org.h2.command.dml.BackupCommand Maven / Gradle / Ivy
/*
* Copyright 2004-2019 H2 Group. Multiple-Licensed under the MPL 2.0,
* and the EPL 1.0 (https://h2database.com/html/license.html).
* Initial Developer: H2 Group
*/
package org.h2.command.dml;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;
import org.h2.api.DatabaseEventListener;
import org.h2.api.ErrorCode;
import org.h2.command.CommandInterface;
import org.h2.command.Prepared;
import org.h2.engine.Constants;
import org.h2.engine.Database;
import org.h2.engine.Session;
import org.h2.expression.Expression;
import org.h2.message.DbException;
import org.h2.mvstore.MVStore;
import org.h2.mvstore.db.MVTableEngine.Store;
import org.h2.pagestore.PageStore;
import org.h2.result.ResultInterface;
import org.h2.store.FileLister;
import org.h2.store.fs.FileUtils;
import org.h2.util.IOUtils;
/**
* This class represents the statement
* BACKUP
*/
public class BackupCommand extends Prepared {
private Expression fileNameExpr;
public BackupCommand(Session session) {
super(session);
}
public void setFileName(Expression fileName) {
this.fileNameExpr = fileName;
}
@Override
public int update() {
String name = fileNameExpr.getValue(session).getString();
session.getUser().checkAdmin();
backupTo(name);
return 0;
}
private void backupTo(String fileName) {
Database db = session.getDatabase();
if (!db.isPersistent()) {
throw DbException.get(ErrorCode.DATABASE_IS_NOT_PERSISTENT);
}
try {
Store store = db.getStore();
if (store != null) {
store.flush();
}
String name = db.getName();
name = FileUtils.getName(name);
try (OutputStream zip = FileUtils.newOutputStream(fileName, false)) {
ZipOutputStream out = new ZipOutputStream(zip);
db.flush();
if (db.getPageStore() != null) {
String fn = db.getName() + Constants.SUFFIX_PAGE_FILE;
backupPageStore(out, fn, db.getPageStore());
}
// 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();
String dir = FileUtils.getParent(prefix);
dir = FileLister.getDir(dir);
ArrayList fileList = FileLister.getDatabaseFiles(dir, name, true);
for (String n : fileList) {
if (n.endsWith(Constants.SUFFIX_LOB_FILE)) {
backupFile(out, base, n);
}
if (n.endsWith(Constants.SUFFIX_MV_FILE) && store != null) {
MVStore s = store.getMvStore();
boolean before = s.getReuseSpace();
s.setReuseSpace(false);
try {
InputStream in = store.getInputStream();
backupFile(out, base, n, in);
} finally {
s.setReuseSpace(before);
}
}
}
}
out.close();
}
} catch (IOException e) {
throw DbException.convertIOException(e, fileName);
}
}
private void backupPageStore(ZipOutputStream out, String fileName,
PageStore store) throws IOException {
Database db = session.getDatabase();
fileName = FileUtils.getName(fileName);
out.putNextEntry(new ZipEntry(fileName));
int pos = 0;
try {
store.setBackup(true);
while (true) {
pos = store.copyDirect(pos, out);
if (pos < 0) {
break;
}
int max = store.getPageCount();
db.setProgress(DatabaseEventListener.STATE_BACKUP_FILE, fileName, pos, max);
}
} finally {
store.setBackup(false);
}
out.closeEntry();
}
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);
base = FileUtils.toRealPath(base);
if (!f.startsWith(base)) {
DbException.throwInternalError(f + " does not start with " + base);
}
f = f.substring(base.length());
f = correctFileName(f);
out.putNextEntry(new ZipEntry(f));
IOUtils.copyAndCloseInput(in, out);
out.closeEntry();
}
@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;
}
@Override
public ResultInterface queryMeta() {
return null;
}
@Override
public int getType() {
return CommandInterface.BACKUP;
}
}