From c0b9d06b6688088fd167b0c1f897934185074c01 Mon Sep 17 00:00:00 2001 From: KunoiSayami Date: Sun, 7 Nov 2021 20:06:38 +0800 Subject: feat: Add googletest Signed-off-by: KunoiSayami --- headers/random.h | 57 -------------------------------------------------------- 1 file changed, 57 deletions(-) delete mode 100644 headers/random.h (limited to 'headers/random.h') diff --git a/headers/random.h b/headers/random.h deleted file mode 100644 index 2b04757..0000000 --- a/headers/random.h +++ /dev/null @@ -1,57 +0,0 @@ -#ifndef CLEVELDB_RANDOM_H -#define CLEVELDB_RANDOM_H -#include - -namespace cleveldb { - -// A very simple random number generator. Not especially good at -// generating truly random bits, but good enough for our needs in this -// package. - class Random { - private: - uint32_t seed_; - - public: - explicit Random(uint32_t s) : seed_(s & 0x7fffffffu) { - // Avoid bad seeds. - if (seed_ == 0 || seed_ == 2147483647L) { - seed_ = 1; - } - } - uint32_t Next() { - static const uint32_t M = 2147483647L; // 2^31-1 - static const uint64_t A = 16807; // bits 14, 8, 7, 5, 2, 1, 0 - // We are computing - // seed_ = (seed_ * A) % M, where M = 2^31-1 - // - // seed_ must not be zero or M, or else all subsequent computed values - // will be zero or M respectively. For all other values, seed_ will end - // up cycling through every number in [1,M-1] - uint64_t product = seed_ * A; - - // Compute (product % M) using the fact that ((x << 31) % M) == x. - seed_ = static_cast((product >> 31) + (product & M)); - // The first reduction may overflow by 1 bit, so we may need to - // repeat. mod == M is not possible; using > allows the faster - // sign-bit-based test. - if (seed_ > M) { - seed_ -= M; - } - return seed_; - } - // Returns a uniformly distributed value in the range [0..n-1] - // REQUIRES: n > 0 - uint32_t Uniform(int n) { return Next() % n; } - - // Randomly returns true ~"1/n" of the time, and false otherwise. - // REQUIRES: n > 0 - bool OneIn(int n) { return (Next() % n) == 0; } - - // Skewed: pick "base" uniformly from range [0,max_log] and then - // return "base" random bits. The effect is to pick a number in the - // range [0,2^max_log-1] with exponential bias towards smaller numbers. - uint32_t Skewed(int max_log) { return Uniform(1 << Uniform(max_log + 1)); } - }; - -} // namespace cleveldb -#endif //CLEVELDB_RANDOM_H -- cgit v1.3.1