Implementation of a B+ Tree.
This works best with a large number of records and a large fan-out.
Requires C++20.
MIT license.
Note main branch is usually a work in progress. You will be much
better served using the latest release.
The benchmark code in examples/set-benchmark.cpp was run and the following
results were obtained as an average of 5 runs.
| Structure | build | probe |
|---|---|---|
| std::set<int> | 967ms | 608ms |
| std::map<int,int> | 956ms | 587ms |
| BPT::set<int> | 725ms | 272ms |
| BPT::BPlusTree<int, int> | 701ms | 272ms |
| BPT::BPlusTree<int, int, 100> | 764ms | 210ms |
This is not concurrency safe without additional locking. The tree methods can be called without problems from different threads. However, two threads may not call methods at the same time - unless they are both reads.
Caveat Scriptor
See B+ API
A replacement for std::set is available.
C.f. Set documentation
This is a header only project. All that would be needed is to copy the contents
of the src directory along with its subdirectories to some suitable place
and point your compiler there as an include directory.
An easier way, if you use cmake, is to use CPM.
Something like the following :
include(CPM)
...
CPMAddPackage("gh:mhhollomon/[email protected]")
target_link_libraries(my_project PRIVATE bplustree)You can control the creation of the tests by setting
BPLUSTREE_BUILD_TESTS. it is on by default.
There will be a rebuild method that will take care of reclaiming space.
Use Optimistic Lock Coupling to allow concurrency.
(c.f. http://sites.computer.org/debull/A19mar/p73.pdf)
This will probably be a new separate class that uses BPlusTree internally.
I don't plan to support all the really gnarly bits about hinting and node_ptrs.
Similar to above.
- work on the splitting algorithm. It still does more data copies/moves than really necessary.
Provide reverse iterators.