nathansgreen / fast_int_to_string Goto Github PK

A faster C++ routine to convert 64 bit integers to ASCII form or std::string.

A Java implementation was created to be as algorithmically close as possible to the C++ code. The initial code supports only 32-bit unsigned integers for simplicity and ease of comparison. It also supports only direct writes to a ByteBuffer to avoid any allocation overhead.

Just include the source file fast_int_to_string.hpp into the translation unit.

In big data processing (e.g. columnar storage engines) even 10% improvement due to algorithmic/macro optimization results in cumulative effect (assuming other parts of the code is competitive enough). In my testing the conversion routine is 30-90% faster than standard counterparts.

Added few unit and performance tests.

The Java implementation has both unit tests and microbenchmarks. The initial code takes a bit more than twice as much time as built-in Java APIs for larger numbers. A collection of benchmark outcomes are stored in src/jmh/reports.

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