slp_compare.c

SLP协议在linux下的实现。此版本为1.2.1版。官方网站为www.openslp.org

    }

    return 0;
}


/*=========================================================================*/
int SLPIntersectStringList(int list1len,
                           const char* list1,
                           int list2len,
                           const char* list2)
/* Calculates the number of common entries between two string-lists        */
/*                                                                         */
/* list1 -      pointer to the string-list to be checked                   */
/*                                                                         */
/* list1len -   length in bytes of the list to be checked                  */
/*                                                                         */
/* list2 -      pointer to the string-list to be checked                   */
/*                                                                         */
/* list2len -   length in bytes of the list to be checked                  */
/*                                                                         */
/* Returns -    The number of common entries.                              */
/*=========================================================================*/
{
    int result = 0;
    char* listend = (char*)list1 + list1len;
    char* itembegin = (char*)list1;
    char* itemend = itembegin;

    while(itemend < listend)
    {
        itembegin = itemend;

        /* seek to the end of the next list item */
        while(1)
        {
            if(itemend == listend || *itemend == ',')
            {
                if(*(itemend - 1) != '\\')
                {
                    break;
                }
            }

            itemend ++;
        }

        if(SLPContainsStringList(list2len,
                                 list2,
                                 itemend - itembegin,
                                 itembegin))
        {
            result ++;
        }

        itemend ++;    
    }

    return result;
}

/*=========================================================================*/
int SLPUnionStringList(int list1len,
                       const char* list1,
                       int list2len,
                       const char* list2,
                       int* unionlistlen,
                       char * unionlist)
/* Generate a string list that is a union of two string lists              */
/*                                                                         */
/* list1len -   length in bytes of list1                                   */
/*                                                                         */
/* list1 -      pointer to a string-list                                   */
/*                                                                         */
/* list2len -   length in bytes of list2                                   */
/*                                                                         */
/* list2 -      pointer to a string-list                                   */
/*                                                                         */
/* unionlistlen - pointer to the size in bytes of the unionlist buffer.    */
/*                also receives the size in bytes of the unionlist buffer  */
/*                on successful return.                                    */
/*                                                                         */
/* unionlist -  pointer to the buffer that will receive the union list.    */ 
/*                                                                         */
/*                                                                         */
/* Returns -    Length of the resulting union list or negative if          */
/*              unionlist is not big enough. If negative is returned       */
/*              *unionlist will be changed indicate the size of unionlist  */
/*              buffer needed                                              */
/*                                                                         */
/* Important: In order ensure that unionlist does not contain any          */
/*            duplicates, at least list1 must not have any duplicates.     */
/*            Also, for speed optimization if list1 and list2 are both     */
/*            with out duplicates, the larger list should be passed in     */
/*            as list1.                                                    */
/*                                                                         */
/* Note: A good size for unionlist (so that non-zero will never be         */
/*       returned) is list1len + list2len + 1                              */
/*=========================================================================*/
{
    char* listend = (char*)list2 + list2len;
    char* itembegin = (char*)list2;
    char* itemend = itembegin;
    int   itemlen;
    int   copiedlen;

    if(unionlist == 0 ||
       *unionlistlen == 0 ||
       *unionlistlen < list1len)
    {
        *unionlistlen = list1len + list2len + 1;
        return -1;
    }

    /* Copy list1 into the unionlist since it should not have any duplicates */
    memcpy(unionlist,list1,list1len);
    copiedlen = list1len;

    while(itemend < listend)
    {
        itembegin = itemend;

        /* seek to the end of the next list item */
        while(1)
        {
            if(itemend == listend || *itemend == ',')
            {
                if(*(itemend - 1) != '\\')
                {
                    break;
                }
            }

            itemend ++;
        }

        itemlen = itemend - itembegin;
        if(SLPContainsStringList(list1len,
                                 list1,
                                 itemlen,
                                 itembegin) == 0)
        {
            if(copiedlen + itemlen + 1 > *unionlistlen)
            {

                *unionlistlen = list1len + list2len + 1;
                return -1;
            }

            /* append a comma if not the first entry*/
            if(copiedlen)
            {
                unionlist[copiedlen] = ',';
                copiedlen++;
            }
            memcpy(unionlist + copiedlen, itembegin, itemlen);
            copiedlen += itemlen;

        }

        itemend ++;    
    }

    *unionlistlen = copiedlen;

    return copiedlen;
}

/*=========================================================================*/
int SLPSubsetStringList(int listlen,
                        const char* list,
                        int sublistlen,
                        const char* sublist)
/* Test if sublist is a set of list                                        */
/*                                                                         */
/* list  -      pointer to the string-list to be checked                   */
/*                                                                         */
/* listlen -    length in bytes of the list to be checked                  */
/*                                                                         */
/* sublistlistlen -   pointer to the string-list to be checked             */
/*                                                                         */
/* sublist -   length in bytes of the list to be checked                   */
/*                                                                         */
/* Returns -    non-zero is sublist is a subset of list.  Zero otherwise   */
/*=========================================================================*/
{
    /* count the items in sublist */
    int curpos;
    int sublistcount;

    if(sublistlen ==0 || listlen == 0)
    {
        return 0;
    }

    curpos = 0;
    sublistcount = 1;
    while(curpos < sublistlen)
    {
        if(sublist[curpos] == ',')
        {
            sublistcount ++;
        }
        curpos ++;
    }

    if(SLPIntersectStringList(listlen,
                              list,
                              sublistlen,
                              sublist) == sublistcount)
    {
        return sublistcount;
    }

    return 0;
}


/*=========================================================================*/
int SLPCheckServiceUrlSyntax(const char* srvurl,
			     int srvurllen)
/* Test if a service url conforms to accepted syntax
 *
 * srvurl -     (IN) service url string to check
 *
 * srvurllen -  (IN) length of srvurl in bytes
 *
 * Returns - zero if srvurl has acceptable syntax, non-zero on failure
 *
 *=========================================================================*/
{
    /* TODO: Do we actually need to do something here to ensure correct
     * service-url syntax, or should we expect that it will be used
     * by smart developers who know that ambiguities could be encountered
     * if they don't?
     
    if(srvurllen < 8)
    {
        return 1;
    }
   
    if(strncasecmp(srvurl,"service:",8))
    {
        return 1;
    }        
   
    return 0;
    */

    return 0;
}
 
 
/*=========================================================================*/
int SLPCheckAttributeListSyntax(const char* attrlist,
				int attrlistlen)
/* Test if a service url conforms to accepted syntax
 *
 * attrlist -     (IN) attribute list string to check
 *
 * attrlistlen -  (IN) length of attrlist in bytes
 *
 * Returns - zero if srvurl has acceptable syntax, non-zero on failure
 *
 *=========================================================================*/
{
    const char* slider;
    const char* end;
   
    if(attrlistlen)
    {
        slider = attrlist;
        end = attrlist + attrlistlen;
        while(slider != end)
        {
            if(*slider == '(')
            {
	        while(slider != end)
	        {
	            if(*slider == '=')
	            {
		        return 0;
		    }
		    slider++;
	        }
	    
	        return 1;
	    }
	    slider++;
	}
    }    
    return 0;
}