src/tint/fuzzers/random_generator_engine.h

// Copyright 2021 The Dawn & Tint Authors
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#ifndef SRC_TINT_FUZZERS_RANDOM_GENERATOR_ENGINE_H_
#define SRC_TINT_FUZZERS_RANDOM_GENERATOR_ENGINE_H_

#include <memory>
#include <random>
#include <vector>

namespace tint::fuzzers {

/// Wrapper interface around STL random number engine
class RandomGeneratorEngine {
  public:
    /// Constructor
    RandomGeneratorEngine();

    /// Destructor
    virtual ~RandomGeneratorEngine();

    /// Move Constructor
    RandomGeneratorEngine(RandomGeneratorEngine&&);

    /// Generates a random uint32_t value from uniform distribution.
    /// @param lower - lower bound of integer generated
    /// @param upper - upper bound of integer generated
    /// @returns i, where lower <= i < upper
    virtual uint32_t RandomUInt32(uint32_t lower, uint32_t upper) = 0;

    /// Generates a random uint64_t value from uniform distribution.
    /// @param lower - lower bound of integer generated
    /// @param upper - upper bound of integer generated
    /// @returns i, where lower <= i < upper
    virtual uint64_t RandomUInt64(uint64_t lower, uint64_t upper) = 0;

    /// Generates N bytes of pseudo-random data
    /// @param dest - memory location to store data
    /// @param n - number of bytes of data to generate
    virtual void RandomNBytes(uint8_t* dest, size_t n) = 0;

  private:
    // Disallow copy & assign
    RandomGeneratorEngine(const RandomGeneratorEngine&) = delete;
    RandomGeneratorEngine& operator=(const RandomGeneratorEngine&) = delete;
};  // class RandomGeneratorEngine

}  // namespace tint::fuzzers

#endif  // SRC_TINT_FUZZERS_RANDOM_GENERATOR_ENGINE_H_