squall/storm/array/TSGrowableArray.hpp

#ifndef STORM_ARRAY_TS_GROWABLE_ARRAY_HPP
#define STORM_ARRAY_TS_GROWABLE_ARRAY_HPP

#include "storm/array/TSFixedArray.hpp"
#include <algorithm>
#include <cstdint>
#include <cstring>
#include <new>

template <class T>
class TSGrowableArray : public TSFixedArray<T> {
    public:
    uint32_t m_chunk = 0;

    uint32_t Add(uint32_t count, const T* data);
    uint32_t Add(uint32_t count, uint32_t incr, const T* data);
    uint32_t CalcChunkSize(uint32_t count);
    void GrowToFit(uint32_t index, int32_t zero);
    T* New(void);
    void Reserve(uint32_t count, int32_t round);
    uint32_t RoundToChunk(uint32_t count, uint32_t chunk);
    void SetCount(uint32_t count);
};

template <class T>
uint32_t TSGrowableArray<T>::Add(uint32_t count, const T* data) {
    this->Reserve(count, 1);

    for (int32_t i = 0; i < count; i++) {
        T* element = &this->m_data[this->m_count + i];
        *element = data[i];
    }

    this->m_count += count;
    return this->m_count - count;
}

template <class T>
uint32_t TSGrowableArray<T>::Add(uint32_t count, uint32_t incr, const T* data) {
    this->Reserve(count, 1);

    const char* dataptr = reinterpret_cast<const char*>(data);

    for (int32_t i = 0; i < count; i++) {
        T* element = &this->m_data[this->m_count + i];
        *element = *reinterpret_cast<const T*>(dataptr);
        dataptr += incr;
    }

    this->m_count += count;
    return this->m_count - count;
}

template <class T>
uint32_t TSGrowableArray<T>::CalcChunkSize(uint32_t count) {
    uint32_t maxChunk = std::max(static_cast<int32_t>(256 / sizeof(T)), 8);

    if (count >= maxChunk) {
        this->m_chunk = maxChunk;
        return maxChunk;
    }

    uint32_t result = count;

    for (uint32_t i = count & (count - 1); i; i &= i - 1) {
        result = i;
    }

    if (result < 1) {
        result = 1;
    }

    return result;
}

template <class T>
void TSGrowableArray<T>::GrowToFit(uint32_t index, int32_t zero) {
    uint32_t count = this->m_count;

    if (index >= count) {
        this->Reserve(index - count + 1, 1);

        if (zero) {
            memset(&this->m_data[count], 0, sizeof(T) * (index - count + 1));
        }

        this->m_count = index + 1;
    }
}

template <class T>
T* TSGrowableArray<T>::New() {
    this->Reserve(1, 1);
    void* element = &this->m_data[this->m_count++];
    return new (element) T();
}

template <class T>
void TSGrowableArray<T>::Reserve(uint32_t count, int32_t round) {
    if (count + this->m_count > this->m_alloc) {
        if (round) {
            uint32_t chunk = this->m_chunk;

            if (!chunk) {
                chunk = this->CalcChunkSize(count + this->m_count);
            }

            count = this->RoundToChunk(count, chunk);
        }

        this->ReallocData(count + this->m_count);
    }
}

template <class T>
uint32_t TSGrowableArray<T>::RoundToChunk(uint32_t count, uint32_t chunk) {
    if (count % chunk) {
        return chunk - count % chunk + count;
    } else {
        return count;
    }
}

template <class T>
void TSGrowableArray<T>::SetCount(uint32_t count) {
    if (count > this->m_count) {
        // Expand size
        this->Reserve(count - this->m_count, 1);

        T* element;

        for (int32_t i = this->m_count; i < count; ++i) {
            element = &this->m_data[i];
            new (element) T();
        }
    }

    this->m_count = count;
}

#endif