parseutil.cpp

UPnP的SDK源代码

        }
        
        HttpHeaderValue* data;
        data = (HttpHeaderValue *) node->data;
        data->toString( s );
        node = list.next( node );
    }
}

// can't include ctype.h because of a xerces bug
static bool IsAlpha( char c )
{
    return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z');
}

// returns true if the tag matches language tag syntax
//  (1*8ALPHA * ("-" 1*8ALPHA)) | *
static bool ValidLanguageTag( const char* tag )
{
    int i;
    char c;
    int count;
    
    if ( strcmp(tag, "*") == 0 )
    {
        return true;
    }
    
    i = 0;
    while ( true )
    {
        // match 1..8 alpha
        for ( count = 0; count < 8; count++ )
        {
            c = tag[i++];
            if ( !IsAlpha(c) )
            {
                if ( count == 0 )
                {
                    return false;   // no alpha found
                }
                i--;    // put back char
                break;  // okay; valid alpha str
            }
        }
        
        c = tag[i++];
        
        if ( c == '\0' )
        {
            return true;    // end of valid tag
        }
        
        if ( c != '-' )
        {
            return false;   // expected '-'
        }
    }
    
    return false;       // this line never executes
}


// parses a header from input stream; returns header type and
//  and value
// on success: headerID > 0  and returnValue != NULL
//             headerID == -1 and returnValue = UnknownHeader
// on failure: returnValue == NULL
static HttpHeaderValue* ParseHeader( IN Tokenizer& scanner,
    OUT int& headerID )
{
    int id;
    Token* token;
    xstring name;

    // read header name
    ParseHeaderName( scanner, name );

    // map name to id
    id = NameToID( name.c_str(), HeaderNameTable, NUM_HEADERS, false );
    if ( id < 0 )
    {
        // header type currently not known; process raw

        id = HDR_UNKNOWN;

        scanner.pushBack(); // return unknown header name
    }

    // skip past colon;
    if ( id != HDR_UNKNOWN )
    {
        SkipColonLWS( scanner );
    }
    // now pointing at first non-whitespace token after colon

    HttpHeaderValue *header = NULL;
        
    switch ( id )
    {
        case HDR_ACCEPT:
            header = new CommaSeparatedList( true, CreateMediaRange );
            break;
            
        case HDR_ACCEPT_CHARSET:
        case HDR_ACCEPT_ENCODING:
            header = new CommaSeparatedList( true, CreateIdentifierQValue, 1 );
            break;
            
        case HDR_ACCEPT_LANGUAGE:
            header = new CommaSeparatedList( true, CreateLanguageTag, 1 );
            break;

        case HDR_AGE:
        case HDR_CONTENT_LENGTH:
        case HDR_MAX_FORWARDS:
            header = new HttpNumber;
            break;          
            
        case HDR_ALLOW:
        case HDR_CONNECTION:
        case HDR_CONTENT_ENCODING:
        case HDR_TRANSFER_ENCODING:
            header = new CommaSeparatedList( false, CreateIdentifierValue );
            break;
            
        case HDR_CACHE_CONTROL:
            header = new CommaSeparatedList( false, CreateCacheDirective );
            break;
            
        case HDR_CONTENT_LANGUAGE:
            header = new CommaSeparatedList( false, CreateLanguageTag );
            break;
            
        case HDR_CONTENT_LOCATION:
        case HDR_LOCATION:
            header = new UriType;
            break;
            
        case HDR_CONTENT_TYPE:
            header = new MediaRange;
            break;
            
        case HDR_DATE:
        case HDR_EXPIRES:
        case HDR_IF_MODIFIED_SINCE:
        case HDR_IF_UNMODIFIED_SINCE:
        case HDR_LAST_MODIFIED:
            header = new HttpDateValue;
            break;
            
        case HDR_HOST:
            header = new HostPortValue;
            break;
            
        case HDR_RETRY_AFTER:
            header = new HttpDateOrSeconds;
            break;
        
		/*	--trimming down parser
        case HDR_UPNP_NTS:
            header = new NTSType;
            break;
		*/

        case HDR_UNKNOWN:
            header = new UnknownHeader;
            break;

        default:
            header = new RawHeaderValue;
    }
    
    if ( header == NULL )
    {
        throw OutOfMemoryException( "ParseHeader()" );
    }

    try
    {
        header->load( scanner );

        // skip whitespace after value
        SkipOptionalLWS( scanner );

        // end of header -- crlf
        token = scanner.getToken();
        if ( token->tokType != Token::CRLF )
        {
            throw HttpParseException();
        }
    }
    catch ( HttpParseException& /* e */ )
    {
            SkipHeader( scanner );  // bad header -- ignore it

            id = -2;
            delete header;
            header = NULL;
    }

    headerID = id;
        
    return header;
}

// precond: scanner pointing to the line after the start line
static void ParseHeaders( IN Tokenizer& scanner,
    OUT HttpHeaderList& list )
{
    Token *token;
    int id;
    HttpHeaderValue* headerValue;
    HttpHeader* header;
    
    while ( true )
    {
        token = scanner.getToken();
        if ( token->tokType == Token::CRLF )
        {
            // end of headers
            break;
        }
        else if ( token->tokType == Token::END_OF_STREAM )
        {
            // bad format
            scanner.pushBack();
            throw HttpParseException( "ParseHeaders(): unexpected end of msg" );
            break;
        }
        else
        {
            // token was probably start of a header
            scanner.pushBack();
        }
    
        headerValue = ParseHeader( scanner, id );
        if ( headerValue != NULL )
        {
            header = new HttpHeader;
            if ( header == NULL )
            {
                throw OutOfMemoryException( "ParseHeaders()" );
            }

            header->type = id;
            header->value = headerValue;
            
            list.addAfterTail( header );
        }
    }
}

/////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////

// HttpHeaderQValue
void HttpQHeaderValue::toString( xstring& s )
{
    if ( qIsUsed )
    {
        char buf[100];
        sprintf( buf, ";q=%1.3f", q );
        s += buf;
    }
}

void HttpQHeaderValue::loadOptionalQValue( IN Tokenizer& scanner )
{
    q = 1.0;    // default value
    
    // try getting q
    try
    {
        Token* token;
        
        if ( qIsUsed )
        {
            SkipOptionalLWS( scanner );
        
            token = scanner.getToken();
            if ( token->s != ';' )
            {
                scanner.pushBack();
                //DBG( printf("HttpQHeaderValue: did not find ;\n"); )
                throw 1;
            }
            SkipOptionalLWS( scanner );
            q = LoadQValue( scanner );
        }
    }
    catch ( int /* code */ )
    {
        // no q value
        //DBG( printf("HttpQHeaderValue: did not find semicolon\n"); )
    }
}

// HttpNumber
void HttpNumber::toString( xstring& s )
{
    char buf[50];
    
    sprintf( buf, "%d", num );
    s += buf;
}

void HttpNumber::load( Tokenizer& scanner )
{
    num = loadNum( scanner, 10 );   
}

// HttpHexNumber
void HttpHexNumber::toString( xstring& s )
{
    char buf[50];
    
    sprintf( buf, "%X", num );
    s += buf;
}

void HttpHexNumber::load( Tokenizer& scanner )
{
    num = loadNum( scanner, 16 );
}

// MediaExtension
void MediaExtension::toString( xstring& s )
{
    s += ';';
    s += name;
    s += "=";
    s += value;
}

// match: ext = value
void MediaExtension::load( Tokenizer& scanner )
{
    Token* token;
    HttpParseException e("MediaExtension::load()",
        scanner.getLineNum() );
    
    token = scanner.getToken();
    if ( token->tokType != Token::IDENTIFIER )
    {
        throw e;
    }
    name = token->s;
    
    SkipOptionalLWS( scanner );
    
    token = scanner.getToken();
    if ( token->s != "=" )
    {
        throw e;
    }
    
    SkipOptionalLWS( scanner );
    
    token = scanner.getToken();
    if ( token->tokType != Token::IDENTIFIER &&
         token->tokType != Token::QUOTED_STRING )
    {
        throw e;
    }
    value = token->s;
}

// MediaParam
void MediaParam::load( Tokenizer& scanner )
{
    Token* token;
    
    token = scanner.getToken();
    if ( token->s != ';' )
    {
        scanner.pushBack();
        throw HttpParseException( "MediaParam::load(): ; missing",
            scanner.getLineNum() );
    }
    
    SkipOptionalLWS( scanner );
    
    token = scanner.getToken();
    if ( token->s == 'q' )
    {
        scanner.pushBack();
        q = LoadQValue( scanner );
    }
    
    SkipOptionalLWS( scanner );
    
    while ( true )
    {
        MediaExtension* ext;
        
        token = scanner.getToken();
        if ( token->s != ';' )
        {
            scanner.pushBack();
            break;  // no more extensions
        }
        
        ext = new MediaExtension();
        if ( ext == NULL )
        {
            throw OutOfMemoryException( "MediaParam::load()" );
        }

        SkipOptionalLWS( scanner );

        ext->load( scanner );
        
        extList.addAfterTail( ext );
    }
}

void MediaParam::toString( xstring& s )
{
    HttpQHeaderValue::toString( s );    // print q
    
    HttpHeaderValue* value;
    HttpHeaderValueNode* node;
    
    node = extList.getFirstItem();
    while ( node != NULL )
    {
        value = (HttpHeaderValue *)node->data;
        value->toString( s );
        
        node = extList.next( node );
    }
}

// MediaRange
void MediaRange::toString( xstring& s )
{
    s += type;
    s += '/';
    s += subtype;

    mparam.toString( s );
}

void MediaRange::load( Tokenizer& scanner )
{
    Token* token;
    
    token = scanner.getToken();
    if ( token->tokType != Token::IDENTIFIER )
    {
        scanner.pushBack();
        throw HttpParseException( "MediaRange::load(): type expected",
            scanner.getLineNum() );
    }
    type = token->s;

    SkipOptionalLWS( scanner );

    token = scanner.getToken();
    if ( token->s != '/' )
    {
        scanner.pushBack();
        throw HttpParseException( "MediaRange::load(): / expected",
            scanner.getLineNum() );
    }

    SkipOptionalLWS( scanner );

    token = scanner.getToken();
    if ( token->tokType != Token::IDENTIFIER ||
         (type == '*' && token->s != '*')
        )
    {
        scanner.pushBack();
        throw HttpParseException( "MediaRange::load(): subtype expected",
            scanner.getLineNum() );
    }
    subtype = token->s;

    mparam.load( scanner );
}

// returns: 0 same, -1 this < r, 1 this > r, -2 unrelated
// returns true if 'this' range has higher precedence than r
int MediaRange::compare( const MediaRange& r ) const
{
    if ( mparam.q > r.mparam.q )
    {
        return 1;
    }
    else if ( mparam.q < r.mparam.q )
    {
        return -1;
    }
    else    // equal
    {
        bool t = false, rt = false;
        
        t = (type == '*');
        rt = (type == '*');
        
        if ( t && !rt ) return -1;
        else if ( !t && rt ) return 1;
        else if ( type == r.type )
        {
            if ( subtype == r.subtype )
            {
                return 0;
            }
            else if ( subtype == '*' && r.subtype != '*' )
            {
                return 1;
            }
            else if ( subtype != '*' && r.subtype == '*' )
            {
                return -1;
            }
            else
            {
                return 0;
            }
        }
        else if ( type != r.type )
        {
            return -2;
        }
    }
    
    return -2;
}

// MediaRangeList
void MediaRangeList::toString( xstring& s )
{
    HeaderValueListToString( mediaList, s );
}

/*
static void ReadCommaSeperatedList( IN Tokenizer& scanner,
    OUT HttpHeaderValueList& list,
    IN int minItems, IN int maxItems,
    IN ReadHttpValueCallback callback,
    IN AddValueToListCallback addCallback = NULL )
*/


// add media range in a sorted manner
static void AddMediaRangeToList( HttpHeaderValueList& list,
    HttpHeaderValue *value )
{
    MediaRange* b = (MediaRange*) value;
    MediaRange* a;
    HttpHeaderValueNode* node;
    int inserted = false;
    int comp = 0;
    
    node = list.getFirstItem();
    while ( node != NULL )
    {
        a = (MediaRange*) node->data;
        comp = a->compare( *b );
        if ( comp == 1 || comp == 0 )
        {
            list.addBefore( node, b );
            inserted = true;
            break;
        }
        else if ( comp == -1 )
        {
            list.addAfter( node, b );
            inserted = true;
            break;
        }