helios::ecs::AsyncMessageReader< T > Class Template Reference

Type-safe, move-based reader for async messages. More...

#include <async_reader.hpp>

Public Types
using	size_type = AsyncMessageQueue::size_type

Public Member Functions
	AsyncMessageReader (MessageManager &manager) noexcept
	Constructs an AsyncMessageReader from the message manager.
	AsyncMessageReader (AsyncMessageQueue &async_queue)
	Constructs an AsyncMessageReader by draining messages from the async queue.
	AsyncMessageReader (const AsyncMessageReader &)=delete
	AsyncMessageReader (AsyncMessageReader &&) noexcept=default
	~AsyncMessageReader () noexcept=default
AsyncMessageReader &	operator= (const AsyncMessageReader &)=delete
AsyncMessageReader &	operator= (AsyncMessageReader &&) noexcept=default
T	Dequeue () const
	Dequeues a single message from the queue.
bool	Dequeue (T &dest) const
	Dequeues a single message from the queue.
template<std::output_iterator< T > It>
size_type	Into (It out, size_type max_count=std::numeric_limits< size_type >::max()) const
	Moves messages into an output iterator (dequeues them).
template<typename Action> requires std::invocable<Action, T&>
void	ForEach (const Action &action) const
	Applies an action to every message in the queue (dequeues them).
bool	Empty () const noexcept
	Checks if there are no messages.
size_type	CountApprox () const noexcept
	Returns an approximate count of messages.

Detailed Description

template<AsyncMessageTrait T>
class helios::ecs::AsyncMessageReader< T >

Type-safe, move-based reader for async messages.

Drains all async messages of type T from the shared AsyncMessageQueue into a local buffer on construction. After draining, the messages are owned by the reader and can be iterated over, moved out, or queried.

Note

Thread-safe.

Template Parameters

T	Async message type satisfying AsyncMessageTrait

for (auto& message : reader) {
  Process(std::move(message));
}
 
// Or move all messages out:
auto messages = reader.TakeAll();

Definition at line 34 of file async_reader.hpp.

Member Typedef Documentation

size_type

template<AsyncMessageTrait T>

using helios::ecs::AsyncMessageReader< T >::size_type = AsyncMessageQueue::size_type

Definition at line 36 of file async_reader.hpp.

Constructor & Destructor Documentation

AsyncMessageReader() [1/4]

template<AsyncMessageTrait T>

helios::ecs::AsyncMessageReader< T >::AsyncMessageReader ( MessageManager & manager )

inlineexplicitnoexcept

Constructs an AsyncMessageReader from the message manager.

Parameters

manager

Reference to the message manager

Definition at line 42 of file async_reader.hpp.

AsyncMessageReader() [2/4]

template<AsyncMessageTrait T>

helios::ecs::AsyncMessageReader< T >::AsyncMessageReader ( AsyncMessageQueue & async_queue )

inlineexplicit

Constructs an AsyncMessageReader by draining messages from the async queue.

Warning

Triggers assertion if type 'T' is not registered.

Parameters

async_queue

Reference to the async message queue

Definition at line 51 of file async_reader.hpp.

AsyncMessageReader() [3/4]

template<AsyncMessageTrait T>

helios::ecs::AsyncMessageReader< T >::AsyncMessageReader ( const AsyncMessageReader< T > & )

delete

AsyncMessageReader() [4/4]

template<AsyncMessageTrait T>

helios::ecs::AsyncMessageReader< T >::AsyncMessageReader ( AsyncMessageReader< T > && )

defaultnoexcept

~AsyncMessageReader()

template<AsyncMessageTrait T>

helios::ecs::AsyncMessageReader< T >::~AsyncMessageReader ( )

defaultnoexcept

Member Function Documentation

CountApprox()

template<AsyncMessageTrait T>

size_type helios::ecs::AsyncMessageReader< T >::CountApprox ( ) const

inlinenodiscardnoexcept

Returns an approximate count of messages.

Returns

Message count

Definition at line 110 of file async_reader.hpp.

Dequeue() [1/2]

template<AsyncMessageTrait T>

T helios::ecs::AsyncMessageReader< T >::Dequeue ( ) const

inline

Dequeues a single message from the queue.

Returns

Dequeued message or default-constructed T if the queue is empty

Definition at line 65 of file async_reader.hpp.

Dequeue() [2/2]

template<AsyncMessageTrait T>

bool helios::ecs::AsyncMessageReader< T >::Dequeue ( T & dest ) const

inline

Dequeues a single message from the queue.

Parameters

dest	Reference to store the dequeued message

Returns

True if an message was dequeued and stored in dest, false if the queue was empty (dest is unchanged)

Definition at line 73 of file async_reader.hpp.

Empty()

template<AsyncMessageTrait T>

bool helios::ecs::AsyncMessageReader< T >::Empty ( ) const

inlinenodiscardnoexcept

Checks if there are no messages.

Returns

True if the reader holds no messages, false otherwise

Definition at line 104 of file async_reader.hpp.

ForEach()

template<AsyncMessageTrait T>
requires std::invocable<Action, T&>

template<typename Action>
requires std::invocable<Action, T&>

void helios::ecs::AsyncMessageReader< T >::ForEach ( const Action & action ) const

inline

Applies an action to every message in the queue (dequeues them).

Note

It is possible that the queue is modified by other writers while this method is executing, so the number of messages processed may be less than the total number of messages at the time of calling.

Template Parameters

Action

Callable type (const T&) -> void

Parameters

action

Action to apply

Definition at line 124 of file async_reader.hpp.

Into()

template<AsyncMessageTrait T>

template<std::output_iterator< T > It>

size_type helios::ecs::AsyncMessageReader< T >::Into ( It out, size_type max_count = std::numeric_limits<size_type>::max() ) const

inline

Moves messages into an output iterator (dequeues them).

Template Parameters

It	Output iterator type

Parameters

out	Output iterator to receive messages
max_count	Maximum number of messages to move (default: all messages)

Returns

Number of messages actually dequeued

Definition at line 83 of file async_reader.hpp.

operator=() [1/2]

template<AsyncMessageTrait T>

AsyncMessageReader & helios::ecs::AsyncMessageReader< T >::operator= ( AsyncMessageReader< T > && )

defaultnoexcept

operator=() [2/2]

template<AsyncMessageTrait T>

AsyncMessageReader & helios::ecs::AsyncMessageReader< T >::operator= ( const AsyncMessageReader< T > & )

delete