FifoQueue

FifoQueue is a final class template defined in Fw/DataStructures. It represents a FIFO queue with internal storage.

1. Template Parameters

FifoQueue has the following template parameters.

Kind	Name	Purpose
`typename`	`T`	The type of a queue item
`FwSizeType`	`C`	The queue capacity in items

FifoQueue statically asserts the following:

T is default constructible.
C > 0.

2. Base Class

FifoQueue<T, C> is publicly derived from FifoQueueBase<T>.

3. Private Member Variables

FifoQueue has the following private member variables.

Name	Type	Purpose	Default Value
`m_extQueue`	`ExternalFifoQueue<T>`	The external queue implementation	C++ default initialization
`m_items`	`T[C]`	The array providing the backing memory for `m_extQueue`	C++ default initialization

mermaid

classDiagram
    FifoQueue *-- ExternalFifoQueue

4. Public Constructors and Destructors

4.1. Zero-Argument Constructor

c++

FifoQueue()

Initialize m_extQueue with ExternalFifoQueue<T>(m_items, C).

Example:

c++

FifoQueue<U32, 10> queue;

4.2. Copy Constructor

c++

FifoQueue(const FifoQueue<T, C>& queue)

Initialize m_extQueue with ExternalFifoQueue<T>(m_items, C).
Set *this = queue.

Example:

c++

FifoQueue<U32, 10> q1;
auto status = q1.enqueue(3);
ASSERT_EQ(status, Success::SUCCESS);
FifoQueue<U32, 10> q2(q1);
ASSERT_EQ(q2.size(), 1);
U32 value = 0;
status = q2.dequeue(value);
ASSERT_EQ(status, Success::SUCCESS);
ASSERT_EQ(value, 3);

4.3. Destructor

c++

~FifoQueue() override

Defined as = default.

5. Public Member Functions

5.1. operator=

c++

FifoQueue<T, C>& operator=(const FifoQueue<T, C>& queue)

Return m_extQueue.copyDataFrom(queue).

Example:

c++

FifoQueue<U32, 10> q1;
auto status = q1.enqueue(3);
ASSERT_EQ(status, Success::SUCCESS);
FifoQueue<U32, 10> q2;
ASSERT_EQ(q2.size(), 0);
q2 = q1;
ASSERT_EQ(q2.size(), 1);
U32 value = 0;
status = q2.dequeue(value);
ASSERT_EQ(status, Success::SUCCESS);
ASSERT_EQ(value, 3);

5.2. clear

c++

void clear() override

Call m_extQueue.clear().

5.3. enqueue

c++

Success enqueue(const T& e) override

Return m_extQueue.enqueue(e).

5.4. at

c++

const T& at(FwSizeType index) const override

Return m_extQueue.at(index).

5.5. dequeue

c++

Success dequeue(T& e) override

Return m_extQueue.dequeue(e).

5.6. getSize

c++

FwSizeType getSize() const override

Return m_extQueue.getSize().

5.7. getCapacity

c++

FwSizeType getCapacity() const override

Return m_extQueue.getCapacity().

6. Public Static Functions

6.1. getStaticCapacity

c++

static constexpr FwSizeType getStaticCapacity()

Return the static capacity C.

Example:

c++

const auto capacity = FifoQueue<U32, 3>::getStaticCapacity();
ASSERT_EQ(capacity, 3);