Template Class CacheManager

Nested Relationships

Nested Types

Class Documentation

template<typename TreeNode, bool force_hash_collisions>
class CacheManager

This class implements a cache manager useful for the cases when the number of times the cached objects will be accessed is known.

Template Parameters:

  • TreeNode – The evaluation tree node type used as the cache key.

  • force_hash_collisions – If true, forces all hash values to 0 (for testing collision safety).

Public Types

using key_type = TreeNode

Public Functions

template<typename Iterable1>
inline explicit CacheManager(Iterable1 &&decaying) noexcept
inline void reset() noexcept

Resets all cached data.

inline ResultPtr access(key_type const &key) noexcept

Access cached data.

Parameters:

key – The key that identifies the cached data.

Returns:

ResultPtr to Result

inline ResultPtr store(key_type const &key, ResultPtr data) noexcept
Parameters:

  • key – The key to identify the cached data.

  • data – The data to be cached.

Returns:

Pointer to the stored data. Implictly accesses the stored data, hence, decays the lifetime if the key accesses a decaying cache entry. Passing key that was not present during construction of this CacheManager object, stores nothing, but still returns a valid pointer to data.

inline bool exists(key_type const &key) const noexcept

Check if the key exists in the database: does not check if cache exists.

inline int life(key_type const &key) const noexcept

if the key exists in the database, return the current lifetime count of the cached data otherwise return -1

inline int max_life(key_type const &key) const noexcept

if the key exists in the database, return the maximum lifetime count of the cached data that implies the maximum number of accesses allowed for this key before the cache is released. This value was set by the c’tor.

inline size_t alive_count() const noexcept
Returns:

The number of entries with life_count greater than zero.

inline size_t size_in_bytes() const noexcept
Returns:

Returns the sum of Result::size_in_bytes of alive entries.

Public Static Functions

static inline CacheManager empty() noexcept

Get an empty cache manager.

Friends

friend struct access_by
template<typename T>
struct access_by