Class Minisketch

src/minisketch/include/minisketch.h:196–364

Simple RAII C++11 wrapper around the minisketch API. */

#if __cplusplus >= 201103L
/** Simple RAII C++11 wrapper around the minisketch API. */
class Minisketch
{
    struct Deleter
    {
        void operator()(minisketch* ptr) const
        {
            minisketch_destroy(ptr);
        }
    };

    std::unique_ptr<minisketch, Deleter> m_minisketch;

public:
    /** Check whether the library supports fields of the given size. */
    static bool BitsSupported(uint32_t bits) noexcept { return minisketch_bits_supported(bits); }

    /** Get the highest supported implementation number. */
    static uint32_t MaxImplementation() noexcept { return minisketch_implementation_max(); }

    /** Check whether the library supports fields with a given size and implementation number.
     *  If a particular field size `bits` is supported, implementation 0 is always supported for it.
     *  Higher implementation numbers may or may not be available as well, up to MaxImplementation().
     */
    static bool ImplementationSupported(uint32_t bits, uint32_t implementation) noexcept { return minisketch_implementation_supported(bits, implementation); }

    /** Given field size and a maximum number of decodable elements n, compute what capacity c to
     *  use so that sketches with more elements than n have a chance no higher than 2^-fpbits of
     *  being decoded incorrectly (and will instead fail when decoding for up to n elements).
     *
     *  See minisketch_compute_capacity for more details. */
    static size_t ComputeCapacity(uint32_t bits, size_t max_elements, uint32_t fpbits) noexcept { return minisketch_compute_capacity(bits, max_elements, fpbits); }

    /** Reverse operation of ComputeCapacity. See minisketch_compute_max_elements. */
    static size_t ComputeMaxElements(uint32_t bits, size_t capacity, uint32_t fpbits) noexcept { return minisketch_compute_max_elements(bits, capacity, fpbits); }

    /** Construct a clone of the specified sketch. */
    Minisketch(const Minisketch& sketch) noexcept
    {
        if (sketch.m_minisketch) {
            m_minisketch = std::unique_ptr<minisketch, Deleter>(minisketch_clone(sketch.m_minisketch.get()));
        }
    }

    /** Make this Minisketch a clone of the specified one. */
    Minisketch& operator=(const Minisketch& sketch) noexcept
    {
        if (sketch.m_minisketch) {
            m_minisketch = std::unique_ptr<minisketch, Deleter>(minisketch_clone(sketch.m_minisketch.get()));
        }
        return *this;
    }

    /** Check whether this Minisketch object is valid. */
    explicit operator bool() const noexcept { return bool{m_minisketch}; }

    /** Construct an (invalid) Minisketch object. */
    Minisketch() noexcept = default;