fsfw/inc/fsfw/container/FixedMap.h

#ifndef FSFW_CONTAINER_FIXEDMAP_H_
#define FSFW_CONTAINER_FIXEDMAP_H_

#include "ArrayList.h"
#include "../returnvalues/HasReturnvaluesIF.h"
#include <utility>
#include <type_traits>

/**
 * @brief    Map implementation for maps with a pre-defined size.
 * @details
 * Can be initialized with desired maximum size.
 * Iterator is used to access <key,value> pair and iterate through map entries.
 * Complexity O(n).
 * @warning Iterators return a non-const key_t in the pair.
 * @warning A User is not allowed to change the key, otherwise the map is corrupted.
 * @ingroup container
 */
template<typename key_t, typename T>
class FixedMap: public SerializeIF {
    static_assert (std::is_trivially_copyable<T>::value or
            std::is_base_of<SerializeIF, T>::value,
            "Types used in FixedMap must either be trivial copy-able or a "
            "derived class from SerializeIF to be serialize-able");
public:
    static const uint8_t INTERFACE_ID = CLASS_ID::FIXED_MAP;
    static const ReturnValue_t KEY_ALREADY_EXISTS = MAKE_RETURN_CODE(0x01);
    static const ReturnValue_t MAP_FULL = MAKE_RETURN_CODE(0x02);
    static const ReturnValue_t KEY_DOES_NOT_EXIST = MAKE_RETURN_CODE(0x03);

private:
    static const key_t EMPTY_SLOT = -1;
    ArrayList<std::pair<key_t, T>, uint32_t> theMap;
    uint32_t _size;

    uint32_t findIndex(key_t key) const {
        if (_size == 0) {
            return 1;
        }
        uint32_t i = 0;
        for (i = 0; i < _size; ++i) {
            if (theMap[i].first == key) {
                return i;
            }
        }
        return i;
    }
public:
    FixedMap(uint32_t maxSize) :
            theMap(maxSize), _size(0) {
    }

    class Iterator: public ArrayList<std::pair<key_t, T>, uint32_t>::Iterator {
    public:
        Iterator() :
                ArrayList<std::pair<key_t, T>, uint32_t>::Iterator() {
        }

        Iterator(std::pair<key_t, T> *pair) :
                ArrayList<std::pair<key_t, T>, uint32_t>::Iterator(pair) {
        }
    };

    friend bool operator==(const typename FixedMap::Iterator& lhs,
            const typename FixedMap::Iterator& rhs) {
        return (lhs.value == rhs.value);
    }

    friend bool operator!=(const typename FixedMap::Iterator& lhs,
            const typename FixedMap::Iterator& rhs) {
        return not (lhs.value == rhs.value);
    }

    Iterator begin() const {
        return Iterator(&theMap[0]);
    }

    Iterator end() const {
        return Iterator(&theMap[_size]);
    }

    uint32_t size() const {
        return _size;
    }

    ReturnValue_t insert(key_t key, T value, Iterator *storedValue = nullptr) {
        if (exists(key) == HasReturnvaluesIF::RETURN_OK) {
            return KEY_ALREADY_EXISTS;
        }
        if (_size == theMap.maxSize()) {
            return MAP_FULL;
        }
        theMap[_size].first = key;
        theMap[_size].second = value;
        if (storedValue != nullptr) {
            *storedValue = Iterator(&theMap[_size]);
        }
        ++_size;
        return HasReturnvaluesIF::RETURN_OK;
    }

    ReturnValue_t insert(std::pair<key_t, T> pair) {
        return insert(pair.first, pair.second);
    }

    ReturnValue_t exists(key_t key) const {
        ReturnValue_t result = KEY_DOES_NOT_EXIST;
        if (findIndex(key) < _size) {
            result = HasReturnvaluesIF::RETURN_OK;
        }
        return result;
    }

    ReturnValue_t erase(Iterator *iter) {
        uint32_t i;
        if ((i = findIndex((*iter).value->first)) >= _size) {
            return KEY_DOES_NOT_EXIST;
        }
        theMap[i] = theMap[_size - 1];
        --_size;
        --((*iter).value);
        return HasReturnvaluesIF::RETURN_OK;
    }

    ReturnValue_t erase(key_t key) {
        uint32_t i;
        if ((i = findIndex(key)) >= _size) {
            return KEY_DOES_NOT_EXIST;
        }
        theMap[i] = theMap[_size - 1];
        --_size;
        return HasReturnvaluesIF::RETURN_OK;
    }

    T *findValue(key_t key) const {
        return &theMap[findIndex(key)].second;
    }

    Iterator find(key_t key) const {
        ReturnValue_t result = exists(key);
        if (result != HasReturnvaluesIF::RETURN_OK) {
            return end();
        }
        return Iterator(&theMap[findIndex(key)]);
    }

    ReturnValue_t find(key_t key, T **value) const {
        ReturnValue_t result = exists(key);
        if (result != HasReturnvaluesIF::RETURN_OK) {
            return result;
        }
        *value = &theMap[findIndex(key)].second;
        return HasReturnvaluesIF::RETURN_OK;
    }

    bool empty() {
        if(_size == 0) {
            return true;
        }
        else {
            return false;
        }
    }

    bool full() {
        if(_size >= theMap.maxSize()) {
            return true;
        }
        else {
            return false;
        }
    }

    void clear() {
        _size = 0;
    }

    uint32_t maxSize() const {
        return theMap.maxSize();
    }

    virtual ReturnValue_t serialize(uint8_t** buffer, size_t* size,
            size_t maxSize, Endianness streamEndianness) const {
        ReturnValue_t result = SerializeAdapter::serialize(&this->_size,
                buffer, size, maxSize, streamEndianness);
        uint32_t i = 0;
        while ((result == HasReturnvaluesIF::RETURN_OK) && (i < this->_size)) {
            result = SerializeAdapter::serialize(&theMap[i].first, buffer,
                    size, maxSize, streamEndianness);
            result = SerializeAdapter::serialize(&theMap[i].second, buffer, size,
                    maxSize, streamEndianness);
            ++i;
        }
        return result;
    }

    virtual size_t getSerializedSize() const {
        uint32_t printSize = sizeof(_size);
        uint32_t i = 0;

        for (i = 0; i < _size; ++i) {
            printSize += SerializeAdapter::getSerializedSize(
                    &theMap[i].first);
            printSize += SerializeAdapter::getSerializedSize(&theMap[i].second);
        }

        return printSize;
    }

    virtual ReturnValue_t deSerialize(const uint8_t** buffer, size_t* size,
            Endianness streamEndianness) {
        ReturnValue_t result = SerializeAdapter::deSerialize(&this->_size,
                buffer, size, streamEndianness);
        if (this->_size > theMap.maxSize()) {
            return SerializeIF::TOO_MANY_ELEMENTS;
        }
        uint32_t i = 0;
        while ((result == HasReturnvaluesIF::RETURN_OK) && (i < this->_size)) {
            result = SerializeAdapter::deSerialize(&theMap[i].first, buffer,
                    size, streamEndianness);
            result = SerializeAdapter::deSerialize(&theMap[i].second, buffer, size,
                    streamEndianness);
            ++i;
        }
        return result;
    }

};

#endif /* FSFW_CONTAINER_FIXEDMAP_H_ */