Interface for storing and retrieving MQTT session state.
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#include <ISessionStatePersistantStore.h>
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| virtual bool | initialize (const char *clientId)=0 |
| | Initializes the session state store for a specific client ID.
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| virtual bool | write (const char *clientId, uint32_t sessionExpiryInterval, const SavedData &data)=0 |
| | Writes a Publish packets to the session state persistant storage.
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| virtual bool | readAll (const char *clientId, std::vector< const SavedData > &outData)=0 |
| | Reads all persisted Publish packets from the session state store.
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| virtual bool | removeMessage (const char *clientId, std::uint16_t packetId)=0 |
| | Removes a specific Publish packets from the session state store.
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| virtual bool | updateMessage (const char *clientId, std::uint16_t packetId, PublishMessageStatus newStatus, bool bringToEnd)=0 |
| | Updates a specific Publish packet in the session state store.
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| virtual bool | removeFromStore (const char *clientId)=0 |
| | Remove all data associated with this client id from store.
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| virtual bool | removeExpiredFromStore ()=0 |
| | Remove all expired session states in store.
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Interface for storing and retrieving MQTT session state.
This interface allows SDK users to implement custom persistence mechanisms for MQTT session state, specifically for QoS 1 and QoS 2 publish messages that need to be tracked across sessions.
◆ initialize()
| virtual bool kmMqtt::mqtt::ISessionStatePersistantStore::initialize |
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const char * | clientId | ) |
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pure virtual |
Initializes the session state store for a specific client ID.
This method is called when an MQTT client finishes connecting.
- Parameters
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| clientId | The identifier of the mqtt client. |
- Returns
- true if the initialization was successful, false otherwise.
◆ readAll()
| virtual bool kmMqtt::mqtt::ISessionStatePersistantStore::readAll |
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const char * | clientId, |
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std::vector< const SavedData > & | outData ) |
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pure virtual |
Reads all persisted Publish packets from the session state store.
These NEED to be read in the same order as they have been written. I.E. Last message written needs to be the last message in the outMsgData vector.
This method is called when an MQTT client attempts to resume a valid session (after broker connect response).
- Parameters
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| clientId | The identifier of the mqtt client. |
| [out] | packets | A vector that will be populated with the Publish packets read from the session state. |
- Returns
- true if the session state was successfully read (even if no packets were stored), false if an error occurred during reading.
◆ removeExpiredFromStore()
| virtual bool kmMqtt::mqtt::ISessionStatePersistantStore::removeExpiredFromStore |
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| ) |
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pure virtual |
Remove all expired session states in store.
Called at MQTT start-up before connection.
- Returns
- true if expired session have been removed or none to remove were found.
◆ removeFromStore()
| virtual bool kmMqtt::mqtt::ISessionStatePersistantStore::removeFromStore |
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const char * | clientId | ) |
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pure virtual |
Remove all data associated with this client id from store.
This might be called when a clean session is started, or when the user explicitly requests to clear any stored session data.
- Parameters
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| clientId | The identifier of the mqtt client. |
- Returns
- true if the session state was successfully cleared or not found, false otherwise.
◆ removeMessage()
| virtual bool kmMqtt::mqtt::ISessionStatePersistantStore::removeMessage |
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const char * | clientId, |
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std::uint16_t | packetId ) |
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pure virtual |
Removes a specific Publish packets from the session state store.
This method will be called after a QoS 1 message is acknowledged, a QoS 2 message is fully acknowledged, or when a message is deemed no longer necessary to keep in the session state.
- Parameters
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| clientId | The identifier of the mqtt client. |
| packetId | The identifier of the packet to remove. |
- Returns
- true if the packet was successfully removed or was not found, false if an error occurred during removal.
◆ updateMessage()
| virtual bool kmMqtt::mqtt::ISessionStatePersistantStore::updateMessage |
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const char * | clientId, |
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std::uint16_t | packetId, |
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PublishMessageStatus | newStatus, |
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bool | bringToEnd ) |
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pure virtual |
Updates a specific Publish packet in the session state store.
- Parameters
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| clientId | The identifier of the mqtt client. |
| packetId | The identifier of the packet to update. |
| newStatus | The new status of the packet. |
| bringToFront | If true, the packet will be moved to the end of the list. |
- Returns
- true if the packet was successfully updated, false otherwise.
◆ write()
| virtual bool kmMqtt::mqtt::ISessionStatePersistantStore::write |
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const char * | clientId, |
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uint32_t | sessionExpiryInterval, |
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const SavedData & | data ) |
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pure virtual |
Writes a Publish packets to the session state persistant storage.
This method is called when an outgoing QoS 1 or QoS 2 PUBLISH packet is sent, or when an incoming QoS 2 PUBLISH packet is received but not yet fully acknowledged.
- Parameters
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| clientId | The identifier of the mqtt client. |
| sessionExpiryInterval | The session expiry interval after which session is considered obsolete. |
| msgData | The Publish packet to be stored. |
- Returns
- true if the packet was successfully written to the session state storage, false otherwise.
The documentation for this class was generated from the following file:
1.16.1