mirror-chatterino2/src/messages/LimitedQueueSnapshot.hpp
Daniel Sage 81caf1aae0
Rewrite & optimize LimitedQueue (#3798)
* Use circular buffer for LimitedQueue

* Reduce copying of snapshot

* Small optimizations

* Remove unneeded lock statements

* Add LimitedQueue tests

* Fix includes for limited queue benchmark

* Update CHANGELOG.md

* Use correct boost version iterators

* Use a shared_mutex to clarify reads and writes

* Update `find`/`rfind` to return the result as a boost::optional

* Use `[[nodiscard]]` where applicable

* Update comments

* Add a couple more doc comments

* Replace size with get

get is a safe (locked & checked) version of at

* Use std::vector in LimitedQueueSnapshot

* Update LimitedQueue benchmarks

* Add mutex guard to buffer accessors

We do not know whether T is an atomic type or not
so we can't safely say that we can copy the value
at a certain address of the buffer.

See https://stackoverflow.com/a/2252478

* Update doc comments, add first/last getters

* Make limit_ const

* Omit `else` if the if-case always returns

* Title case category comments

* Remove `at`

* Fix `get` comment

* Privatize/comment/lock property accessors

 - `limit` is now private
 - `space` is now private
 - `full` has been removed
 - `empty` now locks

* Remove `front` function

* Remove `back` method

* Add comment to `first`

* Add comment to `last`

Co-authored-by: Rasmus Karlsson <rasmus.karlsson@pajlada.com>
2022-06-18 10:44:48 +00:00

62 lines
963 B
C++

#pragma once
#include <boost/circular_buffer.hpp>
#include <cassert>
#include <memory>
#include <vector>
namespace chatterino {
template <typename T>
class LimitedQueue;
template <typename T>
class LimitedQueueSnapshot
{
private:
friend class LimitedQueue<T>;
LimitedQueueSnapshot(const boost::circular_buffer<T> &buf)
: buffer_(buf.begin(), buf.end())
{
}
public:
LimitedQueueSnapshot() = default;
size_t size() const
{
return this->buffer_.size();
}
const T &operator[](size_t index) const
{
return this->buffer_[index];
}
auto begin() const
{
return this->buffer_.begin();
}
auto end() const
{
return this->buffer_.end();
}
auto rbegin() const
{
return this->buffer_.rbegin();
}
auto rend() const
{
return this->buffer_.rend();
}
private:
std::vector<T> buffer_;
};
} // namespace chatterino