fsfw/container/FixedOrderedMultimap.h

207 lines
5.8 KiB
C++

#ifndef FSFW_CONTAINER_FIXEDORDEREDMULTIMAP_H_
#define FSFW_CONTAINER_FIXEDORDEREDMULTIMAP_H_
#include "ArrayList.h"
#include <cstring>
/**
* @brief An associative container which allows multiple entries of the same key.
* @details
* Same keys are ordered by KEY_COMPARE function which is std::less<key_t> > by default.
*
* It uses the ArrayList, so technically this is not a real map, it is an array of pairs
* of type key_t, T. It is ordered by key_t as FixedMap but allows same keys. Thus it has a linear
* complexity O(n). As long as the number of entries remains low, this
* should not be an issue.
* The number of insertion and deletion operation should be minimized
* as those incur extensive memory move operations (the underlying container
* is not node based).
*
* Its of fixed size so no allocations are performed after the construction.
*
* The maximum size is given as first parameter of the constructor.
*
* It provides an iterator to do list iterations.
*
* The type T must have a copy constructor if it is not trivial copy-able.
*
* @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, typename KEY_COMPARE = std::less<key_t>>
class FixedOrderedMultimap {
public:
static const uint8_t INTERFACE_ID = CLASS_ID::FIXED_MULTIMAP;
static const ReturnValue_t MAP_FULL = MAKE_RETURN_CODE(0x01);
static const ReturnValue_t KEY_DOES_NOT_EXIST = MAKE_RETURN_CODE(0x02);
/***
* Constructor which needs a size_t for the maximum allowed size
*
* Can not be resized during runtime
*
* Allocates memory at construction
* @param maxSize size_t of Maximum allowed size
*/
FixedOrderedMultimap(size_t maxSize):theMap(maxSize), _size(0){
}
/***
* Virtual destructor frees Memory by deleting its member
*/
virtual ~FixedOrderedMultimap() {
}
/***
* Special iterator for FixedOrderedMultimap
*/
class Iterator: public ArrayList<std::pair<key_t, T>, size_t>::Iterator {
public:
Iterator() :
ArrayList<std::pair<key_t, T>, size_t>::Iterator() {
}
Iterator(std::pair<key_t, T> *pair) :
ArrayList<std::pair<key_t, T>, size_t>::Iterator(pair) {
}
};
/***
* Returns an iterator pointing to the first element
* @return Iterator pointing to first element
*/
Iterator begin() const {
return Iterator(&theMap[0]);
}
/**
* Returns an iterator pointing to one element past the end
* @return Iterator pointing to one element past the end
*/
Iterator end() const {
return Iterator(&theMap[_size]);
}
/***
* Returns the current size of the map (not maximum size!)
* @return Current size
*/
size_t size() const{
return _size;
}
/**
* Clears the map, does not deallocate any memory
*/
void clear(){
_size = 0;
}
/**
* Returns the maximum size of the map
* @return Maximum size of the map
*/
size_t maxSize() const{
return theMap.maxSize();
}
/***
* Used to insert a key and value separately.
*
* @param[in] key Key of the new element
* @param[in] value Value of the new element
* @param[in/out] (optional) storedValue On success this points to the new value, otherwise a nullptr
* @return RETURN_OK if insert was successful, MAP_FULL if no space is available
*/
ReturnValue_t insert(key_t key, T value, Iterator *storedValue = nullptr);
/***
* Used to insert new pair instead of single values
*
* @param pair Pair to be inserted
* @return RETURN_OK if insert was successful, MAP_FULL if no space is available
*/
ReturnValue_t insert(std::pair<key_t, T> pair);
/***
* Can be used to check if a certain key is in the map
* @param key Key to be checked
* @return RETURN_OK if the key exists KEY_DOES_NOT_EXIST otherwise
*/
ReturnValue_t exists(key_t key) const;
/***
* Used to delete the element in the iterator
*
* The iterator will point to the element before or begin(),
* but never to one element in front of the map.
*
* @warning The iterator needs to be valid and dereferenceable
* @param[in/out] iter Pointer to iterator to the element that needs to be ereased
* @return RETURN_OK if erased, KEY_DOES_NOT_EXIST if the there is no element like this
*/
ReturnValue_t erase(Iterator *iter);
/***
* Used to erase by key
* @param key Key to be erased
* @return RETURN_OK if erased, KEY_DOES_NOT_EXIST if the there is no element like this
*/
ReturnValue_t erase(key_t key);
/***
* Find returns the first appearance of the key
*
* If the key does not exist, it points to end()
*
* @param key Key to search for
* @return Iterator pointing to the first entry of key
*/
Iterator find(key_t key) const{
ReturnValue_t result = exists(key);
if (result != HasReturnvaluesIF::RETURN_OK) {
return end();
}
return Iterator(&theMap[findFirstIndex(key)]);
};
/***
* Finds first entry of the given key and returns a
* pointer to the value
*
* @param key Key to search for
* @param value Found value
* @return RETURN_OK if it points to the value,
* KEY_DOES_NOT_EXIST if the key is not in the map
*/
ReturnValue_t find(key_t key, T **value) const;
friend bool operator==(const typename FixedOrderedMultimap::Iterator& lhs,
const typename FixedOrderedMultimap::Iterator& rhs) {
return (lhs.value == rhs.value);
}
friend bool operator!=(const typename FixedOrderedMultimap::Iterator& lhs,
const typename FixedOrderedMultimap::Iterator& rhs) {
return not (lhs.value == rhs.value);
}
private:
typedef KEY_COMPARE compare;
compare myComp;
ArrayList<std::pair<key_t, T>, size_t> theMap;
size_t _size;
size_t findFirstIndex(key_t key, size_t startAt = 0) const;
size_t findNicePlace(key_t key) const;
void removeFromPosition(size_t position);
};
#include "FixedOrderedMultimap.tpp"
#endif /* FSFW_CONTAINER_FIXEDORDEREDMULTIMAP_H_ */