void
rangelist_remove_range(struct RangeList *task, unsigned begin, unsigned end)
{
unsigned i;
struct Range x;
x.begin = begin;
x.end = end;
/* See if the range overlaps any exist range already in the
* list */
for (i = 0; i < task->count; i++) {
if (!range_is_overlap(task->list[i], x))
continue;
/* If the removal-range wholly covers the range, delete
* it completely */
if (begin <= task->list[i].begin && end >= task->list[i].end) {
todo_remove_at(task, i);
i--;
continue;
}
/* If the removal-range bisects the target-rage, truncate
* the lower end and add a new high-end */
if (begin > task->list[i].begin && end < task->list[i].end) {
struct Range newrange;
newrange.begin = end+1;
newrange.end = task->list[i].end;
task->list[i].end = begin-1;
rangelist_add_range(task, newrange.begin, newrange.end);
i--;
continue;
}
/* If overlap on the lower side */
if (end >= task->list[i].begin && end < task->list[i].end) {
task->list[i].begin = end+1;
}
/* If overlap on the upper side */
if (begin > task->list[i].begin && begin <= task->list[i].end) {
task->list[i].end = begin-1;
}
//assert(!"impossible");
}
}
/***************************************************************************
* Add the IPv4 range to our list of ranges.
***************************************************************************/
void
rangelist_add_range(struct RangeList *task, unsigned begin, unsigned end)
{
unsigned i;
struct Range range;
range.begin = begin;
range.end = end;
/* auto-expand the list if necessary */
if (task->count + 1 >= task->max) {
size_t new_max = (size_t)task->max * 2 + 1;
struct Range *new_list;
if (new_max >= SIZE_MAX/sizeof(*new_list))
exit(1); /* integer overflow */
new_list = (struct Range *)malloc(sizeof(*new_list) * new_max);
if (new_list == NULL)
exit(1); /* out of memory */
memcpy(new_list, task->list, task->count * sizeof(*new_list));
if (task->list)
free(task->list);
task->list = new_list;
task->max = (unsigned)new_max;
}
/* See if the range overlaps any exist range already in the
* list */
for (i = 0; i < task->count; i++) {
if (range_is_overlap(task->list[i], range)) {
range_combine(&range, task->list[i]);
todo_remove_at(task, i);
rangelist_add_range(task, range.begin, range.end);
return;
}
}
/* Find a spot to insert in sorted order */
for (i = 0; i < task->count; i++) {
if (range.begin < task->list[i].begin) {
memmove(task->list+i+1, task->list+i, (task->count - i) * sizeof(task->list[0]));
break;
}
}
/* Add to end of list */
task->list[i].begin = begin;
task->list[i].end = end;
task->count++;
}
/***************************************************************************
* Add the IPv4 range to our list of ranges.
***************************************************************************/
void
rangelist_add_range(struct RangeList *task, unsigned begin, unsigned end)
{
int first, middle, last;
struct Range range;
range.begin = begin;
range.end = end;
/* auto-expand the list if necessary */
if (task->count + 1 >= task->max) {
size_t new_max = (size_t)task->max * 2 + 1;
struct Range *new_list;
if (new_max >= SIZE_MAX/sizeof(*new_list))
exit(1); /* integer overflow */
new_list = (struct Range *)malloc(sizeof(*new_list) * new_max);
if (new_list == NULL)
exit(1); /* out of memory */
memcpy(new_list, task->list, task->count * sizeof(*new_list));
if (task->list)
free(task->list);
task->list = new_list;
task->max = (unsigned)new_max;
}
if (!task->count) {
task->list[0].begin = begin;
task->list[0].end = end;
task->count++;
return;
}
/* Binary search to find where the current IP range belongs by comparing range beginnings */
first = 0;
last = task->count - 1;
middle = (first + last) / 2;
while (first <= last) {
if (task->list[middle].begin < range.begin)
first = middle + 1;
else if (task->list[middle].begin == range.begin)
break;
else
last = middle - 1;
middle = (first + last) / 2;
}
/* `middle` now points to the IP range numerically smaller than or equal to it. Try to merge it
* with the numerically smaller, and then greater ranges. */
if (range_is_overlap(task->list[middle], range)) {
range_combine(&range, task->list[middle]);
todo_remove_at(task, middle);
rangelist_add_range(task, range.begin, range.end);
return;
}
if (task->count > (middle+1) && range_is_overlap(task->list[middle+1], range)) {
range_combine(&range, task->list[middle+1]);
todo_remove_at(task, middle+1);
rangelist_add_range(task, range.begin, range.end);
return;
}
/* Make space for the current range respecting sorted order by placing it in entry `middle+1` */
memmove(task->list+middle+2, task->list+middle+1, (task->count - middle - 1) * sizeof(task->list[0]));
/* Add to the list */
task->list[middle+1].begin = begin;
task->list[middle+1].end = end;
task->count++;
}