dash: Avoid some copies & useless initializations

Signed-off-by: Rémi Denis-Courmont <remi@remlab.net>

modules/stream_filter/dash/mpd/BasicCMManager.cpp

@@ -60,10 +60,11 @@ std::vector<ISegment*>  BasicCMManager::getSegments             (Representation
 
     return retSegments;
 }
-std::vector<Period*>    BasicCMManager::getPeriods              ()
+const std::vector<Period*>&    BasicCMManager::getPeriods              () const
 {
     return this->mpd->getPeriods();
 }
+
 Representation*         BasicCMManager::getBestRepresentation   (Period *period)
 {
     std::vector<Group *> groups = period->getGroups();

modules/stream_filter/dash/mpd/BasicCMManager.h

@@ -51,7 +51,7 @@ namespace dash
                 BasicCMManager          (MPD *mpd);
                 virtual ~BasicCMManager ();
 
-                std::vector<Period *>   getPeriods              ();
+                const std::vector<Period *>&   getPeriods              () const;
                 Period*                 getFirstPeriod          ();
                 Period*                 getNextPeriod           (Period *period);
                 Representation*         getBestRepresentation   (Period *period);

modules/stream_filter/dash/mpd/IMPDManager.h

@@ -26,7 +26,7 @@ namespace dash
         class IMPDManager
         {
             public:
-                virtual std::vector<Period *>   getPeriods              ()                              = 0;
+                virtual const std::vector<Period *>&   getPeriods              () const                 = 0;
                 virtual Period*                 getFirstPeriod          ()                              = 0;
                 virtual Period*                 getNextPeriod           (Period *period)                = 0;
                 virtual Representation*         getBestRepresentation   (Period *period)                = 0;

modules/stream_filter/dash/mpd/NullManager.cpp

@@ -37,9 +37,9 @@ NullManager::~NullManager   ()
 {
 }
 
-std::vector<Period *>   NullManager::getPeriods              ()
+const std::vector<Period *>&   NullManager::getPeriods              () const
 {
-    return std::vector<Period *>();
+    return this->periods;
 }
 Period*                 NullManager::getFirstPeriod          ()
 {
@@ -55,7 +55,7 @@ Representation*         NullManager::getBestRepresentation   (Period *)
 }
 std::vector<ISegment *> NullManager::getSegments             (Representation *)
 {
-    return std::vector<ISegment *>();
+    return this->segments;
 }
 Representation*         NullManager::getRepresentation       (Period *, long )
 {

modules/stream_filter/dash/mpd/NullManager.h

@@ -42,12 +42,16 @@ namespace dash
                 NullManager         ();
                 virtual ~NullManager();
 
-                std::vector<Period *>   getPeriods              ();
+                const std::vector<Period *>&   getPeriods              () const;
                 Period*                 getFirstPeriod          ();
                 Period*                 getNextPeriod           (Period *period);
                 Representation*         getBestRepresentation   (Period *period);
                 std::vector<ISegment *> getSegments             (Representation *rep);
                 Representation*         getRepresentation       (Period *period, long bitrate);
+
+            private:
+                std::vector<Period *>   periods;
+                std::vector<ISegment *> segments;
         };
     }
 }