mirror of
https://github.com/oxen-io/session-android.git
synced 2025-01-11 14:33:39 +00:00
59 lines
1.9 KiB
C++
59 lines
1.9 KiB
C++
|
#pragma once
|
||
|
|
#include <oxenc/bt_value.h>
|
||
|
|
|
||
|
|
#include <cassert>
|
||
|
|
#ifndef NDEBUG
|
||
|
|
#include <algorithm>
|
||
|
|
#endif
|
||
|
|
|
||
|
|
namespace session::bt {
|
||
|
|
|
||
|
|
using oxenc::bt_dict;
|
||
|
|
using oxenc::bt_list;
|
||
|
|
|
||
|
|
/// Merges two bt dicts together: the returned dict includes all keys in a or b. Keys in *both*
|
||
|
|
/// dicts get their value from `a`, otherwise the value is that of the dict that contains the key.
|
||
|
|
bt_dict merge(const bt_dict& a, const bt_dict& b);
|
||
|
|
|
||
|
|
/// Merges two ordered bt_lists together using a predicate to determine order. The input lists must
|
||
|
|
/// be sorted to begin with. `cmp` must be callable with a pair of `const bt_value&` arguments and
|
||
|
|
/// must return true if the first argument should be considered less than the second argument. By
|
||
|
|
/// default this skips elements from b that compare equal to a value of a, but you can include all
|
||
|
|
/// the duplicates by specifying the `duplicates` parameter as true.
|
||
|
|
template <typename Compare>
|
||
|
|
bt_list merge_sorted(const bt_list& a, const bt_list& b, Compare cmp, bool duplicates = false) {
|
||
|
|
bt_list result;
|
||
|
|
auto it_a = a.begin();
|
||
|
|
auto it_b = b.begin();
|
||
|
|
|
||
|
|
assert(std::is_sorted(it_a, a.end(), cmp));
|
||
|
|
assert(std::is_sorted(it_b, b.end(), cmp));
|
||
|
|
|
||
|
|
if (duplicates) {
|
||
|
|
while (it_a != a.end() && it_b != b.end()) {
|
||
|
|
if (!cmp(*it_a, *it_b)) // *b <= *a
|
||
|
|
result.push_back(*it_b++);
|
||
|
|
else // *a < *b
|
||
|
|
result.push_back(*it_a++);
|
||
|
|
}
|
||
|
|
} else {
|
||
|
|
while (it_a != a.end() && it_b != b.end()) {
|
||
|
|
if (cmp(*it_b, *it_a)) // *b < *a
|
||
|
|
result.push_back(*it_b++);
|
||
|
|
else if (cmp(*it_a, *it_b)) // *a < *b
|
||
|
|
result.push_back(*it_a++);
|
||
|
|
else // *a == *b
|
||
|
|
++it_b; // skip it
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
if (it_a != a.end())
|
||
|
|
result.insert(result.end(), it_a, a.end());
|
||
|
|
else if (it_b != b.end())
|
||
|
|
result.insert(result.end(), it_b, b.end());
|
||
|
|
|
||
|
|
return result;
|
||
|
|
}
|
||
|
|
|
||
|
|
} // namespace session::bt
|