Array.h

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#ifndef ARRAY_H
#define ARRAY_H
 
#include "Element.h"
 
#include "Bridges.h"
 
namespace bridges {
    namespace datastructure {
        template <typename E>
        class Array : public DataStructure {
 
                friend class Element<E>;
            private:
                Element<E> *array_data;
                int num_dims;
                int dims[3];
                int size;
 
            protected:
                Array()
                    : array_data(nullptr), num_dims(0), dims{0, 0, 0}, size(0) {
                }
 
                virtual ~Array() {
                    if (array_data != nullptr)
                        delete [] array_data;
                }
 
                Array(int sz)
                    : array_data(nullptr) {
                    int dim[] = {1, 1, sz};
                    setSize(sz, dim);
                }
 
                void setSize(int nd, int *dim) {
                    if (dim[0] <= 0 || dim[1] <= 0 || dim[2] <= 0) {
                        cout << "Dimensions of array must be positive!" << endl
                            << "\tProvided dimensions: " << dim[0]
                            << "," << dim[1] << "," << dim[2] << endl;
                        throw;
                    }
                    dims[0] = dim[0];
                    dims[1] = dim[1];
                    dims[2] = dim[2];
                    num_dims = nd;
                    size = dim[0] * dim[1] * dim[2];
 
                    // allocate space for the array
                    if (array_data != nullptr)
                        delete[] array_data;
                    array_data = new Element<E>[size];
                }
                void getDimensions(int *dim) {
                    switch (num_dims) {
                        case 1:
                            dim[0] = dims[0];
                            break;
                        case 2:
                            dim[0] = dims[0];
                            dim[1] = dims[1];
                            break;
                        case 3:
                            dim[0] = dims[0];
                            dim[1] = dims[1];
                            dim[2] = dims[2];
                            break;
                    }
                }
 
                int const * getDimensions() const {
                    return dims;
                }
                Element<E>& getElement(int index) {
                    return array_data[index];
                }
 
                Element<E> const & getElement(int index) const {
                    return array_data[index];
                }
 
                void setElement(int ind, Element<E> el) {
                    array_data[ind] = el;
                }
            public:
                virtual const string getDStype() const override {
                    return "Array";
                }
 
                virtual const string getDataStructureRepresentation() const override final {
                    using bridges::JSONUtil::JSONencode;
 
                    vector<const Element<E>*> nodes;
 
                    for (int k = 0; k < size; k++) {
                        nodes.push_back(&array_data[k]);
                    }
                    //  first write out dimensions
                    string array_json =
                        QUOTE + "dims" + QUOTE + COLON +
                        OPEN_BOX +
                        JSONencode(dims[0]) + COMMA +
                        JSONencode(dims[1]) + COMMA +
                        JSONencode(dims[2]) +
                        CLOSE_BOX + COMMA +
 
                        QUOTE + "nodes"  + QUOTE + COLON +
                        OPEN_BOX +
                        generateJSON(nodes) +
                        CLOSE_BOX + CLOSE_CURLY;
 
                    return array_json;
                }
 
                Array(const Array&) = delete; //would be incorrect, so disabled.
                Array& operator=(const Array&) = delete; //would be incorrect, so disabled.
 
            private:
                const string generateJSON( const vector<const Element<E>*>& nodes) const {
                    if (MAX_ELEMENTS_ALLOWED <= nodes.size()) {
                        // cant exceed max number of elements
                        throw "Max allowed elements(for visualization) exceeded.. " +
                        to_string(nodes.size()) + " Must be less than " +
                        to_string(MAX_ELEMENTS_ALLOWED);
                    }
                    // map the nodes to a sequence of ids, 0...N-1
                    // then get the JSON string for nodes placeholder
                    // nullptr prevents insertion of other nullptrs
                    unordered_map<const Element<E>*, int> map{{nullptr, -1}};
 
                    string nodes_JSON;
 
                    int i = 0; // get the JSON string for nodes
                    for (const auto * e : nodes) {
                        if (map.emplace(e, i).second && ++i)  {
                            // short circut only incriments i and gets rep
                            // upon successful emplacement
                            nodes_JSON += e->getElementRepresentation() + COMMA;
                        }
                    }
                    map.erase(nullptr); //Remove trailing comma and nullptr entry
                    if (nodes_JSON.size()) {
                        nodes_JSON = nodes_JSON.erase(nodes_JSON.size() - 1);
                    }
 
                    return nodes_JSON;
                };
 
        }; // Array
    }
}// end namespace bridges
 
#endif