Is there any good known file based key->value datastructure available in c++?

Question

Is there any good file based key->value data-structure available in c++.

similar to std::map(template based) with a insert/delete/get of O(logn).

Answer 1

You could look at Oracle Berkeley DB it provides the underlying key, data storage mechanism that you require or as already suggested sqlite.

Answer 2

Perhaps you can add your own template mechanism to Databases like redist. If you have a string-based database, you need some methods to serialize/deserialize your own objects. Perhaps Google Protocol Buffers or a custom JSON/XML exporter/importer does that for you, depends whether you just want speed or easy to use.

Answer 3

STXXL - Standard Template Library for XXL Data Sets implements file-based containers.

It's stxxl::map is quite similar to std::map, based on B+ tree with an insert/delete/get of O(logn).