feat(versioned): Add versioned feature

features/versioned/pom.xml

@@ -0,0 +1,51 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <parent>
+        <groupId>cc.carm.lib</groupId>
+        <artifactId>easyconfiguration-parent</artifactId>
+        <version>3.9.1</version>
+        <relativePath>../../pom.xml</relativePath>
+    </parent>
+    <properties>
+        <maven.compiler.source>${project.jdk.version}</maven.compiler.source>
+        <maven.compiler.target>${project.jdk.version}</maven.compiler.target>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+        <maven.compiler.encoding>UTF-8</maven.compiler.encoding>
+    </properties>
+
+    <artifactId>easyconfiguration-feature-versioned</artifactId>
+    <packaging>jar</packaging>
+
+    <dependencies>
+        <dependency>
+            <groupId>${project.groupId}</groupId>
+            <artifactId>easyconfiguration-core</artifactId>
+            <version>${project.version}</version>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-jar-plugin</artifactId>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-source-plugin</artifactId>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-javadoc-plugin</artifactId>
+            </plugin>
+        </plugins>
+    </build>
+
+</project>

features/versioned/src/main/java/cc/carm/lib/configuration/annotation/ConfigVersion.java

@@ -0,0 +1,28 @@
+package cc.carm.lib.configuration.annotation;
+
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Range;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+
+/**
+ * The version of specific {@link cc.carm.lib.configuration.value.ConfigValue}.
+ * <br> Used for versioning target field for rewrite/upgrade.
+ */
+@Target({ElementType.FIELD})
+@Retention(RetentionPolicy.RUNTIME)
+public @interface ConfigVersion {
+
+    /**
+     * The version of the configuration field.
+     *
+     * @return the version of the configuration field
+     */
+    @Range(from = 0, to = Integer.MAX_VALUE)
+    int value() default 0;
+
+}

features/versioned/src/main/java/cc/carm/lib/configuration/commentable/VersionedMetaTypes.java

@@ -0,0 +1,25 @@
+package cc.carm.lib.configuration.commentable;
+
+import cc.carm.lib.configuration.annotation.ConfigVersion;
+import cc.carm.lib.configuration.source.ConfigurationHolder;
+import cc.carm.lib.configuration.source.loader.ConfigurationInitializer;
+import cc.carm.lib.configuration.source.meta.ConfigurationMetadata;
+import org.jetbrains.annotations.NotNull;
+
+public interface VersionedMetaTypes {
+
+    /**
+     * The version of specific {@link cc.carm.lib.configuration.value.ConfigValue}.
+     * <br> Used for versioning target field for rewrite/upgrade.
+     */
+    ConfigurationMetadata<Integer> VERSION = ConfigurationMetadata.of(0);
+
+    static void register(@NotNull ConfigurationHolder<?> provider) {
+        register(provider.initializer());
+    }
+
+    static void register(@NotNull ConfigurationInitializer initializer) {
+        initializer.registerAnnotation(ConfigVersion.class, VERSION, ConfigVersion::value);
+    }
+
+}

features/versioned/src/main/java/cc/carm/lib/configuration/option/VersionedOptions.java

@@ -0,0 +1,13 @@
+package cc.carm.lib.configuration.option;
+
+import cc.carm.lib.configuration.source.option.ConfigurationOption;
+
+public interface VersionedOptions {
+
+    /**
+     * Whether to set newer defaults when a {@link cc.carm.lib.configuration.value.ConfigValue}'s marked version
+     * is newer than the current in storage.
+     */
+    ConfigurationOption<Boolean> RESET_NEWER_DEFAULTS = ConfigurationOption.of(true);
+
+}

pom.xml

@@ -20,6 +20,7 @@
         <module>core</module>
         <module>features/commentable</module>
         <module>features/file</module>
+        <module>features/versioned</module>
 
         <module>providers/yaml</module>
         <module>providers/gson</module>