parser.c

SIP（Session Initiation Protocol）是由IETF定义

 */
xmlParserInputPtr
xmlNewInputStream(xmlParserCtxtPtr ctxt) {
    xmlParserInputPtr input;

    input = (xmlParserInputPtr) xmlMalloc(sizeof(xmlParserInput));
    if (input == NULL) {
	if (ctxt != NULL) {
	    ctxt->errNo = XML_ERR_NO_MEMORY;
	    if ((ctxt->sax != NULL) && (ctxt->sax->error != NULL))
		ctxt->sax->error(ctxt->userData, 
			 "malloc: couldn't allocate a new input stream\n");
	    ctxt->errNo = XML_ERR_NO_MEMORY;
	}
	return(NULL);
    }
    memset(input, 0, sizeof(xmlParserInput));
    input->line = 1;
    input->col = 1;
    input->standalone = -1;
    return(input);
}

/**
 * xmlNewIOInputStream:
 * @ctxt:  an XML parser context
 * @input:  an I/O Input
 * @enc:  the charset encoding if known
 *
 * Create a new input stream structure encapsulating the @input into
 * a stream suitable for the parser.
 *
 * Returns the new input stream or NULL
 */
xmlParserInputPtr
xmlNewIOInputStream(xmlParserCtxtPtr ctxt, xmlParserInputBufferPtr input,
	            xmlCharEncoding enc) {
    xmlParserInputPtr inputStream;

    inputStream = xmlNewInputStream(ctxt);
    if (inputStream == NULL) {
	return(NULL);
    }
    inputStream->filename = NULL;
    inputStream->buf = input;
    inputStream->base = inputStream->buf->buffer->content;
    inputStream->cur = inputStream->buf->buffer->content;
    if (enc != XML_CHAR_ENCODING_NONE) {
        xmlSwitchEncoding(ctxt, enc);
    }

    return(inputStream);
}

/**
 * xmlNewEntityInputStream:
 * @ctxt:  an XML parser context
 * @entity:  an Entity pointer
 *
 * Create a new input stream based on an xmlEntityPtr
 *
 * Returns the new input stream or NULL
 */
xmlParserInputPtr
xmlNewEntityInputStream(xmlParserCtxtPtr ctxt, xmlEntityPtr entity) {
    xmlParserInputPtr input;

    if (entity == NULL) {
        ctxt->errNo = XML_ERR_INTERNAL_ERROR;
        if ((ctxt->sax != NULL) && (ctxt->sax->error != NULL))
	    ctxt->sax->error(ctxt->userData,
	      "internal: xmlNewEntityInputStream entity = NULL\n");
	ctxt->errNo = XML_ERR_INTERNAL_ERROR;
	return(NULL);
    }
    if (entity->content == NULL) {
	switch (entity->etype) {
            case XML_EXTERNAL_GENERAL_UNPARSED_ENTITY:
	        ctxt->errNo = XML_ERR_UNPARSED_ENTITY;
		if ((ctxt->sax != NULL) && (ctxt->sax->error != NULL))
		    ctxt->sax->error(ctxt->userData,
		      "xmlNewEntityInputStream unparsed entity !\n");
                break;
            case XML_EXTERNAL_GENERAL_PARSED_ENTITY:
            case XML_EXTERNAL_PARAMETER_ENTITY:
		return(xmlLoadExternalEntity((char *) entity->SystemID,
		       (char *) entity->ExternalID, ctxt));
            case XML_INTERNAL_GENERAL_ENTITY:
		if ((ctxt->sax != NULL) && (ctxt->sax->error != NULL))
		    ctxt->sax->error(ctxt->userData,
	  "Internal entity %s without content !\n", entity->name);
                break;
            case XML_INTERNAL_PARAMETER_ENTITY:
		ctxt->errNo = XML_ERR_INTERNAL_ERROR;
		if ((ctxt->sax != NULL) && (ctxt->sax->error != NULL))
		    ctxt->sax->error(ctxt->userData,
	  "Internal parameter entity %s without content !\n", entity->name);
                break;
            case XML_INTERNAL_PREDEFINED_ENTITY:
		ctxt->errNo = XML_ERR_INTERNAL_ERROR;
		if ((ctxt->sax != NULL) && (ctxt->sax->error != NULL))
		    ctxt->sax->error(ctxt->userData,
	      "Predefined entity %s without content !\n", entity->name);
                break;
	}
	return(NULL);
    }
    input = xmlNewInputStream(ctxt);
    if (input == NULL) {
	return(NULL);
    }
    input->filename = (char *) entity->SystemID;
    input->base = entity->content;
    input->cur = entity->content;
    input->length = entity->length;
    return(input);
}

/**
 * xmlNewStringInputStream:
 * @ctxt:  an XML parser context
 * @buffer:  an memory buffer
 *
 * Create a new input stream based on a memory buffer.
 * Returns the new input stream
 */
xmlParserInputPtr
xmlNewStringInputStream(xmlParserCtxtPtr ctxt, const xmlChar *buffer) {
    xmlParserInputPtr input;

    if (buffer == NULL) {
	ctxt->errNo = XML_ERR_INTERNAL_ERROR;
        if ((ctxt->sax != NULL) && (ctxt->sax->error != NULL))
	    ctxt->sax->error(ctxt->userData,
	      "internal: xmlNewStringInputStream string = NULL\n");
	return(NULL);
    }
    input = xmlNewInputStream(ctxt);
    if (input == NULL) {
	return(NULL);
    }
    input->base = buffer;
    input->cur = buffer;
    input->length = xmlStrlen(buffer);
    return(input);
}

/**
 * xmlNewInputFromFile:
 * @ctxt:  an XML parser context
 * @filename:  the filename to use as entity
 *
 * Create a new input stream based on a file.
 *
 * Returns the new input stream or NULL in case of error
 */
xmlParserInputPtr
xmlNewInputFromFile(xmlParserCtxtPtr ctxt, const char *filename) {
    xmlParserInputBufferPtr buf;
    xmlParserInputPtr inputStream;
    char *directory = NULL;

    if (ctxt == NULL) return(NULL);
    buf = xmlParserInputBufferCreateFilename(filename, XML_CHAR_ENCODING_NONE);
    if (buf == NULL) {
	char name[XML_PARSER_BIG_BUFFER_SIZE];

        if ((ctxt->input != NULL) && (ctxt->input->directory != NULL)) {
#ifdef WIN32
            sprintf(name, "%s\\%s", ctxt->input->directory, filename);
#else
            sprintf(name, "%s/%s", ctxt->input->directory, filename);
#endif
            buf = xmlParserInputBufferCreateFilename(name,
	                                             XML_CHAR_ENCODING_NONE);
	    if (buf != NULL)
		directory = xmlParserGetDirectory(name);
	}
	if ((buf == NULL) && (ctxt->directory != NULL)) {
#ifdef WIN32
            sprintf(name, "%s\\%s", ctxt->directory, filename);
#else
            sprintf(name, "%s/%s", ctxt->directory, filename);
#endif
            buf = xmlParserInputBufferCreateFilename(name,
	                                             XML_CHAR_ENCODING_NONE);
	    if (buf != NULL)
		directory = xmlParserGetDirectory(name);
	}
	if (buf == NULL)
	    return(NULL);
    }
    if (directory == NULL)
        directory = xmlParserGetDirectory(filename);

    inputStream = xmlNewInputStream(ctxt);
    if (inputStream == NULL) {
	if (directory != NULL) xmlFree((char *) directory);
	return(NULL);
    }

    inputStream->filename = xmlMemStrdup(filename);
    inputStream->directory = directory;
    inputStream->buf = buf;

    inputStream->base = inputStream->buf->buffer->content;
    inputStream->cur = inputStream->buf->buffer->content;
    if ((ctxt->directory == NULL) && (directory != NULL))
        ctxt->directory = (char *) xmlStrdup((const xmlChar *) directory);
    return(inputStream);
}

/************************************************************************
 *									*
 *		Commodity functions to handle parser contexts		*
 *									*
 ************************************************************************/

/**
 * xmlInitParserCtxt:
 * @ctxt:  an XML parser context
 *
 * Initialize a parser context
 */

void
xmlInitParserCtxt(xmlParserCtxtPtr ctxt)
{
    xmlSAXHandler *sax;

    xmlDefaultSAXHandlerInit();

    sax = (xmlSAXHandler *) xmlMalloc(sizeof(xmlSAXHandler));
    if (sax == NULL) {
        fprintf(stderr, "xmlInitParserCtxt: out of memory\n");
    }
    memset(sax, 0, sizeof(xmlSAXHandler));

    /* Allocate the Input stack */
    ctxt->inputTab = (xmlParserInputPtr *) xmlMalloc(5 * sizeof(xmlParserInputPtr));
    ctxt->inputNr = 0;
    ctxt->inputMax = 5;
    ctxt->input = NULL;

    ctxt->version = NULL;
    ctxt->encoding = NULL;
    ctxt->standalone = -1;
    ctxt->hasExternalSubset = 0;
    ctxt->hasPErefs = 0;
    ctxt->html = 0;
    ctxt->external = 0;
    ctxt->instate = XML_PARSER_START;
    ctxt->token = 0;
    ctxt->directory = NULL;

    /* Allocate the Node stack */
    ctxt->nodeTab = (xmlNodePtr *) xmlMalloc(10 * sizeof(xmlNodePtr));
    ctxt->nodeNr = 0;
    ctxt->nodeMax = 10;
    ctxt->node = NULL;

    /* Allocate the Name stack */
    ctxt->nameTab = (xmlChar **) xmlMalloc(10 * sizeof(xmlChar *));
    ctxt->nameNr = 0;
    ctxt->nameMax = 10;
    ctxt->name = NULL;

    /* Allocate the space stack */
    ctxt->spaceTab = (int *) xmlMalloc(10 * sizeof(int));
    ctxt->spaceNr = 1;
    ctxt->spaceMax = 10;
    ctxt->spaceTab[0] = -1;
    ctxt->space = &ctxt->spaceTab[0];

    if (sax == NULL) {
	ctxt->sax = &xmlDefaultSAXHandler;
    } else {
        ctxt->sax = sax;
	memcpy(sax, &xmlDefaultSAXHandler, sizeof(xmlSAXHandler));
    }
    ctxt->userData = ctxt;
    ctxt->myDoc = NULL;
    ctxt->wellFormed = 1;
    ctxt->valid = 1;
    ctxt->validate = xmlDoValidityCheckingDefaultValue;
    ctxt->keepBlanks = xmlKeepBlanksDefaultValue;
    ctxt->vctxt.userData = ctxt;
    if (ctxt->validate) {
	ctxt->vctxt.error = xmlParserValidityError;
	if (xmlGetWarningsDefaultValue == 0)
	    ctxt->vctxt.warning = NULL;
	else
	    ctxt->vctxt.warning = xmlParserValidityWarning;
	/* Allocate the Node stack */
	ctxt->vctxt.nodeTab = (xmlNodePtr *) xmlMalloc(4 * sizeof(xmlNodePtr));
	ctxt->vctxt.nodeNr = 0;
	ctxt->vctxt.nodeMax = 4;
	ctxt->vctxt.node = NULL;
    } else {
	ctxt->vctxt.error = NULL;
	ctxt->vctxt.warning = NULL;
    }
    ctxt->replaceEntities = xmlSubstituteEntitiesDefaultValue;
    ctxt->record_info = 0;
    ctxt->nbChars = 0;
    ctxt->checkIndex = 0;
    ctxt->inSubset = 0;
    ctxt->errNo = XML_ERR_OK;
    ctxt->depth = 0;
    xmlInitNodeInfoSeq(&ctxt->node_seq);
}

/**
 * xmlFreeParserCtxt:
 * @ctxt:  an XML parser context
 *
 * Free all the memory used by a parser context. However the parsed
 * document in ctxt->myDoc is not freed.
 */

void
xmlFreeParserCtxt(xmlParserCtxtPtr ctxt)
{
    xmlParserInputPtr input;
    xmlChar *oldname;

    if (ctxt == NULL) return;

    while ((input = inputPop(ctxt)) != NULL) {
        xmlFreeInputStream(input);
    }
    while ((oldname = namePop(ctxt)) != NULL) {
	xmlFree(oldname);
    }
    if (ctxt->spaceTab != NULL) xmlFree(ctxt->spaceTab);
    if (ctxt->nameTab != NULL) xmlFree(ctxt->nameTab);
    if (ctxt->nodeTab != NULL) xmlFree(ctxt->nodeTab);
    if (ctxt->inputTab != NULL) xmlFree(ctxt->inputTab);
    if (ctxt->version != NULL) xmlFree((char *) ctxt->version);
    if (ctxt->encoding != NULL) xmlFree((char *) ctxt->encoding);
    if (ctxt->intSubName != NULL) xmlFree((char *) ctxt->intSubName);
    if (ctxt->extSubURI != NULL) xmlFree((char *) ctxt->extSubURI);
    if (ctxt->extSubSystem != NULL) xmlFree((char *) ctxt->extSubSystem);
    if (ctxt->vctxt.nodeTab != NULL) xmlFree(ctxt->vctxt.nodeTab);
    if ((ctxt->sax != NULL) && (ctxt->sax != &xmlDefaultSAXHandler))
        xmlFree(ctxt->sax);
    if (ctxt->directory != NULL) xmlFree((char *) ctxt->directory);
    xmlFree(ctxt);
}

/**
 * xmlNewParserCtxt:
 *
 * Allocate and initialize a new parser context.
 *
 * Returns the xmlParserCtxtPtr or NULL
 */

xmlParserCtxtPtr
xmlNewParserCtxt()
{
    xmlParserCtxtPtr ctxt;

    ctxt = (xmlParserCtxtPtr) xmlMalloc(sizeof(xmlParserCtxt));
    if (ctxt == NULL) {
        fprintf(stderr, "xmlNewParserCtxt : cannot allocate context\n");
        perror("malloc");
	return(NULL);
    }
    memset(ctxt, 0, sizeof(xmlParserCtxt));
    xmlInitParserCtxt(ctxt);
    return(ctxt);
}

/**
 * xmlClearParserCtxt:
 * @ctxt:  an XML parser context
 *
 * Clear (release owned resources) and reinitialize a parser context
 */

void
xmlClearParserCtxt(xmlParserCtxtPtr ctxt)
{
  xmlClearNodeInfoSeq(&ctxt->node_seq);
  xmlInitParserCtxt(ctxt);
}

/************************************************************************
 *									*
 *		Commodity functions to handle entities			*
 *									*
 ************************************************************************/

/**
 * xmlCheckEntity:
 * @ctxt:  an XML parser context
 * @content:  the entity content string
 *
 * Parse an entity content and checks the WF constraints
 *
 */

void
xmlCheckEntity(xmlParserCtxtPtr ctxt, const xmlChar *content) {
}

/**
 * xmlParseCharRef:
 * @ctxt:  an XML parser context
 *
 * parse Reference declarations
 *
 * [66] CharRef ::= '&#' [0-9]+ ';' |
 *                  '&#x' [0-9a-fA-F]+ ';'
 *
 * [ WFC: Legal Character ]
 * Characters referred to using character references must match the
 * production for Char. 
 *
 * Returns the value parsed (as an int), 0 in case of error
 */
int
xmlParseCharRef(xmlParserCtxtPtr ctxt) {
    int val = 0;

    if (ctxt->token != 0) {
	val = ctxt->token;
        ctxt->token = 0;
        return(val);
    }
    if ((RAW == '&') && (NXT(1) == '#') &&
        (NXT(2) == 'x')) {
	SKIP(3);
	while (RAW != ';') {
	    if ((RAW >= '0') && (RAW <= '9')) 
	        val = val * 16 + (CUR - '0');
	    else if ((RAW >= 'a') && (RAW <= 'f'))
	        val = val * 16 + (CUR - 'a') + 10;
	    else if ((RAW >= 'A') && (RAW <= 'F'))
	        val = val * 16 + (CUR - 'A') + 10;
	    else {
		ctxt->errNo = XML_ERR_INVALID_HEX_CHARREF;
	        if ((ctxt->sax != NULL) && (ctxt->sax->error != NULL))
		    ctxt->sax->error(ctxt->userData, 
		         "xmlParseCharRef: invalid hexadecimal value\n");
		ctxt->wellFormed = 0;
		ctxt->disableSAX = 1;
		val = 0;
		break;
	    }
	    NEXT;
	}
	if (RAW == ';') {
	    /* on purpose to avoid reentrancy problems with NEXT and SKIP */
	    ctxt->nbChars ++;
	    ctxt->input->cur++;
	}