LoRa support (#48)

Author: mirkokurt

ArduinoCloudProperty.cpp

@@ -47,7 +47,10 @@ ArduinoCloudProperty::ArduinoCloudProperty()
       _update_interval_millis(0),
       _last_local_change_timestamp(0),
       _last_cloud_change_timestamp(0),
-      _map_data_list(nullptr) {
+      _map_data_list(nullptr),
+      _identifier(0),
+      _attributeIdentifier(0),
+      _lightPayload(false) {
 }
 
 /******************************************************************************
@@ -115,7 +118,9 @@ void ArduinoCloudProperty::execCallbackOnSync() {
   }
 }
 
-void ArduinoCloudProperty::append(CborEncoder *encoder) {
+void ArduinoCloudProperty::append(CborEncoder *encoder, bool lightPayload) {
+  _lightPayload = lightPayload;
+  _attributeIdentifier = 0;
   appendAttributesToCloudReal(encoder);
   fromLocalToCloud();
   _has_been_updated_once = true;
@@ -151,20 +156,35 @@ void ArduinoCloudProperty::appendAttributeReal(String value, String attributeNam
 }
 
 void ArduinoCloudProperty::appendAttributeName(String attributeName, std::function<void (CborEncoder& mapEncoder)>appendValue, CborEncoder *encoder) {
+  if (attributeName != "") {
+    // when the attribute name string is not empty, the attribute identifier is incremented in order to be encoded in the message if the _lightPayload flag is set
+    _attributeIdentifier++;
+  }
   CborEncoder mapEncoder;
   cbor_encoder_create_map(encoder, &mapEncoder, 2);
   cbor_encode_int(&mapEncoder, static_cast<int>(CborIntegerMapKey::Name));
-  String completeName = _name;
-  if (attributeName != "") {
-    completeName += ":" + attributeName;
+
+  // if _lightPayload is true, the property and attribute identifiers will be encoded instead of the property name
+  if (_lightPayload) {
+    // the most significant byte of the identifier to be encoded represent the property identifier
+    int completeIdentifier = _attributeIdentifier * 256;
+    // the least significant byte of the identifier to be encoded represent the attribute identifier
+    completeIdentifier += _identifier;
+    cbor_encode_int(&mapEncoder, completeIdentifier);
+  } else {
+    String completeName = _name;
+    if (attributeName != "") {
+      completeName += ":" + attributeName;
+    }
+    cbor_encode_text_stringz(&mapEncoder, completeName.c_str());
   }
-  cbor_encode_text_stringz(&mapEncoder, completeName.c_str());
   appendValue(mapEncoder);
   cbor_encoder_close_container(encoder, &mapEncoder);
 }
 
 void ArduinoCloudProperty::setAttributesFromCloud(LinkedList<CborMapData *> *map_data_list) {
   _map_data_list = map_data_list;
+  _attributeIdentifier = 0;
   setAttributesFromCloud();
 }
 
@@ -204,16 +224,30 @@ void ArduinoCloudProperty::setAttributeReal(String& value, String attributeName)
 }
 
 void ArduinoCloudProperty::setAttributeReal(String attributeName, std::function<void (CborMapData *md)>setValue) {
+  if (attributeName != "") {
+    _attributeIdentifier++;
+  }
   for (int i = 0; i < _map_data_list->size(); i++) {
     CborMapData *map = _map_data_list->get(i);
     if (map != nullptr) {
-      String an = map->attribute_name.get();
-      if (an == attributeName) {
-        setValue(map);
-        break;
+      if (map->light_payload.isSet() && map->light_payload.get()) {
+        // if a light payload is detected, the attribute identifier is retrieved from the cbor map and the corresponding attribute is updated
+        int attid = map->attribute_identifier.get();
+        if (attid == _attributeIdentifier) {
+          setValue(map);
+          break;
+        }
+      } else {
+        // if a normal payload is detected, the name of the attribute to be updated is extracted directly from the cbor map
+        String an = map->attribute_name.get();
+        if (an == attributeName) {
+          setValue(map);
+          break;
+        }
       }
     }
   }
+
 }
 
 String ArduinoCloudProperty::getAttributeName(String propertyName, char separator) {
@@ -244,3 +278,7 @@ unsigned long ArduinoCloudProperty::getLastCloudChangeTimestamp() {
 unsigned long ArduinoCloudProperty::getLastLocalChangeTimestamp() {
   return _last_local_change_timestamp;
 }
+
+void ArduinoCloudProperty::setIdentifier(int identifier) {
+  _identifier = identifier;
+}

ArduinoCloudProperty.h

@@ -98,7 +98,11 @@ class CborMapData {
     MapEntry<String> base_name;
     MapEntry<double> base_time;
     MapEntry<String> name;
+    MapEntry<int>    name_identifier;
+    MapEntry<bool>   light_payload;
     MapEntry<String> attribute_name;
+    MapEntry<int>    attribute_identifier;
+    MapEntry<int>    property_identifier;
     MapEntry<float>  val;
     MapEntry<String> str_val;
     MapEntry<bool>   bool_val;
@@ -138,6 +142,9 @@ class ArduinoCloudProperty {
     inline String name() const {
       return _name;
     }
+    inline int identifier() const {
+      return _identifier;
+    }
     inline bool   isReadableByCloud() const {
       return (_permission == Permission::Read) || (_permission == Permission::ReadWrite);
     }
@@ -152,9 +159,10 @@ class ArduinoCloudProperty {
     void setLastLocalChangeTimestamp(unsigned long localChangeTime);
     unsigned long getLastCloudChangeTimestamp();
     unsigned long getLastLocalChangeTimestamp();
+    void setIdentifier(int identifier);
 
     void updateLocalTimestamp();
-    void append(CborEncoder * encoder);
+    void append(CborEncoder * encoder, bool lightPayload);
     void appendAttributeReal(bool value, String attributeName = "", CborEncoder *encoder = nullptr);
     void appendAttributeReal(int value, String attributeName = "", CborEncoder *encoder = nullptr);
     void appendAttributeReal(float value, String attributeName = "", CborEncoder *encoder = nullptr);
@@ -197,6 +205,11 @@ class ArduinoCloudProperty {
     unsigned long      _last_local_change_timestamp;
     unsigned long      _last_cloud_change_timestamp;
     LinkedList<CborMapData *> * _map_data_list;
+    /* Store the identifier of the property in the array list */
+    int                _identifier;
+    int                _attributeIdentifier;
+    /* Indicates if the property shall be encoded using the identifier instead of the name */
+    bool               _lightPayload;
 };
 
 /******************************************************************************

ArduinoCloudThing.cpp

@@ -45,6 +45,7 @@ void PrintFreeRam(void) {
 
 ArduinoCloudThing::ArduinoCloudThing() :
   _numPrimitivesProperties(0),
+  _numProperties(0),
   _isSyncMessage(false),
   _currentPropertyName(""),
   _currentPropertyBaseTime(0),
@@ -58,7 +59,8 @@ ArduinoCloudThing::ArduinoCloudThing() :
 void ArduinoCloudThing::begin() {
 }
 
-int ArduinoCloudThing::encode(uint8_t * data, size_t const size) {
+int ArduinoCloudThing::encode(uint8_t * data, size_t const size, bool lightPayload) {
+
   // check if backing storage and cloud has diverged
   // time interval may be elapsed or property may be changed
   CborEncoder encoder, arrayEncoder;
@@ -69,7 +71,7 @@ int ArduinoCloudThing::encode(uint8_t * data, size_t const size) {
     return -1;
   }
 
-  if (appendChangedProperties(&arrayEncoder) < 1) {
+  if (appendChangedProperties(&arrayEncoder, lightPayload) < 1) {
     return -1;
   }
 
@@ -84,17 +86,19 @@ int ArduinoCloudThing::encode(uint8_t * data, size_t const size) {
   return bytes_encoded;
 }
 
-ArduinoCloudProperty& ArduinoCloudThing::addPropertyReal(ArduinoCloudProperty & property, String const & name, Permission const permission) {
+ArduinoCloudProperty& ArduinoCloudThing::addPropertyReal(ArduinoCloudProperty & property, String const & name, Permission const permission, int propertyIdentifier) {
   property.init(name, permission);
   if (isPropertyInContainer(name)) {
     return (*getProperty(name));
   } else {
     if (property.isPrimitive()) {
       _numPrimitivesProperties++;
     }
-    addProperty(&property);
+    _numProperties++;
+    addProperty(&property, propertyIdentifier);
     return (property);
   }
+
 }
 
 void ArduinoCloudThing::decode(uint8_t const * const payload, size_t const length, bool isSyncMessage) {
@@ -158,18 +162,19 @@ bool ArduinoCloudThing::isPropertyInContainer(String const & name) {
   return false;
 }
 
-int ArduinoCloudThing::appendChangedProperties(CborEncoder * arrayEncoder) {
+int ArduinoCloudThing::appendChangedProperties(CborEncoder * arrayEncoder, bool lightPayload) {
   int appendedProperties = 0;
   for (int i = 0; i < _property_list.size(); i++) {
     ArduinoCloudProperty * p = _property_list.get(i);
     if (p->shouldBeUpdated() && p->isReadableByCloud()) {
-      p->append(arrayEncoder);
+      p->append(arrayEncoder, lightPayload);
       appendedProperties++;
     }
   }
   return appendedProperties;
 }
 
+//retrieve property by name
 ArduinoCloudProperty * ArduinoCloudThing::getProperty(String const & name) {
   for (int i = 0; i < _property_list.size(); i++) {
     ArduinoCloudProperty * p = _property_list.get(i);
@@ -180,6 +185,17 @@ ArduinoCloudProperty * ArduinoCloudThing::getProperty(String const & name) {
   return NULL;
 }
 
+//retrieve property by identifier
+ArduinoCloudProperty * ArduinoCloudThing::getProperty(int const & pos) {
+  for (int i = 0; i < _property_list.size(); i++) {
+    ArduinoCloudProperty * p = _property_list.get(i);
+    if (p->identifier() == pos) {
+      return p;
+    }
+  }
+  return NULL;
+}
+
 // this function updates the timestamps on the primitive properties that have been modified locally since last cloud synchronization
 void ArduinoCloudThing::updateTimestampOnLocallyChangedProperties() {
   if (_numPrimitivesProperties == 0) {
@@ -312,6 +328,7 @@ ArduinoCloudThing::MapParserState ArduinoCloudThing::handle_Name(CborValue * val
   MapParserState next_state = MapParserState::Error;
 
   if (cbor_value_is_text_string(value_iter)) {
+    // if the value in the cbor message is a string, it corresponds to the name of the property to be updated (int the form [property_name]:[attribute_name])
     char * val      = nullptr;
     size_t val_size = 0;
     if (cbor_value_dup_text_string(value_iter, &val, &val_size, value_iter) == CborNoError) {
@@ -326,8 +343,26 @@ ArduinoCloudThing::MapParserState ArduinoCloudThing::handle_Name(CborValue * val
       map_data->attribute_name.set(attribute_name);
       next_state = MapParserState::MapKey;
     }
+  } else if (cbor_value_is_integer(value_iter)) {
+    // if the value in the cbor message is an integer, a light payload has been used and an integer identifier should be decode in order to retrieve the corresponding property and attribute name to be updated
+    int val = 0;
+    if (cbor_value_get_int(value_iter, &val) == CborNoError) {
+      map_data->light_payload.set(true);
+      map_data->name_identifier.set(val & 255);
+      map_data->attribute_identifier.set(val >> 8);
+      map_data->light_payload.set(true);
+      String name = getPropertyNameByIdentifier(val);
+      map_data->name.set(name);
+
+
+      if (cbor_value_advance(value_iter) == CborNoError) {
+        next_state = MapParserState::MapKey;
+      }
+    }
   }
 
+
+
   return next_state;
 }
 
@@ -404,7 +439,6 @@ ArduinoCloudThing::MapParserState ArduinoCloudThing::handle_LeaveMap(CborValue *
     }
 
     if (_currentPropertyName != "" && propertyName != _currentPropertyName) {
-
       /* Update the property containers depending on the parsed data */
       updateProperty(_currentPropertyName, _currentPropertyBaseTime + _currentPropertyTime);
       /* Reset current property data */
@@ -461,6 +495,18 @@ void ArduinoCloudThing::updateProperty(String propertyName, unsigned long cloudC
     }
   }
 }
+
+// retrieve the property name by the identifier
+String ArduinoCloudThing::getPropertyNameByIdentifier(int propertyIdentifier) {
+  ArduinoCloudProperty* property;
+  if (propertyIdentifier > 255) {
+    property = getProperty(propertyIdentifier & 255);
+  } else {
+    property = getProperty(propertyIdentifier);
+  }
+  return property->name();
+}
+
 bool ArduinoCloudThing::ifNumericConvertToDouble(CborValue * value_iter, double * numeric_val) {
 
   if (cbor_value_is_integer(value_iter)) {

ArduinoCloudThing.h

@@ -77,23 +77,26 @@ class ArduinoCloudThing {
     ArduinoCloudThing();
 
     void begin();
-
-    ArduinoCloudProperty   & addPropertyReal(ArduinoCloudProperty   & property, String const & name, Permission const permission);
+    //if propertyIdentifier is different from -1, an integer identifier is associated to the added property to be use instead of the property name when the parameter lightPayload is true in the encode method
+    ArduinoCloudProperty   & addPropertyReal(ArduinoCloudProperty   & property, String const & name, Permission const permission, int propertyIdentifier = -1);
 
     /* encode return > 0 if a property has changed and encodes the changed properties in CBOR format into the provided buffer */
-    int encode(uint8_t * data, size_t const size);
+    /* if lightPayload is true the integer identifier of the property will be encoded in the message instead of the property name in order to reduce the size of the message payload*/
+    int encode(uint8_t * data, size_t const size, bool lightPayload = false);
     /* decode a CBOR payload received from the cloud */
     void decode(uint8_t const * const payload, size_t const length, bool isSyncMessage = false);
 
     bool isPropertyInContainer(String const & name);
-    int appendChangedProperties(CborEncoder * arrayEncoder);
+    int appendChangedProperties(CborEncoder * arrayEncoder, bool lightPayload);
     void updateTimestampOnLocallyChangedProperties();
     void updateProperty(String propertyName, unsigned long cloudChangeEventTime);
+    String getPropertyNameByIdentifier(int propertyIdentifier);
 
   private:
     LinkedList<ArduinoCloudProperty *>   _property_list;
     /* Keep track of the number of primitive properties in the Thing. If 0 it allows the early exit in updateTimestampOnLocallyChangedProperties() */
     int                                  _numPrimitivesProperties;
+    int                                  _numProperties;
     /* Indicates the if the message received to be decoded is a response to the getLastValues inquiry */
     bool                                 _isSyncMessage;
     /* List of map data that will hold all the attributes of a property */
@@ -135,11 +138,18 @@ class ArduinoCloudThing {
 
     static bool   ifNumericConvertToDouble(CborValue * value_iter, double * numeric_val);
     static double convertCborHalfFloatToDouble(uint16_t const half_val);
-    void freeMapDataList(LinkedList<CborMapData *> *map_data_list);
-    inline void addProperty(ArduinoCloudProperty   * property_obj) {
+    void freeMapDataList(LinkedList<CborMapData *> * map_data_list);
+    inline void addProperty(ArduinoCloudProperty   * property_obj, int propertyIdentifier) {
+      if (propertyIdentifier != -1) {
+        property_obj->setIdentifier(propertyIdentifier);
+      } else {
+        // if property identifier is -1, an incremental value will be assigned as identifier.
+        property_obj->setIdentifier(_numProperties);
+      }
       _property_list.add(property_obj);
     }
     ArduinoCloudProperty * getProperty(String const & name);
+    ArduinoCloudProperty * getProperty(int const & identifier);
 
 };
 

types/CloudLocation.h

@@ -83,7 +83,6 @@ class CloudLocation : public ArduinoCloudProperty {
       return _value;
     }
 
-
     virtual void fromCloudToLocal() {
       _value = _cloud_value;
     }