TrixelCache

A simple integer indexed elastically cached wrapper around std::vector to hold container types content which are cheap to construct empty and provide a default constructor, as well as [], size and swap members (think std::vector and std::list).

The caching mechanism will be short-circuited if the cache size equals the data size.

The container is resized to a given data_size by default initializing its elements. The elements are stored as TrixelCache::element objects and retrieved by index and LRU cached on the fly. To test if a given element is cached (or not empty) the TrixelCache::element::is_set() can be queried. Setting an element works by just assigning it with the new data. The data from an element can be retrieved through the TrixelCache::element::data() member. Modifying the data through that reference is allowed.

Setting an element is done by assigning it the new data.

When it is convenient TrixelCache::prune() may be called, which clears the least recently used elements (by default initializing them) until the number of elements does not exceed the cache size. This is expensive relative to setting an elment which has almost no cost.

Template Parameters

content

The content type to use. Most likely a QList, std::vector or std::list.

Todo

Use std::optional when C++17 is adopted in kstars.

Example

Definition at line 59 of file trixelcache.h.