int Q_Find( queue *q, void *data, int(*Comp)( const void *, const void * ) )
{
void *d;
d = Q_First( q );
do
{
if ( Comp( d, data ) == 0 ) return True_;
d = Q_Next( q );
}
while ( !Q_End( q ) );
if ( Comp( d, data ) == 0 ) return True_;
return False_;
}
int Q_Sort(queue *q, int (*Comp)(const void *, const void *))
{
int i;
void *d;
datanode *dn;
/* if already sorted free memory for tag array */
if (q->sorted)
{
free(Q_index);
free(posn_index);
q->sorted = False_;
}
/* Now allocate memory of array, array of pointers */
Q_index = malloc(q->size * sizeof(q->cursor->data));
if (Q_index == NULL)
return False_;
posn_index = malloc(q->size * sizeof(q->cursor));
if (posn_index == NULL)
{
free(Q_index);
return False_;
}
/* Walk queue putting pointers into array */
d = Q_First(q);
for (i=0; i < q->size; i++)
{
Q_index[i] = d;
posn_index[i] = q->cursor;
d = Q_Next(q);
}
/* Now sort the index */
QuickSort(Q_index, 0, q->size - 1, Comp);
/* Rearrange the actual queue into correct order */
dn = q->head;
i = 0;
while (dn != NULL)
{
dn->data = Q_index[i++];
dn = dn->next;
}
/* Re-position to original element */
if (d != NULL)
Q_Find(q, d, Comp);
else Q_First(q);
q->sorted = True_;
return True_;
}
