feature: configurable CoW incremental backup

9 files changed, 175 insertions, 4 deletions

diff --git a/src/main/java/com/keuin/kbackupfabric/KBCommandsRegister.java b/src/main/java/com/keuin/kbackupfabric/KBCommandsRegister.java
index 5bf92e4..7e454d2 100644
--- a/src/main/java/com/keuin/kbackupfabric/KBCommandsRegister.java
+++ b/src/main/java/com/keuin/kbackupfabric/KBCommandsRegister.java
@@ -58,6 +58,10 @@ public final class KBCommandsRegister {
                         .requires(Permissions.require("kb.list", DEFAULT_REQUIRED_LEVEL))
                         .executes(KBCommands::list)));
 
+        dispatcher.register(CommandManager.literal("kb")
+                .then(CommandManager.literal("cow-info")
+                        .executes(KBCommands::cowInfo)));
+
         // register /kb delete [name] for deleting an existing backup. OP is required.
         dispatcher.register(CommandManager.literal("kb")
                 .then(CommandManager.literal("delete")
diff --git a/src/main/java/com/keuin/kbackupfabric/KBPluginEvents.java b/src/main/java/com/keuin/kbackupfabric/KBPluginEvents.java
index 362abb8..20e9058 100644
--- a/src/main/java/com/keuin/kbackupfabric/KBPluginEvents.java
+++ b/src/main/java/com/keuin/kbackupfabric/KBPluginEvents.java
@@ -2,6 +2,7 @@ package com.keuin.kbackupfabric;
 
 import com.keuin.kbackupfabric.backup.BackupFilesystemUtil;
 import com.keuin.kbackupfabric.backup.suggestion.BackupNameSuggestionProvider;
+import com.keuin.kbackupfabric.config.KBackupConfig;
 import com.keuin.kbackupfabric.event.OnPlayerConnect;
 import com.keuin.kbackupfabric.metadata.BackupMetadata;
 import com.keuin.kbackupfabric.metadata.MetadataHolder;
@@ -32,7 +33,15 @@ public final class KBPluginEvents implements ModInitializer {
 
     @Override
     public void onInitialize() {
-        System.out.println("Binding events and commands ...");
+        PrintUtil.info("Reading config...");
+        try {
+            KBackupConfig.load();
+        } catch (IOException e) {
+            PrintUtil.error("Failed to read config file, using default values: " + e + e.getMessage());
+        }
+        boolean incCow = KBackupConfig.getInstance().getIncbakCow();
+        PrintUtil.info("Incremental backup CoW: " + (incCow ? "enabled" : "disabled"));
+        PrintUtil.info("Binding events and commands...");
         CommandRegistrationCallback.EVENT.register(KBCommandsRegister::registerCommands);
         OnPlayerConnect.ON_PLAYER_CONNECT.register((connection, player)
                 -> NotificationManager.INSTANCE.notifyPlayer(DistinctNotifiable.fromServerPlayerEntity(player)));
diff --git a/src/main/java/com/keuin/kbackupfabric/backup/incremental/manager/IncrementalBackupStorageManager.java b/src/main/java/com/keuin/kbackupfabric/backup/incremental/manager/IncrementalBackupStorageManager.java
index 7870620..53143f8 100644
--- a/src/main/java/com/keuin/kbackupfabric/backup/incremental/manager/IncrementalBackupStorageManager.java
+++ b/src/main/java/com/keuin/kbackupfabric/backup/incremental/manager/IncrementalBackupStorageManager.java
@@ -4,15 +4,18 @@ import com.keuin.kbackupfabric.backup.incremental.ObjectCollection2;
 import com.keuin.kbackupfabric.backup.incremental.ObjectCollectionIterator;
 import com.keuin.kbackupfabric.backup.incremental.ObjectElement;
 import com.keuin.kbackupfabric.backup.incremental.identifier.ObjectIdentifier;
+import com.keuin.kbackupfabric.config.KBackupConfig;
 import com.keuin.kbackupfabric.util.FilesystemUtil;
 import com.keuin.kbackupfabric.util.PrintUtil;
+import com.keuin.kbackupfabric.util.cow.FileCopier;
+import com.keuin.kbackupfabric.util.cow.FileCowCopier;
+import com.keuin.kbackupfabric.util.cow.FileEagerCopier;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.IOException;
-import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.*;
 import java.util.logging.Logger;
@@ -27,9 +30,26 @@ public class IncrementalBackupStorageManager {
     private final Logger logger = Logger.getLogger(IncrementalBackupStorageManager.class.getName());
     private final Path backupStorageBase;
     private final Logger LOGGER = Logger.getLogger(IncrementalBackupStorageManager.class.getName());
+    private FileCopier copier;
 
     public IncrementalBackupStorageManager(Path backupStorageBase) {
         this.backupStorageBase = backupStorageBase;
+        if (KBackupConfig.getInstance().getIncbakCow()) {
+            // try to use cow copier, if failed, fallback to normal copier
+            try {
+                this.copier = FileCowCopier.getInstance();
+            } catch (Exception | UnsatisfiedLinkError ex) {
+                PrintUtil.error("Failed to initialize kbackup-cow: " + ex + ex.getMessage());
+                this.copier = new FileEagerCopier();
+            }
+        } else {
+            this.copier = new FileEagerCopier();
+        }
+        if (this.copier.isCow()) {
+            PrintUtil.info("Copy-on-write is enabled");
+        } else {
+            PrintUtil.info("Copy-on-write is disabled");
+        }
     }
 
     /**
@@ -85,7 +105,7 @@ public class IncrementalBackupStorageManager {
             if (!contains(entry.getValue())) {
                 // element does not exist. copy.
                 logger.fine("Copy new file `" + copySourceFile.getName() + "`.");
-                Files.copy(copySourceFile.toPath(), copyDestination.toPath());
+                copier.copy(copyDestination.getAbsolutePath(), copySourceFile.getAbsolutePath());
                 copyCount = copyCount.addWith(new IncCopyResult(1, 1, fileBytes, fileBytes));
             } else {
                 // element exists (file reused). Just update the stat info
@@ -198,7 +218,7 @@ public class IncrementalBackupStorageManager {
                 }
             }
 
-            Files.copy(copySource.toPath(), copyTarget.toPath());
+            copier.copy(copyTarget.getAbsolutePath(), copySource.getAbsolutePath());
             ++copyCount;
         }
 
diff --git a/src/main/java/com/keuin/kbackupfabric/config/KBackupConfig.java b/src/main/java/com/keuin/kbackupfabric/config/KBackupConfig.java
new file mode 100644
index 0000000..8ece8d2
--- /dev/null
+++ b/src/main/java/com/keuin/kbackupfabric/config/KBackupConfig.java
@@ -0,0 +1,56 @@
+package com.keuin.kbackupfabric.config;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.ObjectWriter;
+import com.keuin.kbackupfabric.util.PrintUtil;
+
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+
+public class KBackupConfig {
+
+    private static KBackupConfig instance = getDefault();
+    private static final String CONFIG_FILE = "kbackup.json";
+
+    @JsonProperty("incbak_cow")
+    private Boolean incbakCow;
+
+    public static KBackupConfig getInstance() {
+        return instance;
+    }
+
+    private static KBackupConfig getDefault() {
+        return new KBackupConfig(false);
+    }
+
+    public static void load() throws IOException {
+        File file = new File(CONFIG_FILE);
+        ObjectMapper om = new ObjectMapper();
+        try {
+            instance = om.readValue(file, KBackupConfig.class);
+        } catch (FileNotFoundException ignored) {
+            // generate default config file
+            PrintUtil.info("Config file does not exist. Creating default config: " + CONFIG_FILE);
+            instance = getDefault();
+            ObjectWriter w = om.writerWithDefaultPrettyPrinter();
+            w.writeValue(file, instance);
+        }
+    }
+
+    public KBackupConfig() {
+    }
+
+    public KBackupConfig(Boolean incbakCow) {
+        this.incbakCow = incbakCow;
+    }
+
+    public Boolean getIncbakCow() {
+        return this.incbakCow;
+    }
+
+    public void setIncbakCow(Boolean incbakCow) {
+        this.incbakCow = incbakCow;
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/com/keuin/kbackupfabric/operation/backup/method/ConfiguredIncrementalBackupMethod.java b/src/main/java/com/keuin/kbackupfabric/operation/backup/method/ConfiguredIncrementalBackupMethod.java
index cfc9b81..3d9007d 100644
--- a/src/main/java/com/keuin/kbackupfabric/operation/backup/method/ConfiguredIncrementalBackupMethod.java
+++ b/src/main/java/com/keuin/kbackupfabric/operation/backup/method/ConfiguredIncrementalBackupMethod.java
@@ -99,6 +99,7 @@ public class ConfiguredIncrementalBackupMethod implements ConfiguredBackupMethod
             PrintUtil.info("Incremental backup finished.");
             feedback = new IncrementalBackupFeedback(true, copyResult);
         } catch (IOException e) {
+            PrintUtil.error("Incremental backup failed: " + e + e.getMessage());
             feedback = new IncrementalBackupFeedback(e);
         }
 
diff --git a/src/main/java/com/keuin/kbackupfabric/ui/KBCommands.java b/src/main/java/com/keuin/kbackupfabric/ui/KBCommands.java
index d23a6fd..0dff99a 100644
--- a/src/main/java/com/keuin/kbackupfabric/ui/KBCommands.java
+++ b/src/main/java/com/keuin/kbackupfabric/ui/KBCommands.java
@@ -14,6 +14,7 @@ import com.keuin.kbackupfabric.operation.backup.method.ConfiguredIncrementalBack
 import com.keuin.kbackupfabric.operation.backup.method.ConfiguredPrimitiveBackupMethod;
 import com.keuin.kbackupfabric.util.DateUtil;
 import com.keuin.kbackupfabric.util.PrintUtil;
+import com.keuin.kbackupfabric.util.cow.FileCowCopier;
 import com.mojang.brigadier.arguments.StringArgumentType;
 import com.mojang.brigadier.context.CommandContext;
 import net.minecraft.server.MinecraftServer;
@@ -75,6 +76,7 @@ public final class KBCommands {
         msgInfo(context, "/kb restore <backup_name> - Delete the whole current level and restore from given backup. /kb restore is identical with /kb list.");
         msgInfo(context, "/kb confirm - Confirm and start restoring.");
         msgInfo(context, "/kb cancel - Cancel the restoration to be confirmed. If cancelled, /kb confirm will not run.");
+        msgInfo(context, "/kb cow-info - Display copy-on-write support info (Experimental)");
         return SUCCESS;
     }
 
@@ -135,6 +137,15 @@ public final class KBCommands {
         return SUCCESS;
     }
 
+    public static int cowInfo(CommandContext<ServerCommandSource> context) {
+        try {
+            msgInfo(context, "KBackup-cow library version: " + FileCowCopier.getVersion());
+        } catch (Exception | UnsatisfiedLinkError ignored) {
+            msgErr(context, "KBackup-cow library is not loaded");
+        }
+        return SUCCESS;
+    }
+
     /**
      * Print backup information.
      *
diff --git a/src/main/java/com/keuin/kbackupfabric/util/cow/FileCopier.java b/src/main/java/com/keuin/kbackupfabric/util/cow/FileCopier.java
new file mode 100644
index 0000000..eb21af7
--- /dev/null
+++ b/src/main/java/com/keuin/kbackupfabric/util/cow/FileCopier.java
@@ -0,0 +1,9 @@
+package com.keuin.kbackupfabric.util.cow;
+
+import java.io.IOException;
+
+public interface FileCopier {
+    void copy(String dst, String src) throws IOException;
+
+    boolean isCow();
+}
diff --git a/src/main/java/com/keuin/kbackupfabric/util/cow/FileCowCopier.java b/src/main/java/com/keuin/kbackupfabric/util/cow/FileCowCopier.java
new file mode 100644
index 0000000..e5819de
--- /dev/null
+++ b/src/main/java/com/keuin/kbackupfabric/util/cow/FileCowCopier.java
@@ -0,0 +1,44 @@
+package com.keuin.kbackupfabric.util.cow;
+
+import com.keuin.kbackupfabric.util.PrintUtil;
+
+import java.io.IOException;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+public final class FileCowCopier {
+    private static final AtomicBoolean initialized = new AtomicBoolean(false);
+
+    static {
+        try {
+            System.loadLibrary("kbackup_cow");
+        } catch (SecurityException | UnsatisfiedLinkError ignored) {
+        }
+    }
+
+    public static native void init();
+
+    public static native void copy(String dst, String src) throws IOException;
+
+    public static native String getVersion();
+
+    public static FileCopier getInstance() {
+        if (initialized.compareAndSet(false, true)) {
+            FileCowCopier.init();
+            PrintUtil.info("kbackup-cow version: " + FileCowCopier.getVersion());
+        }
+        // call a native method to ensure the dynamic library is correctly loaded, JVM will throw if failed
+        // so the outside fallback logic could work
+        FileCowCopier.getVersion();
+        return new FileCopier() {
+            @Override
+            public void copy(String dst, String src) throws IOException {
+                FileCowCopier.copy(dst, src);
+            }
+
+            @Override
+            public boolean isCow() {
+                return true;
+            }
+        };
+    }
+}
diff --git a/src/main/java/com/keuin/kbackupfabric/util/cow/FileEagerCopier.java b/src/main/java/com/keuin/kbackupfabric/util/cow/FileEagerCopier.java
new file mode 100644
index 0000000..0f12374
--- /dev/null
+++ b/src/main/java/com/keuin/kbackupfabric/util/cow/FileEagerCopier.java
@@ -0,0 +1,17 @@
+package com.keuin.kbackupfabric.util.cow;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+
+public class FileEagerCopier implements FileCopier {
+    @Override
+    public void copy(String dst, String src) throws IOException {
+        Files.copy(Paths.get(src), Paths.get(dst));
+    }
+
+    @Override
+    public boolean isCow() {
+        return false;
+    }
+}