Function arr_to_sdata

methods/svec/src/pg_gp/SparseData.c:1335–1369

* @param array The array of elements to be converted to a SparseData * @param width The size of the elements in array * @param type_of_data The object ID of the elements in array * @param count The size of array * @return A SparseData representation of an input array */

 * @return A SparseData representation of an input array
 */
SparseData arr_to_sdata(char *array, size_t width, Oid type_of_data, int count){
	char *run_val=array;
	int64 run_len=1;
	SparseData sdata = makeSparseData();

	sdata->type_of_data=type_of_data;

	for (int i=1; i<count; i++) {
		char *curr_val=array+ (i*size_of_type(type_of_data));

		/*
		 * Note that special double values like denormalized numbers and exceptions
		 * like NaN are treated like any other value - if there are duplicates, the
		 * value of the special number is preserved and they are counted.
		 */
		if (memcmp(curr_val,run_val,width))
		{       /*run is interrupted, initiate new run */
			/* package up the finished run */
			add_run_to_sdata(run_val,run_len,width,sdata);
			/* mark beginning of new run */
			run_val=curr_val;
			run_len=1;
		} else
		{ /* we're still in the same run */
			run_len++;
		}
	}
	add_run_to_sdata(run_val, run_len, width, sdata); /* package up the last run */

	/* Add the final tallies */
	sdata->unique_value_count = sdata->vals->len/width;
	sdata->total_value_count = count;

	return sdata;
}

int compar(const void *i, const void *j){
	return (int)((int64*)array_pos_ref)[*(int*)i] - ((int64*)array_pos_ref)[*(int*)j];