xpath.c

SIP 1.5.0源代码

        valuePush(ctxt, arg);					\
        xmlXPathNumberFunction(ctxt, 1);			\
	arg = valuePop(ctxt);					\
    }

/**
 * xmlXPathEqualNodeSetString
 * @arg:  the nodeset object argument
 * @str:  the string to compare to.
 *
 * Implement the equal operation on XPath objects content: @arg1 == @arg2
 * If one object to be compared is a node-set and the other is a string,
 * then the comparison will be true if and only if there is a node in
 * the node-set such that the result of performing the comparison on the
 * string-value of the node and the other string is true.
 *
 * Returns 0 or 1 depending on the results of the test.
 */
int
xmlXPathEqualNodeSetString(xmlXPathObjectPtr arg, const xmlChar *str) {
    int i;
    xmlNodeSetPtr ns;
    xmlChar *str2;

    if ((str == NULL) || (arg == NULL) || (arg->type != XPATH_NODESET))
        return(0);
    ns = arg->nodesetval;
    for (i = 0;i < ns->nodeNr;i++) {
         str2 = xmlNodeGetContent(ns->nodeTab[i]);
	 if ((str2 != NULL) && (!xmlStrcmp(str, str2))) {
	     xmlFree(str2);
	     return(1);
	 }
	 xmlFree(str2);
    }
    return(0);
}

/**
 * xmlXPathEqualNodeSetFloat
 * @arg:  the nodeset object argument
 * @f:  the float to compare to
 *
 * Implement the equal operation on XPath objects content: @arg1 == @arg2
 * If one object to be compared is a node-set and the other is a number,
 * then the comparison will be true if and only if there is a node in
 * the node-set such that the result of performing the comparison on the
 * number to be compared and on the result of converting the string-value
 * of that node to a number using the number function is true.
 *
 * Returns 0 or 1 depending on the results of the test.
 */
int
xmlXPathEqualNodeSetFloat(xmlXPathObjectPtr arg, float f) {
    char buf[100] = "";

    if ((arg == NULL) || (arg->type != XPATH_NODESET))
        return(0);

    if (isnan(f))
	sprintf(buf, "NaN");
    else if (isinf(f) > 0)
	sprintf(buf, "+Infinity");
    else if (isinf(f) < 0)
	sprintf(buf, "-Infinity");
    else
	sprintf(buf, "%0g", f);

    return(xmlXPathEqualNodeSetString(arg, BAD_CAST buf));
}


/**
 * xmlXPathEqualNodeSets
 * @arg1:  first nodeset object argument
 * @arg2:  second nodeset object argument
 *
 * Implement the equal operation on XPath nodesets: @arg1 == @arg2
 * If both objects to be compared are node-sets, then the comparison
 * will be true if and only if there is a node in the first node-set and
 * a node in the second node-set such that the result of performing the
 * comparison on the string-values of the two nodes is true.
 *
 * (needless to say, this is a costly operation)
 *
 * Returns 0 or 1 depending on the results of the test.
 */
int
xmlXPathEqualNodeSets(xmlXPathObjectPtr arg1, xmlXPathObjectPtr arg2) {
    int i;
    xmlNodeSetPtr ns;
    xmlChar *str;

    if ((arg1 == NULL) || (arg1->type != XPATH_NODESET))
        return(0);
    if ((arg2 == NULL) || (arg2->type != XPATH_NODESET))
        return(0);

    ns = arg1->nodesetval;
    for (i = 0;i < ns->nodeNr;i++) {
         str = xmlNodeGetContent(ns->nodeTab[i]);
	 if ((str != NULL) && (xmlXPathEqualNodeSetString(arg2, str))) {
	     xmlFree(str);
	     return(1);
	 }
	 xmlFree(str);
    }
    return(0);
}

/**
 * xmlXPathEqualValues:
 * @ctxt:  the XPath Parser context
 *
 * Implement the equal operation on XPath objects content: @arg1 == @arg2
 *
 * Returns 0 or 1 depending on the results of the test.
 */
int
xmlXPathEqualValues(xmlXPathParserContextPtr ctxt) {
    xmlXPathObjectPtr arg1, arg2;
    int ret = 0;

    arg1 = valuePop(ctxt);
    if (arg1 == NULL)
	ERROR0(XPATH_INVALID_OPERAND);

    arg2 = valuePop(ctxt);
    if (arg2 == NULL) {
	xmlXPathFreeObject(arg1);
	ERROR0(XPATH_INVALID_OPERAND);
    }
  
    if (arg1 == arg2) {
#ifdef DEBUG_EXPR
        fprintf(xmlXPathDebug, "Equal: by pointer\n");
#endif
        return(1);
    }

    switch (arg1->type) {
        case XPATH_UNDEFINED:
#ifdef DEBUG_EXPR
	    fprintf(xmlXPathDebug, "Equal: undefined\n");
#endif
	    break;
        case XPATH_NODESET:
	    switch (arg2->type) {
	        case XPATH_UNDEFINED:
#ifdef DEBUG_EXPR
		    fprintf(xmlXPathDebug, "Equal: undefined\n");
#endif
		    break;
		case XPATH_NODESET:
		    ret = xmlXPathEqualNodeSets(arg1, arg2);
		    break;
		case XPATH_BOOLEAN:
		    if ((arg1->nodesetval == NULL) ||
			(arg1->nodesetval->nodeNr == 0)) ret = 0;
		    else 
			ret = 1;
		    ret = (ret == arg2->boolval);
		    break;
		case XPATH_NUMBER:
		    ret = xmlXPathEqualNodeSetFloat(arg1, arg2->floatval);
		    break;
		case XPATH_STRING:
		    ret = xmlXPathEqualNodeSetString(arg1, arg2->stringval);
		    break;
	    }
	    break;
        case XPATH_BOOLEAN:
	    switch (arg2->type) {
	        case XPATH_UNDEFINED:
#ifdef DEBUG_EXPR
		    fprintf(xmlXPathDebug, "Equal: undefined\n");
#endif
		    break;
		case XPATH_NODESET:
		    if ((arg2->nodesetval == NULL) ||
			(arg2->nodesetval->nodeNr == 0)) ret = 0;
		    else 
			ret = 1;
		    break;
		case XPATH_BOOLEAN:
#ifdef DEBUG_EXPR
		    fprintf(xmlXPathDebug, "Equal: %d boolean %d \n",
			    arg1->boolval, arg2->boolval);
#endif
		    ret = (arg1->boolval == arg2->boolval);
		    break;
		case XPATH_NUMBER:
		    if (arg2->floatval) ret = 1;
		    else ret = 0;
		    ret = (arg1->boolval == ret);
		    break;
		case XPATH_STRING:
		    if ((arg2->stringval == NULL) ||
			(arg2->stringval[0] == 0)) ret = 0;
		    else 
			ret = 1;
		    ret = (arg1->boolval == ret);
		    break;
	    }
	    break;
        case XPATH_NUMBER:
	    switch (arg2->type) {
	        case XPATH_UNDEFINED:
#ifdef DEBUG_EXPR
		    fprintf(xmlXPathDebug, "Equal: undefined\n");
#endif
		    break;
		case XPATH_NODESET:
		    ret = xmlXPathEqualNodeSetFloat(arg2, arg1->floatval);
		    break;
		case XPATH_BOOLEAN:
		    if (arg1->floatval) ret = 1;
		    else ret = 0;
		    ret = (arg2->boolval == ret);
		    break;
		case XPATH_STRING:
		    valuePush(ctxt, arg2);
		    xmlXPathNumberFunction(ctxt, 1);
		    arg2 = valuePop(ctxt);
		    /* no break on purpose */
		case XPATH_NUMBER:
		    ret = (arg1->floatval == arg2->floatval);
		    break;
	    }
	    break;
        case XPATH_STRING:
	    switch (arg2->type) {
	        case XPATH_UNDEFINED:
#ifdef DEBUG_EXPR
		    fprintf(xmlXPathDebug, "Equal: undefined\n");
#endif
		    break;
		case XPATH_NODESET:
		    ret = xmlXPathEqualNodeSetString(arg2, arg1->stringval);
		    break;
		case XPATH_BOOLEAN:
		    if ((arg1->stringval == NULL) ||
			(arg1->stringval[0] == 0)) ret = 0;
		    else 
			ret = 1;
		    ret = (arg2->boolval == ret);
		    break;
		case XPATH_STRING:
		    ret = !xmlStrcmp(arg1->stringval, arg2->stringval);
		    break;
		case XPATH_NUMBER:
		    valuePush(ctxt, arg1);
		    xmlXPathNumberFunction(ctxt, 1);
		    arg1 = valuePop(ctxt);
		    ret = (arg1->floatval == arg2->floatval);
		    break;
	    }
	    break;
    }
    xmlXPathFreeObject(arg1);
    xmlXPathFreeObject(arg2);
    return(ret);
}

/**
 * xmlXPathCompareValues:
 * @ctxt:  the XPath Parser context
 * @inf:  less than (1) or greater than (2)
 * @strict:  is the comparison strict
 *
 * Implement the compare operation on XPath objects: 
 *     @arg1 < @arg2    (1, 1, ...
 *     @arg1 <= @arg2   (1, 0, ...
 *     @arg1 > @arg2    (0, 1, ...
 *     @arg1 >= @arg2   (0, 0, ...
 *
 * When neither object to be compared is a node-set and the operator is
 * <=, <, >=, >, then the objects are compared by converted both objects
 * to numbers and comparing the numbers according to IEEE 754. The <
 * comparison will be true if and only if the first number is less than the
 * second number. The <= comparison will be true if and only if the first
 * number is less than or equal to the second number. The > comparison
 * will be true if and only if the first number is greater than the second
 * number. The >= comparison will be true if and only if the first number
 * is greater than or equal to the second number.
 */
int
xmlXPathCompareValues(xmlXPathParserContextPtr ctxt, int inf, int strict) {
    int ret = 0;
    xmlXPathObjectPtr arg1, arg2;

    arg2 = valuePop(ctxt);
    if ((arg2 == NULL) || (arg2->type == XPATH_NODESET)) {
        if (arg2 != NULL)
	    xmlXPathFreeObject(arg2);
	ERROR0(XPATH_INVALID_OPERAND);
    }
  
    arg1 = valuePop(ctxt);
    if ((arg1 == NULL) || (arg1->type == XPATH_NODESET)) {
        if (arg1 != NULL)
	    xmlXPathFreeObject(arg1);
	xmlXPathFreeObject(arg2);
	ERROR0(XPATH_INVALID_OPERAND);
    }

    if (arg1->type != XPATH_NUMBER) {
	valuePush(ctxt, arg1);
	xmlXPathNumberFunction(ctxt, 1);
	arg1 = valuePop(ctxt);
    }
    if (arg1->type != XPATH_NUMBER) {
	xmlXPathFreeObject(arg1);
	xmlXPathFreeObject(arg2);
	ERROR0(XPATH_INVALID_OPERAND);
    }
    if (arg2->type != XPATH_NUMBER) {
	valuePush(ctxt, arg2);
	xmlXPathNumberFunction(ctxt, 1);
	arg2 = valuePop(ctxt);
    }
    if (arg2->type != XPATH_NUMBER) {
	xmlXPathFreeObject(arg1);
	xmlXPathFreeObject(arg2);
	ERROR0(XPATH_INVALID_OPERAND);
    }
    /*
     * Add tests for infinity and nan
     * => feedback on 3.4 for Inf and NaN
     */
    if (inf && strict) 
        ret = (arg1->floatval < arg2->floatval);
    else if (inf && !strict)
        ret = (arg1->floatval <= arg2->floatval);
    else if (!inf && strict)
        ret = (arg1->floatval > arg2->floatval);
    else if (!inf && !strict)
        ret = (arg1->floatval >= arg2->floatval);
    xmlXPathFreeObject(arg1);
    xmlXPathFreeObject(arg2);
    return(ret);
}

/**
 * xmlXPathValueFlipSign:
 * @ctxt:  the XPath Parser context
 *
 * Implement the unary - operation on an XPath object
 * The numeric operators convert their operands to numbers as if
 * by calling the number function.
 */
void
xmlXPathValueFlipSign(xmlXPathParserContextPtr ctxt) {
    xmlXPathObjectPtr arg;
    
    POP_FLOAT
    arg->floatval = -arg->floatval;
    valuePush(ctxt, arg);
}

/**
 * xmlXPathAddValues:
 * @ctxt:  the XPath Parser context
 *
 * Implement the add operation on XPath objects:
 * The numeric operators convert their operands to numbers as if
 * by calling the number function.
 */
void
xmlXPathAddValues(xmlXPathParserContextPtr ctxt) {
    xmlXPathObjectPtr arg;
    double val;

    POP_FLOAT
    val = arg->floatval;
    xmlXPathFreeObject(arg);

    POP_FLOAT
    arg->floatval += val;
    valuePush(ctxt, arg);
}

/**
 * xmlXPathSubValues:
 * @ctxt:  the XPath Parser context
 *
 * Implement the substraction operation on XPath objects:
 * The numeric operators convert their operands to numbers as if
 * by calling the number function.
 */
void
xmlXPathSubValues(xmlXPathParserContextPtr ctxt) {
    xmlXPathObjectPtr arg;
    double val;

    POP_FLOAT
    val = arg->floatval;
    xmlXPathFreeObject(arg);

    POP_FLOAT
    arg->floatval -= val;
    valuePush(ctxt, arg);
}

/**
 * xmlXPathMultValues:
 * @ctxt:  the XPath Parser context
 *
 * Implement the multiply operation on XPath objects:
 * The numeric operators convert their operands to numbers as if
 * by calling the number function.
 */
void
xmlXPathMultValues(xmlXPathParserContextPtr ctxt) {
    xmlXPathObjectPtr arg;
    double val;

    POP_FLOAT
    val = arg->floatval;
    xmlXPathFreeObject(arg);

    POP_FLOAT
    arg->floatval *= val;
    valuePush(ctxt, arg);
}

/**
 * xmlXPathDivValues:
 * @ctxt:  the XPath Parser context
 *
 * Implement the div operation on XPath objects:
 * The numeric operators convert their operands to numbers as if
 * by calling the number function.
 */
void
xmlXPathDivValues(xmlXPathParserContextPtr ctxt) {
    xmlXPathObjectPtr arg;
    double val;

    POP_FLOAT
    val = arg->floatval;
    xmlXPathFreeObject(arg);

    POP_FLOAT
    arg->floatval /= val;
    valuePush(ctxt, arg);
}

/**
 * xmlXPathModValues:
 * @ctxt:  the XPath Parser context
 *
 * Implement the div operation on XPath objects: @arg1 / @arg2
 * The numeric operators convert their operands to numbers as if
 * by calling the number function.
 */
void
xmlXPathModValues(xmlXPathParserContextPtr ctxt) {
    xmlXPathObjectPtr arg;
    double val;

    POP_FLOAT
    val = arg->floatval;
    xmlXPathFreeObject(arg);

    POP_FLOAT
    arg->floatval /= val;
    valuePush(ctxt, arg);
}

/************************************************************************
 *									*
 *		The traversal functions					*
 *									*
 ************************************************************************/

#define AXIS_ANCESTOR			1
#define AXIS_ANCESTOR_OR_SELF		2
#define AXIS_ATTRIBUTE			3
#define AXIS_CHILD			4
#define AXIS_DESCENDANT			5
#define AXIS_DESCENDANT_OR_SELF		6