From ee0fb82da6a0d511e2aa7e6071ea0fb05cb405e9 Mon Sep 17 00:00:00 2001
From: Paul Davis <paul@linuxaudiosystems.com>
Date: Mon, 11 Dec 2006 12:52:40 +0000
Subject: [PATCH] never save more than Config->get_saved_history_depth() undo
 transactions to history file

git-svn-id: svn://localhost/ardour2/trunk@1200 d708f5d6-7413-0410-9779-e7cbd77b26cf
---
 libs/ardour/ardour/configuration_vars.h |  1 +
 libs/ardour/session_state.cc            | 17 ++++++++++------
 libs/pbd/pbd/undo.h                     |  2 +-
 libs/pbd/undo.cc                        | 26 +++++++++++++++++++++----
 4 files changed, 35 insertions(+), 11 deletions(-)

diff --git a/libs/ardour/ardour/configuration_vars.h b/libs/ardour/ardour/configuration_vars.h
index f54fe15b71..89857ac9f5 100644
--- a/libs/ardour/ardour/configuration_vars.h
+++ b/libs/ardour/ardour/configuration_vars.h
@@ -120,6 +120,7 @@ CONFIG_VARIABLE (bool, verify_remove_last_capture, "verify-remove-last-capture",
 CONFIG_VARIABLE (bool, no_new_session_dialog, "no-new-session-dialog", false)
 CONFIG_VARIABLE (bool, use_vst, "use-vst", true)
 CONFIG_VARIABLE (uint32_t, subframes_per_frame, "subframes-per-frame", 100)
+CONFIG_VARIABLE (uint32_t, saved_history_depth, "save-history-depth", 100)
 
 /* BWAV */
 
diff --git a/libs/ardour/session_state.cc b/libs/ardour/session_state.cc
index 0d54e2535e..e97d2b6831 100644
--- a/libs/ardour/session_state.cc
+++ b/libs/ardour/session_state.cc
@@ -2796,8 +2796,13 @@ Session::save_history (string snapshot_name)
     XMLTree tree;
     string xml_path;
     string bak_path;
-    
-    tree.set_root (&_history.get_state());
+    XMLNode& history_node (history.get_state (Config->get_saved_history_depth()));
+
+    if (history_node.children().empty()) {
+	    return 0;
+    }
+
+    tree.set_root (
 
     if (snapshot_name.empty()) {
 	snapshot_name = _current_snapshot_name;
@@ -2850,13 +2855,13 @@ Session::restore_history (string snapshot_name)
     cerr << string_compose(_("Loading history from '%1'."), xmlpath) << endmsg;
 
     if (access (xmlpath.c_str(), F_OK)) {
-        error << string_compose(_("%1: session history file \"%2\" doesn't exist!"), _name, xmlpath) << endmsg;
-        return 1;
+	    info << string_compose (_("%1: no history file \"%2\" for this session."), _name, xmlpath) << endmsg;
+	    return 1;
     }
 
     if (!tree.read (xmlpath)) {
-        error << string_compose(_("Could not understand ardour file %1"), xmlpath) << endmsg;
-        return -1;
+	    error << string_compose (_("Could not understand session history file \"%1\""), xmlpath) << endmsg;
+	    return -1;
     }
 
     /* replace history */
diff --git a/libs/pbd/pbd/undo.h b/libs/pbd/pbd/undo.h
index eb46750e4f..4dfab5178f 100644
--- a/libs/pbd/pbd/undo.h
+++ b/libs/pbd/pbd/undo.h
@@ -94,7 +94,7 @@ class UndoHistory : public sigc::trackable
 	void clear_undo ();
 	void clear_redo ();
 
-        XMLNode &get_state();
+        XMLNode &get_state(uint32_t depth = 0);
         void save_state();
 
 	sigc::signal<void> Changed;
diff --git a/libs/pbd/undo.cc b/libs/pbd/undo.cc
index 277b83bfce..4719d0968e 100644
--- a/libs/pbd/undo.cc
+++ b/libs/pbd/undo.cc
@@ -236,13 +236,31 @@ UndoHistory::clear ()
 	Changed (); /* EMIT SIGNAL */
 }
 
-XMLNode & UndoHistory::get_state()
+XMLNode& 
+UndoHistory::get_state (uint32_t depth)
 {
     XMLNode *node = new XMLNode ("UndoHistory");
 
-    list<UndoTransaction*>::iterator it;
-    for (it = UndoList.begin(); it != UndoList.end(); it++) {
-	    node->add_child_nocopy((*it)->get_state());
+    if (depth == 0) {
+	    /* everything */
+
+	    for (list<UndoTransaction*>::iterator it = UndoList.begin(); it != UndoList.end(); ++it) {
+		    node->add_child_nocopy((*it)->get_state());
+	    }
+	    
+    } else {
+
+	    /* just the last "depth" transactions */
+
+	    list<UndoTransaction*> in_order;
+
+	    for (list<UndoTransaction*>::reverse_iterator it = UndoList.rbegin(); it != UndoList.rend() && depth; ++it, depth--) {
+		    in_order.push_front (*it);
+	    }
+
+	    for (list<UndoTransaction*>::iterator it = in_order.begin(); it != in_order.end(); it++) {
+		    node->add_child_nocopy((*it)->get_state());
+	    }
     }
 
     return *node;