xpath.c

xml开源解析代码.版本为libxml2-2.6.29,可支持GB3212.网络消息发送XML时很有用.

    xmlFree(list);
}

/************************************************************************
 * 									*
 * 			Parser Types					*
 * 									*
 ************************************************************************/

/*
 * Types are private:
 */

typedef enum {
    XPATH_OP_END=0,
    XPATH_OP_AND,
    XPATH_OP_OR,
    XPATH_OP_EQUAL,
    XPATH_OP_CMP,
    XPATH_OP_PLUS,
    XPATH_OP_MULT,
    XPATH_OP_UNION,
    XPATH_OP_ROOT,
    XPATH_OP_NODE,
    XPATH_OP_RESET, /* 10 */
    XPATH_OP_COLLECT,
    XPATH_OP_VALUE, /* 12 */
    XPATH_OP_VARIABLE,
    XPATH_OP_FUNCTION,
    XPATH_OP_ARG,
    XPATH_OP_PREDICATE,
    XPATH_OP_FILTER, /* 17 */
    XPATH_OP_SORT /* 18 */
#ifdef LIBXML_XPTR_ENABLED
    ,XPATH_OP_RANGETO
#endif
} xmlXPathOp;

typedef enum {
    AXIS_ANCESTOR = 1,
    AXIS_ANCESTOR_OR_SELF,
    AXIS_ATTRIBUTE,
    AXIS_CHILD,
    AXIS_DESCENDANT,
    AXIS_DESCENDANT_OR_SELF,
    AXIS_FOLLOWING,
    AXIS_FOLLOWING_SIBLING,
    AXIS_NAMESPACE,
    AXIS_PARENT,
    AXIS_PRECEDING,
    AXIS_PRECEDING_SIBLING,
    AXIS_SELF    
} xmlXPathAxisVal;

typedef enum {
    NODE_TEST_NONE = 0,
    NODE_TEST_TYPE = 1,
    NODE_TEST_PI = 2,
    NODE_TEST_ALL = 3,
    NODE_TEST_NS = 4,
    NODE_TEST_NAME = 5
} xmlXPathTestVal;

typedef enum {
    NODE_TYPE_NODE = 0,
    NODE_TYPE_COMMENT = XML_COMMENT_NODE,
    NODE_TYPE_TEXT = XML_TEXT_NODE,
    NODE_TYPE_PI = XML_PI_NODE   
} xmlXPathTypeVal;

#define XP_REWRITE_DOS_CHILD_ELEM 1

typedef struct _xmlXPathStepOp xmlXPathStepOp;
typedef xmlXPathStepOp *xmlXPathStepOpPtr;
struct _xmlXPathStepOp {
    xmlXPathOp op;		/* The identifier of the operation */
    int ch1;			/* First child */
    int ch2;			/* Second child */
    int value;
    int value2;
    int value3;
    void *value4;
    void *value5;
    void *cache;
    void *cacheURI;
    int rewriteType;
};

struct _xmlXPathCompExpr {
    int nbStep;			/* Number of steps in this expression */
    int maxStep;		/* Maximum number of steps allocated */
    xmlXPathStepOp *steps;	/* ops for computation of this expression */
    int last;			/* index of last step in expression */
    xmlChar *expr;		/* the expression being computed */
    xmlDictPtr dict;		/* the dictionnary to use if any */
#ifdef DEBUG_EVAL_COUNTS
    int nb;
    xmlChar *string;
#endif
#ifdef XPATH_STREAMING
    xmlPatternPtr stream;
#endif
};

/************************************************************************
 * 									*
 * 			Forward declarations				*
 * 									*
 ************************************************************************/
static void
xmlXPathFreeValueTree(xmlNodeSetPtr obj);
static void
xmlXPathReleaseObject(xmlXPathContextPtr ctxt, xmlXPathObjectPtr obj);
static int
xmlXPathCompOpEvalFirst(xmlXPathParserContextPtr ctxt,
                        xmlXPathStepOpPtr op, xmlNodePtr *first);
static int
xmlXPathCompOpEvalToBoolean(xmlXPathParserContextPtr ctxt,
			    xmlXPathStepOpPtr op,
			    int isPredicate);

/************************************************************************
 * 									*
 * 			Parser Type functions 				*
 * 									*
 ************************************************************************/

/**
 * xmlXPathNewCompExpr:
 *
 * Create a new Xpath component
 *
 * Returns the newly allocated xmlXPathCompExprPtr or NULL in case of error
 */
static xmlXPathCompExprPtr
xmlXPathNewCompExpr(void) {
    xmlXPathCompExprPtr cur;

    cur = (xmlXPathCompExprPtr) xmlMalloc(sizeof(xmlXPathCompExpr));
    if (cur == NULL) {
        xmlXPathErrMemory(NULL, "allocating component\n");
	return(NULL);
    }
    memset(cur, 0, sizeof(xmlXPathCompExpr));
    cur->maxStep = 10;
    cur->nbStep = 0;
    cur->steps = (xmlXPathStepOp *) xmlMalloc(cur->maxStep *
	                                   sizeof(xmlXPathStepOp));
    if (cur->steps == NULL) {
        xmlXPathErrMemory(NULL, "allocating steps\n");
	xmlFree(cur);
	return(NULL);
    }
    memset(cur->steps, 0, cur->maxStep * sizeof(xmlXPathStepOp));
    cur->last = -1;
#ifdef DEBUG_EVAL_COUNTS
    cur->nb = 0;
#endif
    return(cur);
}

/**
 * xmlXPathFreeCompExpr:
 * @comp:  an XPATH comp
 *
 * Free up the memory allocated by @comp
 */
void
xmlXPathFreeCompExpr(xmlXPathCompExprPtr comp)
{
    xmlXPathStepOpPtr op;
    int i;

    if (comp == NULL)
        return;
    if (comp->dict == NULL) {
	for (i = 0; i < comp->nbStep; i++) {
	    op = &comp->steps[i];
	    if (op->value4 != NULL) {
		if (op->op == XPATH_OP_VALUE)
		    xmlXPathFreeObject(op->value4);
		else
		    xmlFree(op->value4);
	    }
	    if (op->value5 != NULL)
		xmlFree(op->value5);
	}
    } else {
	for (i = 0; i < comp->nbStep; i++) {
	    op = &comp->steps[i];
	    if (op->value4 != NULL) {
		if (op->op == XPATH_OP_VALUE)
		    xmlXPathFreeObject(op->value4);
	    }
	}
        xmlDictFree(comp->dict);
    }
    if (comp->steps != NULL) {
        xmlFree(comp->steps);
    }
#ifdef DEBUG_EVAL_COUNTS
    if (comp->string != NULL) {
        xmlFree(comp->string);
    }
#endif
#ifdef XPATH_STREAMING
    if (comp->stream != NULL) {
        xmlFreePatternList(comp->stream);
    }
#endif
    if (comp->expr != NULL) {
        xmlFree(comp->expr);
    }

    xmlFree(comp);
}

/**
 * xmlXPathCompExprAdd:
 * @comp:  the compiled expression
 * @ch1: first child index
 * @ch2: second child index
 * @op:  an op
 * @value:  the first int value
 * @value2:  the second int value
 * @value3:  the third int value
 * @value4:  the first string value
 * @value5:  the second string value
 *
 * Add a step to an XPath Compiled Expression
 *
 * Returns -1 in case of failure, the index otherwise
 */
static int
xmlXPathCompExprAdd(xmlXPathCompExprPtr comp, int ch1, int ch2,
   xmlXPathOp op, int value,
   int value2, int value3, void *value4, void *value5) {
    if (comp->nbStep >= comp->maxStep) {
	xmlXPathStepOp *real;

	comp->maxStep *= 2;
	real = (xmlXPathStepOp *) xmlRealloc(comp->steps,
		                      comp->maxStep * sizeof(xmlXPathStepOp));
	if (real == NULL) {
	    comp->maxStep /= 2;
	    xmlXPathErrMemory(NULL, "adding step\n");
	    return(-1);
	}
	comp->steps = real;
    }
    comp->last = comp->nbStep;
    comp->steps[comp->nbStep].rewriteType = 0;
    comp->steps[comp->nbStep].ch1 = ch1;
    comp->steps[comp->nbStep].ch2 = ch2;
    comp->steps[comp->nbStep].op = op;
    comp->steps[comp->nbStep].value = value;
    comp->steps[comp->nbStep].value2 = value2;
    comp->steps[comp->nbStep].value3 = value3;
    if ((comp->dict != NULL) &&
        ((op == XPATH_OP_FUNCTION) || (op == XPATH_OP_VARIABLE) ||
	 (op == XPATH_OP_COLLECT))) {
        if (value4 != NULL) {
	    comp->steps[comp->nbStep].value4 = (xmlChar *)
	        (void *)xmlDictLookup(comp->dict, value4, -1);
	    xmlFree(value4);
	} else
	    comp->steps[comp->nbStep].value4 = NULL;
        if (value5 != NULL) {
	    comp->steps[comp->nbStep].value5 = (xmlChar *)
	        (void *)xmlDictLookup(comp->dict, value5, -1);
	    xmlFree(value5);
	} else
	    comp->steps[comp->nbStep].value5 = NULL;
    } else {
	comp->steps[comp->nbStep].value4 = value4;
	comp->steps[comp->nbStep].value5 = value5;
    }
    comp->steps[comp->nbStep].cache = NULL;
    return(comp->nbStep++);
}

/**
 * xmlXPathCompSwap:
 * @comp:  the compiled expression
 * @op: operation index
 *
 * Swaps 2 operations in the compiled expression
 */
static void
xmlXPathCompSwap(xmlXPathStepOpPtr op) {
    int tmp;

#ifndef LIBXML_THREAD_ENABLED
    /*
     * Since this manipulates possibly shared variables, this is
     * disabled if one detects that the library is used in a multithreaded
     * application
     */
    if (xmlXPathDisableOptimizer)
	return;
#endif

    tmp = op->ch1;
    op->ch1 = op->ch2;
    op->ch2 = tmp;
}

#define PUSH_FULL_EXPR(op, op1, op2, val, val2, val3, val4, val5)	\
    xmlXPathCompExprAdd(ctxt->comp, (op1), (op2),			\
	                (op), (val), (val2), (val3), (val4), (val5))
#define PUSH_LONG_EXPR(op, val, val2, val3, val4, val5)			\
    xmlXPathCompExprAdd(ctxt->comp, ctxt->comp->last, -1,		\
	                (op), (val), (val2), (val3), (val4), (val5))

#define PUSH_LEAVE_EXPR(op, val, val2) 					\
xmlXPathCompExprAdd(ctxt->comp, -1, -1, (op), (val), (val2), 0 ,NULL ,NULL)

#define PUSH_UNARY_EXPR(op, ch, val, val2) 				\
xmlXPathCompExprAdd(ctxt->comp, (ch), -1, (op), (val), (val2), 0 ,NULL ,NULL)

#define PUSH_BINARY_EXPR(op, ch1, ch2, val, val2) 			\
xmlXPathCompExprAdd(ctxt->comp, (ch1), (ch2), (op),			\
			(val), (val2), 0 ,NULL ,NULL)

/************************************************************************
 *									*
 * 		XPath object cache structures				*
 *									*
 ************************************************************************/

/* #define XP_DEFAULT_CACHE_ON */

#define XP_HAS_CACHE(c) ((c != NULL) && ((c)->cache != NULL))

typedef struct _xmlXPathContextCache xmlXPathContextCache;
typedef xmlXPathContextCache *xmlXPathContextCachePtr;
struct _xmlXPathContextCache {
    xmlPointerListPtr nodesetObjs;  /* contains xmlXPathObjectPtr */
    xmlPointerListPtr stringObjs;   /* contains xmlXPathObjectPtr */
    xmlPointerListPtr booleanObjs;  /* contains xmlXPathObjectPtr */
    xmlPointerListPtr numberObjs;   /* contains xmlXPathObjectPtr */
    xmlPointerListPtr miscObjs;     /* contains xmlXPathObjectPtr */
    int maxNodeset;
    int maxString;
    int maxBoolean;
    int maxNumber;
    int maxMisc;
#ifdef XP_DEBUG_OBJ_USAGE
    int dbgCachedAll;
    int dbgCachedNodeset;
    int dbgCachedString;
    int dbgCachedBool;
    int dbgCachedNumber;
    int dbgCachedPoint;
    int dbgCachedRange;
    int dbgCachedLocset;
    int dbgCachedUsers;
    int dbgCachedXSLTTree;
    int dbgCachedUndefined; 
    

    int dbgReusedAll;
    int dbgReusedNodeset;
    int dbgReusedString;
    int dbgReusedBool;
    int dbgReusedNumber;
    int dbgReusedPoint;
    int dbgReusedRange;
    int dbgReusedLocset;
    int dbgReusedUsers;
    int dbgReusedXSLTTree;
    int dbgReusedUndefined;

#endif
};

/************************************************************************
 *									*
 * 		Debugging related functions				*
 *									*
 ************************************************************************/

#define STRANGE 							\
    xmlGenericError(xmlGenericErrorContext,				\
	    "Internal error at %s:%d\n",				\
            __FILE__, __LINE__);

#ifdef LIBXML_DEBUG_ENABLED
static void
xmlXPathDebugDumpNode(FILE *output, xmlNodePtr cur, int depth) {
    int i;
    char shift[100];

    for (i = 0;((i < depth) && (i < 25));i++)
        shift[2 * i] = shift[2 * i + 1] = ' ';
    shift[2 * i] = shift[2 * i + 1] = 0;
    if (cur == NULL) {
	fprintf(output, shift);
	fprintf(output, "Node is NULL !\n");
	return;
        
    }

    if ((cur->type == XML_DOCUMENT_NODE) ||
	     (cur->type == XML_HTML_DOCUMENT_NODE)) {
	fprintf(output, shift);
	fprintf(output, " /\n");
    } else if (cur->type == XML_ATTRIBUTE_NODE)
	xmlDebugDumpAttr(output, (xmlAttrPtr)cur, depth);
    else
	xmlDebugDumpOneNode(output, cur, depth);
}
static void
xmlXPathDebugDumpNodeList(FILE *output, xmlNodePtr cur, int depth) {
    xmlNodePtr tmp;
    int i;
    char shift[100];

    for (i = 0;((i < depth) && (i < 25));i++)
        shift[2 * i] = shift[2 * i + 1] = ' ';
    shift[2 * i] = shift[2 * i + 1] = 0;
    if (cur == NULL) {
	fprintf(output, shift);
	fprintf(output, "Node is NULL !\n");
	return;
        
    }

    while (cur != NULL) {
	tmp = cur;
	cur = cur->next;
	xmlDebugDumpOneNode(output, tmp, depth);
    }
}

static void
xmlXPathDebugDumpNodeSet(FILE *output, xmlNodeSetPtr cur, int depth) {
    int i;
    char shift[100];

    for (i = 0;((i < depth) && (i < 25));i++)
        shift[2 * i] = shift[2 * i + 1] = ' ';
    shift[2 * i] = shift[2 * i + 1] = 0;

    if (cur == NULL) {
	fprintf(output, shift);
	fprintf(output, "NodeSet is NULL !\n");
	return;
        
    }

    if (cur != NULL) {
	fprintf(output, "Set contains %d nodes:\n", cur->nodeNr);
	for (i = 0;i < cur->nodeNr;i++) {
	    fprintf(output, shift);
	    fprintf(output, "%d", i + 1);
	    xmlXPathDebugDumpNode(output, cur->nodeTab[i], depth + 1);
	}
    }
}

static void
xmlXPathDebugDumpValueTree(FILE *output, xmlNodeSetPtr cur, int depth) {
    int i;
    char shift[100];

    for (i = 0;((i < depth) && (i < 25));i++)
        shift[2 * i] = shift[2 * i + 1] = ' ';
    shift[2 * i] = shift[2 * i + 1] = 0;

    if ((cur == NULL) || (cur->nodeNr == 0) || (cur->nodeTab[0] == NULL)) {
	fprintf(output, shift);
	fprintf(output, "Value Tree is NULL !\n");
	return;
        
    }

    fprintf(output, shift);
    fprintf(output, "%d", i + 1);
    xmlXPathDebugDumpNodeList(output, cur->nodeTab[0]->children, depth + 1);
}
#if defined(LIBXML_XPTR_ENABLED)
static void
xmlXPathDebugDumpLocationSet(FILE *output, xmlLocationSetPtr cur, int depth) {