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Plugins/MqttClient/Source/DTMqtt/MqttCPP/subscribe_options.h

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+// Copyright 2023 Dexter.Wan. All Rights Reserved. 
+// EMail: 45141961@qq.com
+
+#ifndef __mqtt_subscribe_options_h
+#define __mqtt_subscribe_options_h
+
+#include "MQTTAsync.h"
+#include "MQTTSubscribeOpts.h"
+#include "types.h"
+
+namespace mqtt {
+
+/////////////////////////////////////////////////////////////////////////////
+
+/**
+ * The MQTT v5 subscription options.
+ * These are defined in section 3.8.3.1 of the MQTT v5 spec.
+ * The defaults use the behavior that was present in MQTT v3.1.1.
+ */
+class subscribe_options
+{
+	/** The underlying C structure */
+	MQTTSubscribe_options opts_;
+
+	/** The client and response have special access */
+	friend class async_client;
+	friend class response_options;
+
+public:
+	/** Smart/shared pointer to an object of this class. */
+	using ptr_t = std::shared_ptr<subscribe_options>;
+	/** Smart/shared pointer to a const object of this class. */
+	using const_ptr_t = std::shared_ptr<const subscribe_options>;
+
+	/** Don't receive our own publications */
+	static constexpr bool SUBSCRIBE_NO_LOCAL = true;
+	/** Receive our own publications */
+	static constexpr bool SUBSCRIBE_LOCAL = false;
+
+	/**
+	 * Retain flag is only set on publications sent by a broker if in
+	 * response to a subscribe request
+	 */
+	static constexpr bool NO_RETAIN_AS_PUBLISHED = false;
+	/** Keep the retain flag as on the original publish message */
+	static constexpr bool RETAIN_AS_PUBLISHED = true;
+
+	/** The options for subscription retain handling */
+	enum RetainHandling {
+		/** Send retained messages at the time of the subscribe */
+		SEND_RETAINED_ON_SUBSCRIBE = 0,
+		/** Send retained messages on subscribe only if subscription is new */
+		SEND_RETAINED_ON_NEW = 1,
+		/** Do not send retained messages at all */
+		DONT_SEND_RETAINED = 2
+	};
+
+	/**
+	 * Create default subscription options.
+	 * These are the default options corresponding to the original MQTT (v3)
+	 * behaviors.
+	 */
+	subscribe_options()
+			: opts_(MQTTSubscribe_options_initializer) {}
+	/**
+	 * Creates a set of subscription options.
+	 *
+	 * @param noLocal Whether the server should send back our own
+	 *  			  publications, if subscribed.
+	 * @param retainAsPublished Whether to keep the retained flag as in the
+	 *  						original published message (true).
+	 * @param retainHandling When to send retained messages:
+	 *  	@li (SEND_RETAINED_ON_SUBSCRIBE, 0) At the time of the subscribe
+	 *  	@li (SEND_RETAINED_ON_NEW, 1) Only at the time of a new
+	 *  		subscribe
+	 *  	@li (DONT_SEND_RETAINED, 2) Not at the time of subscribe
+	 */
+	explicit subscribe_options(bool noLocal, uint8_t retainAsPublished=false,
+							   RetainHandling retainHandling=SEND_RETAINED_ON_SUBSCRIBE)
+			: opts_(MQTTSubscribe_options_initializer) {
+		opts_.noLocal = noLocal ? 1 : 0;
+		opts_.retainAsPublished = retainAsPublished ? 1 : 0;
+		opts_.retainHandling = (unsigned char) retainHandling;
+	}
+	/**
+	 * Gets the value of the "no local" flag.
+	 * @return Whether the server should send back our own publications, if
+	 *  	   subscribed.
+	 */
+	bool get_no_local() const {
+		return to_bool(opts_.noLocal);
+	}
+	/**
+	 * Sets the "no local" flag on or off.
+	 * @param on Whether the server should send back our own publications,
+	 *  		 if subscribed.
+	 */
+	void set_no_local(bool on=true) {
+		opts_.noLocal = on ? 1 : 0;
+	}
+	/**
+	 * Gets the "retain as published" flag.
+	 * @return Whether to keep the retained flag as in the original
+	 *  		 published message.
+	 */
+	bool get_retain_as_published() const {
+		return to_bool(opts_.retainAsPublished);
+	}
+	/**
+	 * Sets the "retain as published" flag on or off.
+	 * @param on Whether to keep the retained flag as in the original
+	 *  		 published message.
+	 */
+	void set_retain_as_published(bool on) {
+		opts_.retainAsPublished = on ? 1 : 0;
+	}
+	/**
+	 * Gets the "retasin handling" option.
+	 * @return When to send retained messages:
+	 *  	@li (SEND_RETAINED_ON_SUBSCRIBE, 0) At the time of the subscribe
+	 *  	@li (SEND_RETAINED_ON_NEW, 1) Only at the time of a new
+	 *  		subscribe
+	 *  	@li (DONT_SEND_RETAINED, 2) Not at the time of subscribe
+	 */
+	auto get_retain_handling() const -> RetainHandling {
+		return RetainHandling(opts_.retainHandling);
+	}
+	/**
+	 * Sets the "retain handling" option.
+	 * @param retainHandling When to send retained messages:
+	 *  	@li (SEND_RETAINED_ON_SUBSCRIBE, 0) At the time of the subscribe
+	 *  	@li (SEND_RETAINED_ON_NEW, 1) Only at the time of a new
+	 *  		subscribe
+	 *  	@li (DONT_SEND_RETAINED, 2) Not at the time of subscribe
+	 */
+	void set_retain_handling(RetainHandling retainHandling) {
+		opts_.retainHandling = (unsigned char) retainHandling;
+	}
+};
+
+
+/** Smart/shared pointer to a subscribe options object. */
+using subscribe_options_ptr = subscribe_options::ptr_t;
+
+/////////////////////////////////////////////////////////////////////////////
+// end namespace mqtt
+}
+
+#endif		// __mqtt_subscribe_options_h
+