07-buzzdb.cpp

#include <iostream>
#include <map>
#include <vector>
#include <fstream>
#include <iostream>
#include <chrono>

#include <iostream>
#include <map>
#include <string>
#include <memory>

enum FieldType { INT, FLOAT, STRING };

// Define a basic Field variant class that can hold different types
class Field {
public:
    FieldType type;

    std::unique_ptr<char[]> data;
    size_t data_length;

public:
    Field(int i) : type(INT) { 
        data_length = sizeof(int);
        data = std::make_unique<char[]>(data_length);
        std::memcpy(data.get(), &i, data_length);
    }

    Field(float f) : type(FLOAT) { 
        data_length = sizeof(float);
        data = std::make_unique<char[]>(data_length);
        std::memcpy(data.get(), &f, data_length);
    }

    Field(const std::string& s) : type(STRING) {
        data_length = s.size() + 1;  // include null-terminator
        data = std::make_unique<char[]>(data_length);
        std::memcpy(data.get(), s.c_str(), data_length);
    }

    Field& operator=(const Field& other) {
        if (&other == this) {
            return *this;
        }
        type = other.type;
        data_length = other.data_length;
        std::memcpy(data.get(), other.data.get(), data_length);
        return *this;
    }

    Field(Field&& other){
        type = other.type;
        data_length = other.data_length;
        std::memcpy(data.get(), other.data.get(), data_length);
    }

    FieldType getType() const { return type; }
    int asInt() const { 
        return *reinterpret_cast<int*>(data.get());
    }
    float asFloat() const { 
        return *reinterpret_cast<float*>(data.get());
    }
    std::string asString() const { 
        return std::string(data.get());
    }

    void print() const{
        switch(getType()){
            case INT: std::cout << asInt(); break;
            case FLOAT: std::cout << asFloat(); break;
            case STRING: std::cout << asString(); break;
        }
    }
};

class Tuple {
    std::vector<std::unique_ptr<Field>> fields;

public:

    void addField(std::unique_ptr<Field> field) {
        fields.push_back(std::move(field));
    }

    void print() const {
        for (const auto& field : fields) {
            field->print();
            std::cout << " ";
        }
        std::cout << "\n";
    }
};

class BuzzDB {
private:
    // a map is an ordered key-value container
    std::map<int, std::vector<int>> index;

public:
    size_t number_of_tuples = 4;

    // a vector of Tuple unique pointers acting as a table
    std::vector<std::unique_ptr<Tuple>> table;

    // insert function
    void insert(int key, int value) {
        auto newTuple = std::make_unique<Tuple>();

        auto key_field = std::make_unique<Field>(key);
        auto value_field = std::make_unique<Field>(value);
        float float_val = 132.04;
        auto float_field = std::make_unique<Field>(float_val);
        auto string_field = std::make_unique<Field>("buzzdb");

        newTuple->addField(std::move(key_field));
        newTuple->addField(std::move(value_field));
        newTuple->addField(std::move(float_field));
        newTuple->addField(std::move(string_field));

        //newTuple->print();

        table.push_back(std::move(newTuple));
        index[key].push_back(value);
    }

    // perform a SELECT ... GROUP BY ... SUM query
    void selectGroupBySum() {
        for (auto const& pair : index) { // for each unique key
            int sum = 0;
            for (auto const& value : pair.second) {
                sum += value; // sum all values for the key
            }
            std::cout << "key: " << pair.first << ", sum: " << sum << '\n';
        }
    }
};

int main() {
    // Get the start time
    auto start = std::chrono::high_resolution_clock::now();

    BuzzDB db;

    std::ifstream inputFile("output.txt");

    if (!inputFile) {
        std::cerr << "Unable to open file" << std::endl;
        return 1;
    }

    int field1, field2;
    while (inputFile >> field1 >> field2) {
        db.insert(field1, field2);
    }
    
    db.selectGroupBySum();

    // Get the end time
    auto end = std::chrono::high_resolution_clock::now();

    // Calculate and print the elapsed time
    std::chrono::duration<double> elapsed = end - start;
    std::cout << "Elapsed time: " << elapsed.count() << " seconds" << std::endl;

    return 0;
}