Some small improvements to RAM usage

Originally committed to SVN as r99.

core/ass_file.cpp

@@ -924,6 +924,23 @@ void AssFile::AddToRecent(wxString file) {
 }
 
 
+////////////////////////////////////////////
+// Compress/decompress for storage on stack
+void AssFile::CompressForStack(bool compress) {
+	AssDialogue *diag;
+	for (entryIter cur=Line.begin();cur!=Line.end();cur++) {
+		diag = AssEntry::GetAsDialogue(*cur);
+		if (diag) {
+			if (compress) {
+				diag->data.Clear();
+				diag->ClearBlocks();
+			}
+			else diag->UpdateData();
+		}
+	}
+}
+
+
 //////////////////////////////
 // Checks if file is modified
 bool AssFile::IsModified() {
@@ -954,6 +971,7 @@ void AssFile::FlagAsModified() {
 void AssFile::StackPush() {
 	// Places copy on stack
 	AssFile *curcopy = new AssFile(*top);
+	curcopy->CompressForStack(true);
 	UndoStack.push_back(curcopy);
 	StackModified = true;
 
@@ -983,8 +1001,10 @@ void AssFile::StackPop() {
 
 	if (!UndoStack.empty()) {
 		//delete top;
+		top->CompressForStack(true);
 		RedoStack.push_back(top);
 		top = UndoStack.back();
+		top->CompressForStack(false);
 		UndoStack.pop_back();
 		Popping = true;
 	}
@@ -1007,8 +1027,10 @@ void AssFile::StackRedo() {
 	}
 
 	if (!RedoStack.empty()) {
+		top->CompressForStack(true);
 		UndoStack.push_back(top);
 		top = RedoStack.back();
+		top->CompressForStack(false);
 		RedoStack.pop_back();
 		Popping = true;
 		//StackModified = false;

core/ass_file.h

@@ -97,6 +97,7 @@ public:
 	bool IsModified();									// Returns if file has unmodified changes
 	void FlagAsModified();								// Flag file as being modified, will automatically put a copy on stack
 	void Clear();										// Wipes file
+	void CompressForStack(bool compress);				// Compress/decompress for storage on stack
 	void LoadDefault(bool noline=true);					// Loads default file. Pass true to prevent it from adding a default line too
 	void InsertStyle(AssStyle *style);					// Inserts a style to file
 	wxArrayString GetStyles();							// Gets a list of all styles available

core/changelog.txt

@@ -39,7 +39,7 @@ Please visit http://aegisub.net to download latest version
 - Added a simple audio resync method afor video playback. (AMZ)
 - Audio timing will now apply to all selected lines, as well as active line. (AMZ)
 - Added a volume slider bar to audio mode. (AMZ)
-- Fixed some internal workings, which should make Aegisub use considerably less RAM (especially for large Karaoke files, 3x less RAM usage measured). (AMZ)
+- Fixed some internal workings, which should make Aegisub use considerably less RAM (especially for large Karaoke files, 3-4x less RAM usage was measured with a 9 MB file). (AMZ)
 - Aegisub will now dump the stack to stack.txt when it crashes with a fatal exception, which might or might not work. (AMZ)
 - Audio display in SSA mode will no longer ignore clicks if it wasn't focused (AMZ)