Parser.cs source code in C# .NET

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Code:

/ 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / clr / src / BCL / System / Security / Util / Parser.cs / 1305376 / Parser.cs

                            // ==++== 
//
//   Copyright (c) Microsoft Corporation.  All rights reserved.
//
// ==--== 
/*============================================================
** 
** CLASS:    Parser 
**
** [....] 
**
**
** PURPOSE:  Parse "Elementary XML", that is, XML without
**           attributes or DTDs, in other words, XML with 
**           elements only.
** 
** 
===========================================================*/
namespace System.Security.Util { 
    using System.Text;
    using System.Runtime.InteropServices;
    using System;
    using BinaryReader = System.IO.BinaryReader ; 
    using ArrayList = System.Collections.ArrayList;
    using Stream = System.IO.Stream; 
    using StreamReader = System.IO.StreamReader; 
    using Encoding = System.Text.Encoding;
 
    sealed internal class Parser
    {
        private SecurityDocument _doc;
        private Tokenizer _t; 

        internal SecurityElement GetTopElement() 
        { 
            if (!ParsedSuccessfully())
                throw new XmlSyntaxException (_t.LineNo); 

            return _doc.GetRootElement();
        }
 
        internal bool ParsedSuccessfully()
        { 
            return true; 
        }
 
        private const short c_flag = 0x4000;
        private const short c_elementtag = (short)(SecurityDocument.c_element << 8 | c_flag);
        private const short c_attributetag = (short)(SecurityDocument.c_attribute << 8 | c_flag);
        private const short c_texttag = (short)(SecurityDocument.c_text << 8 | c_flag); 
        private const short c_additionaltexttag = (short)(SecurityDocument.c_text << 8 | c_flag | 0x2000);
        private const short c_childrentag = (short)(SecurityDocument.c_children << 8 | c_flag); 
        private const short c_wastedstringtag = (short)(0x1000 | c_flag); 

        private void GetRequiredSizes( TokenizerStream stream, ref int index ) 
        {
            //
            // Iteratively collect stuff up until the next end-tag.
            // We've already seen the open-tag. 
            //
 
            bool needToBreak = false; 
            bool needToPop = false;
            bool createdNode = false; 
            bool intag = false;
            int stackDepth = 1;
            SecurityElementType type = SecurityElementType.Regular;
            String strValue = null; 
            bool sawEquals = false;
            bool sawText = false; 
            int status = 0; 

            short i; 

            do
            {
                for (i = stream.GetNextToken() ; i != -1 ; i = stream.GetNextToken()) 
                {
                    switch (i & 0x00FF) 
                    { 
                    case Tokenizer.cstr:
                        { 
                            if (intag)
                            {
                                if (type == SecurityElementType.Comment)
                                { 
                                    // Ignore data in comments but still get the data
                                    // to keep the stream in the right place. 
                                    stream.ThrowAwayNextString(); 
                                    stream.TagLastToken( c_wastedstringtag );
                                } 
                                else
                                {
                                    // We're in a regular tag, so we've found an attribute/value pair.
 
                                    if (strValue == null)
                                    { 
                                        // Found attribute name, save it for later. 

                                        strValue = stream.GetNextString(); 
                                    }
                                    else
                                    {
                                        // Found attribute text, add the pair to the current element. 

                                        if (!sawEquals) 
                                            throw new XmlSyntaxException( _t.LineNo ); 

                                        stream.TagLastToken( c_attributetag ); 
                                        index += SecurityDocument.EncodedStringSize( strValue ) +
                                                 SecurityDocument.EncodedStringSize( stream.GetNextString() ) +
                                                 1;
                                        strValue = null; 
                                        sawEquals = false;
                                    } 
                                } 
                            }
                            else 
                            {
                                // We're not in a tag, so we've found text between tags.

                                if (sawText) 
                                {
                                    stream.TagLastToken( c_additionaltexttag ); 
                                    index += SecurityDocument.EncodedStringSize( stream.GetNextString() ) + 
                                             SecurityDocument.EncodedStringSize( " " );
                                } 
                                else
                                {
                                    stream.TagLastToken( c_texttag );
                                    index += SecurityDocument.EncodedStringSize( stream.GetNextString() ) + 
                                             1;
                                    sawText = true; 
                                } 
                            }
                        } 
                        break;

                    case Tokenizer.bra:
                        intag = true; 
                        sawText = false;
                        i = stream.GetNextToken(); 
 
                        if (i == Tokenizer.slash)
                        { 
                            stream.TagLastToken( c_childrentag );
                            while (true)
                            {
                                // spin; don't care what's in here 
                                i = stream.GetNextToken();
                                if (i == Tokenizer.cstr) 
                                { 
                                    stream.ThrowAwayNextString();
                                    stream.TagLastToken( c_wastedstringtag ); 
                                }
                                else if (i == -1)
                                    throw new XmlSyntaxException (_t.LineNo, Environment.GetResourceString( "XMLSyntax_UnexpectedEndOfFile" ));
                                else 
                                    break;
                            } 
 
                            if (i != Tokenizer.ket)
                            { 
                                throw new XmlSyntaxException (_t.LineNo, Environment.GetResourceString( "XMLSyntax_ExpectedCloseBracket" ));
                            }

                            intag = false; 

                            // Found the end of this element 
                            index++; 

                            sawText = false; 
                            stackDepth--;

                            needToBreak = true;
                        } 
                        else if (i == Tokenizer.cstr)
                        { 
                            // Found a child 

                            createdNode = true; 

                            stream.TagLastToken( c_elementtag );
                            index += SecurityDocument.EncodedStringSize( stream.GetNextString() ) +
                                     1; 

                            if (type != SecurityElementType.Regular) 
                                throw new XmlSyntaxException( _t.LineNo ); 

                            needToBreak = true; 
                            stackDepth++;
                        }
                        else if (i == Tokenizer.bang)
                        { 
                            // Found a child that is a comment node.  Next up better be a cstr.
 
                            status = 1; 

                            do 
                            {
                                i = stream.GetNextToken();

                                switch (i) 
                                {
                                case Tokenizer.bra: 
                                    status++; 
                                    break;
 
                                case Tokenizer.ket:
                                    status--;
                                    break;
 
                                case Tokenizer.cstr:
                                    stream.ThrowAwayNextString(); 
                                    stream.TagLastToken( c_wastedstringtag ); 
                                    break;
 
                                default:
                                    break;
                                }
                            } while (status > 0); 

                            intag = false; 
                            sawText = false; 
                            needToBreak = true;
                        } 
                        else if (i == Tokenizer.quest)
                        {
                            // Found a child that is a format node.  Next up better be a cstr.
 
                            i = stream.GetNextToken();
 
                            if (i != Tokenizer.cstr) 
                                throw new XmlSyntaxException( _t.LineNo );
 
                            createdNode = true;

                            type = SecurityElementType.Format;
 
                            stream.TagLastToken( c_elementtag );
                            index += SecurityDocument.EncodedStringSize( stream.GetNextString() ) + 
                                     1; 

                            status = 1; 
                            stackDepth++;

                            needToBreak = true;
                        } 
                        else
                        { 
                            throw new XmlSyntaxException (_t.LineNo, Environment.GetResourceString( "XMLSyntax_ExpectedSlashOrString" )); 
                        }
                        break ; 

                    case Tokenizer.equals:
                        sawEquals = true;
                        break; 

                    case Tokenizer.ket: 
                        if (intag) 
                        {
                            intag = false; 
                            continue;
                        }
                        else
                        { 
                            throw new XmlSyntaxException (_t.LineNo, Environment.GetResourceString( "XMLSyntax_UnexpectedCloseBracket" ));
                        } 
                        // not reachable 

                    case Tokenizer.slash: 
                        i = stream.GetNextToken();

                        if (i == Tokenizer.ket)
                        { 
                            // Found the end of this element
                            stream.TagLastToken( c_childrentag ); 
                            index++; 
                            stackDepth--;
                            sawText = false; 

                            needToBreak = true;
                        }
                        else 
                        {
                            throw new XmlSyntaxException (_t.LineNo, Environment.GetResourceString( "XMLSyntax_ExpectedCloseBracket" )); 
                        } 
                        break;
 
                    case Tokenizer.quest:
                        if (intag && type == SecurityElementType.Format && status == 1)
                        {
                            i = stream.GetNextToken(); 

                            if (i == Tokenizer.ket) 
                            { 
                                stream.TagLastToken( c_childrentag );
                                index++; 
                                stackDepth--;
                                sawText = false;

                                needToBreak = true; 
                            }
                            else 
                            { 
                                throw new XmlSyntaxException (_t.LineNo, Environment.GetResourceString( "XMLSyntax_ExpectedCloseBracket" ));
                            } 
                        }
                        else
                        {
                            throw new XmlSyntaxException (_t.LineNo); 
                        }
                        break; 
 
                    case Tokenizer.dash:
                    default: 
                        throw new XmlSyntaxException (_t.LineNo) ;
                    }

                    if (needToBreak) 
                    {
                        needToBreak = false; 
                        needToPop = false; 
                        break;
                    } 
                    else
                    {
                        needToPop = true;
                    } 
                }
 
                if (needToPop) 
                {
                    index++; 
                    stackDepth--;
                    sawText = false;
                }
                else if (i == -1 && (stackDepth != 1 || !createdNode)) 
                {
                    // This means that we still have items on the stack, but the end of our 
                    // stream has been reached. 

                    throw new XmlSyntaxException( _t.LineNo, Environment.GetResourceString( "XMLSyntax_UnexpectedEndOfFile" )); 
                }
            }
            while (stackDepth > 1);
        } 

        private int DetermineFormat( TokenizerStream stream ) 
        { 
            if (stream.GetNextToken() == Tokenizer.bra)
            { 
                if (stream.GetNextToken() == Tokenizer.quest)
                {
                    _t.GetTokens( stream, -1, true );
                    stream.GoToPosition( 2 ); 

                    bool sawEquals = false; 
                    bool sawEncoding = false; 

                    short i; 

                    for (i = stream.GetNextToken(); i != -1 && i != Tokenizer.ket; i = stream.GetNextToken())
                    {
                        switch (i) 
                        {
                        case Tokenizer.cstr: 
                            if (sawEquals && sawEncoding) 
                            {
                                _t.ChangeFormat( System.Text.Encoding.GetEncoding( stream.GetNextString() ) ); 
                                return 0;
                            }
                            else if (!sawEquals)
                            { 
                                if (String.Compare( stream.GetNextString(), "encoding", StringComparison.Ordinal) == 0)
                                    sawEncoding = true; 
                            } 
                            else
                            { 
                                sawEquals = false;
                                sawEncoding = false;
                                stream.ThrowAwayNextString();
                            } 
                            break;
 
                        case Tokenizer.equals: 
                            sawEquals = true;
                            break; 

                        default:
                            throw new XmlSyntaxException (_t.LineNo, Environment.GetResourceString( "XMLSyntax_UnexpectedEndOfFile" ));
                        } 
                    }
 
                    return 0; 
                }
            } 

            return 2;
        }
 

        private void ParseContents() 
        { 
            short i;
 
            TokenizerStream stream = new TokenizerStream();

            _t.GetTokens( stream, 2, false );
            stream.Reset(); 

            int gotoPosition = DetermineFormat( stream ); 
 
            stream.GoToPosition( gotoPosition );
            _t.GetTokens( stream, -1, false ); 
            stream.Reset();

            int neededIndex = 0;
 
            GetRequiredSizes( stream, ref neededIndex );
 
            _doc = new SecurityDocument( neededIndex ); 
            int position = 0;
 
            stream.Reset();

            for (i = stream.GetNextFullToken(); i != -1; i = stream.GetNextFullToken())
            { 
                if ((i & c_flag) != c_flag)
                    continue; 
                else 
                {
                    switch((short)(i & 0xFF00)) 
                    {
                    case c_elementtag:
                        _doc.AddToken( SecurityDocument.c_element, ref position );
                        _doc.AddString( stream.GetNextString(), ref position ); 
                        break;
 
                    case c_attributetag: 
                        _doc.AddToken( SecurityDocument.c_attribute, ref position );
                        _doc.AddString( stream.GetNextString(), ref position ); 
                        _doc.AddString( stream.GetNextString(), ref position );
                        break;

                    case c_texttag: 
                        _doc.AddToken( SecurityDocument.c_text, ref position );
                        _doc.AddString( stream.GetNextString(), ref position ); 
                        break; 

                    case c_additionaltexttag: 
                        _doc.AppendString( " ", ref position );
                        _doc.AppendString( stream.GetNextString(), ref position );
                        break;
 
                    case c_childrentag:
                        _doc.AddToken( SecurityDocument.c_children, ref position ); 
                        break; 

                    case c_wastedstringtag: 
                        stream.ThrowAwayNextString();
                        break;

                    default: 
                        throw new XmlSyntaxException();
                    } 
                } 
            }
        } 

        private Parser(Tokenizer t)
        {
            _t = t; 
            _doc = null;
 
            try 
            {
                ParseContents(); 
            }
            finally
            {
                _t.Recycle(); 
            }
        } 
 
        internal Parser (String input)
            : this (new Tokenizer (input)) 
        {
        }

        internal Parser (String input, String[] searchStrings, String[] replaceStrings) 
            : this (new Tokenizer (input, searchStrings, replaceStrings))
        { 
        } 

        internal Parser( byte[] array, Tokenizer.ByteTokenEncoding encoding ) 
            : this (new Tokenizer( array, encoding, 0 ) )
        {
        }
 

        internal Parser( byte[] array, Tokenizer.ByteTokenEncoding encoding, int startIndex ) 
            : this (new Tokenizer( array, encoding, startIndex ) ) 
        {
        } 

        internal Parser( StreamReader input )
            : this (new Tokenizer( input ) )
        { 
        }
 
        internal Parser( char[] array ) 
            : this (new Tokenizer( array ) )
        { 
        }

    }
 
}
 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
                        

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