class Prometheus::Client::DataStores::DirectFileStore::FileMappedDict

A dict of doubles, backed by an file we access directly as a byte array.

The file starts with a 4 byte int, indicating how much of it is used. Then 4 bytes of padding. There’s then a number of entries, consisting of a 4 byte int which is the size of the next field, a utf-8 encoded string key, padding to an 8 byte alignment, and then a 8 byte float which is the value, and then a 8 byte float which is the unix timestamp when the value was set.