Jira 859. Support BLE descriptor processing.

Feature added:

For Central mode, added the support for processing
BLE descriptor from a connected Peripheral.  Enable
the user sketch to access to descriptor value,
length info.

Code modifications:

1. peripheral_explorer.ino:
   - Example sketch with added descriptor processing.
2. BLECharacteristic.cpp:
   - Bug fixed in handling multi-descriptors.
3. BLEDescriptor.cpp:
   - For constructors, added initialization of
     descriptor storage and info.
   - For copy constructor and assignment, take into
     the account of descripter value and info.
   - Added API's for readning and returning descriptor
     info, eg. value, size.
4. BLEDescriptor.h:
   - Prototyping.
5. BLEDevice.h:
   - Added descriptor storage declaration.
6. BLECallbacks.cpp:
   - Added call back event for decriptor arrival.
7. BLECallbacks.h:
   - Prototyping.
8. BLECharacteristicImp.cpp:
   - The processing of the descriptor.
9. BLECharacteristicImp.h:
   - Prototyping.
10. BLEServiceImp.cpp:
   - Added descriptor info to constructor.
   - Made copy constructor to be aware of descriptor info.
11. BLEServiceImp.h:
   - Prototyping.

Author: sgbihu

libraries/CurieBLE/examples/central/peripheral_explorer/peripheral_explorer.ino

@@ -133,9 +133,30 @@ void exploreCharacteristic(BLECharacteristic characteristic) {
       printData(characteristic.value(), characteristic.valueLength());
     }
   }
-
   Serial.println();
 
+  // loop the descriptors of the characteristic and explore each
+  for (int i = 0; i < characteristic.descriptorCount(); i++) {
+    BLEDescriptor descriptor = characteristic.descriptor(i);
+
+    exploreDescriptor(descriptor);
+  }
+}
+
+void exploreDescriptor(BLEDescriptor descriptor) {
+  // print the UUID of the descriptor
+  Serial.print("\t\tDescriptor ");
+  Serial.print(descriptor.uuid());
+
+  // read the descriptor value
+  descriptor.read();
+  delay(1000);
+
+  // print out the value of the descriptor
+  Serial.print(", value 0x");
+  printData(descriptor.value(), descriptor.valueLength());
+
+  Serial.println();
 }
 
 void printData(const unsigned char data[], int length) {

libraries/CurieBLE/src/BLECharacteristic.cpp

@@ -444,15 +444,20 @@ int BLECharacteristic::addDescriptor(BLEDescriptor& descriptor)
     else if (BLEUtils::isLocalBLE(_bledev) == true)
     {
         // Only support the GATT server that create the service in local device.
-        _chrc_local_imp = new BLECharacteristicImp(*this, _bledev);
+        //  Consider to add multi-descriptor
         if (NULL == _chrc_local_imp)
         {
-            retVar = BLE_STATUS_NO_MEMORY;
+            _chrc_local_imp = new BLECharacteristicImp(*this, _bledev);
         }
-        else
+        
+        if (NULL != _chrc_local_imp)
         {
             retVar = _chrc_local_imp->addDescriptor(descriptor);
         }
+        else
+        {
+            retVar = BLE_STATUS_NO_MEMORY;
+        }
     }
     return retVar;
 }

libraries/CurieBLE/src/BLEDescriptor.cpp

@@ -35,28 +35,19 @@ BLEDescriptor::BLEDescriptor(BLEDescriptorImp* descriptorImp,
                              const BLEDevice *bleDev):
     _bledev(bleDev),
     _value_size(0),
-    _value(NULL)
+    _value(NULL),
+    _internal(descriptorImp)
 {
     _properties = descriptorImp->properties();
     memset(_uuid_cstr, 0, sizeof (_uuid_cstr));
     BLEUtils::uuidBT2String(descriptorImp->bt_uuid(), _uuid_cstr);
-    
-    _value_size = descriptorImp->valueSize();
-    _value = (unsigned char*)malloc(_value_size);
-    if (NULL == _value)
-    {
-        memcpy(_value, descriptorImp->value(), _value_size);
-    }
-    else
-    {
-        errno = ENOMEM;
-    }
 }
 
 BLEDescriptor::BLEDescriptor(const char* uuid, 
                              const unsigned char value[], 
                              unsigned short valueLength):
-    _bledev()
+    _bledev(),
+    _internal(NULL)
 {
     bt_uuid_128_t uuid_tmp;
     memset(_uuid_cstr, 0, sizeof (_uuid_cstr));
@@ -65,15 +56,16 @@ BLEDescriptor::BLEDescriptor(const char* uuid,
 
     _bledev.setAddress(*BLEUtils::bleGetLoalAddress());
 
-    _value_size = valueLength > BLE_MAX_ATTR_LONGDATA_LEN ? BLE_MAX_ATTR_LONGDATA_LEN : valueLength;
+    _value_size = (valueLength > BLE_MAX_ATTR_LONGDATA_LEN) ? BLE_MAX_ATTR_LONGDATA_LEN : valueLength;
     _value = (unsigned char*)malloc(_value_size);
-    if (NULL == _value)
+    if (NULL != _value)
     {
         memcpy(_value, value, _value_size);
     }
     else
     {
         errno = ENOMEM;
+        _value_size = 0;
     }
 }
 
@@ -82,22 +74,27 @@ BLEDescriptor::BLEDescriptor(const char* uuid,
      BLEDescriptor(uuid, (const unsigned char*)value, strlen(value))
 {}
 
-BLEDescriptor::BLEDescriptor(const BLEDescriptor& rhs)
+BLEDescriptor::BLEDescriptor(const BLEDescriptor& rhs):
+    _bledev(&rhs._bledev),
+    _properties(rhs._properties),
+    _value_size(0),
+    _value(NULL),
+    _internal(rhs._internal)
 {
-    _value = (unsigned char*)malloc(rhs._value_size);  // Sid. KW: allocate memory for _value, not local
-    if (_value) 
-    {
-        memcpy(_value, rhs._value, rhs._value_size);
-        _value_size = rhs._value_size;
-    }
-    else
+    memcpy(_uuid_cstr, rhs._uuid_cstr, sizeof(_uuid_cstr));
+    if (NULL == _internal && rhs._value_size > 0)
     {
-        _value_size = 0;
-        errno = ENOMEM;
+        _value = (unsigned char*)malloc(rhs._value_size);  // Sid. KW: allocate memory for _value, not local
+        if (_value) 
+        {
+            memcpy(_value, rhs._value, rhs._value_size);
+            _value_size = rhs._value_size;
+        }
+        else
+        {
+            errno = ENOMEM;
+        }
     }
-    memcpy(_uuid_cstr, rhs._uuid_cstr, sizeof(_uuid_cstr));
-    _properties = rhs._properties;
-    _bledev = BLEDevice(&rhs._bledev);
 }
 
 BLEDescriptor& BLEDescriptor::operator= (const BLEDescriptor& rhs)
@@ -107,23 +104,27 @@ BLEDescriptor& BLEDescriptor::operator= (const BLEDescriptor& rhs)
         memcpy(_uuid_cstr, rhs._uuid_cstr, sizeof(_uuid_cstr));
         _properties = rhs._properties;
         _bledev = BLEDevice(&rhs._bledev);
-        if (_value_size < rhs._value_size)
+        _internal = rhs._internal;
+        if (NULL == _internal && rhs._value_size > 0)
         {
-            _value_size = rhs._value_size;
+            if (_value_size < rhs._value_size)
+            {
+                _value_size = rhs._value_size;
+                
+                if (NULL != _value)
+                    free(_value);
+                _value = (unsigned char*)malloc(_value_size);
+            }
 
             if (NULL != _value)
-                free(_value);
-            _value = (unsigned char*)malloc(_value_size);
-        }
-        
-        if (NULL != _value)
-        {
-            memcpy(_value, rhs._value, rhs._value_size);
-        }
-        else
-        {
-            _value_size = 0;
-            errno = ENOMEM;
+            {
+                memcpy(_value, rhs._value, rhs._value_size);
+            }
+            else
+            {
+                _value_size = 0;
+                errno = ENOMEM;
+            }
         }
     }
     return *this;
@@ -145,12 +146,22 @@ const char* BLEDescriptor::uuid() const
 
 const byte* BLEDescriptor::value() const
 {
-    return _value;
+    const byte* ret = _value;
+    if (NULL != _internal)
+    {
+        ret = _internal->value();
+    }
+    return ret;
 }
 
 int BLEDescriptor::valueLength() const
 {
-    return _value_size;
+    int ret = _value_size;
+    if (NULL != _internal)
+    {
+        ret = _internal->valueLength();
+    }
+    return ret;
 }
 
 BLEDescriptor::operator bool() const
@@ -166,6 +177,22 @@ unsigned char BLEDescriptor::properties() const
 
 int BLEDescriptor::valueSize() const
 {
-    return _value_size;
+    int ret = _value_size;
+    if (NULL != _internal)
+    {
+        ret = _internal->valueSize();
+    }
+    return ret;
+}
+
+bool BLEDescriptor::read()
+{
+    bool retVar = false;
+    
+    if (NULL != _internal)
+    {
+        retVar = _internal->read();
+    }
+    return retVar;
 }
 

libraries/CurieBLE/src/BLEDescriptor.h

@@ -37,73 +37,92 @@ class BLEDescriptor
 
     virtual ~BLEDescriptor();
 
+    /**
+     * @brief   Get the descriptor's UUID string
+     *
+     * @param   none
+     *
+     * @return  const char*     The UUID string
+     *
+     * @note  none
+     */
     const char* uuid() const;
 
-    virtual const byte* value() const; // returns the value buffer
-    virtual int valueLength() const; // returns the current length of the value
-    
-    virtual operator bool() const;  // is the descriptor valid (discovered from peripheral)
-
-    unsigned char properties() const;
-    int valueSize() const;
-private:
-    char    _uuid_cstr[37];  // The characteristic UUID
-    BLEDevice _bledev; 
-    
-    unsigned char _properties;      // The characteristic property
-    
-    unsigned short _value_size;       // The value size
-    unsigned char* _value;          // The value. Will delete after create the _internal
-
-
-    // The API reserved for feature release
-    // move here for temp
 
     /**
-     * @brief   Write the value of the descriptor
+     * @brief   Get the value of descriptor
      *
-     * @param   value   The value buffer that want to write to descriptor
+     * @param   none
      *
-     * @param   length  The value buffer's length
+     * @return  const byte*     The value buffer
      *
-     * @return  bool    true - Success, false - Failed
+     * @note  none
+     */
+    virtual const byte* value() const;
+    
+    /**
+     * @brief   Get the current length of the value
+     *
+     * @param   none
+     *
+     * @return  int     The current length of the value string
      *
      * @note  none
      */
-    //virtual bool writeValue(const byte value[], int length);
+    virtual int valueLength() const;
 
     /**
-     * @brief   Write the value of the descriptor
+     * @brief   Is the descriptor valid
+     *
+     * @param   none
      *
-     * @param   value   The value buffer that want to write to descriptor
+     * @return  bool    true/false
      *
-     * @param   length  The value buffer's length
+     * @note  none
+     */
+    virtual operator bool() const;
+    
+    /**
+     * @brief   Read the descriptor value
      *
-     * @param   offset  The offset in the descriptor's data
+     * @param   none
      *
      * @return  bool    true - Success, false - Failed
      *
+     * @note  Only for GATT client. Schedule read request to the GATT server
+     */
+    bool read();
+
+    /**
+     * @brief   Get the property mask of the descriptor
+     *
+     * @param   none
+     *
+     * @return  unsigned char       The property mask of the descriptor
+     *
      * @note  none
      */
-    //bool writeValue(const byte value[], int length, int offset);
+    unsigned char properties() const;
 
     /**
-     * @brief   Write the value of the descriptor
+     * @brief   Get the maximum size of the value
      *
-     * @param   value   The value string that want to write to descriptor
+     * @param   none
      *
-     * @return  bool    true - Success, false - Failed
+     * @return  int     The maximum size of the value
      *
      * @note  none
      */
-    //bool writeValue(const char* value);
-    //virtual byte operator[] (int offset) const; // returns a byte of the value at the specified offset
-
-    // GATT client Write the value of the descriptor
-    //virtual bool write(const byte value[], int length);
-    //bool write(const byte value[], int length, int offset);
-    //bool write(const char* value);
-    //bool read();
+    int valueSize() const;
+private:
+    char    _uuid_cstr[37];  // The characteristic UUID
+    BLEDevice _bledev; 
+    
+    unsigned char _properties;      // The characteristic property
+    
+    unsigned short _value_size;     // The value size
+    unsigned char* _value;          // The value. Will delete after create the _internal
+    BLEDescriptorImp *_internal;    // The real implementation of Descriptor
 };
 
 #endif

libraries/CurieBLE/src/BLEDevice.h

@@ -644,6 +644,7 @@ class BLEDevice
     void setEventHandler(BLEDeviceEvent event, BLEDeviceEventHandler eventHandler); // set an event handler (callback)
 
 protected:
+    friend class BLEDescriptorImp;
     friend class BLECharacteristicImp;
     friend class BLEServiceImp;
     friend class BLEDeviceManager;
@@ -659,6 +660,11 @@ class BLEDevice
                                              bt_gatt_read_params_t *params,
                                              const void *data, 
                                              uint16_t length);
+    friend uint8_t profile_descriptor_read_rsp_process(bt_conn_t *conn, 
+                                            int err,
+                                            bt_gatt_read_params_t *params,
+                                            const void *data, 
+                                            uint16_t length);
     const bt_addr_le_t* bt_le_address() const;
     const bt_le_conn_param* bt_conn_param() const;
     void setAddress(const bt_addr_le_t& addr);