Peter M. Groen / TrueMQTT-cpp

Commit 3c3a273b70a3fa09ffe1c7b1ad9aaaa9efc8ad12

Authored by Patric Stout
1 parent 6f0b3228

feat: callback to be informed about state changes 

Useful if you want to take action when a connection to the broker
is established or lost. For example, after a reconnection you can
expect to receive all retained messages again on the topics you are
subscribed too.
Inline Side-by-side
Showing 6 changed files with 61 additions and 34 deletions
example/pubsub/main.cpp
  View file @3c3a273
... ... @@ -6,7 +6,9 @@
6 6 */
7 7  
8 8 #include <TrueMQTT.h>
  9 +
9 10 #include <iostream>
  11 +#include <magic_enum.hpp>
10 12 #include <thread>
11 13  
12 14 int main()
... ... @@ -15,10 +17,10 @@ int main()
15 17 TrueMQTT::Client client("localhost", 1883, "test");
16 18  
17 19 client.setLogger(TrueMQTT::Client::LogLevel::WARNING, [](TrueMQTT::Client::LogLevel level, std::string_view message)
18   - { std::cout << "Log " << level << ": " << message << std::endl; });
  20 + { std::cout << "Log " << std::string(magic_enum::enum_name(level)) << ": " << message << std::endl; });
19 21 client.setPublishQueue(TrueMQTT::Client::PublishQueueType::FIFO, 10);
20 22 client.setErrorCallback([](TrueMQTT::Client::Error error, std::string_view message)
21   - { std::cout << "Error " << error << ": " << message << std::endl; });
  23 + { std::cout << "Error " << std::string(magic_enum::enum_name(error)) << ": " << message << std::endl; });
22 24 client.setLastWill("example/pubsub/lastwill", "example pubsub finished", true);
23 25  
24 26 client.connect();
... ...
example/stress/main.cpp
  View file @3c3a273
... ... @@ -6,7 +6,9 @@
6 6 */
7 7  
8 8 #include <TrueMQTT.h>
  9 +
9 10 #include <iostream>
  11 +#include <magic_enum.hpp>
10 12 #include <thread>
11 13  
12 14 int main()
... ... @@ -15,10 +17,10 @@ int main()
15 17 TrueMQTT::Client client("localhost", 1883, "test");
16 18  
17 19 client.setLogger(TrueMQTT::Client::LogLevel::WARNING, [](TrueMQTT::Client::LogLevel level, std::string_view message)
18   - { std::cout << "Log " << level << ": " << message << std::endl; });
  20 + { std::cout << "Log " << std::string(magic_enum::enum_name(level)) << ": " << message << std::endl; });
19 21 client.setPublishQueue(TrueMQTT::Client::PublishQueueType::FIFO, 100);
20 22 client.setErrorCallback([](TrueMQTT::Client::Error error, std::string_view message)
21   - { std::cout << "Error " << error << ": " << message << std::endl; });
  23 + { std::cout << "Error " << std::string(magic_enum::enum_name(error)) << ": " << message << std::endl; });
22 24 client.setLastWill("test/lastwill", "example pubsub finished", true);
23 25  
24 26 client.connect();
... ...
include/TrueMQTT.h
  View file @3c3a273
... ... @@ -24,7 +24,7 @@ namespace TrueMQTT
24 24 /**
25 25 * @brief Error codes that can be returned in the callback set by \ref setErrorCallback.
26 26 */
27   - enum Error
  27 + enum class Error
28 28 {
29 29 /**
30 30 * @brief The hostname could not be resolved into either an IPv4 or IPv6 address.
... ... @@ -62,7 +62,7 @@ namespace TrueMQTT
62 62 * After all, memory is finite, so this allows you to configure what scenario
63 63 * works best for you.
64 64 */
65   - enum PublishQueueType
  65 + enum class PublishQueueType
66 66 {
67 67 DROP, ///< Do not queue.
68 68  
... ... @@ -96,7 +96,7 @@ namespace TrueMQTT
96 96 /**
97 97 * @brief The log levels used by this library.
98 98 */
99   - enum LogLevel
  99 + enum class LogLevel
100 100 {
101 101 NONE, ///< Do not log anything (default).
102 102 ERROR, ///< Something went wrong and the library cannot recover.
... ... @@ -107,6 +107,16 @@ namespace TrueMQTT
107 107 };
108 108  
109 109 /**
  110 + * @brief The state of the connection.
  111 + */
  112 + enum class State
  113 + {
  114 + DISCONNECTED, ///< The client is not connected to a broker.
  115 + CONNECTING, ///< The client is (re)connecting to a broker.
  116 + CONNECTED, ///< The client is connected to a broker.
  117 + };
  118 +
  119 + /**
110 120 * @brief Constructor for the MQTT client.
111 121 *
112 122 * @param host The hostname of the MQTT broker. Can be either an IP or a domain name.
... ... @@ -195,6 +205,13 @@ namespace TrueMQTT
195 205 void setSendQueue(size_t size) const;
196 206  
197 207 /**
  208 + * @brief Set the state-change callback.
  209 + *
  210 + * @param callback The callback to call when the state changes.
  211 + */
  212 + void setStateChangeCallback(const std::function<void(State)> &callback) const;
  213 +
  214 + /**
198 215 * @brief Connect to the broker.
199 216 *
200 217 * After calling this function, the library will try a connection to the broker.
... ...
src/Client.cpp
  View file @3c3a273
... ... @@ -64,7 +64,7 @@ void TrueMQTT::Client::setLogger(Client::LogLevel log_level, const std::function
64 64  
65 65 void TrueMQTT::Client::setLastWill(const std::string_view topic, const std::string_view message, bool retain) const
66 66 {
67   - if (m_impl->m_state != Client::Impl::State::DISCONNECTED)
  67 + if (m_impl->m_state != Client::State::DISCONNECTED)
68 68 {
69 69 LOG_ERROR(m_impl, "Cannot set last will when not disconnected");
70 70 return;
... ... @@ -86,7 +86,7 @@ void TrueMQTT::Client::setErrorCallback(const std::function&lt;void(Error, std::str
86 86  
87 87 void TrueMQTT::Client::setPublishQueue(Client::PublishQueueType queue_type, size_t size) const
88 88 {
89   - if (m_impl->m_state != Client::Impl::State::DISCONNECTED)
  89 + if (m_impl->m_state != Client::State::DISCONNECTED)
90 90 {
91 91 LOG_ERROR(m_impl, "Cannot set publish queue when not disconnected");
92 92 return;
... ... @@ -100,7 +100,7 @@ void TrueMQTT::Client::setPublishQueue(Client::PublishQueueType queue_type, size
100 100  
101 101 void TrueMQTT::Client::setSendQueue(size_t size) const
102 102 {
103   - if (m_impl->m_state != Client::Impl::State::DISCONNECTED)
  103 + if (m_impl->m_state != Client::State::DISCONNECTED)
104 104 {
105 105 LOG_ERROR(m_impl, "Cannot set send queue when not disconnected");
106 106 return;
... ... @@ -111,18 +111,27 @@ void TrueMQTT::Client::setSendQueue(size_t size) const
111 111 m_impl->m_send_queue_size = size;
112 112 }
113 113  
  114 +void TrueMQTT::Client::setStateChangeCallback(const std::function<void(State)> &callback) const
  115 +{
  116 + LOG_TRACE(m_impl, "Setting state callback");
  117 +
  118 + m_impl->m_state_change_callback = callback;
  119 +}
  120 +
114 121 void TrueMQTT::Client::connect() const
115 122 {
116 123 std::scoped_lock lock(m_impl->m_state_mutex);
117 124  
118   - if (m_impl->m_state != Client::Impl::State::DISCONNECTED)
  125 + if (m_impl->m_state != Client::State::DISCONNECTED)
119 126 {
  127 + LOG_ERROR(m_impl, "Can't connect when already connecting / connected");
120 128 return;
121 129 }
122 130  
123 131 LOG_INFO(m_impl, "Connecting to " + m_impl->m_host + ":" + std::to_string(m_impl->m_port));
124 132  
125   - m_impl->m_state = Client::Impl::State::CONNECTING;
  133 + m_impl->m_state = Client::State::CONNECTING;
  134 + m_impl->m_state_change_callback(m_impl->m_state);
126 135 m_impl->connect();
127 136 }
128 137  
... ... @@ -130,15 +139,16 @@ void TrueMQTT::Client::disconnect() const
130 139 {
131 140 std::scoped_lock lock(m_impl->m_state_mutex);
132 141  
133   - if (m_impl->m_state == Client::Impl::State::DISCONNECTED)
  142 + if (m_impl->m_state == Client::State::DISCONNECTED)
134 143 {
135   - LOG_TRACE(m_impl, "Already disconnected");
  144 + LOG_ERROR(m_impl, "Can't disconnect when already disconnected");
136 145 return;
137 146 }
138 147  
139 148 LOG_INFO(m_impl, "Disconnecting from broker");
140 149  
141   - m_impl->m_state = Client::Impl::State::DISCONNECTED;
  150 + m_impl->m_state = Client::State::DISCONNECTED;
  151 + m_impl->m_state_change_callback(m_impl->m_state);
142 152 m_impl->disconnect();
143 153 }
144 154  
... ... @@ -150,12 +160,12 @@ bool TrueMQTT::Client::publish(const std::string_view topic, const std::string_v
150 160  
151 161 switch (m_impl->m_state)
152 162 {
153   - case Client::Impl::State::DISCONNECTED:
  163 + case Client::State::DISCONNECTED:
154 164 LOG_ERROR(m_impl, "Cannot publish when disconnected");
155 165 return false;
156   - case Client::Impl::State::CONNECTING:
  166 + case Client::State::CONNECTING:
157 167 return m_impl->toPublishQueue(topic, message, retain);
158   - case Client::Impl::State::CONNECTED:
  168 + case Client::State::CONNECTED:
159 169 return m_impl->sendPublish(topic, message, retain);
160 170 }
161 171  
... ... @@ -166,7 +176,7 @@ void TrueMQTT::Client::subscribe(const std::string_view topic, const std::functi
166 176 {
167 177 std::scoped_lock lock(m_impl->m_state_mutex);
168 178  
169   - if (m_impl->m_state == Client::Impl::State::DISCONNECTED)
  179 + if (m_impl->m_state == Client::State::DISCONNECTED)
170 180 {
171 181 LOG_ERROR(m_impl, "Cannot subscribe when disconnected");
172 182 return;
... ... @@ -210,7 +220,7 @@ void TrueMQTT::Client::subscribe(const std::string_view topic, const std::functi
210 220 subscriptions->callbacks.push_back(callback);
211 221  
212 222 m_impl->m_subscription_topics.emplace(topic);
213   - if (m_impl->m_state == Client::Impl::State::CONNECTED)
  223 + if (m_impl->m_state == Client::State::CONNECTED)
214 224 {
215 225 if (!m_impl->sendSubscribe(topic))
216 226 {
... ... @@ -225,7 +235,7 @@ void TrueMQTT::Client::unsubscribe(const std::string_view topic) const
225 235 {
226 236 std::scoped_lock lock(m_impl->m_state_mutex);
227 237  
228   - if (m_impl->m_state == Client::Impl::State::DISCONNECTED)
  238 + if (m_impl->m_state == Client::State::DISCONNECTED)
229 239 {
230 240 LOG_ERROR(m_impl, "Cannot unsubscribe when disconnected");
231 241 return;
... ... @@ -302,7 +312,7 @@ void TrueMQTT::Client::unsubscribe(const std::string_view topic) const
302 312 }
303 313  
304 314 m_impl->m_subscription_topics.erase(m_impl->m_subscription_topics.find(topic));
305   - if (m_impl->m_state == Client::Impl::State::CONNECTED)
  315 + if (m_impl->m_state == Client::State::CONNECTED)
306 316 {
307 317 if (!m_impl->sendUnsubscribe(topic))
308 318 {
... ... @@ -321,7 +331,8 @@ void TrueMQTT::Client::Impl::connectionStateChange(bool connected)
321 331 {
322 332 LOG_INFO(this, "Connected to broker");
323 333  
324   - m_state = Client::Impl::State::CONNECTED;
  334 + m_state = Client::State::CONNECTED;
  335 + m_state_change_callback(m_state);
325 336  
326 337 // Restoring subscriptions and flushing the queue is done while still under
327 338 // the lock. This to prevent \ref disconnect from being called while we are
... ... @@ -356,13 +367,14 @@ void TrueMQTT::Client::Impl::connectionStateChange(bool connected)
356 367 else
357 368 {
358 369 LOG_INFO(this, "Disconnected from broker");
359   - m_state = Client::Impl::State::CONNECTING;
  370 + m_state = Client::State::CONNECTING;
  371 + m_state_change_callback(m_state);
360 372 }
361 373 }
362 374  
363 375 bool TrueMQTT::Client::Impl::toPublishQueue(const std::string_view topic, const std::string_view message, bool retain)
364 376 {
365   - if (m_state != Client::Impl::State::CONNECTING)
  377 + if (m_state != Client::State::CONNECTING)
366 378 {
367 379 LOG_ERROR(this, "Cannot queue publish message when not connecting");
368 380 return false;
... ...
src/ClientImpl.h
  View file @3c3a273
... ... @@ -31,13 +31,6 @@ public:
31 31 std::chrono::milliseconds keep_alive_interval);
32 32 ~Impl();
33 33  
34   - enum State
35   - {
36   - DISCONNECTED, ///< The client is not connected to the broker, nor is it trying to connect.
37   - CONNECTING, ///< The client is either connecting or reconnecting to the broker. This can be in any stage of the connection process.
38   - CONNECTED, ///< The client is connected to the broker.
39   - };
40   -
41 34 class SubscriptionPart
42 35 {
43 36 public:
... ... @@ -70,6 +63,8 @@ public:
70 63 Client::LogLevel m_log_level = Client::LogLevel::NONE; ///< The log level to use.
71 64 std::function<void(Client::LogLevel, std::string_view)> m_logger = [](Client::LogLevel, std::string_view) { /* empty */ }; ///< Logger callback.
72 65  
  66 + std::function<void(State)> m_state_change_callback = [](State) { /* empty */ }; ///< Callback when the connection state changes.
  67 +
73 68 std::string m_last_will_topic = ""; ///< Topic to publish the last will message to.
74 69 std::string m_last_will_message = ""; ///< Message to publish on the last will topic.
75 70 bool m_last_will_retain = false; ///< Whether to retain the last will message.
... ...
src/Packet.cpp
  View file @3c3a273
... ... @@ -10,8 +10,7 @@
10 10 #include "Log.h"
11 11 #include "Packet.h"
12 12  
13   -#include "magic_enum.hpp"
14   -
  13 +#include <magic_enum.hpp>
15 14 #include <string.h>
16 15  
17 16 ssize_t TrueMQTT::Client::Impl::Connection::recv(char *buffer, size_t length)
... ...