                            // End of headers!

                            // Was there a required host header?
                            if (!_host && _version==HttpVersion.HTTP_1_1 && _requestHandler!=null)
                            {
                                throw new BadMessageException(HttpStatus.BAD_REQUEST_400,"No Host");
                            }

                            // is it a response that cannot have a body?
                            if (_responseHandler !=null  && // response  
                                    (_responseStatus == 304  || // not-modified response
                                    _responseStatus == 204 || // no-content response
                                    _responseStatus < 200)) // 1xx response
                                _endOfContent=EndOfContent.NO_CONTENT; // ignore any other headers set

                            // else if we don't know framing
                            else if (_endOfContent == EndOfContent.UNKNOWN_CONTENT)
                            {
                                if (_responseStatus == 0  // request
                                        || _responseStatus == 304 // not-modified response
                                        || _responseStatus == 204 // no-content response
                                        || _responseStatus < 200) // 1xx response
                                    _endOfContent=EndOfContent.NO_CONTENT;
                                else
                                    _endOfContent=EndOfContent.EOF_CONTENT;
                            }

                            // How is the message ended?
                            switch (_endOfContent)
                            {
                                case EOF_CONTENT:
                                    setState(State.EOF_CONTENT);
                                    handle=_handler.headerComplete()||handle;
                                    return handle;

                                case CHUNKED_CONTENT:
                                    setState(State.CHUNKED_CONTENT);
                                    handle=_handler.headerComplete()||handle;
                                    return handle;

                                case NO_CONTENT:
                                    handle=_handler.headerComplete()||handle;
                                    setState(State.END);
                                    handle=_handler.messageComplete()||handle;
                                    return handle;

                                default:
                                    setState(State.CONTENT);
                                    handle=_handler.headerComplete()||handle;
                                    return handle;
                            }
                        }

                        default:
                        {
                            // now handle the ch
                            if (ch<=HttpTokens.SPACE)
                                throw new BadMessageException();

                            if (buffer.hasRemaining())
                            {
                                // Try a look ahead for the known header name and value.
                                HttpField field=_connectionFields==null?null:_connectionFields.getBest(buffer,-1,buffer.remaining());
                                if (field==null)
                                    field=CACHE.getBest(buffer,-1,buffer.remaining());

                                if (field!=null)
                                {
                                    final String n;
                                    final String v;

                                    if (_strict)
                                    {
                                        // Have to get the fields exactly from the buffer to match case
                                        String fn=field.getName();
                                        String fv=field.getValue();
                                        n=BufferUtil.toString(buffer,buffer.position()-1,fn.length(),StandardCharsets.US_ASCII);
                                        if (fv==null)
                                            v=null;
                                        else
                                        {
                                            v=BufferUtil.toString(buffer,buffer.position()+fn.length()+1,fv.length(),StandardCharsets.ISO_8859_1);
                                            field=new HttpField(field.getHeader(),n,v);
                                        }
                                    }
                                    else
                                    {
                                        n=field.getName();
                                        v=field.getValue(); 
                                    }

                                    _header=field.getHeader();
                                    _headerString=n;

                                    if (v==null)
                                    {
                                        // Header only
                                        setState(State.HEADER_VALUE);
                                        _string.setLength(0);
                                        _length=0;
                                        buffer.position(buffer.position()+n.length()+1);
                                        break;
                                    }
                                    else
                                    {
                                        // Header and value
                                        int pos=buffer.position()+n.length()+v.length()+1;
                                        byte b=buffer.get(pos);

                                        if (b==HttpTokens.CARRIAGE_RETURN || b==HttpTokens.LINE_FEED)
                                        {                     
                                            _field=field;
                                            _valueString=v;
                                            setState(State.HEADER_IN_VALUE);

                                            if (b==HttpTokens.CARRIAGE_RETURN)
                                            {
                                                _cr=true;
                                                buffer.position(pos+1);
                                            }
                                            else
                                                buffer.position(pos);
                                            break;
                                        }
                                        else
                                        {
                                            setState(State.HEADER_IN_VALUE);
                                            setString(v);
                                            buffer.position(pos);
                                            break;
                                        }
                                    }
                                }
                            }

                            // New header
                            setState(State.HEADER_IN_NAME);
                            _string.setLength(0);
                            _string.append((char)ch);
                            _length=1;

                        }
                    }
                    break;

                case HEADER_IN_NAME:
                    if (ch==HttpTokens.COLON)
                    {
                        if (_headerString==null)
                        {
                            _headerString=takeString();
                            _header=HttpHeader.CACHE.get(_headerString);
                        }
                        _length=-1;

                        setState(State.HEADER_VALUE);
                        break;
                    }
                    
                    if (ch>HttpTokens.SPACE)
                    {
                        if (_header!=null)
                        {
                            setString(_header.asString());
                            _header=null;
                            _headerString=null;
                        }

                        _string.append((char)ch);
                        if (ch>HttpTokens.SPACE)
                            _length=_string.length();
                        break;
                    }

                    throw new IllegalCharacterException(_state,ch,buffer);

                case HEADER_VALUE:
                    if (ch>HttpTokens.SPACE || ch<0)
                    {
                        _string.append((char)(0xff&ch));
                        _length=_string.length();
                        setState(State.HEADER_IN_VALUE);
                        break;
                    }
                    
                    if (ch==HttpTokens.SPACE || ch==HttpTokens.TAB)
                        break;

                    if (ch==HttpTokens.LINE_FEED)
                    {
                        _value=null;
                        _string.setLength(0);
                        _valueString=null;
                        _length=-1;
                        
                        parsedHeader();
                        setState(State.HEADER);
                        break;
                    }
                    throw new IllegalCharacterException(_state,ch,buffer);

                case HEADER_IN_VALUE:
                    if (ch>=HttpTokens.SPACE || ch<0 || ch==HttpTokens.TAB)
                    {
                        if (_valueString!=null)
                        {
                            setString(_valueString);
                            _valueString=null;
                            _field=null;
                        }
                        _string.append((char)(0xff&ch));
                        if (ch>HttpTokens.SPACE || ch<0)
                            _length=_string.length();
                        break;
                    }
                    
                    if (ch==HttpTokens.LINE_FEED)
                    {
                        if (_length > 0)
                        {
                            _value=null;
                            _valueString=takeString();
                            _length=-1;
                        }
                        parsedHeader();
                        setState(State.HEADER);
                        break;
                    }

                    throw new IllegalCharacterException(_state,ch,buffer);
                    
                default:
                    throw new IllegalStateException(_state.toString());

            }
        }

        return handle;
    }

    /* ------------------------------------------------------------------------------- */
    /**
     * Parse until next Event.
     * @param buffer the buffer to parse
     * @return True if an {@link RequestHandler} method was called and it returned true;
     */
    public boolean parseNext(ByteBuffer buffer)
    {
        if (DEBUG)
            LOG.debug("parseNext s={} {}",_state,BufferUtil.toDetailString(buffer));
        try
        {
            // Start a request/response
            if (_state==State.START)
            {
                _version=null;
                _method=null;
                _methodString=null;
                _endOfContent=EndOfContent.UNKNOWN_CONTENT;
                _header=null;
                if (quickStart(buffer))
                    return true;
            }
            
            // Request/response line
            if (_state.ordinal()>= State.START.ordinal() && _state.ordinal()<State.HEADER.ordinal())
            {
                if (parseLine(buffer))
                    return true;
            }

            // parse headers
            if (_state.ordinal()>= State.HEADER.ordinal() && _state.ordinal()<State.CONTENT.ordinal())
            {
                if (parseHeaders(buffer))
                    return true;
            }
            
            // parse content
            if (_state.ordinal()>= State.CONTENT.ordinal() && _state.ordinal()<State.END.ordinal())
            {
                // Handle HEAD response
                if (_responseStatus>0 && _headResponse)
                {
                    setState(State.END);
                    return _handler.messageComplete();
                }
                else
                {
                    if (parseContent(buffer))
                        return true;
                }
            }
            
            // handle end states
            if (_state==State.END)
            {
                // eat white space
                while (buffer.remaining()>0 && buffer.get(buffer.position())<=HttpTokens.SPACE)
                    buffer.get();
            }
            else if (_state==State.CLOSE)
            {
                // Seeking EOF
                if (BufferUtil.hasContent(buffer))
                {
                    // Just ignore data when closed
                    _headerBytes+=buffer.remaining();
                    BufferUtil.clear(buffer);
                    if (_maxHeaderBytes>0 && _headerBytes>_maxHeaderBytes)
                    {
                        // Don't want to waste time reading data of a closed request
                        throw new IllegalStateException("too much data seeking EOF");
                    }
                }
            }
            else if (_state==State.CLOSED)
            {
                BufferUtil.clear(buffer);
            }
            
            // Handle EOF
            if (_eof && !buffer.hasRemaining())
            {
                switch(_state)
                {
                    case CLOSED:
                        break;
                        
                    case START:
                        setState(State.CLOSED);
                        _handler.earlyEOF();
                        break;
                        
                    case END:
                    case CLOSE:
                        setState(State.CLOSED);
                        break;
                        
                    case EOF_CONTENT:
                        setState(State.CLOSED);
                        return _handler.messageComplete();

                    case  CONTENT:
                    case  CHUNKED_CONTENT:
                    case  CHUNK_SIZE:
                    case  CHUNK_PARAMS:
                    case  CHUNK:
                        setState(State.CLOSED);
                        _handler.earlyEOF();
                        break;

                    default:
                        if (DEBUG)
                            LOG.debug("{} EOF in {}",this,_state);
                        setState(State.CLOSED);
                        _handler.badMessage(400,null);
                        break;
                }
            }
        }
        catch(BadMessageException e)
        {
            BufferUtil.clear(buffer);

            Throwable cause = e.getCause();
            boolean stack = LOG.isDebugEnabled() || 
                    (!(cause instanceof NumberFormatException )  && (cause instanceof RuntimeException || cause instanceof Error));
            
            if (stack)
                LOG.warn("bad HTTP parsed: "+e._code+(e.getReason()!=null?" "+e.getReason():"")+" for "+_handler,e);
            else
                LOG.warn("bad HTTP parsed: "+e._code+(e.getReason()!=null?" "+e.getReason():"")+" for "+_handler);
            setState(State.CLOSE);
            _handler.badMessage(e.getCode(), e.getReason());
        }
        catch(NumberFormatException|IllegalStateException e)
        {
            BufferUtil.clear(buffer);
            LOG.warn("parse exception: {} in {} for {}",e.toString(),_state,_handler);
            if (DEBUG)
                LOG.debug(e);
            
            switch(_state)
            {
                case CLOSED:
                    break;
                case CLOSE:
                    _handler.earlyEOF();
                    break;
                default:
                    setState(State.CLOSE);
                    _handler.badMessage(400,null);
            }
        }
        catch(Exception|Error e)
        {
            BufferUtil.clear(buffer);

            LOG.warn("parse exception: "+e.toString()+" for "+_handler,e);

            switch(_state)
            {
                case CLOSED:
                    break;
                case CLOSE:
                    _handler.earlyEOF();
                    break;
                default:
                    setState(State.CLOSE);
                    _handler.badMessage(400,null);
            }
        }
        return false;
    }

    protected boolean parseContent(ByteBuffer buffer)
    {
        int remaining=buffer.remaining();
        if (remaining==0 && _state==State.CONTENT)
        {
            long content=_contentLength - _contentPosition;
            if (content == 0)
            {
                setState(State.END);
                return _handler.messageComplete();
            }
        }
        
        // Handle _content
        byte ch;
        while (_state.ordinal() < State.END.ordinal() && remaining>0)
        {
            switch (_state)
            {
                case EOF_CONTENT:
                    _contentChunk=buffer.asReadOnlyBuffer();
                    _contentPosition += remaining;
                    buffer.position(buffer.position()+remaining);
                    if (_handler.content(_contentChunk))
                        return true;
                    break;

                case CONTENT:
                {
                    long content=_contentLength - _contentPosition;
                    if (content == 0)
                    {
                        setState(State.END);
                        return _handler.messageComplete();
                    }
                    else
                    {
                        _contentChunk=buffer.asReadOnlyBuffer();

                        // limit content by expected size
                        if (remaining > content)
                        {
                            // We can cast remaining to an int as we know that it is smaller than
                            // or equal to length which is already an int.
                            _contentChunk.limit(_contentChunk.position()+(int)content);
                        }

                        _contentPosition += _contentChunk.remaining();
                        buffer.position(buffer.position()+_contentChunk.remaining());

                        if (_handler.content(_contentChunk))
                            return true;

                        if(_contentPosition == _contentLength)
                        {
                            setState(State.END);
                            return _handler.messageComplete();
                        }
                    }
                    break;
                }

                case CHUNKED_CONTENT:
                {
                    ch=next(buffer);
                    if (ch>HttpTokens.SPACE)
                    {
                        _chunkLength=TypeUtil.convertHexDigit(ch);
                        _chunkPosition=0;
                        setState(State.CHUNK_SIZE);
                    }

                    break;
                }

                case CHUNK_SIZE:
                {
                    ch=next(buffer);
                    if (ch==0)
                        break;
                    if (ch == HttpTokens.LINE_FEED)
                    {
                        if (_chunkLength == 0)
                            setState(State.CHUNK_END);
                        else
                            setState(State.CHUNK);
                    }
                    else if (ch <= HttpTokens.SPACE || ch == HttpTokens.SEMI_COLON)
                        setState(State.CHUNK_PARAMS);
                    else
                        _chunkLength=_chunkLength * 16 + TypeUtil.convertHexDigit(ch);
                    break;
                }

                case CHUNK_PARAMS:
                {
                    ch=next(buffer);
                    if (ch == HttpTokens.LINE_FEED)
                    {
                        if (_chunkLength == 0)
                            setState(State.CHUNK_END);
                        else
                            setState(State.CHUNK);
                    }
                    break;
                }

                case CHUNK:
                {
                    int chunk=_chunkLength - _chunkPosition;
                    if (chunk == 0)
                    {
                        setState(State.CHUNKED_CONTENT);
                    }
                    else
                    {
                        _contentChunk=buffer.asReadOnlyBuffer();

                        if (remaining > chunk)
                            _contentChunk.limit(_contentChunk.position()+chunk);
                        chunk=_contentChunk.remaining();

                        _contentPosition += chunk;
                        _chunkPosition += chunk;
                        buffer.position(buffer.position()+chunk);
                        if (_handler.content(_contentChunk))
                            return true;
                    }
                    break;
                }
                
                case CHUNK_END:
                {
                    // TODO handle chunk trailer
                    ch=next(buffer);
                    if (ch==0)
                        break;
                    if (ch == HttpTokens.LINE_FEED)
                    {
                        setState(State.END);
                        return _handler.messageComplete();
                    }
                    throw new IllegalCharacterException(_state,ch,buffer);
                }
                
                case CLOSED:
                {
                    BufferUtil.clear(buffer);
                    return false;
                }

                default: 
                    break;
                    
            }
            
            remaining=buffer.remaining();
        }
        return false;
    }

    /* ------------------------------------------------------------------------------- */
    public boolean isAtEOF()
 
    {
        return _eof;
    }
    
    /* ------------------------------------------------------------------------------- */
    /** Signal that the associated data source is at EOF
     */
    public void atEOF()
    {        
        if (DEBUG)
            LOG.debug("atEOF {}", this);
        _eof=true;
    }

    /* ------------------------------------------------------------------------------- */
    /** Request that the associated data source be closed
     */
    public void close()
    {
        if (DEBUG)
            LOG.debug("close {}", this);
        setState(State.CLOSE);
    }
    
    /* ------------------------------------------------------------------------------- */
    public void reset()
    {
        if (DEBUG)
            LOG.debug("reset {}", this);

        // reset state
        if (_state==State.CLOSE || _state==State.CLOSED)
            return;
        
        setState(State.START);
        _endOfContent=EndOfContent.UNKNOWN_CONTENT;
        _contentLength=-1;
        _contentPosition=0;
        _responseStatus=0;
        _contentChunk=null;
        _headerBytes=0;
        _host=false;
    }

    /* ------------------------------------------------------------------------------- */
    protected void setState(State state)
    {
        if (DEBUG)
            LOG.debug("{} --> {}",_state,state);
        _state=state;
    }

    /* ------------------------------------------------------------------------------- */
    public Trie<HttpField> getFieldCache()
    {
        return _connectionFields;
    }

    /* ------------------------------------------------------------------------------- */
    private String getProxyField(ByteBuffer buffer)
    {
        _string.setLength(0);
        _length=0;
        
        while (buffer.hasRemaining())
        {
            // process each character
            byte ch=next(buffer);
            if (ch<=' ')
                return _string.toString();
            _string.append((char)ch);    
        }
        throw new BadMessageException();
    }
    
    /* ------------------------------------------------------------------------------- */
    @Override
    public String toString()
    {
        return String.format("%s{s=%s,%d of %d}",
                getClass().getSimpleName(),
                _state,
                _contentPosition,
                _contentLength);
    }

    /* ------------------------------------------------------------ */
    /* ------------------------------------------------------------ */
    /* ------------------------------------------------------------ */
    /* Event Handler interface
     * These methods return true if the caller should process the events
     * so far received (eg return from parseNext and call HttpChannel.handle).
     * If multiple callbacks are called in sequence (eg 
     * headerComplete then messageComplete) from the same point in the parsing
     * then it is sufficient for the caller to process the events only once.
     */
    public interface HttpHandler
    {
        public boolean content(ByteBuffer item);

        public boolean headerComplete();

        public boolean messageComplete();

        /**
         * This is the method called by parser when a HTTP Header name and value is found
         * @param field The field parsed
         */
        public void parsedHeader(HttpField field);
        
        /* ------------------------------------------------------------ */
        /** Called to signal that an EOF was received unexpectedly
         * during the parsing of a HTTP message
         */
        public void earlyEOF();

        /* ------------------------------------------------------------ */
        /** Called to signal that a bad HTTP message has been received.
         * @param status The bad status to send
         * @param reason The textual reason for badness
         */
        public void badMessage(int status, String reason);
        
        /* ------------------------------------------------------------ */
        /** @return the size in bytes of the per parser header cache
         */
        public int getHeaderCacheSize();
    }

    /* ------------------------------------------------------------------------------- */
    /* ------------------------------------------------------------------------------- */
    /* ------------------------------------------------------------------------------- */
    public interface RequestHandler extends HttpHandler
    {
        /**
         * This is the method called by parser when the HTTP request line is parsed
         * @param method The method 
         * @param uri The raw bytes of the URI.  These are copied into a ByteBuffer that will not be changed until this parser is reset and reused.
         * @param version the http version in use
         * @return true if handling parsing should return.
         */
        public boolean startRequest(String method, String uri, HttpVersion version);

    }

    /* ------------------------------------------------------------------------------- */
    /* ------------------------------------------------------------------------------- */
    /* ------------------------------------------------------------------------------- */
    public interface ResponseHandler extends HttpHandler
    {
        /**
         * This is the method called by parser when the HTTP request line is parsed
         * @param version the http version in use
         * @param status the response status
         * @param reason the response reason phrase
         * @return true if handling parsing should return
         */
        public boolean startResponse(HttpVersion version, int status, String reason);
    }

    /* ------------------------------------------------------------------------------- */
    @SuppressWarnings("serial")
    private static class IllegalCharacterException extends BadMessageException
    {
        private IllegalCharacterException(State state,byte ch,ByteBuffer buffer)
        {
            super(400,String.format("Illegal character 0x%X",ch));
            // Bug #460642 - don't reveal buffers to end user
            LOG.warn(String.format("Illegal character 0x%X in state=%s for buffer %s",ch,state,BufferUtil.toDetailString(buffer)));
        }
    }
}