1. 23 Feb, 2022 1 commit
    • refactor: make util an object library · c3b7ace9
      Instead of simply including the utility files directly, make them a
      cmake object library for easy reusability between other projects within
      libgit2.
      
      Now the top-level `src` is responsible for platform selection, while the
      next-level `libgit2` and `util` configurations are responsible for
      identifying what objects they include.
      Edward Thomson committed
  2. 09 Feb, 2022 1 commit
    • rand: introduce git_rand PRNG · 3c53796c
      Introduce `git_rand`, a PRNG based on xoroshiro256**, a fast,
      all-purpose pseudo-random number generator: https://prng.di.unimi.it
      
      The PRNG will be seeded by the system's entropy store when possible,
      falling back to current time and system data (pid, uptime, etc).
      Inspiration for this was taken from libressl, but since our PRNG is
      not used for cryptographic purposes (and indeed currently only generates
      a unique temp file name that is written in a protected directory),
      this should be more than sufficient.
      
      Our implementation of xoroshiro256** was taken almost strictly from
      the original author's sources, but was tested against PractRand to
      ensure that there were no foolish mistranslations:
      
      ```
      RNG_test using PractRand version 0.94
      RNG = RNG_stdin64, seed = unknown
      test set = core, folding = standard (64 bit)
      
      rng=RNG_stdin64, seed=unknown
      length= 256 megabytes (2^28 bytes), time= 2.9 seconds
        no anomalies in 210 test result(s)
      
      rng=RNG_stdin64, seed=unknown
      length= 512 megabytes (2^29 bytes), time= 6.2 seconds
        no anomalies in 226 test result(s)
      
      rng=RNG_stdin64, seed=unknown
      length= 1 gigabyte (2^30 bytes), time= 12.7 seconds
        no anomalies in 243 test result(s)
      
      rng=RNG_stdin64, seed=unknown
      length= 2 gigabytes (2^31 bytes), time= 25.4 seconds
        no anomalies in 261 test result(s)
      
      rng=RNG_stdin64, seed=unknown
      length= 4 gigabytes (2^32 bytes), time= 50.6 seconds
        no anomalies in 277 test result(s)
      
      rng=RNG_stdin64, seed=unknown
      length= 8 gigabytes (2^33 bytes), time= 104 seconds
        no anomalies in 294 test result(s)
      ```
      Edward Thomson committed