From 99a7eece9c719e2cf34703cac180abb9e0bbb96e Mon Sep 17 00:00:00 2001
From: Thomas Goyne <plorkyeran@aegisub.org>
Date: Thu, 26 Jan 2012 20:08:54 +0000
Subject: [PATCH] Significantly speed up duplicating multiple lines

SubtitlesGrid::DuplicateLines iterated over the entire file multiple
times for each line duplicated, making duplicating large numbers of
lines extremely slow.

Originally committed to SVN as r6366.
---
 aegisub/src/subs_grid.cpp | 43 ++++++++++++++++++++-------------------
 1 file changed, 22 insertions(+), 21 deletions(-)

diff --git a/aegisub/src/subs_grid.cpp b/aegisub/src/subs_grid.cpp
index 19002ab2c..277b291f6 100644
--- a/aegisub/src/subs_grid.cpp
+++ b/aegisub/src/subs_grid.cpp
@@ -371,34 +371,35 @@ void SubtitlesGrid::AdjoinLines(int n1,int n2,bool setStart) {
 	context->ass->Commit(_("adjoin"), AssFile::COMMIT_DIAG_TIME);
 }
 
-void SubtitlesGrid::DuplicateLines(int n1,int n2,bool nextFrame) {
-	AssDialogue *cur;
-	bool update = false;
-	int step=0;
-	for (int i=n1;i<=n2;i++) {
-		// Create
-		if (i == n2) update = true;
-		cur = new AssDialogue(GetDialogue(i)->GetEntryData());
+void SubtitlesGrid::DuplicateLines(int n1, int n2, bool nextFrame) {
+	std::list<AssEntry*>::iterator insert_pos = find(context->ass->Line.begin(), context->ass->Line.end(), GetDialogue(n2));
+	if (insert_pos != context->ass->Line.end())
+		++insert_pos;
+
+	Selection newsel;
+
+	AssDialogue *first = 0;
+
+	for (int i = n1; i <= n2; ++i) {
+		AssDialogue *diag = new AssDialogue(*GetDialogue(i));
+		if (!first)
+			first = diag;
+
+		context->ass->Line.insert(insert_pos, diag);
+		newsel.insert(diag);
 
 		// Shift to next frame
 		if (nextFrame) {
-			int posFrame = context->videoController->FrameAtTime(cur->End,agi::vfr::END) + 1;
-			cur->Start = context->videoController->TimeAtFrame(posFrame,agi::vfr::START);
-			cur->End = context->videoController->TimeAtFrame(posFrame,agi::vfr::END);
+			int posFrame = context->videoController->FrameAtTime(diag->End, agi::vfr::END) + 1;
+			diag->Start = context->videoController->TimeAtFrame(posFrame, agi::vfr::START);
+			diag->End = context->videoController->TimeAtFrame(posFrame, agi::vfr::END);
 		}
-
-		// Insert
-		InsertLine(cur,n2+step,true,update);
-		step++;
 	}
 
-	// Select new lines
-	Selection newsel;
-	for (int i=n1;i<=n2;i++) {
-		newsel.insert(GetDialogue(i+step));
-	}
+	context->ass->Commit(_("duplicate lines"), AssFile::COMMIT_DIAG_ADDREM);
+
 	SetSelectedSet(newsel);
-	SetActiveLine(GetDialogue(n1+step));
+	SetActiveLine(first);
 }
 
 /// @brief Retrieve a list of selected lines in the actual ASS file (ie. not as displayed in the grid but as represented in the file)