painlessmesh::MessageQueue Class Reference

#include <message_queue.hpp>

Public Member Functions
	MessageQueue (uint32_t maxSize=1000)
uint32_t	enqueue (MessagePriority priority, const TSTRING &payload, const TSTRING &destination="")
bool	remove (uint32_t messageId)
std::vector< QueuedMessage >	getMessages () const
uint32_t	size () const
uint32_t	size (MessagePriority priority) const
bool	empty () const
void	clear ()
QueueStats	getStats () const
void	onStateChanged (queueStateChangedCallback_t callback)
uint32_t	incrementAttempts (uint32_t messageId)
uint32_t	pruneOldMessages (uint32_t maxAgeMs)

Detailed Description

Manual priority buffer for offline / Internet-unavailable mode

This is a storage container only. It does NOT transmit anything on its own: painlessMesh will not enqueue, flush, or deliver messages automatically, and there is no connectivity-restored trigger inside the library. The application owns the send loop — enqueue when your upstream (MQTT/HTTP/etc.) is down, drain via getMessages() / mesh.flushMessageQueue() and remove() / mesh.removeQueuedMessage() when your own connectivity check tells you it is safe to resend.

Provides priority-based message queueing with support for:

• Priority levels (CRITICAL messages evicted last, but may still be dropped if the queue is full and all entries are CRITICAL)
• Queue size limits with intelligent eviction
• Statistics tracking
• State change callbacks

Example usage:

MessageQueue queue(1000);  // Max 1000 messages
 
// Queue a critical message while upstream is offline
uint32_t msgId = queue.enqueue(PRIORITY_CRITICAL, "alarm_data", "mqtt://...");
 
// Get queue size
uint32_t size = queue.size();
 
// When your app detects the upstream is back, drain manually:
auto messages = queue.getMessages();
for (auto& msg : messages) {
  if (sendToCloud(msg.payload, msg.destination)) {
    queue.remove(msg.id);
  }
}

Constructor & Destructor Documentation

MessageQueue()

painlessmesh::MessageQueue::MessageQueue ( uint32_t  maxSize = 1000 )

inlineexplicit

Constructor

Parameters

maxSize

Maximum number of messages in queue

Member Function Documentation

clear()

void painlessmesh::MessageQueue::clear ( )

inline

Clear all messages from queue

empty()

bool painlessmesh::MessageQueue::empty ( ) const

inline

Check if queue is empty

Returns

true if no messages queued

enqueue()

uint32_t painlessmesh::MessageQueue::enqueue ( MessagePriority  priority, const TSTRING &  payload, const TSTRING &  destination = ""  )

inline

Enqueue a message with priority

Parameters

priority	Message priority level
payload	Message content
destination	Optional destination metadata

Returns

Message ID if queued, 0 if dropped

getMessages()

std::vector< QueuedMessage > painlessmesh::MessageQueue::getMessages ( ) const

inline

Get all queued messages

Returns

Vector of queued messages (ordered by timestamp)

getStats()

QueueStats painlessmesh::MessageQueue::getStats ( ) const

inline

Get queue statistics

Returns

QueueStats structure

incrementAttempts()

uint32_t painlessmesh::MessageQueue::incrementAttempts ( uint32_t  messageId )

inline

Increment send attempt counter for a message

Parameters

messageId

ID of message

Returns

New attempt count, or 0 if message not found

onStateChanged()

void painlessmesh::MessageQueue::onStateChanged ( queueStateChangedCallback_t  callback )

inline

Set queue state change callback

Parameters

callback

Function to call when queue state changes

pruneOldMessages()

uint32_t painlessmesh::MessageQueue::pruneOldMessages ( uint32_t  maxAgeMs )

inline

Remove old messages (for queue pruning)

Parameters

maxAgeMs

Maximum age in milliseconds

Returns

Number of messages removed

remove()

bool painlessmesh::MessageQueue::remove ( uint32_t  messageId )

inline

Remove a message from the queue

Parameters

messageId

ID of message to remove

Returns

true if message was found and removed

size() [1/2]

uint32_t painlessmesh::MessageQueue::size ( ) const

inline

Get current queue size

Returns

Number of messages in queue

size() [2/2]

uint32_t painlessmesh::MessageQueue::size ( MessagePriority  priority ) const

inline

Get count of messages with specific priority

Parameters

priority

Priority level to count

Returns

Number of messages with that priority

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The documentation for this class was generated from the following file:

• src/painlessmesh/message_queue.hpp