Variable Backup Files Purger

src/main/java/ch/njol/skript/util/FileUtils.java

@@ -27,15 +27,18 @@
 import java.nio.file.StandardCopyOption;
 import java.text.SimpleDateFormat;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
+import java.util.Comparator;
 
 import org.skriptlang.skript.lang.converter.Converter;
 
+
 /**
  * @author Peter Güttinger
  */
 public abstract class FileUtils {
-	
+
 	private static boolean RUNNINGJAVA6 = true;// = System.getProperty("java.version").startsWith("1.6"); // doesn't work reliably?
 	static {
 		try {
@@ -47,11 +50,11 @@ public abstract class FileUtils {
 			RUNNINGJAVA6 = false;
 		}
 	}
-	
+
 	private FileUtils() {}
-	
+
 	private final static SimpleDateFormat backupFormat = new SimpleDateFormat("yyyy-MM-dd_HH-mm-ss");
-	
+
 	/**
 	 * @return The current date and time
 	 */
@@ -60,7 +63,32 @@ public static String getBackupSuffix() {
 			return "" + backupFormat.format(System.currentTimeMillis());
 		}
 	}
-
+
+	/**
+	 * Deletes files in backup directory to meet desired target, starting from oldest to newest
+	 *
+	 * @param csvFile Variable file in order to get 'backups' directory
+	 * @param toKeep Integer of how many files are to be left remaining
+	 * @throws IOException If 'backups' directory is not found
+	 * @throws IllegalArgumentException If 'toKeep' parameter is less than 0
+	 */
+	public static void backupPurge(File varFile, int toKeep) throws IOException, IllegalArgumentException {
+		if (toKeep < 0)
+			throw new IllegalArgumentException("Called with invalid input, 'toKeep' can not be less than 0");
+		File backupDir = new File(varFile.getParentFile(), "backups" + File.separator);
+		if (!backupDir.exists() || !backupDir.isDirectory())
+			throw new IOException("Backup directory not found");
+		ArrayList<File> files = new ArrayList<File>(Arrays.asList(backupDir.listFiles()));
+		if (files == null || files.size() <= toKeep)
+			return;
+		if (toKeep > 0)
+			files.sort(Comparator.comparingLong(File::lastModified));
+		int numberToRemove = files.size() - toKeep;
+		for (int i = 0; i < numberToRemove; i++) {
+			files.get(i).delete();
+		}
+	}
+
 	public static File backup(final File f) throws IOException {
 		String name = f.getName();
 		final int c = name.lastIndexOf('.');
@@ -76,7 +104,7 @@ public static File backup(final File f) throws IOException {
 		copy(f, backup);
 		return backup;
 	}
-	
+
 	public static File move(final File from, final File to, final boolean replace) throws IOException {
 		if (!replace && to.exists())
 			throw new IOException("Can't rename " + from.getName() + " to " + to.getName() + ": The target file already exists");
@@ -105,7 +133,7 @@ public static File move(final File from, final File to, final boolean replace) t
 		}
 		return to;
 	}
-	
+
 	public static void copy(final File from, final File to) throws IOException {
 		if (!RUNNINGJAVA6) {
 			Files.copy(from.toPath(), to.toPath(), StandardCopyOption.COPY_ATTRIBUTES);
@@ -135,7 +163,7 @@ public static void copy(final File from, final File to) throws IOException {
 			}
 		}
 	}
-	
+
 	/**
 	 * @param directory
 	 * @param renamer Renames files. Return null to leave a file as-is.
@@ -161,10 +189,10 @@ public static Collection<File> renameAll(final File directory, final Converter<S
 		}
 		return changed;
 	}
-	
+
 	/**
 	 * Saves the contents of an InputStream in a file.
-	 * 
+	 *
 	 * @param in The InputStream to read from. This stream will not be closed when this method returns.
 	 * @param file The file to save to. Will be replaced if it exists, or created if it doesn't.
 	 * @throws IOException
@@ -184,5 +212,5 @@ public static void save(final InputStream in, final File file) throws IOExceptio
 				out.close();
 		}
 	}
-	
+
 }

src/main/java/ch/njol/skript/variables/VariablesStorage.java

@@ -47,6 +47,7 @@
  * @see DatabaseStorage
  */
 // FIXME ! large databases (>25 MB) cause the server to be unresponsive instead of loading slowly
+@SuppressWarnings("SuspiciousIndentAfterControlStatement")
 public abstract class VariablesStorage implements Closeable {
 
 	/**
@@ -224,9 +225,24 @@ public final boolean load(SectionNode sectionNode) {
 			// Set the backup interval, if present & enabled
 			if (!"0".equals(getValue(sectionNode, "backup interval"))) {
 				Timespan backupInterval = getValue(sectionNode, "backup interval", Timespan.class);
-
+				int toKeep = getValue(sectionNode, "backups to keep", Integer.class);
+				boolean removeBackups = false;
+				boolean startBackup = true;
 				if (backupInterval != null)
-					startBackupTask(backupInterval);
+					if (toKeep == 0) {
+						startBackup = false;
+					} else if (toKeep >= 1) {
+						removeBackups = true;
+					}
+					if (startBackup) {
+						startBackupTask(backupInterval, removeBackups, toKeep);
+					} else {
+						try {
+							FileUtils.backupPurge(file, toKeep);
+						} catch (IOException e) {
+							Skript.error("Variables backup wipe failed: " + e.getLocalizedMessage());
+						}
+					}
 			}
 		}
 
@@ -307,11 +323,10 @@ public final boolean load(SectionNode sectionNode) {
 	 *
 	 * @param backupInterval the backup interval.
 	 */
-	public void startBackupTask(Timespan backupInterval) {
+	public void startBackupTask(Timespan backupInterval, boolean removeBackups, int toKeep) {
 		// File is null or backup interval is invalid
 		if (file == null || backupInterval.getTicks() == 0)
 			return;
-
 		backupTask = new Task(Skript.getInstance(), backupInterval.getTicks(), backupInterval.getTicks(), true) {
 			@Override
 			public void run() {
@@ -321,6 +336,13 @@ public void run() {
 					try {
 						// ..., then backup
 						FileUtils.backup(file);
+						if (removeBackups) {
+							try {
+								FileUtils.backupPurge(file, toKeep);
+							} catch (IOException | IllegalArgumentException e) {
+								Skript.error("Automatic variables backup purge failed: " + e.getLocalizedMessage());
+							}
+						}
 					} catch (IOException e) {
 						Skript.error("Automatic variables backup failed: " + e.getLocalizedMessage());
 					} finally {

src/main/resources/config.sk

@@ -289,6 +289,12 @@ databases:
 		# Variables are saved constantly no matter what is set here, thus a server crash will never make you loose any variables.
 		# Set this to 0 to disable this feature.
 
+		backups to keep: -1
+		# if set to a value greater than -1, Skript will ensure only that many backups are kept.
+		# Backups are removed from oldest to newest.
+		# If disabled (set to -1), no backup files will be deleted.
+		# WARNING: Setting to 0 will delete all files located in the backup directory upon plugin start/reload
+
 
 	MySQL example:
 		# A MySQL database example, with options unrelated to MySQL removed.
@@ -325,6 +331,8 @@ databases:
 		monitor changes: false
 		monitor interval: 20 seconds
 
+		backups to keep: -1
+
 	default:
 		# The default "database" is a simple text file, with each variable on a separate line and the variable's name, type, and value separated by commas.
 		# This is the last database in this list to catch all variables that have not been saved anywhere else.
@@ -338,6 +346,9 @@ databases:
 
 		backup interval: 2 hours
 
+		backups to keep: -1
+
+
 	# PS: If you don't want some variables to be saved in any database (e.g. variables that contain an %entity% which usually despawn when the server is shut down)
 	# you can modify the last database's pattern to not match all variables, e.g. use '(?!x_).*' to match all variables that don't start with 'x_'.
 	# Be very cautious when doing this however as unsaved variables cannot be recovered after the server has been stopped.

src/test/java/org/skriptlang/skript/test/tests/files/BackupPurgeTest.java

@@ -0,0 +1,51 @@
+package org.skriptlang.skript.test.tests.files;
+
+import ch.njol.skript.util.FileUtils;
+import java.io.File;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Arrays;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertThrows;
+
+public class BackupPurgeTest {
+
+	@Test
+	public void testPurge() throws IOException {
+		File dir = new File("plugins/Skript/backups/");
+		if (!dir.exists()) {
+			dir.mkdir();
+		}
+
+		File vars = new File("plugins/Skript/variables.csv");
+		if (!vars.exists()) {
+			vars.createNewFile();
+		}
+
+		// Create Filler Files to be used for testing
+		for (int i = 0; i < 100; i++) {
+			(new File(dir, ("PurgeTest_"+i))).createNewFile();
+		}
+		// Test 100 filler files were created
+		assertEquals("Filler Files != 100", 100, (new ArrayList<File>(Arrays.asList(dir.listFiles()))).size());
+
+		// Test 'backupPurge' method deleting to 50
+		FileUtils.backupPurge(vars, 50);
+		assertEquals("Backup Purge did not delete down to 50", 50, (new ArrayList<File>(Arrays.asList(dir.listFiles()))).size());
+
+		// Test 'backupPurge' method deleting to 20
+		FileUtils.backupPurge(vars, 20);
+		assertEquals("Backup Purge did not delete down to 20", 20, (new ArrayList<File>(Arrays.asList(dir.listFiles()))).size());
+
+		// Test 'backupPurge' method deleting all files
+		FileUtils.backupPurge(vars, 0);
+		assertEquals("Backup Purge did not delete all files", 0, (new ArrayList<File>(Arrays.asList(dir.listFiles()))).size());
+
+		// Test calling with invalid input
+		assertThrows("Backup Purge did not throw exception for invalid input", IllegalArgumentException.class, () -> FileUtils.backupPurge(vars, -1));
+
+	}
+
+}