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/*-
* Public Domain 2014-present MongoDB, Inc.
* Public Domain 2008-2014 WiredTiger, Inc.
*
* This is free and unencumbered software released into the public domain.
*
* Anyone is free to copy, modify, publish, use, compile, sell, or
* distribute this software, either in source code form or as a compiled
* binary, for any purpose, commercial or non-commercial, and by any
* means.
*
* In jurisdictions that recognize copyright laws, the author or authors
* of this software dedicate any and all copyright interest in the
* software to the public domain. We make this dedication for the benefit
* of the public at large and to the detriment of our heirs and
* successors. We intend this dedication to be an overt act of
* relinquishment in perpetuity of all present and future rights to this
* software under copyright law.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*/
#ifndef RANDOM_GENERATOR_H
#define RANDOM_GENERATOR_H
/* Following definitions are required in order to use printing format specifiers in C++. */
#define __STDC_LIMIT_MACROS
#define __STDC_FORMAT_MACROS
#include <random>
#include <string>
namespace test_harness {
/* Helper class to generate random values using uniform distributions. */
enum characters_type { PSEUDO_ALPHANUMERIC, ALPHABET };
class random_generator {
public:
static random_generator &instance();
/* No copies of the singleton allowed. */
random_generator(random_generator const &) = delete;
random_generator &operator=(random_generator const &) = delete;
/* Generate a random string of a given length. */
std::string generate_random_string(
std::size_t length, characters_type type = PSEUDO_ALPHANUMERIC);
/*
* Generate a pseudo random string which compresses better. It should not be used to generate
* keys due to the limited randomness.
*/
std::string generate_pseudo_random_string(
std::size_t length, characters_type type = PSEUDO_ALPHANUMERIC);
/* Generate a random integer between min and max. */
template <typename T>
T
generate_integer(T min, T max)
{
std::uniform_int_distribution<T> dis(min, max);
return dis(_generator);
}
private:
random_generator();
std::uniform_int_distribution<> &get_distribution(characters_type type);
const std::string &get_characters(characters_type type);
std::mt19937 _generator;
std::uniform_int_distribution<> _alphanum_distrib, _alpha_distrib;
const std::string _alphabet = "abcdefghijklmnopqrstuvwxyz";
const std::string _pseudo_alphanum =
"0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
};
} // namespace test_harness
#endif
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