Implement multi-subject and incremental backup

src/main/java/io/ib67/sfcraft/BackupWorker.java

@@ -1,8 +1,6 @@
 package io.ib67.sfcraft;
 
 import io.ib67.sfcraft.bundler.BundleWriter;
-import io.ib67.sfcraft.config.JustBackupConfig;
-import io.ib67.sfcraft.mixin.LevelStorageAccessor;
 import io.ib67.sfcraft.strategy.BackupStrategy;
 import lombok.SneakyThrows;
 import lombok.extern.log4j.Log4j2;
@@ -10,20 +8,25 @@ import net.minecraft.server.MinecraftServer;
 
 import java.nio.file.Files;
 import java.nio.file.Path;
-import java.time.LocalDateTime;
-import java.time.format.DateTimeFormatter;
-import java.util.List;
 import java.util.function.Supplier;
+import java.util.function.UnaryOperator;
 
-import static io.ib67.sfcraft.JustBackupMod.BACKUP_LOCK;
+import static io.ib67.sfcraft.Globals.BACKUP_LOCK;
 
 @Log4j2
 public record BackupWorker(
         MinecraftServer server,
         BackupStrategy strategy,
-        JustBackupConfig config
+        Path tmpDir,
+        BackupSubject subject,
+        UnaryOperator<BundleWriter.BundleWriterBuilder> config
 ) implements Supplier<Backup> {
 
+    @SneakyThrows
+    public BackupWorker {
+        if (Files.notExists(tmpDir)) Files.createDirectories(tmpDir);
+    }
+
     @Override
     @SneakyThrows
     public Backup get() {
@@ -37,29 +40,17 @@ public record BackupWorker(
             Thread.sleep(2000);
         }
         // performing backup is now true
-        var backupName = "Backup_" + DateTimeFormatter.ISO_LOCAL_DATE_TIME.format(LocalDateTime.now());
-        var backupParentRoot = Path.of(config.temporaryBackupDir());
-        if (Files.notExists(backupParentRoot)) Files.createDirectories(backupParentRoot);
-        var backupFile = backupParentRoot.resolve(backupName + ".jbp.zst");
+        var tmpBundle = tmpDir.resolve("backup_" + subject + "_" + System.currentTimeMillis() + ".swb.zst");
         try {
             if (i == 0) {
                 // not saved yet.
                 server.saveAll(true, true, false);
             }
-            var session = ((LevelStorageAccessor) server).getSession();
-            var path = session.getDirectory().getRootPath();
-            log.info("Creating bundle {}", backupName);
-            //todo diff
-            Path worldDir = Path.of(path);
-            var tree = new WorldDir(worldDir);
-            BundleWriter.createBundle(backupFile, tree.everything(), c -> c.allowGunzip(config.allowGunzip())
-                    .relativeRoot(worldDir)
-                    .compressionLevel(config.compressionLevel()));
-            var backup = strategy.createBackup(worldDir, backupFile);
-            Files.deleteIfExists(backupFile);
-            return backup;
+            // tmp file path
+            log.info("Creating bundle {}", tmpBundle);
+            BundleWriter.createBundle(tmpBundle, subject.changedFiles(), config);
+            return strategy.createBackup(subject.name(), subject.root(), tmpBundle);
         } catch (Exception e) {
-            Files.deleteIfExists(backupFile);
             throw e;
         } finally {
             // Though we won't access the state within backup progress, there are certain cases
@@ -69,6 +60,7 @@ public record BackupWorker(
                 log.error("Expect BACKUP state but got {}", BACKUP_LOCK.get());
                 Thread.sleep(2000);
             }
+            Files.deleteIfExists(tmpBundle);
         }
     }
 }