BACKUP实现

lealone-sql/src/main/java/org/lealone/command/dml/BackupCommand.java

@@ -30,35 +30,17 @@ public void setFileName(Expression fileName) {
 
     @Override
     public int update() {
-        String name = fileNameExpr.getValue(session).getString();
+        String fileName = fileNameExpr.getValue(session).getString();
         session.getUser().checkAdmin();
-        backupTo(name);
-        return 0;
-    }
-
-    private void backupTo(String fileName) {
         session.getDatabase().backupTo(fileName);
+        return 0;
     }
 
     @Override
     public boolean isTransactional() {
         return true;
     }
 
-    /**
-     * Fix the file name, replacing backslash with slash.
-     *
-     * @param f the file name
-     * @return the corrected file name
-     */
-    public static String correctFileName(String f) {
-        f = f.replace('\\', '/');
-        if (f.startsWith("/")) {
-            f = f.substring(1);
-        }
-        return f;
-    }
-
     @Override
     public boolean needRecompile() {
         return false;

lealone-storage/engine/src/main/java/org/lealone/storage/MVStorageEngine.java

@@ -5,14 +5,18 @@
  */
 package org.lealone.storage;
 
+import java.io.IOException;
 import java.io.InputStream;
+import java.io.OutputStream;
 import java.lang.Thread.UncaughtExceptionHandler;
 import java.nio.channels.FileChannel;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
+import java.util.zip.ZipEntry;
+import java.util.zip.ZipOutputStream;
 
 import org.lealone.api.ErrorCode;
 import org.lealone.command.ddl.CreateTableData;
@@ -37,6 +41,7 @@
 import org.lealone.type.DataType;
 import org.lealone.util.BitField;
 import org.lealone.util.DataUtils;
+import org.lealone.util.IOUtils;
 import org.lealone.util.New;
 
 /**
@@ -45,7 +50,7 @@
 public class MVStorageEngine extends StorageEngineBase implements TransactionStorageEngine {
     public static final String NAME = Constants.DEFAULT_STORAGE_ENGINE_NAME;
 
-    //见StorageEngineManager.StorageEngineService中的注释
+    // 见StorageEngineManager.StorageEngineService中的注释
     public MVStorageEngine() {
         StorageEngineManager.registerStorageEngine(this);
     }
@@ -498,7 +503,140 @@ public <K, V> TransactionMap<K, V> openMap(Session session, String name, DataTyp
 
     @Override
     public void backupTo(Database db, String fileName) {
-        // TODO
+        if (!db.isPersistent()) {
+            throw DbException.get(ErrorCode.DATABASE_IS_NOT_PERSISTENT);
+        }
+        try {
+            Store mvStore = getStore(db);
+            if (mvStore != null) {
+                mvStore.flush();
+            }
+            // 生成fileName表示的文件，如果已存在则覆盖原有的，也就是文件为空
+            OutputStream zip = FileUtils.newOutputStream(fileName, false);
+            ZipOutputStream out = new ZipOutputStream(zip);
+
+            // synchronize on the database, to avoid concurrent temp file
+            // creation / deletion / backup
+            String base = FileUtils.getParent(db.getName());
+            synchronized (db.getLobSyncObject()) {
+                String prefix = db.getDatabasePath(); // 返回E:/H2/baseDir/mydb
+                String dir = FileUtils.getParent(prefix); // 返回E:/H2/baseDir
+                dir = getDir(dir); // 返回E:/H2/baseDir
+                String name = db.getName(); // 返回E:/H2/baseDir/mydb
+                name = FileUtils.getName(name); // 返回mydb(也就是只取简单文件名)
+                ArrayList<String> fileList = getDatabaseFiles(dir, name, true);
+
+                // 把".lob.db"和".mv.db"文件备份到fileName表示的文件中(是一个zip文件)
+                for (String n : fileList) {
+                    if (n.endsWith(Constants.SUFFIX_LOB_FILE)) { // 备份".lob.db"文件
+                        backupFile(out, base, n);
+                    } else if (n.endsWith(Constants.SUFFIX_MV_FILE) && mvStore != null) { // 备份".mv.db"文件
+                        MVStore s = mvStore.getStore();
+                        boolean before = s.getReuseSpace();
+                        s.setReuseSpace(false);
+                        try {
+                            InputStream in = mvStore.getInputStream();
+                            backupFile(out, base, n, in);
+                        } finally {
+                            s.setReuseSpace(before);
+                        }
+                    }
+                }
+            }
+            out.close();
+            zip.close();
+        } catch (IOException e) {
+            throw DbException.convertIOException(e, fileName);
+        }
+    }
+
+    private static void backupFile(ZipOutputStream out, String base, String fn) throws IOException {
+        InputStream in = FileUtils.newInputStream(fn);
+        backupFile(out, base, fn, in);
+    }
+
+    private static void backupFile(ZipOutputStream out, String base, String fn, InputStream in) throws IOException {
+        String f = FileUtils.toRealPath(fn); // 返回E:/H2/baseDir/mydb.mv.db
+        base = FileUtils.toRealPath(base); // 返回E:/H2/baseDir
+        if (!f.startsWith(base)) {
+            DbException.throwInternalError(f + " does not start with " + base);
+        }
+        f = f.substring(base.length()); // 返回/mydb.mv.db
+        f = correctFileName(f); // 返回mydb.mv.db
+        out.putNextEntry(new ZipEntry(f));
+        IOUtils.copyAndCloseInput(in, out);
+        out.closeEntry();
+    }
+
+    /**
+     * Fix the file name, replacing backslash with slash.
+     *
+     * @param f the file name
+     * @return the corrected file name
+     */
+    private static String correctFileName(String f) {
+        f = f.replace('\\', '/');
+        if (f.startsWith("/")) {
+            f = f.substring(1);
+        }
+        return f;
+    }
+
+    /**
+     * Normalize the directory name.
+     *
+     * @param dir the directory (null for the current directory)
+     * @return the normalized directory name
+     */
+    private static String getDir(String dir) {
+        if (dir == null || dir.equals("")) {
+            return ".";
+        }
+        return FileUtils.toRealPath(dir);
+    }
+
+    /**
+     * Get the list of database files.
+     *
+     * @param dir the directory (must be normalized)
+     * @param db the database name (null for all databases)
+     * @param all if true, files such as the lock, trace, and lob
+     *            files are included. If false, only data, index, log,
+     *            and lob files are returned
+     * @return the list of files
+     */
+    private static ArrayList<String> getDatabaseFiles(String dir, String db, boolean all) {
+        ArrayList<String> files = New.arrayList();
+        // for Windows, File.getCanonicalPath("...b.") returns just "...b"
+        String start = db == null ? null : (FileUtils.toRealPath(dir + "/" + db) + ".");
+        for (String f : FileUtils.newDirectoryStream(dir)) {
+            boolean ok = false;
+            if (f.endsWith(Constants.SUFFIX_LOBS_DIRECTORY)) {
+                if (start == null || f.startsWith(start)) {
+                    files.addAll(getDatabaseFiles(f, null, all));
+                    ok = true;
+                }
+            } else if (f.endsWith(Constants.SUFFIX_LOB_FILE)) {
+                ok = true;
+            } else if (f.endsWith(Constants.SUFFIX_MV_FILE)) {
+                ok = true;
+            } else if (all) {
+                if (f.endsWith(Constants.SUFFIX_LOCK_FILE)) {
+                    ok = true;
+                } else if (f.endsWith(Constants.SUFFIX_TEMP_FILE)) {
+                    ok = true;
+                } else if (f.endsWith(Constants.SUFFIX_TRACE_FILE)) {
+                    ok = true;
+                }
+            }
+            if (ok) {
+                if (db == null || f.startsWith(start)) {
+                    String fileName = f;
+                    files.add(fileName);
+                }
+            }
+        }
+        return files;
     }
 
     @Override

lealone-test/src/test/java/org/lealone/test/sql/SqlTestBase.java

@@ -143,9 +143,13 @@ public boolean getBooleanValue(int i, boolean closeResultSet) throws Exception {
         }
     }
 
-    public void executeQuery() throws Exception {
-        rs = stmt.executeQuery(sql);
-        rs.next();
+    public void executeQuery() {
+        try {
+            rs = stmt.executeQuery(sql);
+            rs.next();
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
     }
 
     public void closeResultSet() throws Exception {

lealone-test/src/test/java/org/lealone/test/sql/dml/BackupCommandTest.java

@@ -0,0 +1,44 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.lealone.test.sql.dml;
+
+import org.junit.Test;
+import org.lealone.test.sql.SqlTestBase;
+
+public class BackupCommandTest extends SqlTestBase {
+    @Test
+    public void run() {
+        executeUpdate("drop table IF EXISTS BackupCommandTest");
+        executeUpdate("create table IF NOT EXISTS BackupCommandTest(id int, name varchar(500), b boolean)");
+        executeUpdate("CREATE INDEX IF NOT EXISTS BackupCommandTestIndex ON BackupCommandTest(name)");
+
+        executeUpdate("insert into BackupCommandTest(id, name, b) values(1, 'a1', true)");
+        executeUpdate("insert into BackupCommandTest(id, name, b) values(1, 'b1', true)");
+        executeUpdate("insert into BackupCommandTest(id, name, b) values(2, 'a2', false)");
+        executeUpdate("insert into BackupCommandTest(id, name, b) values(2, 'b2', true)");
+        executeUpdate("insert into BackupCommandTest(id, name, b) values(3, 'a3', false)");
+        executeUpdate("insert into BackupCommandTest(id, name, b) values(3, 'b3', true)");
+
+        sql = "BACKUP TO " + TEST_DIR + "/myBackup.zip"; // 文件名要加单引号
+        sql = "BACKUP TO '" + TEST_DIR + "/myBackup.zip'";
+        executeUpdate(sql);
+
+        sql = "select * from BackupCommandTest";
+        printResultSet();
+    }
+}