Mapping from access time to the index of an item in the items array. The
map is implemented with an EBTree, so that it is sorted in order of
access times.
The time-to-index mapping records are stored in time_to_index as
so-called EBTree "nodes" of type TimeToIndex.Node. Each node contains a
so-called "key" of type TimeToIndex.Key which consists of two uint
values, "lo" and "hi".
The sort order is ascending by "hi"; records with the same "hi" value
are sorted by "lo". Therefore, since the time-to-index mapping records
should be sorted by access time, time and cache index are stored as
TimeToIndex.Key.hi = access time,
TimeToIndex.Key.lo = cache index.
Mapping from access time to the index of an item in the items array. The map is implemented with an EBTree, so that it is sorted in order of access times.
The time-to-index mapping records are stored in time_to_index as so-called EBTree "nodes" of type TimeToIndex.Node. Each node contains a so-called "key" of type TimeToIndex.Key which consists of two uint values, "lo" and "hi". The sort order is ascending by "hi"; records with the same "hi" value are sorted by "lo". Therefore, since the time-to-index mapping records should be sorted by access time, time and cache index are stored as
TimeToIndex.Key.hi = access time, TimeToIndex.Key.lo = cache index.