fastMap

C++ implementation of a fast, in-memory key-value store
supports get, put, delete; both by value (get("foo")) and by alphabetic index (get(1))
works for arbitrary-length strings keys and values (matching [a-zA-Z]+), as many as your RAM can fit in.
stores ten million entries (max key length=64, max value length=256) in less than 25 seconds (on a medium-end CPU)
supports multiple thread calls
well structured, modular code based on compressed tries and binary search trees

Link to detailed implementation spec

Usage

Including the file src/kvStore.cpp in your source file should be enough. Note that C++14 or newer is required to compile successfully.

Scope for improvement

PRs welcome!

asynchronous non-blocking get calls