Merge pull request #139 from LostLuma/atomic-config-saving

Atomic config saving
juliand665 · Dec 16, 2023 · ec676e0 · ec676e0
2 parents dc8d0d5 + 18b2c08
commit ec676e0
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Showing 2 changed files with 15 additions and 8 deletions.
diff --git a/src/main/java/dynamic_fps/impl/DynamicFPSMod.java b/src/main/java/dynamic_fps/impl/DynamicFPSMod.java
@@ -62,8 +62,6 @@ public class DynamicFPSMod implements ClientModInitializer {
 
 	@Override
 	public void onInitializeClient() {
-		modConfig.save(); // Force create file on disk
-
 		toggleForcedKeyBinding.register();
 		toggleDisabledKeyBinding.register();
 

diff --git a/src/main/java/dynamic_fps/impl/config/DynamicFPSConfig.java b/src/main/java/dynamic_fps/impl/config/DynamicFPSConfig.java
@@ -5,6 +5,7 @@
 import java.nio.file.Files;
 import java.nio.file.NoSuchFileException;
 import java.nio.file.Path;
+import java.nio.file.StandardCopyOption;
 import java.util.EnumMap;
 import java.util.Map;
 
@@ -21,7 +22,9 @@
 public final class DynamicFPSConfig {
 	private Map<PowerState, Config> configs;
 
-	private static final Path PATH = FabricLoader.getInstance().getConfigDir().resolve(DynamicFPSMod.MOD_ID + ".json");
+	private static final Path CONFIGS = FabricLoader.getInstance().getConfigDir();
+	private static final Path CONFIG_FILE = CONFIGS.resolve(DynamicFPSMod.MOD_ID + ".json");
+
 	private static final Codec<Map<PowerState, Config>> STATES_CODEC = Codec.unboundedMap(PowerState.CODEC, Config.CODEC);
 
 	private static final Codec<DynamicFPSConfig> CODEC = RecordCodecBuilder.create(instance -> instance.group(
@@ -54,9 +57,11 @@ public static DynamicFPSConfig load() {
 		String data;
 
 		try {
-			data = Files.readString(PATH);
+			data = Files.readString(CONFIG_FILE);
 		} catch (NoSuchFileException e) {
-			return new DynamicFPSConfig(new EnumMap<>(PowerState.class));
+			var config = new DynamicFPSConfig(new EnumMap<>(PowerState.class));
+			config.save();
+			return config;
 		} catch (IOException e) {
 			throw new RuntimeException("Failed to load Dynamic FPS config.", e);
 		}
@@ -72,10 +77,14 @@ public void save() {
 		var root = data.getOrThrow(false, RuntimeException::new);
 
 		try {
-			Files.writeString(PATH, root.toString(), StandardCharsets.UTF_8);
+			var temp = Files.createTempFile(CONFIGS, "dynamic_fps", ".json");
+			Files.writeString(temp, root.toString(), StandardCharsets.UTF_8);
+
+			Files.deleteIfExists(CONFIG_FILE);
+			Files.move(temp, CONFIG_FILE, StandardCopyOption.ATOMIC_MOVE);
 		} catch (IOException e) {
-			// Cloth Config's automatic saving does not support catching exceptions
-			throw new RuntimeException("Failed to save Dynamic FPS config.", e);
+			// Cloth Config's built-in saving does not support catching exceptions :(
+			throw new RuntimeException("Failed to save or modify Dynamic FPS config!", e);
 		}
 	}