xpath.c

Vovida 社区开源的 SIP 协议源码

#define AXIS_PRECEDING			11
#define AXIS_PRECEDING_SIBLING		12
#define AXIS_SELF			13

/*
 * A traversal function enumerates nodes along an axis.
 * Initially it must be called with NULL, and it indicates
 * termination on the axis by returning NULL.
 */
typedef xmlNodePtr (*xmlXPathTraversalFunction)
                    (xmlXPathParserContextPtr ctxt, xmlNodePtr cur);

/**
 * mlXPathNextSelf:
 * @ctxt:  the XPath Parser context
 * @cur:  the current node in the traversal
 *
 * Traversal function for the "self" direction
 * he self axis contains just the context node itself
 *
 * Returns the next element following that axis
 */
xmlNodePtr
xmlXPathNextSelf(xmlXPathParserContextPtr ctxt, xmlNodePtr cur) {
    if (cur == NULL)
        return(ctxt->context->node);
    return(NULL);
}

/**
 * mlXPathNextChild:
 * @ctxt:  the XPath Parser context
 * @cur:  the current node in the traversal
 *
 * Traversal function for the "child" direction
 * The child axis contains the children of the context node in document order.
 *
 * Returns the next element following that axis
 */
xmlNodePtr
xmlXPathNextChild(xmlXPathParserContextPtr ctxt, xmlNodePtr cur) {
    if (cur == NULL) {
	if (ctxt->context->node == NULL) return(NULL);
	switch (ctxt->context->node->type) {
            case XML_ELEMENT_NODE:
            case XML_TEXT_NODE:
            case XML_CDATA_SECTION_NODE:
            case XML_ENTITY_REF_NODE:
            case XML_ENTITY_NODE:
            case XML_PI_NODE:
            case XML_COMMENT_NODE:
            case XML_NOTATION_NODE:
            case XML_DTD_NODE:
		return(ctxt->context->node->children);
            case XML_DOCUMENT_NODE:
            case XML_DOCUMENT_TYPE_NODE:
            case XML_DOCUMENT_FRAG_NODE:
            case XML_HTML_DOCUMENT_NODE:
		return(((xmlDocPtr) ctxt->context->node)->children);
	    case XML_ELEMENT_DECL:
	    case XML_ATTRIBUTE_DECL:
	    case XML_ENTITY_DECL:
            case XML_ATTRIBUTE_NODE:
		return(NULL);
	}
	return(NULL);
    }
    if ((cur->type == XML_DOCUMENT_NODE) ||
        (cur->type == XML_HTML_DOCUMENT_NODE))
	return(NULL);
    return(cur->next);
}

/**
 * mlXPathNextDescendant:
 * @ctxt:  the XPath Parser context
 * @cur:  the current node in the traversal
 *
 * Traversal function for the "descendant" direction
 * the descendant axis contains the descendants of the context node in document
 * order; a descendant is a child or a child of a child and so on.
 *
 * Returns the next element following that axis
 */
xmlNodePtr
xmlXPathNextDescendant(xmlXPathParserContextPtr ctxt, xmlNodePtr cur) {
    if (cur == NULL) {
	if (ctxt->context->node == NULL)
	    return(NULL);
	if (ctxt->context->node->type == XML_ATTRIBUTE_NODE)
	    return(NULL);

        if (ctxt->context->node == (xmlNodePtr) ctxt->context->doc)
	    return(ctxt->context->doc->children);
        return(ctxt->context->node->children);
    }

    if (cur->children != NULL) return(cur->children);
    if (cur->next != NULL) return(cur->next);
    
    do {
        cur = cur->parent;
	if (cur == NULL) return(NULL);
	if (cur == ctxt->context->node) return(NULL);
	if (cur->next != NULL) {
	    cur = cur->next;
	    return(cur);
	}
    } while (cur != NULL);
    return(cur);
}

/**
 * mlXPathNextDescendantOrSelf:
 * @ctxt:  the XPath Parser context
 * @cur:  the current node in the traversal
 *
 * Traversal function for the "descendant-or-self" direction
 * the descendant-or-self axis contains the context node and the descendants
 * of the context node in document order; thus the context node is the first
 * node on the axis, and the first child of the context node is the second node
 * on the axis
 *
 * Returns the next element following that axis
 */
xmlNodePtr
xmlXPathNextDescendantOrSelf(xmlXPathParserContextPtr ctxt, xmlNodePtr cur) {
    if (cur == NULL) {
	if (ctxt->context->node == NULL)
	    return(NULL);
	if (ctxt->context->node->type == XML_ATTRIBUTE_NODE)
	    return(NULL);
        return(ctxt->context->node);
    }

    return(xmlXPathNextDescendant(ctxt, cur));
}

/**
 * xmlXPathNextParent:
 * @ctxt:  the XPath Parser context
 * @cur:  the current node in the traversal
 *
 * Traversal function for the "parent" direction
 * The parent axis contains the parent of the context node, if there is one.
 *
 * Returns the next element following that axis
 */
xmlNodePtr
xmlXPathNextParent(xmlXPathParserContextPtr ctxt, xmlNodePtr cur) {
    /*
     * the parent of an attribute or namespace node is the element
     * to which the attribute or namespace node is attached
     * Namespace handling !!!
     */
    if (cur == NULL) {
	if (ctxt->context->node == NULL) return(NULL);
	switch (ctxt->context->node->type) {
            case XML_ELEMENT_NODE:
            case XML_TEXT_NODE:
            case XML_CDATA_SECTION_NODE:
            case XML_ENTITY_REF_NODE:
            case XML_ENTITY_NODE:
            case XML_PI_NODE:
            case XML_COMMENT_NODE:
            case XML_NOTATION_NODE:
            case XML_DTD_NODE:
	    case XML_ELEMENT_DECL:
	    case XML_ATTRIBUTE_DECL:
	    case XML_ENTITY_DECL:
		if (ctxt->context->node->parent == NULL)
		    return((xmlNodePtr) ctxt->context->doc);
		return(ctxt->context->node->parent);
            case XML_ATTRIBUTE_NODE: {
		xmlAttrPtr att = (xmlAttrPtr) ctxt->context->node;

		return(att->parent);
	    }
            case XML_DOCUMENT_NODE:
            case XML_DOCUMENT_TYPE_NODE:
            case XML_DOCUMENT_FRAG_NODE:
            case XML_HTML_DOCUMENT_NODE:
                return(NULL);
	}
    }
    return(NULL);
}

/**
 * xmlXPathNextAncestor:
 * @ctxt:  the XPath Parser context
 * @cur:  the current node in the traversal
 *
 * Traversal function for the "ancestor" direction
 * the ancestor axis contains the ancestors of the context node; the ancestors
 * of the context node consist of the parent of context node and the parent's
 * parent and so on; the nodes are ordered in reverse document order; thus the
 * parent is the first node on the axis, and the parent's parent is the second
 * node on the axis
 *
 * Returns the next element following that axis
 */
xmlNodePtr
xmlXPathNextAncestor(xmlXPathParserContextPtr ctxt, xmlNodePtr cur) {
    /*
     * the parent of an attribute or namespace node is the element
     * to which the attribute or namespace node is attached
     * !!!!!!!!!!!!!
     */
    if (cur == NULL) {
	if (ctxt->context->node == NULL) return(NULL);
	switch (ctxt->context->node->type) {
            case XML_ELEMENT_NODE:
            case XML_TEXT_NODE:
            case XML_CDATA_SECTION_NODE:
            case XML_ENTITY_REF_NODE:
            case XML_ENTITY_NODE:
            case XML_PI_NODE:
            case XML_COMMENT_NODE:
	    case XML_DTD_NODE:
	    case XML_ELEMENT_DECL:
	    case XML_ATTRIBUTE_DECL:
	    case XML_ENTITY_DECL:
            case XML_NOTATION_NODE:
		if (ctxt->context->node->parent == NULL)
		    return((xmlNodePtr) ctxt->context->doc);
		return(ctxt->context->node->parent);
            case XML_ATTRIBUTE_NODE: {
		xmlAttrPtr cur = (xmlAttrPtr) ctxt->context->node;

		return(cur->parent);
	    }
            case XML_DOCUMENT_NODE:
            case XML_DOCUMENT_TYPE_NODE:
            case XML_DOCUMENT_FRAG_NODE:
            case XML_HTML_DOCUMENT_NODE:
                return(NULL);
	}
	return(NULL);
    }
    if (cur == ctxt->context->doc->children)
	return((xmlNodePtr) ctxt->context->doc);
    if (cur == (xmlNodePtr) ctxt->context->doc)
	return(NULL);
    switch (cur->type) {
	case XML_ELEMENT_NODE:
	case XML_TEXT_NODE:
	case XML_CDATA_SECTION_NODE:
	case XML_ENTITY_REF_NODE:
	case XML_ENTITY_NODE:
	case XML_PI_NODE:
	case XML_COMMENT_NODE:
	case XML_NOTATION_NODE:
	case XML_DTD_NODE:
        case XML_ELEMENT_DECL:
        case XML_ATTRIBUTE_DECL:
        case XML_ENTITY_DECL:
	    return(cur->parent);
	case XML_ATTRIBUTE_NODE: {
	    xmlAttrPtr att = (xmlAttrPtr) ctxt->context->node;

	    return(att->parent);
	}
	case XML_DOCUMENT_NODE:
	case XML_DOCUMENT_TYPE_NODE:
	case XML_DOCUMENT_FRAG_NODE:
	case XML_HTML_DOCUMENT_NODE:
	    return(NULL);
    }
    return(NULL);
}

/**
 * xmlXPathNextAncestorOrSelf:
 * @ctxt:  the XPath Parser context
 * @cur:  the current node in the traversal
 *
 * Traversal function for the "ancestor-or-self" direction
 * he ancestor-or-self axis contains the context node and ancestors of
 * the context node in reverse document order; thus the context node is
 * the first node on the axis, and the context node's parent the second;
 * parent here is defined the same as with the parent axis.
 *
 * Returns the next element following that axis
 */
xmlNodePtr
xmlXPathNextAncestorOrSelf(xmlXPathParserContextPtr ctxt, xmlNodePtr cur) {
    if (cur == NULL)
        return(ctxt->context->node);
    return(xmlXPathNextAncestor(ctxt, cur));
}

/**
 * xmlXPathNextFollowingSibling:
 * @ctxt:  the XPath Parser context
 * @cur:  the current node in the traversal
 *
 * Traversal function for the "following-sibling" direction
 * The following-sibling axis contains the following siblings of the context
 * node in document order.
 *
 * Returns the next element following that axis
 */
xmlNodePtr
xmlXPathNextFollowingSibling(xmlXPathParserContextPtr ctxt, xmlNodePtr cur) {
    if (cur == (xmlNodePtr) ctxt->context->doc)
        return(NULL);
    if (cur == NULL)
        return(ctxt->context->node->next);
    return(cur->next);
}

/**
 * xmlXPathNextPrecedingSibling:
 * @ctxt:  the XPath Parser context
 * @cur:  the current node in the traversal
 *
 * Traversal function for the "preceding-sibling" direction
 * The preceding-sibling axis contains the preceding siblings of the context
 * node in reverse document order; the first preceding sibling is first on the
 * axis; the sibling preceding that node is the second on the axis and so on.
 *
 * Returns the next element following that axis
 */
xmlNodePtr
xmlXPathNextPrecedingSibling(xmlXPathParserContextPtr ctxt, xmlNodePtr cur) {
    if (cur == (xmlNodePtr) ctxt->context->doc)
        return(NULL);
    if (cur == NULL)
        return(ctxt->context->node->prev);
    return(cur->prev);
}

/**
 * xmlXPathNextFollowing:
 * @ctxt:  the XPath Parser context
 * @cur:  the current node in the traversal
 *
 * Traversal function for the "following" direction
 * The following axis contains all nodes in the same document as the context
 * node that are after the context node in document order, excluding any
 * descendants and excluding attribute nodes and namespace nodes; the nodes
 * are ordered in document order
 *
 * Returns the next element following that axis
 */
xmlNodePtr
xmlXPathNextFollowing(xmlXPathParserContextPtr ctxt, xmlNodePtr cur) {
    if (cur == (xmlNodePtr) ctxt->context->doc)
        return(NULL);
    if (cur == NULL)
        return(ctxt->context->node->next);; /* !!!!!!!!! */
    if (cur->children != NULL) return(cur->children);
    if (cur->next != NULL) return(cur->next);
    
    do {
        cur = cur->parent;
	if (cur == NULL) return(NULL);
	if (cur == ctxt->context->doc->children) return(NULL);
	if (cur->next != NULL) {
	    cur = cur->next;
	    return(cur);
	}
    } while (cur != NULL);
    return(cur);
}

/**
 * xmlXPathNextPreceding:
 * @ctxt:  the XPath Parser context
 * @cur:  the current node in the traversal
 *
 * Traversal function for the "preceding" direction
 * the preceding axis contains all nodes in the same document as the context
 * node that are before the context node in document order, excluding any
 * ancestors and excluding attribute nodes and namespace nodes; the nodes are
 * ordered in reverse document order
 *
 * Returns the next element following that axis
 */
xmlNodePtr
xmlXPathNextPreceding(xmlXPathParserContextPtr ctxt, xmlNodePtr cur) {
    if (cur == (xmlNodePtr) ctxt->context->doc)
        return(NULL);
    if (cur == NULL)
        return(ctxt->context->node->prev); /* !!!!!!!!! */
    if (cur->last != NULL) return(cur->last);
    if (cur->prev != NULL) return(cur->prev);
    
    do {
        cur = cur->parent;
	if (cur == NULL) return(NULL);
	if (cur == ctxt->context->doc->children) return(NULL);
	if (cur->prev != NULL) {
	    cur = cur->prev;
	    return(cur);
	}
    } while (cur != NULL);
    return(cur);
}

/**
 * xmlXPathNextNamespace:
 * @ctxt:  the XPath Parser context
 * @cur:  the current attribute in the traversal
 *
 * Traversal function for the "namespace" direction
 * the namespace axis contains the namespace nodes of the context node;
 * the order of nodes on this axis is implementation-defined; the axis will
 * be empty unless the context node is an element
 *
 * Returns the next element following that axis
 */
xmlNsPtr
xmlXPathNextNamespace(xmlXPathParserContextPtr ctxt, xmlAttrPtr cur) {
    if ((cur == NULL) || (ctxt->context->namespaces == NULL)) {
        if (ctxt->context->namespaces != NULL)
	    xmlFree(ctxt->context->namespaces);
	ctxt->context->namespaces = 
	    xmlGetNsList(ctxt->context->doc, ctxt->context->node);
	if (ctxt->context->namespaces == NULL) return(NULL);
	ctxt->context->nsNr = 0;
    }
    return(ctxt->context->namespaces[ctxt->context->nsNr++]);
}

/**
 * xmlXPathNextAttribute:
 * @ctxt:  the XPath Parser context
 * @cur:  the current attribute in the traversal
 *
 * Traversal function for the "attribute" direction
 * TODO: support DTD inherited default attributes
 *
 * Returns the next element following that axis
 */
xmlAttrPtr
xmlXPathNextAttribute(xmlXPathParserContextPtr ctxt, xmlAttrPtr cur) {
    if (cur == NULL) {
        if (ctxt->context->node == (xmlNodePtr) ctxt->context->doc)
	    return(NULL);
        return(ctxt->context->node->properties);
    }
    return(cur->next);
}

/************************************************************************
 *									*
 *		NodeTest Functions					*
 *									*
 ************************************************************************/

#define NODE_TEST_NONE	0
#define NODE_TEST_TYPE	1
#define NODE_TEST_PI	2
#define NODE_TEST_ALL	3
#define NODE_TEST_NS	4
#define NODE_TEST_NAME	5

#define NODE_TYPE_COMMENT		50
#define NODE_TYPE_TEXT			51
#define NODE_TYPE_PI			52
#define NODE_TYPE_NODE			53

#define IS_FUNCTION			200

/**
 * xmlXPathNodeCollectAndTest:
 * @ctxt:  the XPath Parser context
 * @cur:  the current node to test
 *
 * This is the function implementing a step: based on the current list
 * of nodes, it builds up a new list, looking at all nodes under that
 * axis and selecting them.
 *
 * Returns the new NodeSet resulting from the search.
 */
xmlNodeSetPtr
xmlXPathNodeCollectAndTest(xmlXPathParserContextPtr ctxt, int axis,
                 int test, int type, const xmlChar *prefix, const xmlChar *name) {
#ifdef DEBUG_STEP
    int n = 0, t = 0;