fixup! added Mqtt client Interface definition

Author: andreagilardoni

src/MqttInterface.h

@@ -8,28 +8,6 @@
 // namespace arduino { // namespace net { namespace mqtt {
 typedef int error_t; // TODO move this to be generally available
 
-class IStream {
-public:
-    virtual ~IStream() = default;
-
-    virtual int available() = 0;
-    virtual int read() = 0;
-    // virtual int peek() = 0;
-    virtual size_t readBytes(uint8_t *buffer, size_t length) = 0; // read chars from stream into buffer
-};
-
-class MqttOStream { // if OStream becomes available in arduino core api, we still need to extend its definition
-public:
-    MqttOStream(error_t rc=0): rc(rc) {}
-    virtual ~MqttOStream() = default;
-
-    virtual size_t write(uint8_t) = 0;
-    virtual size_t write(const uint8_t *buffer, size_t size) = 0;
-    virtual int availableForWrite() = 0;
-
-    const error_t rc;
-};
-
 using Topic = const char* const;
 
 #if defined(__has_include)
@@ -38,10 +16,10 @@ using Topic = const char* const;
         #include <functional>
 
         // for incoming published messages
-        using MqttReceiveCallback = std::function<void(Topic, IStream&)>;
+        using MqttReceiveCallback = std::function<void(Topic)>;
     #endif
 #else
-    typedef void(*MqttReceiveCallback)(Topic, IStream&)>;
+    typedef void(*MqttReceiveCallback)(Topic)>;
 #endif
 
 // TODO MQTT 5.0 stuff
@@ -112,16 +90,6 @@ class MqttClientInterface {
         size_t size, MqttQos qos = QosDefault,
         MqttPublishFlag flags = MqttPublishFlags::None) = 0;
 
-    /**
-     * Publish method for publishing messages in "streaming mode", meaning that
-     * they can outsize the available ram. The OStream returned handles the lifecycle of
-     * an mqtt Message, from the opening header to its termaination.
-     * The concrete OStream is defined by the implementation
-     */
-    virtual MqttOStream&& publish(
-        Topic t, MqttQos qos = QosDefault,
-        MqttPublishFlag flags = MqttPublishFlags::None) = 0;
-
     virtual error_t unsubscribe(Topic t) = 0;
     virtual void poll() = 0;
     virtual error_t ping() = 0;
@@ -145,4 +113,16 @@ class MqttClientInterface {
     // virtual void setClient(Client&) = 0;
     // Could this be a better solution?
     // virtual void setClient(Client&&) = 0;
+
+    virtual int read() = 0;
+    virtual int read(uint8_t payload[], size_t size) = 0;
+    virtual int available() = 0;
+
+    // The following methods should return the current rx message parameters.
+    // FIXME what if none?
+    virtual String messageTopic() const = 0;
+    virtual int messageDup()      const = 0;
+    virtual uint16_t messageId()  const = 0;
+    virtual MqttQos messageQoS()  const = 0;
+    virtual int messageRetain()   const = 0;
 };