Use boost::flyweight to intern the wxString members of AssDialogue

100 no-op non-amend commits on a subtitle file with 6689 dialogue lines,
with the undo limit set to 100:

Without flyweight:
	No video open:
		Initial memory usage: 30.6 MB
		Final memory usage: 498.0 MB
		Elapsed time: 6.3 seconds
	Video open, using libass:
		Initial memory usage: 54.3 MB
		Final memory usage: 653.3 MB
		Elapsed time: 23.7 seconds

With flyweight:
	No video open:
		Initial memory usage: 26.0 MB
		Final memory usage: 104.5 MB
		Elapsed time: 3.0 seconds
	Video open, using libass:
		Initial memory usage: 46.7 MB
		Final memory usage: 251.8 MB
		Elapsed time: 13.0 seconds

No video open:
	Memory usage: -79%
	Time: -52%
Video open:
	Memory usage: -61.5%
	Time: -45%

100 no-op amend commits on a line in the middle of a subtitle file with
6689 dialogue lines, with video open:

Without flyweight:
	Initial memory usage: 48.2 MB
	Final memory usage: 182.3 MB
	Elapsed time: 22.3 seconds

With flyweight:
	Initial memory usage: 39.8 MB
	Final memory usage: 165.8 MB
	Elapsed time: 13.8 seconds

Note: The large jump in memory usage here is due to that the benchmark
is blocking the main thread, so at the end there are ~100 video frames
waiting to be displayed.

aegisub/src/agi_pre.h

@@ -69,6 +69,7 @@
 #include <sys/param.h>
 #endif
 
+#include <boost/flyweight.hpp>
 #include <boost/ptr_container/ptr_vector.hpp>
 #include <boost/range/adaptor/filtered.hpp>
 #include <boost/range/adaptor/indirected.hpp>

aegisub/src/ass_dialogue.cpp

@@ -33,6 +33,7 @@
 
 #include "config.h"
 
+#include <boost/algorithm/string/join.hpp>
 #include <fstream>
 #include <list>
 
@@ -47,6 +48,10 @@
 
 #include <libaegisub/of_type_adaptor.h>
 
+std::size_t hash_value(wxString const& s) {
+	return wxStringHash()(s);
+}
+
 AssDialogue::AssDialogue()
 : AssEntry(wxString())
 , Comment(false)
@@ -128,15 +133,11 @@ bool AssDialogue::Parse(wxString const& rawData) {
 
 	// Get style
 	if (!tkn.HasMoreTokens()) return false;
-	Style = tkn.GetNextToken();
+	Style = tkn.GetNextToken().Trim(true).Trim(false);
-	Style.Trim(true);
-	Style.Trim(false);
 
 	// Get actor
 	if (!tkn.HasMoreTokens()) return false;
-	Actor = tkn.GetNextToken();
+	Actor = tkn.GetNextToken().Trim(true).Trim(false);
-	Actor.Trim(true);
-	Actor.Trim(false);
 
 	// Get margins
 	for (int i = 0; i < 3; ++i) {
@@ -145,9 +146,7 @@ bool AssDialogue::Parse(wxString const& rawData) {
 	}
 
 	if (!tkn.HasMoreTokens()) return false;
-	Effect = tkn.GetNextToken();
+	Effect = tkn.GetNextToken().Trim(true).Trim(false);
-	Effect.Trim(true);
-	Effect.Trim(false);
 
 	// Get text
 	Text = rawData.Mid(pos + tkn.GetPosition());
@@ -172,7 +171,7 @@ wxString AssDialogue::GetData(bool ssa) const {
 		s, a,
 		Margin[0], Margin[1], Margin[2],
 		e,
-		Text);
+		Text.get());
 
 	// Make sure that final has no line breaks
 	str.Replace("\n", "");
@@ -193,17 +192,17 @@ std::auto_ptr<boost::ptr_vector<AssDialogueBlock>> AssDialogue::ParseTags() cons
 	boost::ptr_vector<AssDialogueBlock> Blocks;
 
 	// Empty line, make an empty block
-	if (Text.empty()) {
+	if (Text.get().empty()) {
 		Blocks.push_back(new AssDialogueBlockPlain);
 		return Blocks.release();
 	}
 
 	int drawingLevel = 0;
 
-	for (size_t len = Text.size(), cur = 0; cur < len; ) {
+	for (size_t len = Text.get().size(), cur = 0; cur < len; ) {
 		// Overrides block
-		if (Text[cur] == '{') {
+		if (Text.get()[cur] == '{') {
-			size_t end = Text.find('}', cur);
+			size_t end = Text.get().find('}', cur);
 
 			// VSFilter requires that override blocks be closed, while libass
 			// does not. We match VSFilter here.
@@ -212,7 +211,7 @@ std::auto_ptr<boost::ptr_vector<AssDialogueBlock>> AssDialogue::ParseTags() cons
 
 			++cur;
 			// Get contents of block
-			wxString work = Text.substr(cur, end - cur);
+			wxString work = Text.get().substr(cur, end - cur);
 			cur = end + 1;
 
 			if (work.size() && work.find('\\') == wxString::npos) {
@@ -240,13 +239,13 @@ std::auto_ptr<boost::ptr_vector<AssDialogueBlock>> AssDialogue::ParseTags() cons
 		// Plain-text/drawing block
 plain:
 		wxString work;
-		size_t end = Text.find('{', cur + 1);
+		size_t end = Text.get().find('{', cur + 1);
 		if (end == wxString::npos) {
-			work = Text.substr(cur);
+			work = Text.get().substr(cur);
 			cur = len;
 		}
 		else {
-			work = Text.substr(cur, end - cur);
+			work = Text.get().substr(cur, end - cur);
 			cur = end;
 		}
 
@@ -265,12 +264,12 @@ void AssDialogue::StripTags() {
 
 void AssDialogue::StripTag(wxString const& tag_name) {
 	boost::ptr_vector<AssDialogueBlock> blocks(ParseTags());
-	Text.clear();
+	wxString new_text;
 
 	// Look for blocks
 	for (auto& block : blocks) {
 		if (block.GetType() != BLOCK_OVERRIDE) {
-			Text += block.GetText();
+			new_text += block.GetText();
 			continue;
 		}
 
@@ -282,15 +281,16 @@ void AssDialogue::StripTag(wxString const& tag_name) {
 		}
 
 		if (!temp.empty())
-			Text += "{" + temp + "}";
+			new_text += "{" + temp + "}";
 	}
+
+	Text = new_text;
 }
 
+static wxString get_text(AssDialogueBlock &d) { return d.GetText(); }
 void AssDialogue::UpdateText(boost::ptr_vector<AssDialogueBlock>& blocks) {
 	if (blocks.empty()) return;
-	Text.clear();
+	Text = join(blocks | boost::adaptors::transformed(get_text), wxS(""));
-	for (auto& block : blocks)
-		Text += block.GetText();
 }
 
 void AssDialogue::SetMarginString(wxString const& origvalue, int which) {

aegisub/src/ass_dialogue.h

@@ -37,6 +37,7 @@
 
 #include <libaegisub/exception.h>
 
+#include <boost/flyweight.hpp>
 #include <boost/ptr_container/ptr_vector.hpp>
 #include <vector>
 
@@ -50,6 +51,8 @@ enum AssBlockType {
 class AssOverrideParameter;
 class AssOverrideTag;
 
+std::size_t hash_value(wxString const& s);
+
 /// @class AssDialogueBlock
 /// @brief AssDialogue Blocks
 ///
@@ -131,13 +134,13 @@ public:
 	/// Ending time
 	AssTime End;
 	/// Style name
-	wxString Style;
+	boost::flyweight<wxString> Style;
 	/// Actor name
-	wxString Actor;
+	boost::flyweight<wxString> Actor;
 	/// Effect name
-	wxString Effect;
+	boost::flyweight<wxString> Effect;
 	/// Raw text data
-	wxString Text;
+	boost::flyweight<wxString> Text;
 
 	AssEntryGroup Group() const override { return ENTRY_DIALOGUE; }
 

aegisub/src/base_grid.cpp

@@ -607,15 +607,15 @@ void BaseGrid::GetRowStrings(int row, AssDialogue *line, bool *paint_columns, wx
 
 		// Hidden overrides
 		if (replace) {
-			strings[10].reserve(line->Text.size());
+			strings[10].reserve(line->Text.get().size());
 			size_t start = 0, pos;
-			while ((pos = line->Text.find('{', start)) != wxString::npos) {
+			while ((pos = line->Text.get().find('{', start)) != wxString::npos) {
-				strings[10] += line->Text.Mid(start, pos - start);
+				strings[10] += line->Text.get().Mid(start, pos - start);
 				strings[10] += rep_char;
-				start = line->Text.find('}', pos);
+				start = line->Text.get().find('}', pos);
 				if (start != wxString::npos) ++start;
 			}
-			strings[10] += line->Text.Mid(start);
+			strings[10] += line->Text.get().Mid(start);
 		}
 
 		// Show overrides

aegisub/src/command/edit.cpp

@@ -207,7 +207,7 @@ void set_tag(AssDialogue *line, boost::ptr_vector<AssDialogueBlock> &blocks, wxS
 			// Cursor is in a comment block, so try the previous block instead
 			if (plain->GetText().StartsWith("{")) {
 				--blockn;
-				start = line->Text.rfind('{', start);
+				start = line->Text.get().rfind('{', start);
 			}
 			else
 				break;
@@ -227,7 +227,7 @@ void set_tag(AssDialogue *line, boost::ptr_vector<AssDialogueBlock> &blocks, wxS
 	wxString insert = tag + value;
 	int shift = insert.size();
 	if (plain || blockn < 0) {
-		line->Text = line->Text.Left(start) + "{" + insert + "}" + line->Text.Mid(start);
+		line->Text = line->Text.get().Left(start) + "{" + insert + "}" + line->Text.get().Mid(start);
 		shift += 2;
 		blocks = line->ParseTags();
 	}
@@ -681,11 +681,11 @@ static void combine_lines(agi::Context *c, void (*combiner)(AssDialogue *, AssDi
 }
 
 static void combine_karaoke(AssDialogue *first, AssDialogue *second) {
-	first->Text += wxString::Format("{\\k%d}%s", (second->Start - first->End) / 10, second->Text);
+	first->Text = wxString::Format("%s{\\k%d}%s", first->Text.get(), (second->Start - first->End) / 10, second->Text.get());
 }
 
 static void combine_concat(AssDialogue *first, AssDialogue *second) {
-	first->Text += " " + second->Text;
+	first->Text = first->Text + " " + second->Text;
 }
 
 static void combine_drop(AssDialogue *, AssDialogue *) { }

aegisub/src/dialog_resample.cpp

@@ -202,7 +202,7 @@ namespace {
 
 	void resample_line(resample_state *state, AssEntry &line) {
 		AssDialogue *diag = dynamic_cast<AssDialogue*>(&line);
-		if (diag && !(diag->Comment && (diag->Effect.StartsWith("template") || diag->Effect.StartsWith("code")))) {
+		if (diag && !(diag->Comment && (diag->Effect.get().StartsWith("template") || diag->Effect.get().StartsWith("code")))) {
 			boost::ptr_vector<AssDialogueBlock> blocks(diag->ParseTags());
 
 			for (auto block : blocks | agi::of_type<AssDialogueBlockOverride>())

aegisub/src/dialog_search_replace.cpp

@@ -243,6 +243,13 @@ void SearchReplaceEngine::FindNext() {
 	ReplaceNext(false);
 }
 
+static boost::flyweight<wxString> *get_text(AssDialogue *cur, int field) {
+	if (field == 0) return &cur->Text;
+	else if (field == 1) return &cur->Style;
+	else if (field == 2) return &cur->Actor;
+	else if (field == 3) return &cur->Effect;
+	else throw wxString("Invalid field");
+}
 
 void SearchReplaceEngine::ReplaceNext(bool DoReplace) {
 	if (!CanContinue) {
@@ -267,7 +274,6 @@ void SearchReplaceEngine::ReplaceNext(bool DoReplace) {
 	int start = curLine;
 	int nrows = context->subsGrid->GetRows();
 	bool found = false;
-	wxString *Text = nullptr;
 	size_t tempPos;
 	int regFlags = wxRE_ADVANCED;
 	if (!matchCase) {
@@ -276,8 +282,9 @@ void SearchReplaceEngine::ReplaceNext(bool DoReplace) {
 	}
 
 	// Search for it
+	boost::flyweight<wxString> *Text = nullptr;
 	while (!found) {
-		Text = GetText(context->subsGrid->GetDialogue(curLine), field);
+		Text = get_text(context->subsGrid->GetDialogue(curLine), field);
 		if (DoReplace && LastWasFind)
 			tempPos = pos;
 		else
@@ -287,7 +294,7 @@ void SearchReplaceEngine::ReplaceNext(bool DoReplace) {
 		if (isReg) {
 			wxRegEx regex (LookFor,regFlags);
 			if (regex.IsValid()) {
-				if (regex.Matches(Text->Mid(tempPos))) {
+				if (regex.Matches(Text->get().Mid(tempPos))) {
 					size_t match_start;
 					regex.GetMatch(&match_start,&matchLen,0);
 					pos = match_start + tempPos;
@@ -298,7 +305,7 @@ void SearchReplaceEngine::ReplaceNext(bool DoReplace) {
 
 		// Normal
 		else {
-			wxString src = Text->Mid(tempPos);
+			wxString src = Text->get().Mid(tempPos);
 			if (!matchCase) src.MakeLower();
 			int textPos = src.Find(LookFor);
 			if (textPos != -1) {
@@ -325,16 +332,16 @@ void SearchReplaceEngine::ReplaceNext(bool DoReplace) {
 		if (DoReplace) {
 			// Replace with regular expressions
 			if (isReg) {
-				wxString toReplace = Text->Mid(pos,matchLen);
+				wxString toReplace = Text->get().Mid(pos,matchLen);
 				wxRegEx regex(LookFor,regFlags);
 				regex.ReplaceFirst(&toReplace,ReplaceWith);
-				*Text = Text->Left(pos) + toReplace + Text->Mid(pos+matchLen);
+				*Text = Text->get().Left(pos) + toReplace + Text->get().Mid(pos+matchLen);
 				replaceLen = toReplace.Length();
 			}
 
 			// Normal replace
 			else {
-				*Text = Text->Left(pos) + ReplaceWith + Text->Mid(pos+matchLen);
+				*Text = Text->get().Left(pos) + ReplaceWith + Text->get().Mid(pos+matchLen);
 				replaceLen = ReplaceWith.Length();
 			}
 
@@ -387,7 +394,7 @@ void SearchReplaceEngine::ReplaceAll() {
 		if (inSel && hasSelection && !sel.count(diag))
 			continue;
 
-		wxString *Text = GetText(diag, field);
+		boost::flyweight<wxString> *Text = get_text(diag, field);
 
 		// Regular expressions
 		if (isReg) {
@@ -398,7 +405,9 @@ void SearchReplaceEngine::ReplaceAll() {
 				// A zero length match (such as '$') will always be replaced
 				// maxMatches times, which is almost certainly not what the user
 				// wanted, so limit it to one replacement in that situation
-				count += reg.Replace(Text, ReplaceWith, len > 0 ? 1000 : 1);
+				wxString repl(*Text);
+				count += reg.Replace(&repl, ReplaceWith, len > 0 ? 1000 : 1);
+				*Text = repl;
 			}
 		}
 		// Normal replace
@@ -424,8 +433,10 @@ void SearchReplaceEngine::ReplaceAll() {
 					*Text = Left + Right;
 				}
 			}
-			else if(Text->Contains(LookFor)) {
+			else if(Text->get().Contains(LookFor)) {
-				count += Text->Replace(LookFor, ReplaceWith);
+				wxString repl(*Text);
+				count += repl.Replace(LookFor, ReplaceWith);
+				*Text = repl;
 			}
 		}
 	}
@@ -475,12 +486,4 @@ void SearchReplaceEngine::OpenDialog (bool replace) {
 	hasReplace = replace;
 }
 
-wxString *SearchReplaceEngine::GetText(AssDialogue *cur, int field) {
-	if (field == 0) return &cur->Text;
-	else if (field == 1) return &cur->Style;
-	else if (field == 2) return &cur->Actor;
-	else if (field == 3) return &cur->Effect;
-	else throw wxString("Invalid field");
-}
-
 SearchReplaceEngine Search;

aegisub/src/dialog_search_replace.h

@@ -59,8 +59,6 @@ class SearchReplaceEngine {
 	wxString LookFor;
 	wxString ReplaceWith;
 
-	wxString *GetText(AssDialogue *cur, int field);
-
 public:
 	agi::Context *context;
 

aegisub/src/dialog_selection.cpp

@@ -67,7 +67,7 @@ enum {
 
 DEFINE_SIMPLE_EXCEPTION(BadRegex, agi::InvalidInputException, "bad_regex")
 
-static wxString AssDialogue::* get_field(int field_n) {
+static boost::flyweight<wxString> AssDialogue::* get_field(int field_n) {
 	switch(field_n) {
 		case FIELD_TEXT:   return &AssDialogue::Text; break;
 		case FIELD_STYLE:  return &AssDialogue::Style; break;
@@ -109,7 +109,7 @@ static std::set<AssDialogue*> process(wxString match_text, bool match_case, int
 		match_case = false;
 	}
 
-	wxString AssDialogue::*field = get_field(field_n);
+	boost::flyweight<wxString> AssDialogue::*field = get_field(field_n);
 	std::function<bool (wxString)> pred = get_predicate(mode, &re, match_case, match_text);
 
 	std::set<AssDialogue*> matches;

aegisub/src/dialog_spellchecker.cpp

@@ -281,8 +281,10 @@ void DialogSpellChecker::Replace() {
 	AssDialogue *active_line = context->selectionController->GetActiveLine();
 
 	// Only replace if the user hasn't changed the selection to something else
-	if (active_line->Text.Mid(word_start, word_len) == orig_word->GetValue()) {
+	if (active_line->Text.get().Mid(word_start, word_len) == orig_word->GetValue()) {
-		active_line->Text.replace(word_start, word_len, replace_word->GetValue());
+		wxString text = active_line->Text;
+		text.replace(word_start, word_len, replace_word->GetValue());
+		active_line->Text = text;
 		context->ass->Commit(_("spell check replace"), AssFile::COMMIT_DIAG_TEXT);
 		context->textSelectionController->SetInsertionPoint(word_start + replace_word->GetValue().size());
 	}

aegisub/src/dialog_styling_assistant.cpp

@@ -159,7 +159,7 @@ void DialogStyling::OnActiveLineChanged(AssDialogue *new_line) {
 
 	current_line_text->SetValue(active_line->Text);
 	style_name->SetValue(active_line->Style);
-	style_name->SetSelection(0, active_line->Style.size());
+	style_name->SetSelection(0, active_line->Style.get().size());
 	style_name->SetFocus();
 
 	style_list->SetStringSelection(active_line->Style);

aegisub/src/export_fixstyle.cpp

@@ -55,7 +55,7 @@ void AssFixStylesFilter::ProcessSubs(AssFile *subs, wxWindow *) {
 	styles.Sort();
 
 	for (auto diag : subs->Line | agi::of_type<AssDialogue>()) {
-		if (!std::binary_search(styles.begin(), styles.end(), diag->Style.Lower()))
+		if (!std::binary_search(styles.begin(), styles.end(), diag->Style.get().Lower()))
 			diag->Style = "Default";
 	}
 }

aegisub/src/font_file_lister.cpp

@@ -60,7 +60,7 @@ void FontCollector::ProcessDialogueLine(const AssDialogue *line, int index) {
 				wxString name = tag->Name;
 
 				if (name == "\\r") {
-					style = styles[tag->Params[0]->Get(line->Style)];
+					style = styles[tag->Params[0]->Get<wxString>(line->Style)];
 					overriden = false;
 				}
 				else if (name == "\\b") {

aegisub/src/subs_edit_box.cpp

@@ -306,7 +306,7 @@ void SubsEditBox::OnCommit(int type) {
 	}
 }
 
-void SubsEditBox::PopulateList(wxComboBox *combo, wxString AssDialogue::*field) {
+void SubsEditBox::PopulateList(wxComboBox *combo, boost::flyweight<wxString> AssDialogue::*field) {
 	wxEventBlocker blocker(this);
 
 	std::set<wxString> values;
@@ -397,7 +397,7 @@ void SubsEditBox::SetSelectedRows(T AssDialogue::*field, T value, wxString const
 }
 
 void SubsEditBox::CommitText(wxString const& desc) {
-	SetSelectedRows(&AssDialogue::Text, TextEdit->GetText(), desc, AssFile::COMMIT_DIAG_TEXT, true);
+	SetSelectedRows(&AssDialogue::Text, boost::flyweight<wxString>(TextEdit->GetText()), desc, AssFile::COMMIT_DIAG_TEXT, true);
 }
 
 void SubsEditBox::CommitTimes(TimeField field) {
@@ -487,12 +487,12 @@ void SubsEditBox::SetControlsState(bool state) {
 }
 
 void SubsEditBox::OnStyleChange(wxCommandEvent &) {
-	SetSelectedRows(&AssDialogue::Style, StyleBox->GetValue(), _("style change"), AssFile::COMMIT_DIAG_META);
+	SetSelectedRows(&AssDialogue::Style,  boost::flyweight<wxString>(StyleBox->GetValue()), _("style change"), AssFile::COMMIT_DIAG_META);
 }
 
 void SubsEditBox::OnActorChange(wxCommandEvent &evt) {
 	bool amend = evt.GetEventType() == wxEVT_COMMAND_TEXT_UPDATED;
-	SetSelectedRows(&AssDialogue::Actor, ActorBox->GetValue(), _("actor change"), AssFile::COMMIT_DIAG_META, amend);
+	SetSelectedRows(&AssDialogue::Actor, boost::flyweight<wxString>(ActorBox->GetValue()), _("actor change"), AssFile::COMMIT_DIAG_META, amend);
 	PopulateList(ActorBox, &AssDialogue::Actor);
 }
 
@@ -502,7 +502,7 @@ void SubsEditBox::OnLayerEnter(wxCommandEvent &) {
 
 void SubsEditBox::OnEffectChange(wxCommandEvent &evt) {
 	bool amend = evt.GetEventType() == wxEVT_COMMAND_TEXT_UPDATED;
-	SetSelectedRows(&AssDialogue::Effect, Effect->GetValue(), _("effect change"), AssFile::COMMIT_DIAG_META, amend);
+	SetSelectedRows(&AssDialogue::Effect, boost::flyweight<wxString>(Effect->GetValue()), _("effect change"), AssFile::COMMIT_DIAG_META, amend);
 	PopulateList(Effect, &AssDialogue::Effect);
 }
 

aegisub/src/subs_edit_box.h

@@ -35,6 +35,7 @@
 #include <array>
 #include <deque>
 #include <boost/container/map.hpp>
+#include <boost/flyweight/flyweight_fwd.hpp>
 #include <vector>
 
 #include <wx/panel.h>
@@ -178,7 +179,7 @@ class SubsEditBox : public wxPanel {
 	void OnCommit(int type);
 
 	/// Regenerate a dropdown list with the unique values of a dialogue field
-	void PopulateList(wxComboBox *combo, wxString AssDialogue::*field);
+	void PopulateList(wxComboBox *combo, boost::flyweight<wxString> AssDialogue::*field);
 
 	/// @brief Enable or disable frame timing mode
 	void UpdateFrameTiming(agi::vfr::Framerate const& fps);

aegisub/src/subs_edit_ctrl.cpp

@@ -212,7 +212,7 @@ void SubsTextEditCtrl::UpdateStyle() {
 	}
 
 	AssDialogue *diag = context ? context->selectionController->GetActiveLine() : 0;
-	bool template_line = diag && diag->Comment && diag->Effect.Lower().StartsWith("template");
+	bool template_line = diag && diag->Comment && diag->Effect.get().Lower().StartsWith("template");
 
 	tokenized_line = agi::ass::TokenizeDialogueBody(line_text, template_line);
 	agi::ass::SplitWords(line_text, tokenized_line);

aegisub/src/subs_grid.cpp

@@ -57,11 +57,11 @@ SubtitlesGrid::SubtitlesGrid(wxWindow *parent, agi::Context *context)
 {
 }
 
-static void trim_text(AssDialogue *diag) {
+static void trim_text(wxString *text) {
 	static wxRegEx start("^( |\t|\\\\[nNh])+");
 	static wxRegEx end("( |\t|\\\\[nNh])+$");
-	start.ReplaceFirst(&diag->Text, "");
+	start.ReplaceFirst(text, "");
-	end.ReplaceFirst(&diag->Text, "");
+	end.ReplaceFirst(text, "");
 }
 
 static void expand_times(AssDialogue *src, AssDialogue *dst) {
@@ -69,6 +69,25 @@ static void expand_times(AssDialogue *src, AssDialogue *dst) {
 	dst->End = std::max(dst->End, src->End);
 }
 
+static bool check_lines(AssDialogue *d1, AssDialogue *d2, bool (wxString::*pred)(wxString const&, wxString *) const) {
+	wxString rest;
+	if ((d1->Text.get().*pred)(d2->Text.get(), &rest)) {
+		trim_text(&rest);
+		d1->Text = rest;
+		expand_times(d1, d2);
+		return true;
+	}
+	return false;
+}
+
+static bool check_start(AssDialogue *d1, AssDialogue *d2) {
+	return check_lines(d1, d2, &wxString::StartsWith);
+}
+
+static bool check_end(AssDialogue *d1, AssDialogue *d2) {
+	return check_lines(d1, d2, &wxString::EndsWith);
+}
+
 /// @brief Recombine
 void SubtitlesGrid::RecombineLines() {
 	Selection selectedSet = GetSelectedSet();
@@ -77,14 +96,17 @@ void SubtitlesGrid::RecombineLines() {
 	AssDialogue *activeLine = GetActiveLine();
 
 	std::vector<AssDialogue*> sel(selectedSet.begin(), selectedSet.end());
-	for_each(sel.begin(), sel.end(), trim_text);
 	sort(sel.begin(), sel.end(), &AssFile::CompStart);
+	for (auto &diag : sel) {
+		wxString text = diag->Text;
+		trim_text(&text);
+		diag->Text = text;
+	}
 
-	typedef std::vector<AssDialogue*>::iterator diag_iter;
+	auto end = sel.end() - 1;
-	diag_iter end = sel.end() - 1;
+	for (auto cur = sel.begin(); cur != end; ++cur) {
-	for (diag_iter cur = sel.begin(); cur != end; ++cur) {
 		AssDialogue *d1 = *cur;
-		diag_iter d2 = cur + 1;
+		auto d2 = cur + 1;
 
 		// 1, 1+2 (or 2+1), 2 gets turned into 1, 2, 2 so kill the duplicate
 		if (d1->Text == (*d2)->Text) {
@@ -94,43 +116,32 @@ void SubtitlesGrid::RecombineLines() {
 		}
 
 		// 1, 1+2, 1 turns into 1, 2, [empty]
-		if (d1->Text.empty()) {
+		if (d1->Text.get().empty()) {
 			delete d1;
 			continue;
 		}
+
 		// If d2 is the last line in the selection it'll never hit the above test
-		if (d2 == end && (*d2)->Text.empty()) {
+		if (d2 == end && (*d2)->Text.get().empty()) {
 			delete *d2;
 			continue;
 		}
 
 		// 1, 1+2
-		while (d2 <= end && (*d2)->Text.StartsWith(d1->Text, &(*d2)->Text)) {
+		while (d2 <= end && check_start(*d2, d1))
-			expand_times(*d2, d1);
-			trim_text(*d2);
 			++d2;
-		}
 
 		// 1, 2+1
-		while (d2 <= end && (*d2)->Text.EndsWith(d1->Text, &(*d2)->Text)) {
+		while (d2 <= end && check_end(*d2, d1))
-			expand_times(*d2, d1);
-			trim_text(*d2);
 			++d2;
-		}
 
 		// 1+2, 2
-		while (d2 <= end && d1->Text.EndsWith((*d2)->Text, &d1->Text)) {
+		while (d2 <= end && check_end(d1, *d2))
-			expand_times(d1, *d2);
-			trim_text(d1);
 			++d2;
-		}
 
 		// 2+1, 2
-		while (d2 <= end && d1->Text.StartsWith((*d2)->Text, &d1->Text)) {
+		while (d2 <= end && check_start(d1, *d2))
-			expand_times(d1, *d2);
-			trim_text(d1);
 			++d2;
-		}
 	}
 
 	// Remove now non-existent lines from the selection

aegisub/src/subtitle_format.cpp

@@ -170,19 +170,21 @@ void SubtitleFormat::StripTags(AssFile &file) {
 
 void SubtitleFormat::ConvertNewlines(AssFile &file, wxString const& newline, bool mergeLineBreaks) {
 	for (auto current : file.Line | agi::of_type<AssDialogue>()) {
-		current->Text.Replace("\\h", " ");
+		wxString repl(current->Text);
-		current->Text.Replace("\\n", newline);
+		repl.Replace("\\h", " ");
-		current->Text.Replace("\\N", newline);
+		repl.Replace("\\n", newline);
+		repl.Replace("\\N", newline);
 		if (mergeLineBreaks) {
-			while (current->Text.Replace(newline+newline, newline));
+			while (repl.Replace(newline+newline, newline));
 		}
+		current->Text = repl;
 	}
 }
 
 void SubtitleFormat::StripComments(AssFile &file) {
 	file.Line.remove_and_dispose_if([](AssEntry const& e) {
 		const AssDialogue *diag = dynamic_cast<const AssDialogue*>(&e);
-		return diag && (diag->Comment || !diag->Text);
+		return diag && (diag->Comment || !diag->Text.get());
 	}, [](AssEntry *e) { delete e; });
 }
 

aegisub/src/subtitle_format_ebu3264.cpp

@@ -416,7 +416,7 @@ namespace
 			else if (!imline.CheckLineLengths(export_settings.max_line_length))
 			{
 				if (export_settings.line_wrapping_mode == EbuExportSettings::AbortOverLength)
-					throw Ebu3264SubtitleFormat::ConversionFailed(STD_STR(wxString::Format(_("Line over maximum length: %s"), line->Text.c_str())), 0);
+					throw Ebu3264SubtitleFormat::ConversionFailed(STD_STR(wxString::Format(_("Line over maximum length: %s"), line->Text.get())), 0);
 				else // skip over-long lines
 					subs_list.pop_back();
 			}

aegisub/src/subtitle_format_encore.cpp

@@ -70,7 +70,6 @@ void EncoreSubtitleFormat::WriteFile(const AssFile *src, wxString const& filenam
 	StripTags(copy);
 	ConvertNewlines(copy, "\r\n");
 
-
 	// Encode wants ; for NTSC and : for PAL
 	// The manual suggests no other frame rates are supported
 	char sep = fps.NeedsDropFrames() ? ';' : ':';
@@ -79,8 +78,6 @@ void EncoreSubtitleFormat::WriteFile(const AssFile *src, wxString const& filenam
 	// Write lines
 	int i = 0;
 	TextFileWriter file(filename, "UTF-8");
-	for (auto current : copy.Line | agi::of_type<AssDialogue>()) {
+	for (auto current : copy.Line | agi::of_type<AssDialogue>())
-		++i;
+		file.WriteLineToFile(wxString::Format("%i %s %s %s", ++i, ft.ToSMPTE(current->Start), ft.ToSMPTE(current->End), current->Text.get()));
-		file.WriteLineToFile(wxString::Format("%i %s %s %s", i, ft.ToSMPTE(current->Start), ft.ToSMPTE(current->End), current->Text));
-	}
 }

aegisub/src/subtitle_format_microdvd.cpp

@@ -146,6 +146,6 @@ void MicroDVDSubtitleFormat::WriteFile(const AssFile *src, wxString const& filen
 		int start = fps.FrameAtTime(current->Start, agi::vfr::START);
 		int end = fps.FrameAtTime(current->End, agi::vfr::END);
 
-		file.WriteLineToFile(wxString::Format("{%i}{%i}%s", start, end, current->Text));
+		file.WriteLineToFile(wxString::Format("{%i}{%i}%s", start, end, current->Text.get()));
 	}
 }

aegisub/src/subtitle_format_srt.cpp

@@ -402,6 +402,7 @@ void SRTSubtitleFormat::ReadFile(AssFile *target, wxString const& filename, wxSt
 	int line_num = 0;
 	int linebreak_debt = 0;
 	AssDialogue *line = 0;
+	wxString text;
 	while (file.HasMoreLines()) {
 		wxString text_line = file.ReadLineFromFile();
 		line_num++;
@@ -426,8 +427,8 @@ void SRTSubtitleFormat::ReadFile(AssFile *target, wxString const& filename, wxSt
 found_timestamps:
 				if (line) {
 					// finalize active line
-					line->Text = tag_parser.ToAss(line->Text);
+					line->Text = tag_parser.ToAss(text);
-					line = 0;
+					text.clear();
 				}
 				// create new subtitle
 				line = new AssDialogue;
@@ -446,7 +447,7 @@ found_timestamps:
 					linebreak_debt = 0;
 					break;
 				}
-				line->Text.Append(text_line);
+				text.Append(text_line);
 				state = STATE_REST_OF_BODY;
 				break;
 			case STATE_REST_OF_BODY:
@@ -458,7 +459,7 @@ found_timestamps:
 					linebreak_debt = 1;
 					break;
 				}
-				line->Text.Append("\\N").Append(text_line);
+				text.Append("\\N").Append(text_line);
 				break;
 			case STATE_LAST_WAS_BLANK:
 				++linebreak_debt;
@@ -475,20 +476,19 @@ found_timestamps:
 				// assume it's a continuation of the subtitle text
 				// resolve our line break debt and append the line text
 				while (linebreak_debt-- > 0)
-					line->Text.Append("\\N");
+					text.Append("\\N");
-				line->Text.Append(text_line);
+				text.Append(text_line);
 				state = STATE_REST_OF_BODY;
 				break;
 		}
 	}
 
-	if (state == 1 || state == 2) {
+	if (state == 1 || state == 2)
 		throw SRTParseError("Parsing SRT: Incomplete file", 0);
-	}
 
 	if (line)
 		// an unfinalized line
-		line->Text = tag_parser.ToAss(line->Text);
+		line->Text = tag_parser.ToAss(text);
 }
 
 void SRTSubtitleFormat::WriteFile(const AssFile *src, wxString const& filename, wxString const& encoding) const {

aegisub/src/subtitle_format_transtation.cpp

@@ -71,6 +71,8 @@ void TranStationSubtitleFormat::WriteFile(const AssFile *src, wxString const& fi
 	StripComments(copy);
 	RecombineOverlaps(copy);
 	MergeIdentical(copy);
+	StripTags(copy);
+	ConvertNewlines(copy, "\r\n");
 
 	SmpteFormatter ft(fps);
 	TextFileWriter file(filename, encoding);
@@ -106,7 +108,7 @@ wxString TranStationSubtitleFormat::ConvertLine(AssFile *file, AssDialogue *curr
 
 	// Hack: If an italics-tag (\i1) appears anywhere in the line,
 	// make it all italics
-	if (current->Text.Find("\\i1") != wxNOT_FOUND) type = "I";
+	if (current->Text.get().Find("\\i1") != wxNOT_FOUND) type = "I";
 
 	// Write header
 	AssTime end = current->End;
@@ -118,14 +120,5 @@ wxString TranStationSubtitleFormat::ConvertLine(AssFile *file, AssDialogue *curr
 		end = fps.TimeAtFrame(fps.FrameAtTime(end, agi::vfr::END) - 1, agi::vfr::END);
 
 	wxString header = wxString::Format("SUB[%i%s%s ", valign, halign, type) + ft.ToSMPTE(current->Start) + ">" + ft.ToSMPTE(end) + "]\r\n";
-
-	// Process text
-	wxString lineEnd = "\r\n";
-	current->StripTags();
-	current->Text.Replace("\\h", " ", true);
-	current->Text.Replace("\\n", lineEnd, true);
-	current->Text.Replace("\\N", lineEnd, true);
-	while (current->Text.Replace(lineEnd + lineEnd, lineEnd, true));
-
 	return header + current->Text;
 }

aegisub/src/subtitle_format_txt.cpp

@@ -134,7 +134,7 @@ void TXTSubtitleFormat::WriteFile(const AssFile *src, wxString const& filename,
 	for (auto dia : src->Line | agi::of_type<AssDialogue>()) {
 		if (!dia->Comment) {
 			num_dialogue_lines++;
-			if (!dia->Actor.empty())
+			if (!dia->Actor.get().empty())
 				num_actor_names++;
 		}
 	}

aegisub/src/visual_tool_clip.cpp

@@ -117,7 +117,7 @@ void VisualToolClip::CommitHold() {
 	for (auto line : c->selectionController->GetSelectedSet()) {
 		// This check is technically not correct as it could be outside of an
 		// override block... but that's rather unlikely
-		bool has_iclip = line->Text.find("\\iclip") != wxString::npos;
+		bool has_iclip = line->Text.get().find("\\iclip") != wxString::npos;
 		SetOverride(line, has_iclip ? "\\iclip" : "\\clip", value);
 	}
 }

aegisub/src/visual_tool_vector_clip.cpp

@@ -198,7 +198,7 @@ void VisualToolVectorClip::Save() {
 	for (auto line : c->selectionController->GetSelectedSet()) {
 		// This check is technically not correct as it could be outside of an
 		// override block... but that's rather unlikely
-		bool has_iclip = line->Text.find("\\iclip") != wxString::npos;
+		bool has_iclip = line->Text.get().find("\\iclip") != wxString::npos;
 		SetOverride(line, has_iclip ? "\\iclip" : "\\clip", value);
 	}
 }