Merge branch 'main' into timeout

README.md

@@ -24,6 +24,8 @@ TinyMqtt is a small, fast and capable Mqtt Broker and Client for Esp8266 / Esp32
 
 ## Features
 
+- Supports retained messages (not activated by default)
+- Async Wifi compatible (me-no-dev/ESPAsyncTCP@^1.2.2)
 - Very fast broker I saw it re-sent 1000 topics per second for two
   clients that had subscribed (payload ~15 bytes ESP8266). No topic lost.
   The max I've seen was 2k msg/s (1 client 1 subscription)
@@ -63,6 +65,13 @@ TinyMqtt is a small, fast and capable Mqtt Broker and Client for Esp8266 / Esp32
 - tinymqtt-test : This is a complex sketch with a terminal console
   that allows to add clients publish, connect etc with interpreted commands.
 
+## Retained messages
+
+Qos 1 is not supported, but retained messages are. So a new subscription is able to send old messages.
+This feature is disabled by default.
+The default retain parameter of MqttBroker::MqttBroker takes an optional (0 by default) number of retained messages.
+MqttBroker::retain(n) will also make the broker store n messages at max.
+
 ## Standalone mode (zeroconf)
 -> The zeroconf mode is not yet implemented
 zeroconf clients to connect to broker on local network.

bump_version.sh

@@ -1,16 +1,17 @@
 #!/bin/bash
 current_version=$(git describe --tags --abbrev=0)
-cp library.json.skeleton library.json
-while ifs= read -r line; do
-  name=$(echo "$line" | sed "s/=.*//g")
-  value=$(echo "$line" | cut -d= -f 2 | sed 's/"//g')
-  sed -i "s/#$name/$value/g" library.json
-done < library.properties
-
+if [ "$1" == "-d" ]; then
+  do=0
+  shift
+else
+  do=1
+fi
 if [ "$1" == "" ]; then
 	echo
-	echo "Syntax: $0 {new_version}"
+	echo "Syntax: $0 [-d] {new_version} [commit message]"
 	echo
+	echo "  -d : dry run, generate json and update properties but do not run git commands"
+	echo ""
 	echo "  Current version: $current_version"
 	echo
 else
@@ -23,15 +24,35 @@ else
 		grep $current_version library.properties
 		if [ "$?" == "0" ]; then
 			sed -i "s/$current_version/$1/" library.properties
-			if [ 0 == 1 ]; then
+
+      cp library.json.skeleton library.json
+      while ifs= read -r line; do
+        name=$(echo "$line" | sed "s/=.*//g")
+        value=$(echo "$line" | cut -d= -f 2 | sed 's/"//g')
+        echo "  Replacing $name in json"
+        if [ "$name" == "depends" ]; then
+          depends=$(echo "$value" | sed "s/,/ /g")
+          echo "  Depends=$depends"
+        fi
+        sed -i "s@#$name@$value@g" library.json
+      done < library.properties
+      deps=""
+      for depend in $depends; do
+        if [ "$deps" != "" ]; then
+          deps="$deps, "
+        fi
+        deps="$deps'$depend' : '*'"
+      done
+      sed -i "s@#dependencies@$deps@g" library.json
+      sed -i "s/'/\"/g" library.json
+      if [ "$do" == "1" ]; then
+        echo "Pushing all"
         git tag $1
         git add library.properties
         git add library.json
-        git commit -m "Release $1"
+        git commit -m "Release $1 $2"
         git push
         git push --tags
-      else
-        echo "No git operation made"
       fi
 		else
 			echo "Current version does not match library.property version, aborting"

examples/simple-broker/simple-broker.ino

@@ -1,7 +1,9 @@
 #include "TinyMqtt.h"   // https://github.com/hsaturn/TinyMqtt
 
-#define PORT 1883
-MqttBroker broker(PORT);
+const uint16_t PORT 1883;
+const uint8_t  RETAIN = 10;  // Max retained messages
+
+MqttBroker broker(PORT, RETAIN);
 
 /** Basic Mqtt Broker
   *
@@ -16,6 +18,8 @@ MqttBroker broker(PORT);
   *  Your ESP will become a MqttBroker.
 	*  You can test it with any client such as mqtt-spy for example
 	*
+	* Messages are retained *only* if retain > 0
+	*
   */
 
 const char* ssid = "";

examples/simple-client/simple-client.ino

@@ -1,7 +1,7 @@
 #include "TinyMqtt.h"    // https://github.com/hsaturn/TinyMqtt
 #include "TinyStreaming.h" // https://github.com/hsaturn/TinyConsole
 
-/** Simple Client (The simplest configuration)
+/** Simple Client (The simplest configuration, client only sends topics)
   *
   *
   *                   +--------+

examples/tinymqtt-test/tinymqtt-test.ino

@@ -15,8 +15,6 @@
 #include <string>
 #include <map>
 
-using string = TinyString;
-
 bool echo_on = true;
 auto green = TinyConsole::green;
 auto red = TinyConsole::red;
@@ -28,8 +26,11 @@ auto save_cursor = TinyConsole::save_cursor;
 auto restore_cursor = TinyConsole::restore_cursor;
 auto erase_to_end = TinyConsole::erase_to_end;
 
-const char* ssid = "";
-const char* password = "";
+const char *ssid = "Freebox-786A2F";
+const char *password = "usurpavi8dalum64lumine?";
+
+void onCommand(const string &command);
+void eval(string &cmd);
 
 struct free_broker
 {
@@ -43,8 +44,7 @@ struct free_broker
 const std::map<string, free_broker> list =
     {
         {"mqtthq", {"public.mqtthq.com", 8083, "publish/subscribe"}},
-  { "hivemq", { "broker.hivemq.com", 1883, "" }}
-};
+        {"hivemq", {"broker.hivemq.com", 1883, ""}}};
 
 /** Very complex example
  * Console allowing to make any kind of test,
@@ -88,7 +88,8 @@ void setup()
   delay(500);
 
   Console.cls();
-  Console << endl << endl;
+  Console << endl
+          << endl;
   Console << yellow
           << "***************************************************************" << endl;
   Console << "*  Welcome to the TinyMqtt console" << endl;
@@ -99,7 +100,8 @@ void setup()
   if (strlen(ssid) == 0)
     Console << red << "*  ERROR: You must modify ssid/password in order" << endl
             << "          to be able to connect to your Wifi network." << endl;
-  Console << endl << white;
+  Console << endl
+          << white;
 
   Console << "Connecting to '" << ssid << "' ";
 
@@ -109,9 +111,13 @@ void setup()
   WiFi.begin(ssid, password);
 
   while (WiFi.status() != WL_CONNECTED)
-  { Console << '-'; delay(500); }
+  {
+    Console << '-';
+    delay(500);
+  }
 
-  Console << endl << "Connected to " << ssid << "IP address: " << WiFi.localIP() << endl;
+  Console << endl
+          << "Connected to " << ssid << "IP address: " << WiFi.localIP() << endl;
 
   const char *name = "tinytest";
   Console << "Starting MDNS, name= " << name;
@@ -120,12 +126,14 @@ void setup()
   else
     Console << " ok." << endl;
 
-
   MqttBroker *broker = new MqttBroker(1883);
   broker->begin();
   brokers["broker"] = broker;
 
-  if (Console.isTerm()) onCommand("every 333 view");
+  if (Console.isTerm())
+    onCommand("every 333 view");
+
+  Console.prompt();
 }
 
 string getword(string &str, const char *if_empty = nullptr, char sep = ' ');
@@ -137,8 +145,10 @@ int getint(string& str, const int if_empty=0)
   if (sword[0] and isdigit(sword[0]))
   {
     int ret = atoi(sword.c_str());
-    while(isdigit(sword[0]) or sword[0]==' ') sword.erase(0,1);
-    if (sword.length()) str = sword+' '+str;
+    while (isdigit(sword[0]) or sword[0] == ' ')
+      sword.erase(0, 1);
+    if (sword.length())
+      str = sword + ' ' + str;
     return ret;
   }
   str = str2;
@@ -148,7 +158,8 @@ int getint(string& str, const int if_empty=0)
 string getword(string &str, const char *if_empty /*=nullptr*/, char sep /*=' '*/)
 {
   char quote = (str[0] == '"' or str[0] == '\'' ? str[0] : 0);
-  if (quote) str.erase(0,1);
+  if (quote)
+    str.erase(0, 1);
   string sword;
   while (str.length() and (str[0] != sep or quote))
   {
@@ -160,8 +171,10 @@ string getword(string& str, const char* if_empty/*=nullptr*/, char sep/*=' '*/)
     sword += str[0];
     str.erase(0, 1);
   }
-  while(str[0]==sep) str.erase(0,1);
-  if (if_empty and sword.length()==0) return if_empty;
+  while (str[0] == sep)
+    str.erase(0, 1);
+  if (if_empty and sword.length() == 0)
+    return if_empty;
   if (quote == false and sword.length() >= 4 and sword.substr(0, 3) == "rnd")
   {
     sword.erase(0, 3);
@@ -174,7 +187,8 @@ string getword(string& str, const char* if_empty/*=nullptr*/, char sep/*=' '*/)
       {
         sword.erase(0, 1);
         to = getint(sword);
-        if (sword[0]!=')') Console << "Missing ')'" << endl;
+        if (sword[0] != ')')
+          Console << "Missing ')'" << endl;
       }
       else
       {
@@ -188,15 +202,18 @@ string getword(string& str, const char* if_empty/*=nullptr*/, char sep/*=' '*/)
       Console << "Missing '('" << endl;
     }
   }
-  while(str[0]==' ') str.erase(0,1);
+  while (str[0] == ' ')
+    str.erase(0, 1);
   return sword;
 }
 
 bool isaddr(string s)
 {
-  if (s.length()==0 or s.length()>3) return false;
+  if (s.length() == 0 or s.length() > 3)
+    return false;
   for (char c : s)
-    if (c<'0' or c>'9') return false;
+    if (c < '0' or c > '9')
+      return false;
   return true;
 }
 
@@ -225,7 +242,8 @@ string getip(string& str, const char* if_empty=nullptr, char sep=' ')
   }
   for (string s : build)
   {
-    if (addr.length()) addr += '.';
+    if (addr.length())
+      addr += '.';
     addr += s;
   }
   Console << "connect address: " << addr << endl;
@@ -238,20 +256,22 @@ std::set<string> commands = {
     "broker", "blink", "client", "connect",
     "create", "delete", "debug", "help", "interval",
     "list", "ls", "ip", "off", "on", "set",
-  "publish", "reset", "subscribe", "unsubscribe", "view", "echo", "every"
-};
+    "publish", "reset", "subscribe", "unsubscribe", "view", "echo", "every"};
 
 void convertToCommand(string &search)
 {
-  while(search[0]==' ') search.erase(0,1);
-  if (search.length()==0) return;
+  while (search[0] == ' ')
+    search.erase(0, 1);
+  if (search.length() == 0)
+    return;
   string matches;
   int count = 0;
   for (string cmd : commands)
   {
     if (cmd.substr(0, search.length()) == search)
     {
-      if (count) matches +=", ";
+      if (count)
+        matches += ", ";
       count++;
       matches += cmd;
     }
@@ -295,7 +315,6 @@ void replaceVars(string& cmd)
   }
   cmd.erase(0, cmd.find_first_not_of(' '));
   cmd.erase(cmd.find_last_not_of(' ') + 1);
-
 }
 
 bool compare(string s, const char *cmd)
@@ -303,8 +322,10 @@ bool compare(string s, const char* cmd)
   uint8_t p = 0;
   while (s[p++] == *cmd++)
   {
-    if (*cmd==0 or s[p]==0) return true;
-    if (s[p]==' ') return true;
+    if (*cmd == 0 or s[p] == 0)
+      return true;
+    if (s[p] == ' ')
+      return true;
   }
   return false;
 }
@@ -347,10 +368,10 @@ void onCommand(const string& command)
 {
   Console << endl;
   string cmd = command;
-  if (cmd.substr(0,3)!="set") replaceVars(cmd);
+  if (cmd.substr(0, 3) != "set")
+    replaceVars(cmd);
   eval(cmd);
   Console << endl;
-  Console.prompt();
 }
 
 void clientConnect(MqttClient *client, string &cmd)
@@ -406,9 +427,11 @@ void eval(string& cmd)
     }
 
     s = getword(cmd);
-    if (s.length()) convertToCommand(s);
+    if (s.length())
+      convertToCommand(s);
     if (s.length() == 0)
-    {}
+    {
+    }
     else if (compare(s, "debug"))
     {
 #if TINY_MQTT_DEBUG
@@ -445,7 +468,8 @@ void eval(string& cmd)
       {
         for (auto it : clients)
         {
-          if (it.second != client) continue;
+          if (it.second != client)
+            continue;
           Console << "deleted" << endl;
           delete (it.second);
           clients.erase(it.first);
@@ -457,7 +481,8 @@ void eval(string& cmd)
       {
         for (auto it : brokers)
         {
-          if (broker != it.second) continue;
+          if (broker != it.second)
+            continue;
           Console << "deleted" << endl;
           delete (it.second);
           brokers.erase(it.first);
@@ -677,7 +702,8 @@ void eval(string& cmd)
         if (s == "" or brokers.find(s) != brokers.end() or list.find(s) != list.end())
         {
           MqttBroker *broker = nullptr;
-          if (s.length()) broker = brokers[s];
+          if (s.length())
+            broker = brokers[s];
           MqttClient *client = new MqttClient(broker, id);
           clients[id] = client;
           client->setCallback(onPublish);
@@ -790,7 +816,8 @@ void eval(string& cmd)
     }
     else
     {
-      while(s[0]==' ') s.erase(0,1);
+      while (s[0] == ' ')
+        s.erase(0, 1);
       if (s.length())
         Console << "Unknown command (" << s.c_str() << ")" << endl;
     }
@@ -811,7 +838,8 @@ void loop()
 
   for (auto &every : everies)
   {
-    if (not every.active) continue;
+    if (not every.active)
+      continue;
     if (every.ms && every.cmd.length() && ms > every.next)
     {
       string cmd(every.cmd);
@@ -821,6 +849,7 @@ void loop()
       {
         every.next += every.ms;
         Console << yellow << "Underrun every #" << e << ", " << (ms - every.next) << "ms late" << endl;
+        Console.fg(white);
         every.underrun = ms + 5000;
       }
     }

library.json

@@ -6,7 +6,9 @@
         "type": "git",
         "url": "https://github.com/hsaturn/TinyMqtt.git"
     },
-    "version": "0.9.15",
+    "dependencies":
+    { "hsaturn/TinyConsole" : "*" },
+    "version": "0.9.19",
     "exclude": "",
     "examples": "examples/*/*.ino",
     "frameworks": "arduino",

library.json.skeleton

@@ -6,6 +6,8 @@
         "type": "git",
         "url": "https://github.com/hsaturn/TinyMqtt.git"
     },
+    "dependencies":
+    { #dependencies },
     "version": "#version",
     "exclude": "",
     "examples": "examples/*/*.ino",

library.properties

@@ -1,5 +1,5 @@
 name=TinyMqtt
-version=0.9.16
+version=0.9.19
 author=Francois BIOT, HSaturn, <hsaturn@gmail.com>
 maintainer=Francois BIOT <hsaturn@gmail.com>
 sentence=A tiny broker and client library for MQTT messaging.
@@ -7,5 +7,5 @@ paragraph=MQTT is a lightweight messaging protocol. This library allows to host
 category=Communication
 url=https://github.com/hsaturn/TinyMqtt
 architectures=*
-depends=TinyConsole
+depends=hsaturn/TinyConsole
 includes=TinyMqtt.h

src/StringIndexer.h

@@ -107,6 +107,8 @@ class IndexedString
       index = source.index;
     }
 
+    IndexedString(IndexedString&& i) : index(i.index) {}
+
     IndexedString(const char* str, uint8_t len)
     {
       index=StringIndexer::strToIndex(str, len);

src/TinyMqtt.cpp

@@ -15,8 +15,10 @@ int TinyMqtt::debug=2;
   std::map<MqttMessage::Type, int> MqttClient::counters;
 #endif
 
-MqttBroker::MqttBroker(uint16_t port)
+MqttBroker::MqttBroker(uint16_t port, uint8_t max_retain_size)
 {
+  debug("New broker" << port);
+  retain_size = max_retain_size;
   server = new TcpServer(port);
 #ifdef TINY_MQTT_ASYNC
   server->onClient(onClient, this);
@@ -116,7 +118,7 @@ void MqttClient::connect(string broker, uint16_t port, uint16_t ka)
 #ifdef TINY_MQTT_ASYNC
   tcp_client->onData(onData, this);
   tcp_client->onConnect(onConnect, this);
-  tcp_client->connect(broker.c_str(), port, ka);
+  tcp_client->connect(broker.c_str(), port);
 #else
   if (tcp_client->connect(broker.c_str(), port))
   {
@@ -142,6 +144,7 @@ void MqttBroker::connect(const string& host, uint16_t port)
   if (remote_broker == nullptr) remote_broker = new MqttClient;
   remote_broker->connect(host, port);
   remote_broker->local_broker = this;  // Because connect removed the link
+  // TODO shouldn't we resubscribe to all client subscriptions ?
 }
 
 void MqttBroker::removeClient(MqttClient* remove)
@@ -211,9 +214,19 @@ void MqttBroker::loop()
   }
 }
 
-MqttError MqttBroker::subscribe(const Topic& topic, uint8_t qos)
+// Obvioulsy called when the broker is connected to another broker.
+MqttError MqttBroker::subscribe(MqttClient* client, const Topic& topic, uint8_t qos)
 {
-  debug("MqttBroker::subscribe");
+  debug("MqttBroker::subscribe to " << topic.str() << ", retained=" << retained.size() );
+  for(auto& [retained_topic, retain]: retained)
+  {
+    debug("  retained: " << retained_topic.str());
+    if (topic.matches(retained_topic))
+    {
+      debug("  -> sending");
+      client->publishIfSubscribed(retained_topic, retain.msg);
+    }
+  }
   if (remote_broker && remote_broker->connected())
   {
     return remote_broker->subscribe(topic, qos);
@@ -221,10 +234,12 @@ MqttError MqttBroker::subscribe(const Topic& topic, uint8_t qos)
   return MqttNowhereToSend;
 }
 
-MqttError MqttBroker::publish(const MqttClient* source, const Topic& topic, MqttMessage& msg) const
+MqttError MqttBroker::publish(const MqttClient* source, const Topic& topic, MqttMessage& msg)
 {
   MqttError retval = MqttOk;
 
+  retain(topic, msg);
+
   debug("MqttBroker::publish");
   int i=0;
   for(auto client: clients)
@@ -294,25 +309,26 @@ void MqttClient::clientAlive(uint32_t more_seconds)
 
 void MqttClient::loop()
 {
-  if (keep_alive && (millis() >= alive))
+  if (keep_alive && (millis() >= alive - 5000))
   {
-    if (local_broker)
-    {
-      debug(red << "timeout client");
-      close();
-      debug(red << "closed");
-    }
-    else if (tcp_client && tcp_client->connected())
+    if (tcp_client && tcp_client->connected())
     {
       debug("pingreq");
-      uint16_t pingreq = MqttMessage::Type::PingReq;
-      tcp_client->write((const char*)(&pingreq), 2);
+      static MqttMessage pingreq(MqttMessage::Type::PingReq);
+      pingreq.sendTo(this);
       clientAlive(0);
 
       // TODO when many MqttClient passes through a local broker
       // there is no need to send one PingReq per instance.
     }
+    else if (local_broker)
+    {
+      debug(red << "timeout client");
+      close();
+      debug(red << "closed");
     }
+  }
+
 #ifndef TINY_MQTT_ASYNC
   while(tcp_client && tcp_client->available()>0)
   {
@@ -391,13 +407,13 @@ MqttError MqttClient::subscribe(Topic topic, uint8_t qos)
 
   subscriptions.insert(topic);
 
-  if (local_broker==nullptr) // remote broker
+  if (local_broker==nullptr) // connected to a remote broker
   {
     return sendTopic(topic, MqttMessage::Type::Subscribe, qos);
   }
   else
   {
-    return local_broker->subscribe(topic, qos);
+    return local_broker->subscribe(this, topic, qos);
   }
   return ret;
 }
@@ -568,7 +584,7 @@ void MqttClient::processMessage(MqttMessage* mesg)
             }
             else
               qoss.push_back(qos);
-            subscriptions.insert(topic);
+            subscribe(topic);
           }
           else
           {
@@ -618,13 +634,13 @@ void MqttClient::processMessage(MqttMessage* mesg)
           #if TINY_MQTT_DEBUG
             if (TinyMqtt::debug >= 2)
             {
-              Console << (isSubscribedTo(published) ? "not" : "") << " subscribed.\n";
-              Console << "has " << (callback ? "" : "no ") << " callback.\n";
+              Console << (isSubscribedTo(published) ? "not" : "") << " subscribed.\r\n";
+              Console << "has " << (callback ? "" : "no ") << " callback.\r\n";
             }
           #endif
           if (callback and isSubscribedTo(published))
           {
-            callback(this, published, payload, len);  // TODO send the real payload
+            callback(this, published, payload, len);
           }
         }
         else if (local_broker) // from outside to inside
@@ -728,9 +744,9 @@ bool Topic::matches(const Topic& topic) const
 
 
 // publish from local client
-MqttError MqttClient::publish(const Topic& topic, const char* payload, size_t pay_length)
+MqttError MqttClient::publish(const Topic& topic, const char* payload, size_t pay_length, bool retain)
 {
-  MqttMessage msg(MqttMessage::Publish);
+  MqttMessage msg(MqttMessage::Publish, retain ? 1 : 0);
   msg.add(topic);
   msg.add(payload, pay_length, false);
   msg.complete();
@@ -894,6 +910,35 @@ MqttError MqttMessage::sendTo(MqttClient* client)
   return MqttOk;
 }
 
+void MqttBroker::retainDrop()
+{
+  if (retained.size() >= retain_size)
+  {
+    std::map<Topic, Retain>::iterator oldest = retained.begin();
+    auto it = oldest;
+    while(++it != retained.end())
+    {
+      if (oldest->second.timestamp > it->second.timestamp)
+        oldest = it;
+    }
+    retained.erase(oldest);
+  }
+}
+
+void MqttBroker::retain(const Topic& topic, const MqttMessage& msg)
+{
+  debug("MqttBroker::retain msg_type=" << _HEX(msg.type()));
+  if (retain_size==0 or msg.type() != MqttMessage::Publish) return;
+  if (msg.flags() & 1)  // flag RETAIN
+  {
+    debug("  retaining " << topic.str());
+    if (retained.find(topic) == retained.end()) retainDrop();
+    // FIXME if payload size == 0 remove message from retained
+    Retain r(micros(), msg);
+    retained.insert({ topic, std::move(r)});
+  }
+}
+
 void MqttMessage::hexdump(const char* prefix) const
 {
   (void)prefix;

src/TinyMqtt.h

@@ -121,7 +121,10 @@ class MqttMessage
       return (*bun << 8) | bun[1]; }
 
     MqttMessage() { reset(); }
-    MqttMessage(Type t, uint8_t bits_d3_d0=0) { create(t); buffer[0] |= bits_d3_d0; }
+    MqttMessage(Type t, uint8_t bits_d3_d0=0) { create(t); buffer[0] |= (bits_d3_d0 & 0xF); }
+    MqttMessage(const MqttMessage& m)
+      : buffer(m.buffer), vheader(m.vheader), size(m.size), state(m.state) {}
+
     void incoming(char byte);
     void add(char byte) { incoming(byte); }
     void add(const char* p, size_t len, bool addLength=true );
@@ -156,6 +159,15 @@ class MqttMessage
     MqttError sendTo(MqttClient*);
     void hexdump(const char* prefix=nullptr) const;
 
+    MqttMessage& operator = (MqttMessage&& m)
+    {
+      buffer = std::move(m.buffer);
+      vheader = m.vheader;
+      size = m.size;
+      state = m.state;
+      return *this;
+    }
+
   private:
     void encodeLength();
 
@@ -198,6 +210,8 @@ class MqttClient
 
     void connect(MqttBroker* local_broker);
     void connect(string broker, uint16_t port, uint16_t keep_alive = 10);
+    void connect(const IPAddress& ip, uint16_t port, uint16_t keep_alive = 10)
+    { connect(ip.toString().c_str(), port, keep_alive); }
 
     // TODO it seems that connected returns true in tcp mode even if
     // no negociation occurred
@@ -228,11 +242,11 @@ class MqttClient
     };
 
     // Publish from client to the world
-    MqttError publish(const Topic&, const char* payload, size_t pay_length);
-    MqttError publish(const Topic& t, const char* payload) { return publish(t, payload, strlen(payload)); }
-    MqttError publish(const Topic& t, const String& s) { return publish(t, s.c_str(), s.length()); }
-    MqttError publish(const Topic& t, const string& s) { return publish(t,s.c_str(),s.length());}
-    MqttError publish(const Topic& t) { return publish(t, nullptr, 0);};
+    MqttError publish(const Topic&, const char* payload, size_t pay_length, bool retain=false);
+    MqttError publish(const Topic& t, const char* payload, bool retain=false) { return publish(t, payload, strlen(payload), retain); }
+    MqttError publish(const Topic& t, const String& s, bool retain=false) { return publish(t, s.c_str(), s.length(), retain); }
+    MqttError publish(const Topic& t, const string& s, bool retain=false) { return publish(t,s.c_str(),s.length(), retain);}
+    MqttError publish(const Topic& t, bool retain=false) { return publish(t, nullptr, 0, retain);};
 
     MqttError subscribe(Topic topic, uint8_t qos=0);
     MqttError unsubscribe(Topic topic);
@@ -317,15 +331,9 @@ class MqttClient
 
 class MqttBroker
 {
-  enum __attribute__((packed)) State
-  {
-    Disconnected,  // Also the initial state
-    Connecting,    // connect and sends a fake publish to avoid circular cnx
-    Connected,     // this->broker is connected and circular cnx avoided
-  };
   public:
     // TODO limit max number of clients
-    MqttBroker(uint16_t port);
+    MqttBroker(uint16_t port, uint8_t retain_size=0);
     ~MqttBroker();
 
     void begin() { server->begin(); }
@@ -334,9 +342,10 @@ class MqttBroker
     /** Connect the broker to a parent broker */
     void connect(const string& host, uint16_t port=1883);
     /** returns true if connected to another broker */
-    bool connected() const { return state == Connected; }
+    bool connected() const { return remote_broker ? remote_broker->connected() : false; }
 
     size_t clientsCount() const { return clients.size(); }
+    void retain(uint8_t size) { retain_size = size; }
 
     void dump(string indent="")
     {
@@ -356,10 +365,9 @@ class MqttBroker
     bool checkPassword(const char* password, uint8_t len) const
     { return compareString(auth_password, password, len); }
 
+    MqttError publish(const MqttClient* source, const Topic& topic, MqttMessage& msg);
 
-    MqttError publish(const MqttClient* source, const Topic& topic, MqttMessage& msg) const;
-
-    MqttError subscribe(const Topic& topic, uint8_t qos);
+    MqttError subscribe(MqttClient*, const Topic& topic, uint8_t qos);
 
     // For clients that are added not by the broker itself (local clients)
     void addClient(MqttClient* client);
@@ -375,5 +383,25 @@ class MqttBroker
     const char* auth_password = "guest";
     MqttClient* remote_broker = nullptr;
 
-    State state = Disconnected;
+    void retain(const Topic& topic, const MqttMessage& msg);
+    void retainDrop();
+
+    struct Retain
+    {
+      Retain(unsigned long ts, const MqttMessage& m) : timestamp(ts), msg(m) {}
+      Retain(Retain&& r) : timestamp(r.timestamp), msg(std::move(r.msg)) {}
+
+      Retain& operator=(Retain&& r)
+      {
+        timestamp = r.timestamp;
+        msg = std::move(r.msg);
+        return *this;
+      }
+
+      unsigned long timestamp;
+      MqttMessage msg;
+    };
+
+    std::map<Topic, Retain> retained;
+    uint8_t retain_size;
 };

tests/Makefile.opts

@@ -1,7 +1,7 @@
 
 # GCC
 # CXXFLAGS = -Wextra -Wall -std=gnu++11 -fno-exceptions -fno-threadsafe-statics
-EXTRA_CXXFLAGS=-g3 -O0
+EXTRA_CXXFLAGS=-g3 -O0 -std=c++17
 
 CXXFLAGS=-D_GNU_SOURCE -Werror=return-type -std=gnu++17 -Wall -g3 -O0
 

tests/local-tests/local-tests.ino

@@ -18,14 +18,14 @@ MqttBroker broker(1883);
 
 std::map<string, std::map<Topic, int>>  published;    // map[client_id] => map[topic] = count
 
-const char* lastPayload;
+std::string lastPayload;
 size_t lastLength;
 
 void onPublish(const MqttClient* srce, const Topic& topic, const char* payload, size_t length)
 {
   if (srce)
     published[srce->id()][topic]++;
-  lastPayload = payload;
+  lastPayload = std::string(payload, length);
   lastLength = length;
 }
 
@@ -51,6 +51,7 @@ test(local_client_should_unregister_when_destroyed)
 
 test(local_client_do_not_disconnect_after_publishing_and_long_inactivity)
 {
+  published.clear();
   EpoxyTest::set_millis(0);
   MqttBroker broker(1883);
   MqttClient client(&broker, "client");
@@ -121,6 +122,25 @@ test(local_publish_should_be_dispatched)
   assertEqual(published[""]["a/c"], 2);
 }
 
+test(hudge_payload)
+{
+  published.clear();
+  const char* payload="This payload is hudge, just because its length exceeds 127. Thus when encoding length, we have to encode it on two bytes at min. This should not prevent the message from being encoded and decoded successfully !";
+
+  MqttClient subscriber(&broker);
+  assertEqual(broker.clientsCount(), (size_t)1);
+  subscriber.setCallback(onPublish);
+  subscriber.subscribe("a/b");          // Note -> this does not send any byte .... (nowhere to send)
+
+  MqttClient publisher(&broker);
+  publisher.publish("a/b", payload);    // This publish is received
+
+  // onPublish should have filled lastPayload and lastLength
+  assertEqual(payload, lastPayload.c_str());
+  assertEqual(lastLength, strlen(payload));
+  assertEqual(strncmp(payload, lastPayload.c_str(), lastLength), 0);
+}
+
 test(local_publish_should_be_dispatched_to_local_clients)
 {
   published.clear();

tests/network-tests/network-tests.ino

@@ -85,7 +85,7 @@ std::map<string, std::map<Topic, int>>  published;    // map[client_id] => map[t
 char* lastPayload = nullptr;
 size_t lastLength;
 
-void start_servers(int n, bool early_accept = true)
+void start_many_wifi_esp(int n, bool early_accept = true)
 {
     ESP8266WiFiClass::resetInstances();
     ESP8266WiFiClass::earlyAccept = early_accept;
@@ -107,7 +107,7 @@ void onPublish(const MqttClient* srce, const Topic& topic, const char* payload,
   lastLength = length;
 }
 
-test(network_single_broker_begin)
+test(single_broker_begin)
 {
   assertEqual(WiFi.status(), WL_CONNECTED);
 
@@ -119,7 +119,7 @@ test(network_single_broker_begin)
 
 test(suback)
 {
-  start_servers(2, true);
+  start_many_wifi_esp(2, true);
   assertEqual(WiFi.status(), WL_CONNECTED);
 
   MqttBroker broker(1883);
@@ -144,10 +144,10 @@ test(suback)
   assertEqual(MqttClient::counters[MqttMessage::Type::SubAck], 1);
 }
 
-test(network_client_keep_alive_high)
+test(client_keep_alive_high)
 {
   const uint32_t keep_alive=1000;
-  start_servers(2, true);
+  start_many_wifi_esp(2, true);
   assertEqual(WiFi.status(), WL_CONNECTED);
 
   MqttBroker broker(1883);
@@ -179,9 +179,116 @@ test(network_client_keep_alive_high)
 
 }
 
-test(network_client_to_broker_connexion)
+test(retained_message)
 {
-  start_servers(2, true);
+  published.clear();
+
+  start_many_wifi_esp(2, true);
+  assertEqual(WiFi.status(), WL_CONNECTED);
+
+  MqttBroker broker(1883);
+  broker.begin();
+  broker.retain(10);
+  IPAddress broker_ip = WiFi.localIP();
+
+  MqttClient local_client(&broker);
+
+  // Send a retained message
+  // No remote client connected
+  local_client.publish("topic", "retained", true);
+
+  for(int i=0; i<2; i++)
+  {
+    broker.loop();
+    local_client.loop();
+  };
+
+  // No connect a client from 2nd Esp
+  ESP8266WiFiClass::selectInstance(2);
+  MqttClient remote_client;
+  remote_client.connect(broker_ip, 1883);
+  remote_client.setCallback(onPublish);
+
+  assertTrue(remote_client.connected());
+  for(int i=0; i<4; i++) { broker.loop(); local_client.loop(); remote_client.loop(); };
+  assertEqual(broker.clientsCount(), (size_t) 2);
+
+  // Should not have received anything yet
+  assertEqual(published.size(), (size_t)0);
+
+  // Now, remote client subscribes to topic
+  remote_client.subscribe("topic");
+  for(int i=0; i<4; i++) { broker.loop(); local_client.loop(); remote_client.loop(); };
+
+  // Check that the retained message is published
+  assertEqual(published.size(), (size_t)1);
+
+  // FIXME we should check that
+  // 1 - Retained message has the retain flag set
+  // 2 - Published retained messages that are send normally have their retain flag off
+
+  // The next part of this test does not pass yet (due to remote_client.close()
+  // that does not work well.
+  return;
+
+  // Now remove the retained message
+  remote_client.close();
+  for(int i=0; i<4; i++) { broker.loop(); local_client.loop(); remote_client.loop(); };
+  assertFalse(remote_client.connected());
+  assertEqual(broker.clientsCount(), (size_t) 1);
+
+  // Disconnect / reconnect the remote clien that should receive again the message
+  remote_client.connect(broker_ip, 1883);
+  remote_client.subscribe("topic");
+  assertTrue(remote_client.connected());
+  for(int i=0; i<4; i++) { broker.loop(); local_client.loop(); remote_client.loop(); };
+  assertEqual(broker.clientsCount(), (size_t) 2);
+  assertEqual(published.size(), (size_t)2);
+
+  // Remove the retained message now
+  local_client.publish("topic", "", true);
+  assertEqual(published.size(), (size_t)1);
+
+  // And reconnect the remote client
+  remote_client.connect(broker_ip, 1883);
+  for(int i=0; i<4; i++) { broker.loop(); local_client.loop(); remote_client.loop(); };
+  assertEqual(broker.clientsCount(), (size_t) 2);
+
+  // check that the message was received
+  assertEqual(published.size(), (size_t)2);
+}
+
+test(remote_client_disconnect_reconnect)
+{
+  published.clear();
+  start_many_wifi_esp(2, true);
+  assertEqual(WiFi.status(), WL_CONNECTED);
+
+  MqttBroker broker(1883);
+  broker.begin();
+  IPAddress broker_ip = WiFi.localIP();
+
+  ESP8266WiFiClass::selectInstance(2);
+  MqttClient client;
+  client.connect(broker_ip, 1883);
+
+  for(int i=0; i<4; i++) { broker.loop(); client.loop(); };
+  assertEqual(broker.clientsCount(), (size_t) 1);
+
+  // Disconnect the client
+  client.close();
+  for(int i=0; i<4; i++) { broker.loop(); client.loop(); };
+  assertEqual(broker.clientsCount(), (size_t) 0);
+
+  // Reconnect the client
+  client.connect(broker_ip, 1883);
+  for(int i=0; i<4; i++) { broker.loop(); client.loop(); };
+  assertEqual(broker.clientsCount(), (size_t) 1);
+}
+
+test(client_to_broker_connexion)
+{
+  start_many_wifi_esp(2, true);
   assertEqual(WiFi.status(), WL_CONNECTED);
 
   MqttBroker broker(1883);
@@ -197,9 +304,9 @@ test(network_client_to_broker_connexion)
   assertTrue(client.connected());
 }
 
-test(network_one_client_one_broker_publish_and_subscribe_through_network)
+test(one_client_one_broker_publish_and_subscribe)
 {
-  start_servers(2, true);
+  start_many_wifi_esp(2, true);
   published.clear();
   assertEqual(WiFi.status(), WL_CONNECTED);
 
@@ -228,9 +335,9 @@ test(network_one_client_one_broker_publish_and_subscribe_through_network)
   assertEqual((int)lastLength, (int)2); // sizeof(ab)
 }
 
-test(network_one_client_one_broker_hudge_publish_and_subscribe_through_network)
+test(one_client_one_broker_hudge_payload)
 {
-  start_servers(2, true);
+  start_many_wifi_esp(2, true);
   published.clear();
   assertEqual(WiFi.status(), WL_CONNECTED);
 
@@ -247,8 +354,8 @@ test(network_one_client_one_broker_hudge_publish_and_subscribe_through_network)
 
   std::string sent;
 
-  for(int i=0; i<200; i++)
-    sent += char('0'+i%10);
+  for(int i=0; i<400; i++)
+    sent += char('a'+i%26);
 
   client.setCallback(onPublish);
   client.subscribe("a/b");
@@ -264,7 +371,7 @@ test(network_one_client_one_broker_hudge_publish_and_subscribe_through_network)
   assertEqual((unsigned int)lastLength, (unsigned int)sent.size());
 }
 
-test(network_client_should_unregister_when_destroyed)
+test(client_should_unregister_when_destroyed)
 {
   assertEqual(broker.clientsCount(), (size_t)0);
   {
@@ -278,7 +385,7 @@ test(network_client_should_unregister_when_destroyed)
 // THESE TESTS ARE IN LOCAL MODE
 // WE HAVE TO CONVERT THEM TO WIFI MODE (pass through virtual TCP link)
 
-test(network_connect)
+test(connect)
 {
   assertEqual(broker.clientsCount(), (size_t)0);
 
@@ -287,7 +394,7 @@ test(network_connect)
   assertEqual(broker.clientsCount(), (size_t)1);
 }
 
-test(network_publish_should_be_dispatched)
+test(publish_should_be_dispatched)
 {
   published.clear();
   assertEqual(broker.clientsCount(), (size_t)0);
@@ -307,7 +414,7 @@ test(network_publish_should_be_dispatched)
   assertEqual(published[TINY_MQTT_DEFAULT_CLIENT_ID]["a/c"], 2);
 }
 
-test(network_publish_should_be_dispatched_to_clients)
+test(publish_should_be_dispatched_to_clients)
 {
   published.clear();
   assertEqual(broker.clientsCount(), (size_t)0);
@@ -332,7 +439,7 @@ test(network_publish_should_be_dispatched_to_clients)
   assertEqual(published["B"]["a/c"], 0);
 }
 
-test(network_unsubscribe)
+test(unsubscribe)
 {
   published.clear();
   assertEqual(broker.clientsCount(), (size_t)0);
@@ -352,7 +459,7 @@ test(network_unsubscribe)
   assertEqual(published[TINY_MQTT_DEFAULT_CLIENT_ID]["a/b"], 1);  // Only one publish has been received
 }
 
-test(network_nocallback_when_destroyed)
+test(nocallback_when_destroyed)
 {
   published.clear();
   assertEqual(broker.clientsCount(), (size_t)0);
@@ -371,7 +478,7 @@ test(network_nocallback_when_destroyed)
   assertEqual(published.size(), (size_t)1);  // Only one publish has been received
 }
 
-test(network_small_payload)
+test(small_payload)
 {
   published.clear();
 
@@ -389,7 +496,7 @@ test(network_small_payload)
   assertEqual(lastLength, (size_t)4);
 }
 
-test(network_hudge_payload)
+test(hudge_payload)
 {
   const char* payload="This payload is hudge, just because its length exceeds 127. Thus when encoding length, we have to encode it on two bytes at min. This should not prevent the message from being encoded and decoded successfully !";
 
@@ -436,7 +543,7 @@ test(connack)
     }
   );
 
-  start_servers(2, true);
+  start_many_wifi_esp(2, true);
   assertEqual(WiFi.status(), WL_CONNECTED);
 
   MqttBroker broker(1883);
@@ -469,7 +576,7 @@ void setup() {
   while(!Serial);
   */
 
-  Serial.println("=============[ FAKE NETWORK TinyMqtt TESTS       ]========================");
+  Serial.println("=============[ NETWORK TinyMqtt TESTS       ]========================");
 
   WiFi.mode(WIFI_STA);
   WiFi.begin("network", "password");