#include "/include/crc_32.h"

using namespace std;

// calls to the function require an external pointer *crc, and a final return
// variable called url_crc, which is the value that ends up getting used for the db.

unsigned long crc_table[256];

void gen_crc_table(void)                /* build the crc table */
{
    unsigned long crc, poly;
    int i, j;

    poly = 0xEDB88320L;
    for (i = 0; i < 256; i++)
        {
        crc = i;
        for (j = 8; j > 0; j--)
            {
            if (crc & 1)
                crc = (crc >> 1) ^ poly;
            else
                crc >>= 1;
            }
        crc_table[i] = crc;
        }
}


void crc_reset( unsigned long *crc ) {

    *crc = 0xFFFFFFFF;
}


unsigned long get_crc( unsigned long *crc, int ch )    /* calculate the crc value */
{
    *crc = (((*crc)>>8) & 0x00FFFFFF) ^ crc_table[ ((*crc)^ch) & 0xFF ];
    return( (*crc)^0xFFFFFFFF );
}