start mqtt client (based on paho.mqtt.c), basically works

3rd/paho.mqtt.c/src/MQTTPersistence.h

@@ -0,0 +1,99 @@
+/*******************************************************************************
+ * Copyright (c) 2009, 2022 IBM Corp.
+ *
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v2.0
+ * and Eclipse Distribution License v1.0 which accompany this distribution. 
+ *
+ * The Eclipse Public License is available at 
+ *    https://www.eclipse.org/legal/epl-2.0/
+ * and the Eclipse Distribution License is available at 
+ *   http://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * Contributors:
+ *    Ian Craggs - initial API and implementation and/or initial documentation
+ *    Ian Craggs - async client updates
+ *    Ian Craggs - fix for bug 432903 - queue persistence
+ *    Ian Craggs - MQTT V5 updates
+ *******************************************************************************/
+
+#if !defined(MQTTPERSISTENCE_H)
+#define MQTTPERSISTENCE_H
+
+#if defined(__cplusplus)
+ extern "C" {
+#endif
+
+#include "Clients.h"
+#include "MQTTProperties.h"
+
+/** Stem of the key for a sent PUBLISH QoS1 or QoS2 */
+#define PERSISTENCE_PUBLISH_SENT "s-"
+/** Stem of the key for a sent PUBREL */
+#define PERSISTENCE_PUBREL "sc-"
+/** Stem of the key for a received PUBLISH QoS2 */
+#define PERSISTENCE_PUBLISH_RECEIVED "r-"
+
+/** Stem of the key for a sent MQTT V5 PUBLISH QoS1 or QoS2 */
+#define PERSISTENCE_V5_PUBLISH_SENT "s5-"
+/** Stem of the key for a sent MQTT V5 PUBREL */
+#define PERSISTENCE_V5_PUBREL "sc5-"
+/** Stem of the key for a received MQTT V5 PUBLISH QoS2 */
+#define PERSISTENCE_V5_PUBLISH_RECEIVED "r5-"
+
+/** Stem of the key for an async client command */
+#define PERSISTENCE_COMMAND_KEY "c-"
+/** Stem of the key for an MQTT V5 async client command */
+#define PERSISTENCE_V5_COMMAND_KEY "c5-"
+/** Stem of the key for an client incoming message queue */
+#define PERSISTENCE_QUEUE_KEY "q-"
+/** Stem of the key for an MQTT V5 incoming message queue */
+#define PERSISTENCE_V5_QUEUE_KEY "q5-"
+/** Maximum length of a stem for a persistence key */
+#define PERSISTENCE_MAX_STEM_LENGTH 4
+/** Maximum allowed length of a persistence key */
+#define PERSISTENCE_MAX_KEY_LENGTH 10
+/** Maximum size of an integer sequence number appended to a persistence key */
+#define PERSISTENCE_SEQNO_LIMIT 1000000 /*10^(PERSISTENCE_MAX_KEY_LENGTH - PERSISTENCE_MAX_STEM_LENGTH)*/
+
+int MQTTPersistence_create(MQTTClient_persistence** per, int type, void* pcontext);
+int MQTTPersistence_initialize(Clients* c, const char* serverURI);
+int MQTTPersistence_close(Clients* c);
+int MQTTPersistence_clear(Clients* c);
+int MQTTPersistence_restorePackets(Clients* c);
+void* MQTTPersistence_restorePacket(int MQTTVersion, char* buffer, size_t buflen);
+void MQTTPersistence_insertInOrder(List* list, void* content, size_t size);
+int MQTTPersistence_putPacket(SOCKET socket, char* buf0, size_t buf0len, int count,
+						char** buffers, size_t* buflens, int htype, int msgId, int scr, int MQTTVersion);
+int MQTTPersistence_remove(Clients* c, char* type, int qos, int msgId);
+void MQTTPersistence_wrapMsgID(Clients *c);
+
+typedef struct
+{
+	char struct_id[4];
+	int struct_version;
+	int payloadlen;
+	void* payload;
+	int qos;
+	int retained;
+	int dup;
+	int msgid;
+	MQTTProperties properties;
+} MQTTPersistence_message;
+
+typedef struct
+{
+	MQTTPersistence_message* msg;
+	char* topicName;
+	int topicLen;
+	unsigned int seqno; /* only used on restore */
+} MQTTPersistence_qEntry;
+
+int MQTTPersistence_unpersistQueueEntry(Clients* client, MQTTPersistence_qEntry* qe);
+int MQTTPersistence_persistQueueEntry(Clients* aclient, MQTTPersistence_qEntry* qe);
+int MQTTPersistence_restoreMessageQueue(Clients* c);
+#ifdef __cplusplus
+     }
+#endif
+
+#endif