Build configuration DFU system. (#2589)

* Build configuration DFU system.

* Remove redundant object allocation.

* Fix

* Code cleanup

* Remove unnecessary GSON usage.

* Fix compiletime unchecked warning.

HMCL/src/main/java/org/jackhuang/hmcl/setting/ConfigHolder.java

@@ -17,7 +17,6 @@
  */
 package org.jackhuang.hmcl.setting;
 
-import com.google.gson.Gson;
 import com.google.gson.JsonParseException;
 import org.jackhuang.hmcl.Metadata;
 import org.jackhuang.hmcl.util.InvocationDispatcher;
@@ -28,7 +27,6 @@ import org.jackhuang.hmcl.util.platform.OperatingSystem;
 
 import java.io.IOException;
 import java.nio.file.*;
-import java.util.Map;
 import java.util.logging.Level;
 
 import static org.jackhuang.hmcl.util.Logging.LOG;
@@ -167,8 +165,7 @@ public final class ConfigHolder {
                 if (deserialized == null) {
                     LOG.info("Config is empty");
                 } else {
-                    Map<?, ?> raw = new Gson().fromJson(content, Map.class);
+                    ConfigUpgrader.upgradeConfig(deserialized, content);
-                    ConfigUpgrader.upgradeConfig(deserialized, raw);
                     return deserialized;
                 }
             } catch (JsonParseException e) {

HMCL/src/main/java/org/jackhuang/hmcl/setting/ConfigUpgrader.java

@@ -17,49 +17,70 @@
  */
 package org.jackhuang.hmcl.setting;
 
+import com.google.gson.Gson;
+import org.jackhuang.hmcl.util.Lang;
+import org.jackhuang.hmcl.util.Pair;
 import org.jackhuang.hmcl.util.StringUtils;
+
+import java.util.Collections;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
+import java.util.function.BiConsumer;
+import java.util.logging.Level;
 
 import static org.jackhuang.hmcl.util.Lang.tryCast;
+import static org.jackhuang.hmcl.util.Logging.LOG;
 
 final class ConfigUpgrader {
-    private static final int VERSION = 0;
-
     private ConfigUpgrader() {
     }
 
+    private static final int CURRENT_VERSION = 1;
+
     /**
-     * This method is for the compatibility with old HMCL 3.x as well as HMCL 2.x.
+     * This method is for the compatibility with old HMCL versions.
      *
      * @param deserialized deserialized config settings
-     * @param rawJson      raw json structure of the config settings without modification
+     * @param rawContent   raw json content of the config settings without modification
-     * @return true if config version is upgraded
      */
-    static boolean upgradeConfig(Config deserialized, Map<?, ?> rawJson) {
+    static void upgradeConfig(Config deserialized, String rawContent) {
-        boolean upgraded;
+        if (deserialized.getConfigVersion() == CURRENT_VERSION) {
-        if (deserialized.getConfigVersion() < VERSION) {
+            return;
-            deserialized.setConfigVersion(VERSION);
-            // TODO: Add upgrade code here.
-            upgraded = true;
-        } else {
-            upgraded = false;
         }
 
-        upgradeV2(deserialized, rawJson);
+        int configVersion = deserialized.getConfigVersion();
-        upgradeV3(deserialized, rawJson);
+        if (configVersion > CURRENT_VERSION) {
+            LOG.log(Level.WARNING, String.format("Current HMCL only support the configuration version up to %d. However, the version now is %d.", CURRENT_VERSION, configVersion));
+            return;
+        }
 
-        return upgraded;
+        LOG.log(Level.INFO, String.format("Updating configuration from %d to %d.", configVersion, CURRENT_VERSION));
+        Map<?, ?> unmodifiableRawJson = Collections.unmodifiableMap(new Gson().<Map<?, ?>>fromJson(rawContent, Map.class));
+        for (Map.Entry<Integer, BiConsumer<Config, Map<?, ?>>> dfu : collectDFU()) {
+            if (configVersion < dfu.getKey()) {
+                dfu.getValue().accept(deserialized, unmodifiableRawJson);
+                configVersion = dfu.getKey();
+            }
+        }
+
+        deserialized.setConfigVersion(CURRENT_VERSION);
     }
 
     /**
-     * Upgrade configuration of HMCL 2.x
+     * <p>Initialize the dfu of HMCL. Feel free to use lambda as all the lambda here would not be initialized unless HMCL needs to update the configuration.
+     * For each item in this list, it should be a Map.Entry.</p>
      *
-     * @param deserialized deserialized config settings
+     * <p>The key should be a version number. All the configuration with a version number which is less than the specific one will be applied to this upgrader.</p>
-     * @param rawJson      raw json structure of the config settings without modification
+     * <p>The value should be the upgrader. The configuration which is waited to being processed, and the raw unmodifiable value of the json from the configuration file.</p>
+     * <p>The return value should a target version number of this item.</p>
+     *
+     * <p>The last item must return CURRENT_VERSION, as the config file should always being updated to the latest version.</p>
      */
-    private static void upgradeV2(Config deserialized, Map<?, ?> rawJson) {
+    private static List<Map.Entry<Integer, BiConsumer<Config, Map<?, ?>>>> collectDFU() {
-        // Convert OfflineAccounts whose stored uuid is important.
+        List<Map.Entry<Integer, BiConsumer<Config, Map<?, ?>>>> dfu = Lang.immutableListOf(
+                Pair.pair(1, (deserialized, rawJson) -> {
+                    // Upgrade configuration of HMCL 2.x: Convert OfflineAccounts whose stored uuid is important.
                     tryCast(rawJson.get("auth"), Map.class).ifPresent(auth -> {
                         tryCast(auth.get("offline"), Map.class).ifPresent(offline -> {
                             String selected = rawJson.containsKey("selectedAccount") ? null
@@ -79,15 +100,8 @@ final class ConfigUpgrader {
                             });
                         });
                     });
-    }
 
-    /**
+                    // Upgrade configuration of HMCL earlier than 3.1.70
-     * Upgrade configuration of HMCL earlier than 3.1.70
-     *
-     * @param deserialized deserialized config settings
-     * @param rawJson      raw json structure of the config settings without modification
-     */
-    private static void upgradeV3(Config deserialized, Map<?, ?> rawJson) {
                     if (!rawJson.containsKey("commonDirType"))
                         deserialized.setCommonDirType(deserialized.getCommonDirectory().equals(Settings.getDefaultCommonDirectory()) ? EnumCommonDirectory.DEFAULT : EnumCommonDirectory.CUSTOM);
                     if (!rawJson.containsKey("backgroundType"))
@@ -108,5 +122,13 @@ final class ConfigUpgrader {
                                     }
                                 });
                     }
+                })
+        );
+
+        if (dfu.get(dfu.size() - 1).getKey() != CURRENT_VERSION) {
+            throw new IllegalStateException("The last dfu must adapt all the config version below CURRENT_VERSION");
+        }
+
+        return dfu;
     }
 }