archive/blender-archive
Archived
1
1
Fork 0
Code Pull Requests Packages Activity

BLI: Support removing keys from a set during iteration

Browse Source 
This adds the ability to mark slots as removed while iterating through
a mutable set.

Differential Revision: https://developer.blender.org/D12867
This commit is contained in:
Hans Goudey
2021-10-18 22:15:52 -05:00
parent da949c3574
commit a76bb1a277
2 changed files with 48 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

22
source/blender/blenlib/BLI_set.hh
View File

@@ -423,6 +423,8 @@ class Set {
int64_t total_slots_; int64_t total_slots_;
int64_t current_slot_; int64_t current_slot_;
friend Set;
public: public:
Iterator(const Slot *slots, int64_t total_slots, int64_t current_slot) Iterator(const Slot *slots, int64_t total_slots, int64_t current_slot)
: slots_(slots), total_slots_(total_slots), current_slot_(current_slot) : slots_(slots), total_slots_(total_slots), current_slot_(current_slot)
@@ -467,6 +469,12 @@ class Set {
{ {
return !(a != b); return !(a != b);
} }
protected:
const Slot &current_slot() const
{
return slots_[current_slot_];
}
}; };
Iterator begin() const Iterator begin() const
@@ -484,6 +492,20 @@ class Set {
return Iterator(slots_.data(), slots_.size(), slots_.size()); return Iterator(slots_.data(), slots_.size(), slots_.size());
} }
/**
* Remove the key that the iterator is currently pointing at. It is valid to call this method
* while iterating over the set. However, after this method has been called, the removed element
* must not be accessed anymore.
*/
void remove(const Iterator &iterator)
{
/* The const cast is valid because this method itself is not const. */
Slot &slot = const_cast<Slot &>(iterator.current_slot());
BLI_assert(slot.is_occupied());
slot.remove();
removed_slots_++;
}
/** /**
* Print common statistics like size and collision count. This is useful for debugging purposes. * Print common statistics like size and collision count. This is useful for debugging purposes.
*/ */

26
source/blender/blenlib/tests/BLI_set_test.cc
View File

@@ -544,6 +544,32 @@ TEST(set, GenericAlgorithms)
EXPECT_EQ(std::count(set.begin(), set.end(), 20), 1); EXPECT_EQ(std::count(set.begin(), set.end(), 20), 1);
} }
TEST(set, RemoveDuringIteration)
{
Set<int> set;
set.add(6);
set.add(5);
set.add(2);
set.add(3);
EXPECT_EQ(set.size(), 4);
using Iter = Set<int>::Iterator;
Iter begin = set.begin();
Iter end = set.end();
for (Iter iter = begin; iter != end; ++iter) {
int item = *iter;
if (item == 2) {
set.remove(iter);
}
}
EXPECT_EQ(set.size(), 3);
EXPECT_TRUE(set.contains(5));
EXPECT_TRUE(set.contains(6));
EXPECT_TRUE(set.contains(3));
}
/** /**
* Set this to 1 to activate the benchmark. It is disabled by default, because it prints a lot. * Set this to 1 to activate the benchmark. It is disabled by default, because it prints a lot.
*/ */