ArrayMap

ArrayMap is a final class template defined in Fw/DataStructures. It represents an array-based map with internal storage.

1. Template Parameters

ArrayMap has the following template parameters.

Kind	Name	Purpose
`typename`	`K`	The type of a key in the map
`typename`	`V`	The type of a value in the map
`FwSizeType`	`C`	The capacity, i.e., the maximum number of keys that the map can store

ArrayMap statically asserts that C > 0.

2. Base Class

ArrayMap is publicly derived from MapBase<K, V>.

3. Public Types

ArrayMap defines the following public types:

Name	Definition
`ConstIterator`	Alias of `MapConstIterator<K, V>`
`Entry`	Alias of `SetOrMapImplEntry<K, V>`
`Entries`	Alias of `Entry[C]`

4. Private Member Variables

ArrayMap has the following private member variables.

Name	Type	Purpose	Default Value
`m_extMap`	`ExternalArrayMap<K, V>`	The external map implementation	C++ default initialization
`m_entries`	`Entries`	The array providing the backing memory for `m_extMap`	C++ default initialization

mermaid

classDiagram
    ArrayMap *-- ExternalArrayMap

5. Public Constructors and Destructors

5.1. Zero-Argument Constructor

c++

ArrayMap()

Initialize m_extMap with ExternalArrayMap<K, V>(m_entries, C).

Example:

c++

ArrayMap<U16, U32, 10> map;

5.2. Copy Constructor

c++

ArrayMap(const ArrayMap<K, V, C>& map)

Initialize m_extMap with ExternalArrayMap<K, V>(m_entries, C).
Set *this = map.

Example:

c++

using Map = ArrayMap<U16, U32, 10>;
Map m1;
// Insert an item
const U16 key = 0;
const U32 value = 42;
const auto status = m1.insert(key, value);
ASSERT_EQ(status, Success::SUCCESS);
// Call the copy constructor
Map m2(m1);
ASSERT_EQ(m2.getSize(), 1);

5.3. Destructor

c++

~ArrayMap() override

Defined as = default.

6. Public Member Functions

6.1. operator=

c++

ArrayMap<K, V, C>& operator=(const ArrayMap<K, V, C>& map)

Return m_extMap.copyDataFrom(map).

Example:

c++

using Map = ArrayMap<U16, U32, 10>;
Map m1;
// Insert an item
U16 key = 0;
U32 value = 42;
auto status = m1.insert(key, value);
ASSERT_EQ(status, Success::SUCCESS);
// Call the default constructor
Map m2;
ASSERT_EQ(m2.getSize(), 0);
// Call the copy assignment operator
m2 = m1;
ASSERT_EQ(m2.getSize(), 1);
value = 0;
status = m2.find(key, value);
ASSERT_EQ(status, Success::SUCCESS);
ASSERT_EQ(value, 42);

6.2. begin

c++

ConstIterator begin() const

Return m_extMap.begin().

Example:

c++

using Map = ArrayMap<U16, U32, 10>;
Map map;
// Insert an entry in the map
const auto status = map.insert(0, 1);
ASSERT_EQ(status, Fw::Success::SUCCESS);
// Get a map const iterator object
auto it = map.begin();
// Use the iterator to access the underlying map const entry
const key = it->getKey();
const value = it->getValue();
ASSERT_EQ(key, 0);
ASSERT_EQ(value, 1);

6.3. clear

c++

void clear() override

Call m_extMap.clear().

Example:

c++

using Map = ArrayMap<U16, U32, 10>;
Map map;
const auto status = map.insert(0, 3);
ASSERT_EQ(map.getSize(), 1);
map.clear();
ASSERT_EQ(map.getSize(), 0);

6.4. end

c++

ConstIterator end() const

Return m_extMap.end().

Example:

c++

using Map = ArrayMap<U16, U32, 10>;
// Call the constructor providing backing storage
Map map;
// Insert an entry in the map
auto status = map.insert(0, 1);
ASSERT_EQ(status, Fw::Success::SUCCESS);
// Get a map const iterator object
auto iter = map.begin();
// Check that iter is not at the end
ASSERT_NE(iter, map.end());
// Increment iter
it++;
// Check that iter is at the end
ASSERT_EQ(iter, map.end());

6.5. find

c++

Success find(const K& key, V& value) override

Return m_extMap.find(key, value).

Example:

c++

using Map = ArrayMap<U16, U32, 10>;
Map map;
U32 value = 0;
auto status = map.find(0, value);
ASSERT_EQ(status, Success::FAILURE);
status = map.insert(0, 1);
ASSERT_EQ(status, Success::SUCCESS);
status = map.find(0, value);
ASSERT_EQ(status, Success::SUCCESS);
ASSERT_EQ(value, 1);

6.6. getCapacity

c++

FwSizeType getCapacity() const override

Return m_extMap.getCapacity().

Example:

c++

using Map = ArrayMap<U16, U32, 10>;
Map map;
ASSERT_EQ(map.getCapacity(), 10);

6.8. getSize

c++

FwSizeType getSize() const override

Return m_extMap.getSize().

Example:

c++

using Map = ArrayMap<U16, U32, 10>;
Map map;
auto size = map.getSize();
ASSERT_EQ(size, 0);
const auto status = map.insert(0, 3);
ASSERT_EQ(status, Success::SUCCESS);
size = map.getSize();
ASSERT_EQ(size, 1);

6.9. insert

c++

Success insert(const K& key, const V& value) override

Return m_extMap.insert(key, value).

Example:

c++

using Map = ArrayMap<U16, U32, 10>;
Map map;
auto size = map.getSize();
ASSERT_EQ(size, 0);
const auto status = map.insert(0, 1);
ASSERT_EQ(status, Success::SUCCESS);
size = map.getSize();
ASSERT_EQ(size, 1);

6.10. remove

c++

Success remove(const K& key, V& value) override

Return m_extMap.remove(key, value).

Example:

c++

using Map = ArrayMap<U16, U32, 10>;
Map map;
auto size = map.getSize();
ASSERT_EQ(size, 0);
auto status = map.insert(0, 1);
ASSERT_EQ(status, Success::SUCCESS);
size = map.getSize();
ASSERT_EQ(size, 1);
// Key does not exist
U32 value = 0;
status = map.remove(10, value);
ASSERT_EQ(status, Success::FAILURE);
ASSERT_EQ(size, 1);
// Key exists
status = map.remove(0, value);
ASSERT_EQ(status, Success::SUCCESS);
ASSERT_EQ(size, 0);
ASSERT_EQ(value, 1);