From 317bacfa3a5cb0a9228eb741c8759ec11a42f488 Mon Sep 17 00:00:00 2001
From: GZharun <grygoriiz@wavesglobal.com>
Date: Sun, 15 Feb 2015 13:02:16 +0200
Subject: [PATCH] [Summary] Eliminated redundant marker update notification
 which lead to creation of huge amount of redundant session events

---
 libs/ardour/ardour/location.h | 10 +++++++---
 libs/ardour/location.cc       | 26 ++++++++++++++++++++++----
 libs/ardour/session.cc        | 16 ++++++++++++----
 3 files changed, 41 insertions(+), 11 deletions(-)

diff --git a/libs/ardour/ardour/location.h b/libs/ardour/ardour/location.h
index f809dbf280..7d51f6a7f3 100644
--- a/libs/ardour/ardour/location.h
+++ b/libs/ardour/ardour/location.h
@@ -123,11 +123,13 @@ class LIBARDOUR_API Location : public SessionHandleRef, public PBD::StatefulDest
            changes to this object 
         */
 
+    PBD::Signal0<void> Changed;
+    void set_block_change_notifications (bool yn) {_block_change_notifications = yn;}
+    
 	PBD::Signal0<void> NameChanged;
 	PBD::Signal0<void> EndChanged;
 	PBD::Signal0<void> StartChanged;
-	PBD::Signal0<void> Changed;
-	PBD::Signal0<void> FlagsChanged;
+    PBD::Signal0<void> FlagsChanged;
 	PBD::Signal0<void> LockChanged;
 	PBD::Signal0<void> PositionLockStyleChanged;
         
@@ -155,6 +157,8 @@ class LIBARDOUR_API Location : public SessionHandleRef, public PBD::StatefulDest
 	bool               _locked;
 	PositionLockStyle  _position_lock_style;
 	boost::shared_ptr<SceneChange> _scene_change;
+    
+    bool _block_change_notifications; // required for group operations
 
 	void set_mark (bool yn);
 	bool set_flag_internal (bool yn, Flags flag);
@@ -199,7 +203,7 @@ class LIBARDOUR_API Locations : public SessionHandleRef, public PBD::StatefulDes
 	void marks_either_side (framepos_t const, framepos_t &, framepos_t &) const;
 
 	void find_all_between (framepos_t start, framepos_t, LocationList&, Location::Flags);
-
+    
 	PBD::Signal1<void,Location*> current_changed;
 
         /* Objects that care about individual addition and removal of Locations should connect to added/removed.
diff --git a/libs/ardour/location.cc b/libs/ardour/location.cc
index 2c19ebd1e0..31a3f6c3ae 100644
--- a/libs/ardour/location.cc
+++ b/libs/ardour/location.cc
@@ -58,6 +58,7 @@ Location::Location (Session& s)
 	, _flags (Flags (0))
 	, _locked (false)
 	, _position_lock_style (AudioTime)
+    , _block_change_notifications (false)
 {
 	assert (_start >= 0);
 	assert (_end >= 0);
@@ -72,6 +73,8 @@ Location::Location (Session& s, framepos_t sample_start, framepos_t sample_end,
 	, _flags (bits)
 	, _locked (false)
 	, _position_lock_style (s.config.get_glue_new_markers_to_bars_and_beats() ? MusicTime : AudioTime)
+    , _block_change_notifications (false)
+
 {
 	recompute_bbt_from_frames ();
 
@@ -89,6 +92,8 @@ Location::Location (const Location& other)
 	, _bbt_end (other._bbt_end)
 	, _flags (other._flags)
 	, _position_lock_style (other._position_lock_style)
+    , _block_change_notifications (false)
+
 {
 	/* copy is not locked even if original was */
 
@@ -405,7 +410,10 @@ Location::set (framepos_t s, framepos_t e, bool allow_bbt_recompute)
 
         if (start_change && end_change) {
                 changed (this);
+            
+            if (!_block_change_notifications) {
                 Changed ();
+            }
         }
 
         return 0;
@@ -427,8 +435,11 @@ Location::move_to (framepos_t pos)
 		_end = _start + length();
 		recompute_bbt_from_frames ();
 
-		changed (this); /* EMIT SIGNAL */
-		Changed (); /* EMIT SIGNAL */
+        changed (this); /* EMIT SIGNAL */
+        
+        if (!_block_change_notifications) {
+            Changed (); /* EMIT SIGNAL */
+        }
 	}
 
 	assert (_start >= 0);
@@ -687,8 +698,11 @@ Location::set_state (const XMLNode& node, int version)
 
 	recompute_bbt_from_frames ();
 
-	changed (this); /* EMIT SIGNAL */
-	Changed (); /* EMIT SIGNAL */
+    changed (this); /* EMIT SIGNAL */
+    
+    if (!_block_change_notifications) {
+        Changed (); /* EMIT SIGNAL */
+    }
 
 	assert (_start >= 0);
 	assert (_end >= 0);
@@ -1069,7 +1083,11 @@ Locations::set_state (const XMLNode& node, int version)
 				if (i != locations.end()) {
 					/* we can re-use an old Location object */
 					loc = *i;
+                    
+                    // changed locations will be updated by Locations::changed signal
+                    loc->set_block_change_notifications (true);
 					loc->set_state (**niter, version);
+                    loc->set_block_change_notifications (false);
 				} else {
 					loc = new Location (_session, **niter);
 				}
diff --git a/libs/ardour/session.cc b/libs/ardour/session.cc
index 7706aeb37a..c3fbd44f0f 100644
--- a/libs/ardour/session.cc
+++ b/libs/ardour/session.cc
@@ -1740,10 +1740,18 @@ Session::_locations_changed (const Locations::LocationList& locations)
            We might be re-adding a location here but it doesn't actually matter
            for all the locations that the Session takes an interest in.
         */
-
-	for (Locations::LocationList::const_iterator i = locations.begin(); i != locations.end(); ++i) {
-                location_added (*i);
-        }
+    loop_update_connections.drop_connections ();
+    mark_update_connections.drop_connections ();
+    skip_update_connections.drop_connections ();
+    
+    {
+        PBD::Unwinder<bool> protect_ignore_skip_updates (_ignore_skips_updates, true);
+        for (Locations::LocationList::const_iterator i = locations.begin(); i != locations.end(); ++i) {
+                    location_added (*i);
+            }
+    }
+    
+    update_skips (NULL, false);
 }
 
 void
-- 
2.30.2