Add get_first_untaken_info API (eProsima#1104)

* Refs #7918. Uncrustify

* Refs #7918. Adding new method get_first_untaken_info.

* Refs #7918. receptionTimestamp added to CacheChange_t.

* Refs #7918. receptionTimestamp added to SampleInfo_t.

include/fastdds/rtps/common/CacheChange.h

@@ -64,6 +64,8 @@ struct RTPS_DllAPI CacheChange_t
     bool isRead = false;
     //!Source TimeStamp (only used in Readers)
     Time_t sourceTimestamp;
+    //!Reception TimeStamp (only used in Readers)
+    Time_t receptionTimestamp;
 
     WriteParams write_params;
     bool is_untyped_ = true;

include/fastrtps/subscriber/SampleInfo.h

@@ -34,18 +34,30 @@ namespace fastrtps {
  * Class SampleInfo_t with information that is provided along a sample when reading data from a Subscriber.
  * @ingroup FASTRTPS_MODULE
  */
-class RTPS_DllAPI SampleInfo_t {
+class RTPS_DllAPI SampleInfo_t
+{
 public:
-    SampleInfo_t():sampleKind(rtps::ALIVE), ownershipStrength(0),
-    sample_identity(rtps::SampleIdentity::unknown()), related_sample_identity(rtps::SampleIdentity::unknown()) {}
 
-    virtual ~SampleInfo_t(){};
+    SampleInfo_t()
+        : sampleKind(rtps::ALIVE)
+        , ownershipStrength(0)
+        , sample_identity(rtps::SampleIdentity::unknown())
+        , related_sample_identity(rtps::SampleIdentity::unknown())
+    {
+    }
+
+    virtual ~SampleInfo_t()
+    {
+    }
+
     //!Sample kind.
     rtps::ChangeKind_t sampleKind;
     //!Ownership Strength of the writer of the sample (0 if the ownership kind is set to SHARED_OWNERSHIP_QOS).
     uint32_t ownershipStrength;
     //!Source timestamp of the sample.
     rtps::Time_t sourceTimestamp;
+    //!Reception timestamp of the sample.
+    rtps::Time_t receptionTimestamp;
     //!InstanceHandle of the data
     rtps::InstanceHandle_t iHandle;
 
@@ -54,7 +66,7 @@ class RTPS_DllAPI SampleInfo_t {
     rtps::SampleIdentity related_sample_identity;
 };
 
-} /* namespace  */
+} /* namespace fastrtps */
 } /* namespace eprosima */
 
 #endif /* SAMPLEINFO_H_ */

include/fastrtps/subscriber/Subscriber.h

@@ -43,14 +43,21 @@ class RTPS_DllAPI Subscriber
 {
     friend class SubscriberImpl;
 
-    virtual ~Subscriber() {}
+    virtual ~Subscriber()
+    {
+    }
 
 public:
+
     /**
      * Constructor from a SubscriberImpl pointer
      * @param pimpl Actual implementation of the subscriber
      */
-    Subscriber(SubscriberImpl* pimpl) : mp_impl(pimpl) {}
+    Subscriber(
+            SubscriberImpl* pimpl)
+        : mp_impl(pimpl)
+    {
+    }
 
     /**
      * Get the associated GUID
@@ -75,7 +82,8 @@ class RTPS_DllAPI Subscriber
      * @return true in case unread samples are available.
      * In other case, false.
      */
-    bool wait_for_unread_samples(const Duration_t& timeout);
+    bool wait_for_unread_samples(
+            const Duration_t& timeout);
 
     /**
      * @brief Reads next unread sample from the Subscriber.
@@ -101,12 +109,21 @@ class RTPS_DllAPI Subscriber
             void* sample,
             SampleInfo_t* info);
 
+    /**
+     * @brief Returns information about the first untaken sample.
+     * @param [out] info Pointer to a SampleInfo_t structure to store first untaken sample information.
+     * @return true if sample info was returned. false if there is no sample to take.
+     */
+    bool get_first_untaken_info(
+            SampleInfo_t* info);
+
     /**
      * Update the Attributes of the subscriber;
      * @param att Reference to a SubscriberAttributes object to update the parameters;
      * @return True if correctly updated, false if ANY of the updated parameters cannot be updated
      */
-    bool updateAttributes(const SubscriberAttributes& att);
+    bool updateAttributes(
+            const SubscriberAttributes& att);
 
     /**
      * Get the Attributes of the Subscriber.
@@ -141,15 +158,18 @@ class RTPS_DllAPI Subscriber
      * @brief Get the requested deadline missed status
      * @return The deadline missed status
      */
-    void get_requested_deadline_missed_status(RequestedDeadlineMissedStatus& status);
+    void get_requested_deadline_missed_status(
+            RequestedDeadlineMissedStatus& status);
 
     /**
      * @brief Returns the liveliness changed status
      * @param status Liveliness changed status
      */
-    void get_liveliness_changed_status(LivelinessChangedStatus& status);
+    void get_liveliness_changed_status(
+            LivelinessChangedStatus& status);
 
 private:
+
     SubscriberImpl* mp_impl;
 };