STX B+ Tree project is a set of C++ template classes implementing a B+ tree key/data container in main memory. The classes are designed as drop-in replacements of the STL containers set, map, multiset and multimap and follow their interfaces very closely. By packing multiple value pairs into each node of the tree the B+ tree reduces heap fragmentation and utilizes cache-line effects better than the standard red-black binary tree.
The tree algorithms are based on the implementation in Cormen, Leiserson and Rivest's Introduction into Algorithms, Jan Jannink's paper and other algorithm resources. The classes contain extensive assertion and verification mechanisms to ensure the implementation's correctness by testing the tree invariants.
The main B+ tree implementation can be found in doxygen stx/btree.h or with plain text comments btree.h.
Special interest was put into performing a speed comparison test between the standard red-black tree and the new B+ tree implementation. The speed test results are interesting and show the B+ tree to be significantly faster.
What's New in This Release: [ read full changelog ]
· A missing STL function, erase(iterator iter), was implemented.
· Support was added for STL allocators as template parameters.
· A bug when shifting pairs from left to right leaf nodes during deletion was fixed.
· Speed tests were run again on up-to-date hardware.