fifo_entry.hpp#

See Public API for a list of names and headers that are part of the public HPX API.

namespace hpx

namespace util

namespace cache

namespace entries

template<typename Value> class fifo_entry : public hpx::util::cache::entries::entry<Value, fifo_entry<Value>>#

#include <hpx/cache/entries/fifo_entry.hpp>

The fifo_entry type can be used to store arbitrary values in a cache. Using this type as the cache’s entry type makes sure that the least recently inserted entries are discarded from the cache first.

Note

The fifo_entry conforms to the CacheEntry concept.

Note

This type can be used to model a ‘last in first out’ cache policy if it is used with a std::greater as the caches’ UpdatePolicy (instead of the default std::less).

Template Parameters: Value – The data type to be stored in a cache. It has to be default constructible, copy constructible and less_than_comparable.

Public Functions

fifo_entry() = default#: Any cache entry has to be default constructible.

inline explicit fifo_entry(Value const &val) noexcept(std::is_nothrow_constructible_v<base_type, Value const&>)#: Construct a new instance of a cache entry holding the given value.

inline explicit fifo_entry(Value &&val) noexcept#: Construct a new instance of a cache entry holding the given value.

inline constexpr bool insert()#

The function insert is called by a cache whenever it is about to be inserted into the cache.

Note

This function is part of the CacheEntry concept

Returns: This function should return true if the entry should be added to the cache, otherwise it should return false.

inline constexpr time_point const &get_creation_time() const noexcept#

Private Types

using base_type = entry<Value, fifo_entry<Value>>#

using time_point = std::chrono::steady_clock::time_point#

Private Members

time_point insertion_time_#

Friends

inline friend bool operator<(fifo_entry const &lhs, fifo_entry const &rhs) noexcept(noexcept(std::declval<time_point const&>() < std::declval<time_point const&>()))#: Compare the ‘age’ of two entries. An entry is ‘older’ than another entry if it has been created earlier (FIFO).