Attempt to save the game and world data atomically.

src/game/game.c

@@ -345,7 +345,7 @@ void loadGame(int slot)
 	free(filename);
 }
 
-void saveGame(void)
+void saveGame(int isTempFile)
 {
 	cJSON *root, *statsJSON, *keysJSON, *keyJSON, *missionsJSON, *missionJSON, *trophiesJSON, *trophyJSON;
 	char *filename, *out;
@@ -353,7 +353,14 @@ void saveGame(void)
 	Trophy *trophy;
 	int i;
 
-	filename = buildFormattedString("%s/%d/game.json", app.saveDir, game.saveSlot);
+	if (!isTempFile)
+	{
+		filename = buildFormattedString("%s/%d/game.json", app.saveDir, game.saveSlot);
+	}
+	else
+	{
+		filename = buildFormattedString("%s/%d/game.json.tmp", app.saveDir, game.saveSlot);
+	}
 
 	SDL_LogMessage(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_INFO, "Saving game to '%s' ...", filename);
 

src/game/title.c

@@ -339,7 +339,7 @@ static void doOK(void)
 	
 	game.saveSlot = saveSlot;
 	
-	saveGame();
+	saveGame(0);
 }
 
 static void doCancel(void)

src/game/title.h

@@ -49,7 +49,7 @@ extern void loadGame(int slot);
 extern void loadMusic(char *filename);
 extern void newGame(void);
 extern void playMusic(int loop);
-extern void saveGame(void);
+extern void saveGame(int isTempFile);
 extern void setSelectedWidget(char *name, char *group);
 extern void showWidgetGroup(char *group);
 extern void startSectionTransition(void);

src/hub/hub.c

@@ -596,7 +596,7 @@ static void startMission(void)
 {
 	STRNCPY(game.worldId, selectedMission->id, MAX_NAME_LENGTH);
 	
-	saveGame();
+	saveGame(0);
 	
 	stopMusic();
 	
@@ -764,7 +764,7 @@ static void awardMissionTrophies(void)
 	
 	if (save)
 	{
-		saveGame();
+		saveGame(0);
 	}
 }
 

src/hub/hub.h

@@ -67,7 +67,7 @@ extern void playMusic(int loop);
 extern void playSound(int snd, int ch);
 extern double randF(void);
 extern char *readFile(const char *filename);
-extern void saveGame(void);
+extern void saveGame(int isTempFile);
 extern void scrollBackground(float x, float y);
 extern Widget *selectWidgetAt(int x, int y);
 extern void showWidgetGroup(char *group);

src/hub/postMission.c

@@ -24,6 +24,7 @@ static void logic(void);
 static void draw(void);
 static void updateMissionStatus(void);
 static int getPostMissionStatus(void);
+static void saveGameAndWorld(void);
 
 static int status;
 static float missionCompleteY;
@@ -43,9 +44,7 @@ void initPostMission(void)
 	
 	if (world.state == WS_GAME_COMPLETE)
 	{
-		saveGame();
-		
-		saveWorld();
+		saveGameAndWorld();
 
 		destroyWorld();
 		
@@ -66,9 +65,7 @@ void initPostMission(void)
 		app.delegate.logic = &logic;
 		app.delegate.draw = &draw;
 		
-		saveGame();
-		
-		saveWorld();
+		saveGameAndWorld();
 		
 		endSectionTransition();
 	}
@@ -76,26 +73,46 @@ void initPostMission(void)
 	{
 		if (world.isReturnVisit)
 		{
-			saveWorld();
+			saveGameAndWorld();
 		}
 		else
 		{
 			restoreGameState();
+			
+			saveGame(0);
 		}
 		
-		saveGame();
-		
 		destroyWorld();
 
 		initHub();
 	}
 }
 
+static void saveGameAndWorld(void)
+{
+	char *src, *dest;
+	
+	saveGame(1);
+	
+	saveWorld();
+
+	src = buildFormattedString("%s/%d/%s.json.tmp", app.saveDir, game.saveSlot, world.id);
+	dest = buildFormattedString("%s/%d/%s.json", app.saveDir, game.saveSlot, world.id);
+	renameFile(src, dest);
+	
+	src = buildFormattedString("%s/%d/game.json.tmp", app.saveDir, game.saveSlot);
+	dest = buildFormattedString("%s/%d/game.json", app.saveDir, game.saveSlot, world.id);
+	renameFile(src, dest);
+	
+	free(src);
+	free(dest);
+}
+
 void retryMission(void)
 {
 	restoreGameState();
 	
-	saveGame();
+	saveGame(0);
 	
 	initWorld();
 }
@@ -104,7 +121,7 @@ void returnToHub(void)
 {
 	restoreGameState();
 		
-	saveGame();
+	saveGame(0);
 	
 	destroyWorld();
 

src/hub/postMission.h

@@ -34,9 +34,11 @@ extern int isAcceptControl(void);
 extern float limit(float i, float low, float high);
 extern void playSound(int snd, int ch);
 extern void restoreGameState(void);
-extern void saveGame(void);
+extern void saveGame(int isTempFile);
 extern void saveWorld(void);
 extern void startSectionTransition(void);
+extern char *buildFormattedString(const char *format, ...);
+extern int renameFile(char *src, char *dest);
 
 extern App app;
 extern Colors colors;

src/system/io.c

@@ -200,6 +200,11 @@ int deleteFile(char *path)
 	return unlink(path) == 0;
 }
 
+int renameFile(char *src, char *dest)
+{
+	return rename(src, dest) == 0;
+}
+
 static int stringComparator(const void *a, const void *b)
 {
     char **s1 = (char **)a;

src/test/worldTest.c

@@ -24,7 +24,7 @@ void initWorldTest(char *worldId)
 {
 	loadGame(0);
 	
-	saveGame();
+	saveGame(0);
 	
 	if (worldId != NULL)
 	{

src/test/worldTest.h

@@ -23,6 +23,6 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 extern void initHub(void);
 extern void initWorld(void);
 extern void loadGame(int slot);
-extern void saveGame(void);
+extern void saveGame(int isTempFile);
 
 extern Game game;

src/world/worldSaver.c

@@ -32,7 +32,7 @@ void saveWorld(void)
 	cJSON *root;
 	char *filename, *out;
 
-	filename = buildFormattedString("%s/%d/%s.json", app.saveDir, game.saveSlot, world.id);
+	filename = buildFormattedString("%s/%d/%s.json.tmp", app.saveDir, game.saveSlot, world.id);
 
 	SDL_LogMessage(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_INFO, "Saving world to '%s' ...", filename);