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/*
 * Copyright 2004-2010 H2 Group. Multiple-Licensed under the H2 License,
 * Version 1.0, and under the Eclipse Public License, Version 1.0
 * (http://h2database.com/html/license.html).
 * Initial Developer: H2 Group
 */
package org.h2.engine;

import java.io.IOException;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Properties;
import java.util.Set;
import java.util.StringTokenizer;
import org.h2.api.DatabaseEventListener;
import org.h2.command.ddl.CreateTableData;
import org.h2.command.dml.SetTypes;
import org.h2.constant.ErrorCode;
import org.h2.constant.SysProperties;
import org.h2.constraint.Constraint;
import org.h2.index.Cursor;
import org.h2.index.Index;
import org.h2.index.IndexType;
import org.h2.jdbc.JdbcConnection;
import org.h2.message.DbException;
import org.h2.message.Trace;
import org.h2.message.TraceSystem;
import org.h2.result.Row;
import org.h2.result.SearchRow;
import org.h2.schema.Schema;
import org.h2.schema.SchemaObject;
import org.h2.schema.Sequence;
import org.h2.schema.TriggerObject;
import org.h2.store.DataHandler;
import org.h2.store.FileLock;
import org.h2.store.FileStore;
import org.h2.store.InDoubtTransaction;
import org.h2.store.LobStorage;
import org.h2.store.PageStore;
import org.h2.store.WriterThread;
import org.h2.store.fs.FileSystemMemory;
import org.h2.table.Column;
import org.h2.table.IndexColumn;
import org.h2.table.MetaTable;
import org.h2.table.Table;
import org.h2.table.TableLinkConnection;
import org.h2.table.TableView;
import org.h2.tools.DeleteDbFiles;
import org.h2.tools.Server;
import org.h2.util.BitField;
import org.h2.util.IOUtils;
import org.h2.util.MathUtils;
import org.h2.util.NetUtils;
import org.h2.util.New;
import org.h2.util.SmallLRUCache;
import org.h2.util.SourceCompiler;
import org.h2.util.StringUtils;
import org.h2.util.TempFileDeleter;
import org.h2.util.Utils;
import org.h2.value.CompareMode;
import org.h2.value.Value;
import org.h2.value.ValueInt;

/**
 * There is one database object per open database.
 *
 * The format of the meta data table is:
 *  id int, 0, objectType int, sql varchar
 *
 * @since 2004-04-15 22:49
 */
public class Database implements DataHandler {

    private static int initialPowerOffCount;

    /**
     * The default name of the system user. This name is only used as long as
     * there is no administrator user registered.
     */
    private static final String SYSTEM_USER_NAME = "DBA";

    private final boolean persistent;
    private final String databaseName;
    private final String databaseShortName;
    private final String databaseURL;
    private final String cipher;
    private final byte[] filePasswordHash;

    private final HashMap roles = New.hashMap();
    private final HashMap users = New.hashMap();
    private final HashMap settings = New.hashMap();
    private final HashMap schemas = New.hashMap();
    private final HashMap rights = New.hashMap();
    private final HashMap userDataTypes = New.hashMap();
    private final HashMap aggregates = New.hashMap();
    private final HashMap comments = New.hashMap();

    private final Set userSessions = Collections.synchronizedSet(new HashSet());
    private Session exclusiveSession;
    private final BitField objectIds = new BitField();
    private final Object lobSyncObject = new Object();

    private Schema mainSchema;
    private Schema infoSchema;
    private int nextSessionId;
    private int nextTempTableId;
    private User systemUser;
    private Session systemSession;
    private Table meta;
    private Index metaIdIndex;
    private FileLock lock;
    private WriterThread writer;
    private boolean starting;
    private TraceSystem traceSystem;
    private int fileLockMethod;
    private Role publicRole;
    private long modificationDataId;
    private long modificationMetaId;
    private CompareMode compareMode;
    private String cluster = Constants.CLUSTERING_DISABLED;
    private boolean readOnly;
    private boolean noDiskSpace;
    private int writeDelay = Constants.DEFAULT_WRITE_DELAY;
    private DatabaseEventListener eventListener;
    private int maxMemoryRows = Constants.DEFAULT_MAX_MEMORY_ROWS;
    private int maxMemoryUndo = SysProperties.DEFAULT_MAX_MEMORY_UNDO;
    private int lockMode = SysProperties.DEFAULT_LOCK_MODE;
    private int maxLengthInplaceLob;
    private int allowLiterals = Constants.ALLOW_LITERALS_ALL;

    private int powerOffCount = initialPowerOffCount;
    private int closeDelay;
    private DatabaseCloser delayedCloser;
    private volatile boolean closing;
    private boolean ignoreCase;
    private boolean deleteFilesOnDisconnect;
    private String lobCompressionAlgorithm;
    private boolean optimizeReuseResults = true;
    private String cacheType;
    private String accessModeData;
    private boolean referentialIntegrity = true;
    private boolean multiVersion;
    private DatabaseCloser closeOnExit;
    private Mode mode = Mode.getInstance(Mode.REGULAR);
    private boolean multiThreaded;
    private int maxOperationMemory = SysProperties.DEFAULT_MAX_OPERATION_MEMORY;
    private SmallLRUCache lobFileListCache;
    private boolean autoServerMode;
    private Server server;
    private HashMap linkConnections;
    private TempFileDeleter tempFileDeleter = TempFileDeleter.getInstance();
    private PageStore pageStore;
    private Properties reconnectLastLock;
    private volatile long reconnectCheckNext;
    private volatile boolean reconnectChangePending;
    private volatile int checkpointAllowed;
    private volatile boolean checkpointRunning;
    private final Object reconnectSync = new Object();
    private int cacheSize;
    private int compactMode;
    private SourceCompiler compiler;
    private volatile boolean metaTablesInitialized;
    private boolean flushOnEachCommit;
    private LobStorage lobStorage;
    private int pageSize = SysProperties.PAGE_SIZE;
    private int defaultTableType = Table.TYPE_CACHED;

    public Database(ConnectionInfo ci, String cipher) {
        String name = ci.getName();
        this.compareMode = CompareMode.getInstance(null, 0);
        this.persistent = ci.isPersistent();
        this.filePasswordHash = ci.getFilePasswordHash();
        this.databaseName = name;
        this.databaseShortName = parseDatabaseShortName();
        this.maxLengthInplaceLob = SysProperties.LOB_IN_DATABASE ?
                SysProperties.DEFAULT_MAX_LENGTH_INPLACE_LOB2 : SysProperties.DEFAULT_MAX_LENGTH_INPLACE_LOB;
        this.cipher = cipher;
        String lockMethodName = ci.getProperty("FILE_LOCK", null);
        this.accessModeData = ci.getProperty("ACCESS_MODE_DATA", "rw").toLowerCase();
        this.autoServerMode = ci.getProperty("AUTO_SERVER", false);
        this.cacheSize = ci.getProperty("CACHE_SIZE", SysProperties.CACHE_SIZE_DEFAULT);
        this.pageSize = ci.getProperty("PAGE_SIZE", SysProperties.PAGE_SIZE);
        if ("r".equals(accessModeData)) {
            readOnly = true;
        }
        this.fileLockMethod = FileLock.getFileLockMethod(lockMethodName);
        this.databaseURL = ci.getURL();
        String listener = ci.removeProperty("DATABASE_EVENT_LISTENER", null);
        if (listener != null) {
            listener = StringUtils.trim(listener, true, true, "'");
            setEventListenerClass(listener);
        }
        this.multiVersion = ci.getProperty("MVCC", false);
        boolean closeAtVmShutdown = ci.getProperty("DB_CLOSE_ON_EXIT", true);
        int traceLevelFile = ci.getIntProperty(SetTypes.TRACE_LEVEL_FILE, TraceSystem.DEFAULT_TRACE_LEVEL_FILE);
        int traceLevelSystemOut = ci.getIntProperty(SetTypes.TRACE_LEVEL_SYSTEM_OUT,
                TraceSystem.DEFAULT_TRACE_LEVEL_SYSTEM_OUT);
        this.cacheType = StringUtils.toUpperEnglish(ci.removeProperty("CACHE_TYPE", SysProperties.CACHE_TYPE_DEFAULT));
        openDatabase(traceLevelFile, traceLevelSystemOut, closeAtVmShutdown);
    }

    private void openDatabase(int traceLevelFile, int traceLevelSystemOut, boolean closeAtVmShutdown) {
        try {
            open(traceLevelFile, traceLevelSystemOut);
            if (closeAtVmShutdown) {
                try {
                    closeOnExit = new DatabaseCloser(this, 0, true);
                    Runtime.getRuntime().addShutdownHook(closeOnExit);
                } catch (IllegalStateException e) {
                    // shutdown in progress - just don't register the handler
                    // (maybe an application wants to write something into a
                    // database at shutdown time)
                } catch (SecurityException  e) {
                    // applets may not do that - ignore
                    // Google App Engine doesn't allow
                    // to instantiate classes that extend Thread
                }
            }
        } catch (Throwable e) {
            if (e instanceof OutOfMemoryError) {
                e.fillInStackTrace();
            }
            if (traceSystem != null) {
                if (e instanceof SQLException) {
                    SQLException e2 = (SQLException) e;
                    if (e2.getErrorCode() != ErrorCode.DATABASE_ALREADY_OPEN_1) {
                        // only write if the database is not already in use
                        traceSystem.getTrace(Trace.DATABASE).error("opening " + databaseName, e);
                    }
                }
                traceSystem.close();
            }
            closeOpenFilesAndUnlock(false);
            throw DbException.convert(e);
        }
    }

    public static void setInitialPowerOffCount(int count) {
        initialPowerOffCount = count;
    }

    public void setPowerOffCount(int count) {
        if (powerOffCount == -1) {
            return;
        }
        powerOffCount = count;
    }

    /**
     * Check if two values are equal with the current comparison mode.
     *
     * @param a the first value
     * @param b the second value
     * @return true if both objects are equal
     */
    public boolean areEqual(Value a, Value b) {
        // can not use equals because ValueDecimal 0.0 is not equal to 0.00.
        return a.compareTo(b, compareMode) == 0;
    }

    /**
     * Compare two values with the current comparison mode. The values may not
     * be of the same type.
     *
     * @param a the first value
     * @param b the second value
     * @return 0 if both values are equal, -1 if the first value is smaller, and
     *         1 otherwise
     */
    public int compare(Value a, Value b) {
        return a.compareTo(b, compareMode);
    }

    /**
     * Compare two values with the current comparison mode. The values must be
     * of the same type.
     *
     * @param a the first value
     * @param b the second value
     * @return 0 if both values are equal, -1 if the first value is smaller, and
     *         1 otherwise
     */
    public int compareTypeSave(Value a, Value b) {
        return a.compareTypeSave(b, compareMode);
    }

    public long getModificationDataId() {
        return modificationDataId;
    }

    /**
     * Set or reset the pending change flag in the .lock.db file.
     *
     * @param pending the new value of the flag
     * @return true if the call was successful,
     *          false if another connection was faster
     */
    synchronized boolean reconnectModified(boolean pending) {
        if (readOnly || lock == null || fileLockMethod != FileLock.LOCK_SERIALIZED) {
            return true;
        }
        try {
            if (pending == reconnectChangePending) {
                long now = System.currentTimeMillis();
                if (now > reconnectCheckNext) {
                    if (pending) {
                        String pos = pageStore == null ? null : "" + pageStore.getWriteCountTotal();
                        lock.setProperty("logPos", pos);
                        lock.save();
                    }
                    reconnectCheckNext = now + SysProperties.RECONNECT_CHECK_DELAY;
                }
                return true;
            }
            Properties old = lock.load();
            if (pending) {
                if (old.getProperty("changePending") != null) {
                    return false;
                }
                getTrace().debug("wait before writing");
                Thread.sleep((int) (SysProperties.RECONNECT_CHECK_DELAY * 1.1));
                Properties now = lock.load();
                if (!now.equals(old)) {
                    // somebody else was faster
                    return false;
                }
            }
            String pos = pageStore == null ? null : "" + pageStore.getWriteCountTotal();
            lock.setProperty("logPos", pos);
            if (pending) {
                lock.setProperty("changePending", "true-" + Math.random());
            } else {
                lock.setProperty("changePending", null);
            }
            // ensure that the writer thread will
            // not reset the flag before we are done
            reconnectCheckNext = System.currentTimeMillis() + 2 * SysProperties.RECONNECT_CHECK_DELAY;
            old = lock.save();
            if (pending) {
                getTrace().debug("wait before writing again");
                Thread.sleep((int) (SysProperties.RECONNECT_CHECK_DELAY * 1.1));
                Properties now = lock.load();
                if (!now.equals(old)) {
                    // somebody else was faster
                    return false;
                }
            } else {
                Thread.sleep(1);
            }
            reconnectLastLock = old;
            reconnectChangePending = pending;
            reconnectCheckNext = System.currentTimeMillis() + SysProperties.RECONNECT_CHECK_DELAY;
            return true;
        } catch (Exception e) {
            getTrace().error("pending:"+ pending, e);
            return false;
        }
    }

    public long getNextModificationDataId() {
        return ++modificationDataId;
    }

    public long getModificationMetaId() {
        return modificationMetaId;
    }

    public long getNextModificationMetaId() {
        // if the meta data has been modified, the data is modified as well
        // (because MetaTable returns modificationDataId)
        modificationDataId++;
        return modificationMetaId++;
    }

    public int getPowerOffCount() {
        return powerOffCount;
    }

    public void checkPowerOff() {
        if (powerOffCount == 0) {
            return;
        }
        if (powerOffCount > 1) {
            powerOffCount--;
            return;
        }
        if (powerOffCount != -1) {
            try {
                powerOffCount = -1;
                stopWriter();
                if (pageStore != null) {
                    try {
                        pageStore.close();
                    } catch (DbException e) {
                        // ignore
                    }
                    pageStore = null;
                }
                if (lock != null) {
                    stopServer();
                    if (fileLockMethod != FileLock.LOCK_SERIALIZED) {
                        // allow testing shutdown
                        lock.unlock();
                    }
                    lock = null;
                }
                if (traceSystem != null) {
                    traceSystem.close();
                }
            } catch (DbException e) {
                TraceSystem.traceThrowable(e);
            }
        }
        Engine.getInstance().close(databaseName);
        throw DbException.get(ErrorCode.DATABASE_IS_CLOSED);
    }

    /**
     * Check if a database with the given name exists.
     *
     * @param name the name of the database (including path)
     * @return true if one exists
     */
    public static boolean exists(String name) {
        return IOUtils.exists(name + Constants.SUFFIX_PAGE_FILE);
    }

    /**
     * Get the trace object for the given module.
     *
     * @param module the module name
     * @return the trace object
     */
    public Trace getTrace(String module) {
        return traceSystem.getTrace(module);
    }

    public FileStore openFile(String name, String openMode, boolean mustExist) {
        if (mustExist && !IOUtils.exists(name)) {
            throw DbException.get(ErrorCode.FILE_NOT_FOUND_1, name);
        }
        FileStore store = FileStore.open(this, name, openMode, cipher, filePasswordHash);
        try {
            store.init();
        } catch (DbException e) {
            store.closeSilently();
            throw e;
        }
        return store;
    }

    /**
     * Check if the file password hash is correct.
     *
     * @param testCipher the cipher algorithm
     * @param testHash the hash code
     * @return true if the cipher algorithm and the password match
     */
    public boolean validateFilePasswordHash(String testCipher, byte[] testHash) {
        if (!StringUtils.equals(testCipher, this.cipher)) {
            return false;
        }
        return Utils.compareSecure(testHash, filePasswordHash);
    }

    private String parseDatabaseShortName() {
        String n = databaseName;
        if (n.endsWith(":")) {
            n = null;
        }
        if (n != null) {
            StringTokenizer tokenizer = new StringTokenizer(n, "/\\:,;");
            while (tokenizer.hasMoreTokens()) {
                n = tokenizer.nextToken();
            }
        }
        if (n == null || n.length() == 0) {
            n = "unnamed";
        }
        return SysProperties.DATABASE_TO_UPPER ? StringUtils.toUpperEnglish(n) : n;
    }

    private synchronized void open(int traceLevelFile, int traceLevelSystemOut) {
        if (persistent) {
            String dataFileName = databaseName + ".data.db";
            boolean existsData = IOUtils.exists(dataFileName);
            String pageFileName = databaseName + Constants.SUFFIX_PAGE_FILE;
            boolean existsPage = IOUtils.exists(pageFileName);
            if (existsData && !existsPage) {
                throw DbException.get(ErrorCode.FILE_VERSION_ERROR_1,
                        "Old database: " + dataFileName + " - please convert the database to a SQL script and re-create it.");
            }
            if (existsPage && IOUtils.isReadOnly(pageFileName)) {
                // if it is already read-only because ACCESS_MODE_DATA=r
                readOnly = readOnly | IOUtils.isReadOnly(pageFileName);
            }
            if (readOnly) {
                traceSystem = new TraceSystem(null);
            } else {
                traceSystem = new TraceSystem(databaseName + Constants.SUFFIX_TRACE_FILE);
            }
            traceSystem.setLevelFile(traceLevelFile);
            traceSystem.setLevelSystemOut(traceLevelSystemOut);
            traceSystem.getTrace(Trace.DATABASE)
                    .info("opening " + databaseName + " (build " + Constants.BUILD_ID + ")");
            if (autoServerMode) {
                if (readOnly || fileLockMethod == FileLock.LOCK_NO || fileLockMethod == FileLock.LOCK_SERIALIZED || fileLockMethod == FileLock.LOCK_FS) {
                    throw DbException.getUnsupportedException("autoServerMode && (readOnly || fileLockMethod == NO" +
                            " || fileLockMethod == SERIALIZED)");
                }
            }
            String lockFileName = databaseName + Constants.SUFFIX_LOCK_FILE;
            if (readOnly) {
                if (IOUtils.exists(lockFileName)) {
                    throw DbException.get(ErrorCode.DATABASE_ALREADY_OPEN_1, "Lock file exists: " + lockFileName);
                }
            }
            if (!readOnly && fileLockMethod != FileLock.LOCK_NO) {
                if (fileLockMethod != FileLock.LOCK_FS) {
                    lock = new FileLock(traceSystem, lockFileName, Constants.LOCK_SLEEP);
                    lock.lock(fileLockMethod);
                    if (autoServerMode) {
                        startServer(lock.getUniqueId());
                    }
                }
            }
            while (isReconnectNeeded() && !beforeWriting()) {
                // wait until others stopped writing and
                // until we can write (file are not open - no need to re-connect)
            }
            deleteOldTempFiles();
            starting = true;
            getPageStore();
            starting = false;
            writer = WriterThread.create(this, writeDelay);
        } else {
            traceSystem = new TraceSystem(null);
        }
        systemUser = new User(this, 0, SYSTEM_USER_NAME, true);
        mainSchema = new Schema(this, 0, Constants.SCHEMA_MAIN, systemUser, true);
        infoSchema = new Schema(this, -1, "INFORMATION_SCHEMA", systemUser, true);
        schemas.put(mainSchema.getName(), mainSchema);
        schemas.put(infoSchema.getName(), infoSchema);
        publicRole = new Role(this, 0, Constants.PUBLIC_ROLE_NAME, true);
        roles.put(Constants.PUBLIC_ROLE_NAME, publicRole);
        systemUser.setAdmin(true);
        systemSession = new Session(this, systemUser, ++nextSessionId);
        CreateTableData data = new CreateTableData();
        ArrayList cols = data.columns;
        Column columnId = new Column("ID", Value.INT);
        columnId.setNullable(false);
        cols.add(columnId);
        cols.add(new Column("HEAD", Value.INT));
        cols.add(new Column("TYPE", Value.INT));
        cols.add(new Column("SQL", Value.STRING));
        boolean create = true;
        if (pageStore != null) {
            create = pageStore.isNew();
        }
        data.tableName = "SYS";
        data.id = 0;
        data.temporary = false;
        data.persistData = persistent;
        data.persistIndexes = persistent;
        data.create = create;
        data.isHidden = true;
        data.session = systemSession;
        meta = mainSchema.createTable(data);
        IndexColumn[] pkCols = IndexColumn.wrap(new Column[] { columnId });
        metaIdIndex = meta.addIndex(systemSession, "SYS_ID", 0, pkCols, IndexType.createPrimaryKey(
                false, false), true, null);
        objectIds.set(0);
        starting = true;
        Cursor cursor = metaIdIndex.find(systemSession, null, null);
        ArrayList records = New.arrayList();
        while (cursor.next()) {
            MetaRecord rec = new MetaRecord(cursor.get());
            objectIds.set(rec.getId());
            records.add(rec);
        }
        Collections.sort(records);
        for (MetaRecord rec : records) {
            rec.execute(this, systemSession, eventListener);
        }
        recompileInvalidViews(systemSession);
        starting = false;
        if (!readOnly) {
            // set CREATE_BUILD in a new database
            String name = SetTypes.getTypeName(SetTypes.CREATE_BUILD);
            if (settings.get(name) == null) {
                Setting setting = new Setting(this, allocateObjectId(), name);
                setting.setIntValue(Constants.BUILD_ID);
                addDatabaseObject(systemSession, setting);
            }
        }
        systemSession.commit(true);
        traceSystem.getTrace(Trace.DATABASE).info("opened " + databaseName);
        afterWriting();
    }

    private void startServer(String key) {
        try {
            server = Server.createTcpServer(
                    "-tcpPort", "0",
                    "-tcpAllowOthers",
                    "-tcpDaemon",
                    "-key", key, databaseName);
            server.start();
        } catch (SQLException e) {
            throw DbException.convert(e);
        }
        String address = NetUtils.getLocalAddress() + ":" + server.getPort();
        lock.setProperty("server", address);
        lock.save();
    }

    private void stopServer() {
        if (server != null) {
            Server s = server;
            // avoid calling stop recursively
            // because stopping the server will
            // try to close the database as well
            server = null;
            s.stop();
        }
    }

    private void recompileInvalidViews(Session session) {
        boolean recompileSuccessful;
        do {
            recompileSuccessful = false;
            for (Table obj : getAllTablesAndViews(false)) {
                if (obj instanceof TableView) {
                    TableView view = (TableView) obj;
                    if (view.isInvalid()) {
                        try {
                            view.recompile(session);
                        } catch (DbException e) {
                            // ignore
                        }
                        if (!view.isInvalid()) {
                            recompileSuccessful = true;
                        }
                    }
                }
            }
        } while (recompileSuccessful);
        // when opening a database, views are initialized before indexes,
        // so they may not have the optimal plan yet
        // this is not a problem, it is just nice to see the newest plan
        for (Table obj : getAllTablesAndViews(false)) {
            if (obj instanceof TableView) {
                TableView view = (TableView) obj;
                if (!view.isInvalid()) {
                    try {
                        view.recompile(systemSession);
                    } catch (DbException e) {
                        // ignore
                    }
                }
            }
        }
    }

    private void initMetaTables() {
        if (metaTablesInitialized) {
            return;
        }
        synchronized (infoSchema) {
            if (!metaTablesInitialized) {
                for (int type = 0, count = MetaTable.getMetaTableTypeCount(); type < count; type++) {
                    MetaTable m = new MetaTable(infoSchema, -1 - type, type);
                    infoSchema.add(m);
                }
                metaTablesInitialized = true;
            }
        }
    }

    private synchronized void addMeta(Session session, DbObject obj) {
        int id = obj.getId();
        if (id > 0 && !starting && !obj.isTemporary()) {
            Row r = meta.getTemplateRow();
            MetaRecord rec = new MetaRecord(obj);
            rec.setRecord(r);
            objectIds.set(id);
            meta.lock(session, true, true);
            meta.addRow(session, r);
            if (isMultiVersion()) {
                // TODO this should work without MVCC, but avoid risks at the moment
                session.log(meta, UndoLogRecord.INSERT, r);
            }
        }
    }

    /**
     * Remove the given object from the meta data.
     *
     * @param session the session
     * @param id the id of the object to remove
     */
    public synchronized void removeMeta(Session session, int id) {
        if (id > 0 && !starting) {
            SearchRow r = meta.getTemplateSimpleRow(false);
            r.setValue(0, ValueInt.get(id));
            boolean wasLocked = meta.isLockedExclusivelyBy(session);
            meta.lock(session, true, true);
            Cursor cursor = metaIdIndex.find(session, r, r);
            if (cursor.next()) {
                Row found = cursor.get();
                meta.removeRow(session, found);
                if (isMultiVersion()) {
                    // TODO this should work without MVCC, but avoid risks at the
                    // moment
                    session.log(meta, UndoLogRecord.DELETE, found);
                }
                objectIds.clear(id);
                if (SysProperties.CHECK) {
                    checkMetaFree(session, id);
                }
            } else if (!wasLocked) {
                // must not keep the lock if it was not locked
                // otherwise updating sequences may cause a deadlock
                meta.unlock(session);
                session.unlock(meta);
            }
        }
    }

    @SuppressWarnings("unchecked")
    private HashMap getMap(int type) {
        HashMap result;
        switch (type) {
        case DbObject.USER:
            result = users;
            break;
        case DbObject.SETTING:
            result = settings;
            break;
        case DbObject.ROLE:
            result = roles;
            break;
        case DbObject.RIGHT:
            result = rights;
            break;
        case DbObject.SCHEMA:
            result = schemas;
            break;
        case DbObject.USER_DATATYPE:
            result = userDataTypes;
            break;
        case DbObject.COMMENT:
            result = comments;
            break;
        case DbObject.AGGREGATE:
            result = aggregates;
            break;
        default:
            throw DbException.throwInternalError("type=" + type);
        }
        return (HashMap) result;
    }

    /**
     * Add a schema object to the database.
     *
     * @param session the session
     * @param obj the object to add
     */
    public synchronized void addSchemaObject(Session session, SchemaObject obj) {
        int id = obj.getId();
        if (id > 0 && !starting) {
            checkWritingAllowed();
        }
        obj.getSchema().add(obj);
        addMeta(session, obj);
    }

    /**
     * Add an object to the database.
     *
     * @param session the session
     * @param obj the object to add
     */
    public synchronized void addDatabaseObject(Session session, DbObject obj) {
        int id = obj.getId();
        if (id > 0 && !starting) {
            checkWritingAllowed();
        }
        HashMap map = getMap(obj.getType());
        if (obj.getType() == DbObject.USER) {
            User user = (User) obj;
            if (user.isAdmin() && systemUser.getName().equals(SYSTEM_USER_NAME)) {
                systemUser.rename(user.getName());
            }
        }
        String name = obj.getName();
        if (SysProperties.CHECK && map.get(name) != null) {
            DbException.throwInternalError("object already exists");
        }
        addMeta(session, obj);
        map.put(name, obj);
    }

    /**
     * Get the user defined aggregate function if it exists, or null if not.
     *
     * @param name the name of the user defined aggregate function
     * @return the aggregate function or null
     */
    public UserAggregate findAggregate(String name) {
        return aggregates.get(name);
    }

    /**
     * Get the comment for the given database object if one exists, or null if
     * not.
     *
     * @param object the database object
     * @return the comment or null
     */
    public Comment findComment(DbObject object) {
        if (object.getType() == DbObject.COMMENT) {
            return null;
        }
        String key = Comment.getKey(object);
        return comments.get(key);
    }

    /**
     * Get the role if it exists, or null if not.
     *
     * @param roleName the name of the role
     * @return the role or null
     */
    public Role findRole(String roleName) {
        return roles.get(roleName);
    }

    /**
     * Get the schema if it exists, or null if not.
     *
     * @param schemaName the name of the schema
     * @return the schema or null
     */
    public Schema findSchema(String schemaName) {
        Schema schema = schemas.get(schemaName);
        if (schema == infoSchema) {
            initMetaTables();
        }
        return schema;
    }

    /**
     * Get the setting if it exists, or null if not.
     *
     * @param name the name of the setting
     * @return the setting or null
     */
    public Setting findSetting(String name) {
        return settings.get(name);
    }

    /**
     * Get the user if it exists, or null if not.
     *
     * @param name the name of the user
     * @return the user or null
     */
    public User findUser(String name) {
        return users.get(name);
    }

    /**
     * Get the user defined data type if it exists, or null if not.
     *
     * @param name the name of the user defined data type
     * @return the user defined data type or null
     */
    public UserDataType findUserDataType(String name) {
        return userDataTypes.get(name);
    }

    /**
     * Get user with the given name. This method throws an exception if the user
     * does not exist.
     *
     * @param name the user name
     * @return the user
     * @throws SQLException if the user does not exist
     */
    public User getUser(String name) {
        User user = findUser(name);
        if (user == null) {
            throw DbException.get(ErrorCode.USER_NOT_FOUND_1, name);
        }
        return user;
    }

    /**
     * Create a session for the given user.
     *
     * @param user the user
     * @return the session
     * @throws SQLException if the database is in exclusive mode
     */
    public synchronized Session createSession(User user) {
        if (exclusiveSession != null) {
            throw DbException.get(ErrorCode.DATABASE_IS_IN_EXCLUSIVE_MODE);
        }
        Session session = new Session(this, user, ++nextSessionId);
        userSessions.add(session);
        traceSystem.getTrace(Trace.SESSION).info("connecting #" + session.getId() + " to " + databaseName);
        if (delayedCloser != null) {
            delayedCloser.reset();
            delayedCloser = null;
        }
        return session;
    }

    /**
     * Remove a session. This method is called after the user has disconnected.
     *
     * @param session the session
     */
    public synchronized void removeSession(Session session) {
        if (session != null) {
            if (exclusiveSession == session) {
                exclusiveSession = null;
            }
            userSessions.remove(session);
            if (session != systemSession) {
                traceSystem.getTrace(Trace.SESSION).info("disconnecting #" + session.getId());
            }
        }
        if (userSessions.size() == 0 && session != systemSession) {
            if (closeDelay == 0) {
                close(false);
            } else if (closeDelay < 0) {
                return;
            } else {
                delayedCloser = new DatabaseCloser(this, closeDelay * 1000, false);
                delayedCloser.setName("H2 Close Delay " + getShortName());
                delayedCloser.setDaemon(true);
                delayedCloser.start();
            }
        }
        if (session != systemSession && session != null) {
            traceSystem.getTrace(Trace.SESSION).info("disconnected #" + session.getId());
        }
    }

    private synchronized void closeAllSessionsException(Session except) {
        Session[] all = new Session[userSessions.size()];
        userSessions.toArray(all);
        for (Session s : all) {
            if (s != except) {
                try {
                    // must roll back, otherwise the session is removed and
                    // the transaction log that contains its uncommitted operations as well
                    s.rollback();
                    s.close();
                } catch (DbException e) {
                    traceSystem.getTrace(Trace.SESSION).error("disconnecting #" + s.getId(), e);
                }
            }
        }
    }

    /**
     * Close the database.
     *
     * @param fromShutdownHook true if this method is called from the shutdown
     *            hook
     */
    synchronized void close(boolean fromShutdownHook) {
        if (closing) {
            return;
        }
        if (fileLockMethod == FileLock.LOCK_SERIALIZED && !reconnectChangePending) {
            // another connection may have written something - don't write
            try {
                closeOpenFilesAndUnlock(false);
            } catch (DbException e) {
                // ignore
            }
            traceSystem.close();
            Engine.getInstance().close(databaseName);
            return;
        }
        closing = true;
        stopServer();
        if (userSessions.size() > 0) {
            if (!fromShutdownHook) {
                return;
            }
            traceSystem.getTrace(Trace.DATABASE).info("closing " + databaseName + " from shutdown hook");
            closeAllSessionsException(null);
        }
        traceSystem.getTrace(Trace.DATABASE).info("closing " + databaseName);
        if (eventListener != null) {
            // allow the event listener to connect to the database
            closing = false;
            DatabaseEventListener e = eventListener;
            // set it to null, to make sure it's called only once
            eventListener = null;
            e.closingDatabase();
            if (userSessions.size() > 0) {
                // if a connection was opened, we can't close the database
                return;
            }
            closing = true;
        }
        try {
            if (systemSession != null) {
                if (powerOffCount != -1) {
                    for (Table table : getAllTablesAndViews(false)) {
                        if (table.isGlobalTemporary()) {
                            table.removeChildrenAndResources(systemSession);
                        } else {
                            table.close(systemSession);
                        }
                    }
                    for (SchemaObject obj : getAllSchemaObjects(DbObject.SEQUENCE)) {
                        Sequence sequence = (Sequence) obj;
                        sequence.close();
                    }
                }
                for (SchemaObject obj : getAllSchemaObjects(DbObject.TRIGGER)) {
                    TriggerObject trigger = (TriggerObject) obj;
                    try {
                        trigger.close();
                    } catch (SQLException e) {
                        traceSystem.getTrace(Trace.DATABASE).error("close", e);
                    }
                }
                if (powerOffCount != -1) {
                    meta.close(systemSession);
                    systemSession.commit(true);
                }
            }
        } catch (DbException e) {
            traceSystem.getTrace(Trace.DATABASE).error("close", e);
        }
        // remove all session variables
        if (persistent) {
            try {
                getLobStorage();
                lobStorage.removeAllForTable(LobStorage.TABLE_ID_SESSION_VARIABLE);
            } catch (DbException e) {
                traceSystem.getTrace(Trace.DATABASE).error("close", e);
            }
        }
        tempFileDeleter.deleteAll();
        try {
            closeOpenFilesAndUnlock(true);
        } catch (DbException e) {
            traceSystem.getTrace(Trace.DATABASE).error("close", e);
        }
        traceSystem.getTrace(Trace.DATABASE).info("closed");
        traceSystem.close();
        if (closeOnExit != null) {
            closeOnExit.reset();
            try {
                Runtime.getRuntime().removeShutdownHook(closeOnExit);
            } catch (IllegalStateException e) {
                // ignore
            } catch (SecurityException  e) {
                // applets may not do that - ignore
            }
            closeOnExit = null;
        }
        Engine.getInstance().close(databaseName);
        if (deleteFilesOnDisconnect && persistent) {
            deleteFilesOnDisconnect = false;
            try {
                String directory = IOUtils.getParent(databaseName);
                String name = IOUtils.getFileName(databaseName);
                DeleteDbFiles.execute(directory, name, true);
            } catch (Exception e) {
                // ignore (the trace is closed already)
            }
        }
    }

    private void stopWriter() {
        if (writer != null) {
            writer.stopThread();
            writer = null;
        }
    }

    /**
     * Close all open files and unlock the database.
     *
     * @param flush whether writing is allowed
     */
    private synchronized void closeOpenFilesAndUnlock(boolean flush) {
        stopWriter();
        if (pageStore != null) {
            if (flush) {
                try {
                    pageStore.checkpoint();
                    if (!readOnly) {
                        pageStore.compact(compactMode);
                    }
                } catch (DbException e) {
                    if (e.getErrorCode() != ErrorCode.DATABASE_IS_CLOSED) {
                        if (SysProperties.CHECK2) {
                            e.printStackTrace();
                        }
                    }
                    traceSystem.getTrace(Trace.DATABASE).error("close", e);
                } catch (Throwable t) {
                    if (SysProperties.CHECK2) {
                        t.printStackTrace();
                    }
                    traceSystem.getTrace(Trace.DATABASE).error("close", t);
                }
            }
        }
        reconnectModified(false);
        closeFiles();
        if (persistent && lock == null && fileLockMethod != FileLock.LOCK_NO && fileLockMethod != FileLock.LOCK_FS) {
            // everything already closed (maybe in checkPowerOff)
            // don't delete temp files in this case because
            // the database could be open now (even from within another process)
            return;
        }
        if (persistent) {
            deleteOldTempFiles();
        }
        if (systemSession != null) {
            systemSession.close();
            systemSession = null;
        }
        if (lock != null) {
            if (fileLockMethod == FileLock.LOCK_SERIALIZED) {
                // wait before deleting the .lock file,
                // otherwise other connections can not detect that
                try {
                    Thread.sleep((int) (SysProperties.RECONNECT_CHECK_DELAY * 1.1));
                } catch (InterruptedException e) {
                    traceSystem.getTrace(Trace.DATABASE).error("close", e);
                }
            }
            lock.unlock();
            lock = null;
        }
    }

    private void closeFiles() {
        try {
            synchronized (this) {
                if (pageStore != null) {
                    pageStore.close();
                    pageStore = null;
                }
            }
        } catch (DbException e) {
            traceSystem.getTrace(Trace.DATABASE).error("close", e);
        }
    }

    private void checkMetaFree(Session session, int id) {
        SearchRow r = meta.getTemplateSimpleRow(false);
        r.setValue(0, ValueInt.get(id));
        Cursor cursor = metaIdIndex.find(session, r, r);
        if (cursor.next()) {
            DbException.throwInternalError();
        }
    }

    /**
     * Allocate a new object id.
     *
     * @return the id
     */
    public synchronized int allocateObjectId() {
        int i = objectIds.nextClearBit(0);
        objectIds.set(i);
        return i;
    }

    public ArrayList getAllAggregates() {
        return New.arrayList(aggregates.values());
    }

    public ArrayList getAllComments() {
        return New.arrayList(comments.values());
    }

    public int getAllowLiterals() {
        if (starting) {
            return Constants.ALLOW_LITERALS_ALL;
        }
        return allowLiterals;
    }

    public ArrayList getAllRights() {
        return New.arrayList(rights.values());
    }

    public ArrayList getAllRoles() {
        return New.arrayList(roles.values());
    }

    /**
     * Get all schema objects.
     *
     * @return all objects of all types
     */
    public ArrayList getAllSchemaObjects() {
        initMetaTables();
        ArrayList list = New.arrayList();
        for (Schema schema : schemas.values()) {
            list.addAll(schema.getAll());
        }
        return list;
    }

    /**
     * Get all schema objects of the given type.
     *
     * @param type the object type
     * @return all objects of that type
     */
    public ArrayList getAllSchemaObjects(int type) {
        if (type == DbObject.TABLE_OR_VIEW) {
            initMetaTables();
        }
        ArrayList list = New.arrayList();
        for (Schema schema : schemas.values()) {
            list.addAll(schema.getAll(type));
        }
        return list;
    }

    /**
     * Get all tables and views.
     *
     * @param includeMeta whether to include the meta data tables
     * @return all objects of that type
     */
    public ArrayList getAllTablesAndViews(boolean includeMeta) {
        if (includeMeta) {
            initMetaTables();
        }
        ArrayList
list = New.arrayList(); for (Schema schema : schemas.values()) { list.addAll(schema.getAllTablesAndViews()); } return list; } public ArrayList getAllSchemas() { initMetaTables(); return New.arrayList(schemas.values()); } public ArrayList getAllSettings() { return New.arrayList(settings.values()); } public ArrayList getAllUserDataTypes() { return New.arrayList(userDataTypes.values()); } public ArrayList getAllUsers() { return New.arrayList(users.values()); } public String getCacheType() { return cacheType; } public String getCluster() { return cluster; } public CompareMode getCompareMode() { return compareMode; } public String getDatabasePath() { if (persistent) { return IOUtils.getAbsolutePath(databaseName); } return null; } public String getShortName() { return databaseShortName; } public String getName() { return databaseName; } /** * Get all sessions that are currently connected to the database. * * @param includingSystemSession if the system session should also be * included * @return the list of sessions */ public Session[] getSessions(boolean includingSystemSession) { ArrayList list; // need to synchronized on userSession, otherwise the list // may contain null elements synchronized (userSessions) { list = New.arrayList(userSessions); } // copy, to ensure the reference is stable Session sys = systemSession; if (includingSystemSession && sys != null) { list.add(sys); } Session[] array = new Session[list.size()]; list.toArray(array); return array; } /** * Update an object in the system table. * * @param session the session * @param obj the database object */ public synchronized void update(Session session, DbObject obj) { int id = obj.getId(); removeMeta(session, id); addMeta(session, obj); } /** * Rename a schema object. * * @param session the session * @param obj the object * @param newName the new name */ public synchronized void renameSchemaObject(Session session, SchemaObject obj, String newName) { checkWritingAllowed(); obj.getSchema().rename(obj, newName); updateWithChildren(session, obj); } private synchronized void updateWithChildren(Session session, DbObject obj) { ArrayList list = obj.getChildren(); Comment comment = findComment(obj); if (comment != null) { DbException.throwInternalError(); } update(session, obj); // remember that this scans only one level deep! if (list != null) { for (DbObject o : list) { if (o.getCreateSQL() != null) { update(session, o); } } } } /** * Rename a database object. * * @param session the session * @param obj the object * @param newName the new name */ public synchronized void renameDatabaseObject(Session session, DbObject obj, String newName) { checkWritingAllowed(); int type = obj.getType(); HashMap map = getMap(type); if (SysProperties.CHECK) { if (!map.containsKey(obj.getName())) { DbException.throwInternalError("not found: " + obj.getName()); } if (obj.getName().equals(newName) || map.containsKey(newName)) { DbException.throwInternalError("object already exists: " + newName); } } obj.checkRename(); int id = obj.getId(); removeMeta(session, id); map.remove(obj.getName()); obj.rename(newName); map.put(newName, obj); updateWithChildren(session, obj); } /** * Create a temporary file in the database folder. * * @return the file name */ public String createTempFile() { try { boolean inTempDir = readOnly; String name = databaseName; if (!persistent) { name = FileSystemMemory.PREFIX + name; } return IOUtils.createTempFile(name, Constants.SUFFIX_TEMP_FILE, true, inTempDir); } catch (IOException e) { throw DbException.convertIOException(e, databaseName); } } private void deleteOldTempFiles() { String path = IOUtils.getParent(databaseName); String[] list = IOUtils.listFiles(path); for (String name : list) { if (name.endsWith(Constants.SUFFIX_TEMP_FILE) && IOUtils.fileStartsWith(name, databaseName)) { // can't always delete the files, they may still be open IOUtils.tryDelete(name); } } } /** * Get the schema. If the schema does not exist, an exception is thrown. * * @param schemaName the name of the schema * @return the schema * @throws SQLException no schema with that name exists */ public Schema getSchema(String schemaName) { Schema schema = findSchema(schemaName); if (schema == null) { throw DbException.get(ErrorCode.SCHEMA_NOT_FOUND_1, schemaName); } return schema; } /** * Remove the object from the database. * * @param session the session * @param obj the object to remove */ public synchronized void removeDatabaseObject(Session session, DbObject obj) { checkWritingAllowed(); String objName = obj.getName(); int type = obj.getType(); HashMap map = getMap(type); if (SysProperties.CHECK && !map.containsKey(objName)) { DbException.throwInternalError("not found: " + objName); } Comment comment = findComment(obj); if (comment != null) { removeDatabaseObject(session, comment); } int id = obj.getId(); obj.removeChildrenAndResources(session); map.remove(objName); removeMeta(session, id); } /** * Get the first table that depends on this object. * * @param obj the object to find * @param except the table to exclude (or null) * @return the first dependent table, or null */ public Table getDependentTable(SchemaObject obj, Table except) { switch (obj.getType()) { case DbObject.COMMENT: case DbObject.CONSTRAINT: case DbObject.INDEX: case DbObject.RIGHT: case DbObject.TRIGGER: case DbObject.USER: return null; default: } HashSet set = New.hashSet(); for (Table t : getAllTablesAndViews(false)) { if (except == t) { continue; } set.clear(); t.addDependencies(set); if (set.contains(obj)) { return t; } } return null; } /** * Remove an object from the system table. * * @param session the session * @param obj the object to be removed */ public synchronized void removeSchemaObject(Session session, SchemaObject obj) { int type = obj.getType(); if (type == DbObject.TABLE_OR_VIEW) { Table table = (Table) obj; if (table.isTemporary() && !table.isGlobalTemporary()) { session.removeLocalTempTable(table); return; } } else if (type == DbObject.INDEX) { Index index = (Index) obj; Table table = index.getTable(); if (table.isTemporary() && !table.isGlobalTemporary()) { session.removeLocalTempTableIndex(index); return; } } else if (type == DbObject.CONSTRAINT) { Constraint constraint = (Constraint) obj; Table table = constraint.getTable(); if (table.isTemporary() && !table.isGlobalTemporary()) { session.removeLocalTempTableConstraint(constraint); return; } } checkWritingAllowed(); Comment comment = findComment(obj); if (comment != null) { removeDatabaseObject(session, comment); } obj.getSchema().remove(obj); int id = obj.getId(); if (!starting) { Table t = getDependentTable(obj, null); if (t != null) { obj.getSchema().add(obj); throw DbException.get(ErrorCode.CANNOT_DROP_2, obj.getSQL(), t.getSQL()); } obj.removeChildrenAndResources(session); } removeMeta(session, id); } /** * Check if this database disk-based. * * @return true if it is disk-based, false it it is in-memory only. */ public boolean isPersistent() { return persistent; } public TraceSystem getTraceSystem() { return traceSystem; } public synchronized void setCacheSize(int kb) { if (starting) { int max = MathUtils.convertLongToInt(Utils.getMemoryMax()) / 2; kb = Math.min(kb, max); } cacheSize = kb; if (pageStore != null) { pageStore.getCache().setMaxMemory(kb); } } public synchronized void setMasterUser(User user) { addDatabaseObject(systemSession, user); systemSession.commit(true); } public Role getPublicRole() { return publicRole; } /** * Get a unique temporary table name. * * @param session the session * @return a unique name */ public synchronized String getTempTableName(Session session) { String tempName; do { tempName = "TEMP_TABLE_" + session.getId() + "_" + nextTempTableId++; } while (mainSchema.findTableOrView(session, tempName) != null); return tempName; } public void setCompareMode(CompareMode compareMode) { this.compareMode = compareMode; } public void setCluster(String cluster) { this.cluster = cluster; } public void checkWritingAllowed() { if (readOnly) { throw DbException.get(ErrorCode.DATABASE_IS_READ_ONLY); } if (noDiskSpace) { throw DbException.get(ErrorCode.NO_DISK_SPACE_AVAILABLE); } if (fileLockMethod == FileLock.LOCK_SERIALIZED) { if (!reconnectChangePending) { throw DbException.get(ErrorCode.DATABASE_IS_READ_ONLY); } } } public boolean isReadOnly() { return readOnly; } public void setWriteDelay(int value) { writeDelay = value; if (writer != null) { writer.setWriteDelay(value); // TODO check if MIN_WRITE_DELAY is a good value flushOnEachCommit = writeDelay < SysProperties.MIN_WRITE_DELAY; } } /** * Check if flush-on-each-commit is enabled. * * @return true if it is */ public boolean getFlushOnEachCommit() { return flushOnEachCommit; } /** * Get the list of in-doubt transactions. * * @return the list */ public ArrayList getInDoubtTransactions() { return pageStore == null ? null : pageStore.getInDoubtTransactions(); } /** * Prepare a transaction. * * @param session the session * @param transaction the name of the transaction */ public void prepareCommit(Session session, String transaction) { if (readOnly) { return; } synchronized (this) { pageStore.prepareCommit(session, transaction); } } /** * Commit the current transaction of the given session. * * @param session the session */ public void commit(Session session) { if (readOnly) { return; } synchronized (this) { if (pageStore != null) { pageStore.commit(session); } session.setAllCommitted(); } } /** * Flush all pending changes to the transaction log. */ public void flush() { synchronized (this) { if (readOnly || pageStore == null) { return; } pageStore.flushLog(); } } public void setEventListener(DatabaseEventListener eventListener) { this.eventListener = eventListener; } public void setEventListenerClass(String className) { if (className == null || className.length() == 0) { eventListener = null; } else { try { eventListener = (DatabaseEventListener) Utils.loadUserClass(className).newInstance(); String url = databaseURL; if (cipher != null) { url += ";CIPHER=" + cipher; } eventListener.init(url); } catch (Throwable e) { throw DbException.get(ErrorCode.ERROR_SETTING_DATABASE_EVENT_LISTENER_2, e, className, e.toString()); } } } public synchronized void freeUpDiskSpace() { if (eventListener != null) { eventListener.diskSpaceIsLow(); } } /** * Set the progress of a long running operation. * This method calls the {@link DatabaseEventListener} if one is registered. * * @param state the {@link DatabaseEventListener} state * @param name the object name * @param x the current position * @param max the highest value */ public void setProgress(int state, String name, int x, int max) { if (eventListener != null) { try { eventListener.setProgress(state, name, x, max); } catch (Exception e2) { // ignore this (user made) exception } } } /** * This method is called after an exception occurred, to inform the database * event listener (if one is set). * * @param e the exception * @param sql the SQL statement */ public void exceptionThrown(SQLException e, String sql) { if (eventListener != null) { try { eventListener.exceptionThrown(e, sql); } catch (Exception e2) { // ignore this (user made) exception } } } /** * Synchronize the files with the file system. This method is called when * executing the SQL statement CHECKPOINT SYNC. */ public void sync() { synchronized (this) { if (readOnly || pageStore == null) { return; } pageStore.sync(); } } public int getMaxMemoryRows() { return maxMemoryRows; } public void setMaxMemoryRows(int value) { this.maxMemoryRows = value; } public void setMaxMemoryUndo(int value) { this.maxMemoryUndo = value; } public int getMaxMemoryUndo() { return maxMemoryUndo; } public void setLockMode(int lockMode) { switch (lockMode) { case Constants.LOCK_MODE_OFF: if (multiThreaded) { // currently the combination of LOCK_MODE=0 and MULTI_THREADED is not supported throw DbException.get(ErrorCode.CANNOT_CHANGE_SETTING_WHEN_OPEN_1, "LOCK_MODE=0 & MULTI_THREADED"); } break; case Constants.LOCK_MODE_READ_COMMITTED: case Constants.LOCK_MODE_TABLE: case Constants.LOCK_MODE_TABLE_GC: break; default: throw DbException.getInvalidValueException("lock mode", "" + lockMode); } this.lockMode = lockMode; } public int getLockMode() { return lockMode; } public synchronized void setCloseDelay(int value) { this.closeDelay = value; } public Session getSystemSession() { return systemSession; } /** * Check if the database is in the process of closing. * * @return true if the database is closing */ public boolean isClosing() { return closing; } public void setMaxLengthInplaceLob(int value) { this.maxLengthInplaceLob = value; } public int getMaxLengthInplaceLob() { return persistent ? maxLengthInplaceLob : Integer.MAX_VALUE; } public void setIgnoreCase(boolean b) { ignoreCase = b; } public boolean getIgnoreCase() { if (starting) { // tables created at startup must not be converted to ignorecase return false; } return ignoreCase; } public synchronized void setDeleteFilesOnDisconnect(boolean b) { this.deleteFilesOnDisconnect = b; } public String getLobCompressionAlgorithm(int type) { return lobCompressionAlgorithm; } public void setLobCompressionAlgorithm(String stringValue) { this.lobCompressionAlgorithm = stringValue; } public synchronized void setMaxLogSize(long value) { if (pageStore != null) { pageStore.setMaxLogSize(value); } } public void setAllowLiterals(int value) { this.allowLiterals = value; } public boolean getOptimizeReuseResults() { return optimizeReuseResults; } public void setOptimizeReuseResults(boolean b) { optimizeReuseResults = b; } public Object getLobSyncObject() { return lobSyncObject; } public int getSessionCount() { return userSessions.size(); } public void setReferentialIntegrity(boolean b) { referentialIntegrity = b; } public boolean getReferentialIntegrity() { return referentialIntegrity; } /** * Check if the database is currently opening. This is true until all stored * SQL statements have been executed. * * @return true if the database is still starting */ public boolean isStarting() { return starting; } /** * Check if multi version concurrency is enabled for this database. * * @return true if it is enabled */ public boolean isMultiVersion() { return multiVersion; } /** * Called after the database has been opened and initialized. This method * notifies the event listener if one has been set. */ public void opened() { if (eventListener != null) { eventListener.opened(); } if (writer != null) { writer.startThread(); } } public void setMode(Mode mode) { this.mode = mode; } public Mode getMode() { return mode; } public boolean isMultiThreaded() { return multiThreaded; } public void setMultiThreaded(boolean multiThreaded) { if (multiThreaded && multiVersion && this.multiThreaded != multiThreaded) { // currently the combination of MVCC and MULTI_THREADED is not supported throw DbException.get(ErrorCode.CANNOT_CHANGE_SETTING_WHEN_OPEN_1, "MVCC & MULTI_THREADED"); } this.multiThreaded = multiThreaded; } public void setMaxOperationMemory(int maxOperationMemory) { this.maxOperationMemory = maxOperationMemory; } public int getMaxOperationMemory() { return maxOperationMemory; } public Session getExclusiveSession() { return exclusiveSession; } /** * Set the session that can exclusively access the database. * * @param session the session * @param closeOthers whether other sessions are closed */ public void setExclusiveSession(Session session, boolean closeOthers) { this.exclusiveSession = session; if (closeOthers) { closeAllSessionsException(session); } } public SmallLRUCache getLobFileListCache() { if (lobFileListCache == null) { lobFileListCache = SmallLRUCache.newInstance(128); } return lobFileListCache; } /** * Checks if the system table (containing the catalog) is locked. * * @return true if it is currently locked */ public boolean isSysTableLocked() { return meta == null || meta.isLockedExclusively(); } /** * Open a new connection or get an existing connection to another database. * * @param driver the database driver or null * @param url the database URL * @param user the user name * @param password the password * @return the connection */ public TableLinkConnection getLinkConnection(String driver, String url, String user, String password) { if (linkConnections == null) { linkConnections = New.hashMap(); } return TableLinkConnection.open(linkConnections, driver, url, user, password); } public String toString() { return databaseShortName + ":" + super.toString(); } /** * Immediately close the database. */ public void shutdownImmediately() { setPowerOffCount(1); try { checkPowerOff(); } catch (DbException e) { // ignore } closeFiles(); } public TempFileDeleter getTempFileDeleter() { return tempFileDeleter; } public Trace getTrace() { return getTrace(Trace.DATABASE); } public PageStore getPageStore() { if (pageStore == null) { pageStore = new PageStore(this, databaseName + Constants.SUFFIX_PAGE_FILE, accessModeData, cacheSize); if (pageSize != SysProperties.PAGE_SIZE) { pageStore.setPageSize(pageSize); } if (!readOnly && fileLockMethod == FileLock.LOCK_FS) { pageStore.setLockFile(true); } pageStore.open(); } return pageStore; } /** * Get the first user defined table. * * @return the table or null if no table is defined */ public Table getFirstUserTable() { for (Table table : getAllTablesAndViews(false)) { if (table.getCreateSQL() != null) { if (table.isHidden()) { // LOB tables continue; } return table; } } return null; } /** * Check if the contents of the database was changed and therefore it is * required to re-connect. This method waits until pending changes are * completed. If a pending change takes too long (more than 2 seconds), the * pending change is broken (removed from the properties file). * * @return true if reconnecting is required */ public boolean isReconnectNeeded() { if (fileLockMethod != FileLock.LOCK_SERIALIZED) { return false; } if (reconnectChangePending) { return false; } long now = System.currentTimeMillis(); if (now < reconnectCheckNext) { return false; } reconnectCheckNext = now + SysProperties.RECONNECT_CHECK_DELAY; if (lock == null) { lock = new FileLock(traceSystem, databaseName + Constants.SUFFIX_LOCK_FILE, Constants.LOCK_SLEEP); } try { Properties prop = lock.load(), first = prop; while (true) { if (prop.equals(reconnectLastLock)) { return false; } if (prop.getProperty("changePending", null) == null) { break; } if (System.currentTimeMillis() > now + SysProperties.RECONNECT_CHECK_DELAY * 10) { if (first.equals(prop)) { // the writing process didn't update the file - // it may have terminated lock.setProperty("changePending", null); lock.save(); break; } } getTrace().debug("delay (change pending)"); Thread.sleep(SysProperties.RECONNECT_CHECK_DELAY); prop = lock.load(); } reconnectLastLock = prop; } catch (Exception e) { // DbException, InterruptedException getTrace().error("readOnly:" + readOnly, e); // ignore } return true; } /** * Flush all changes when using the serialized mode, and if there are * pending changes, and some time has passed. This switches to a new * transaction log and resets the change pending flag in * the .lock.db file. */ public void checkpointIfRequired() { if (fileLockMethod != FileLock.LOCK_SERIALIZED || readOnly || !reconnectChangePending || closing) { return; } long now = System.currentTimeMillis(); if (now > reconnectCheckNext + SysProperties.RECONNECT_CHECK_DELAY) { if (SysProperties.CHECK && checkpointAllowed < 0) { DbException.throwInternalError(); } synchronized (reconnectSync) { if (checkpointAllowed > 0) { return; } checkpointRunning = true; } synchronized (this) { getTrace().debug("checkpoint start"); flushSequences(); checkpoint(); reconnectModified(false); getTrace().debug("checkpoint end"); } synchronized (reconnectSync) { checkpointRunning = false; } } } public boolean isFileLockSerialized() { return fileLockMethod == FileLock.LOCK_SERIALIZED; } private void flushSequences() { for (SchemaObject obj : getAllSchemaObjects(DbObject.SEQUENCE)) { Sequence sequence = (Sequence) obj; sequence.flushWithoutMargin(); } } /** * Flush all changes and open a new transaction log. */ public void checkpoint() { if (persistent) { synchronized (this) { if (pageStore != null) { pageStore.checkpoint(); } } } getTempFileDeleter().deleteUnused(); } /** * This method is called before writing to the transaction log. * * @return true if the call was successful and writing is allowed, * false if another connection was faster */ public boolean beforeWriting() { if (fileLockMethod != FileLock.LOCK_SERIALIZED) { return true; } while (checkpointRunning) { try { Thread.sleep(10 + (int) (Math.random() * 10)); } catch (Exception e) { // ignore InterruptedException } } synchronized (reconnectSync) { if (reconnectModified(true)) { checkpointAllowed++; if (SysProperties.CHECK && checkpointAllowed > 20) { throw DbException.throwInternalError(); } return true; } } // make sure the next call to isReconnectNeeded() returns true reconnectCheckNext = System.currentTimeMillis() - 1; reconnectLastLock = null; return false; } /** * This method is called after updates are finished. */ public void afterWriting() { if (fileLockMethod != FileLock.LOCK_SERIALIZED) { return; } synchronized (reconnectSync) { checkpointAllowed--; } if (SysProperties.CHECK && checkpointAllowed < 0) { throw DbException.throwInternalError(); } } /** * Switch the database to read-only mode. * * @param readOnly the new value */ public void setReadOnly(boolean readOnly) { this.readOnly = readOnly; } public void setCompactMode(int compactMode) { this.compactMode = compactMode; } public SourceCompiler getCompiler() { if (compiler == null) { compiler = new SourceCompiler(); } return compiler; } public LobStorage getLobStorage() { if (lobStorage == null) { lobStorage = new LobStorage(this); } return lobStorage; } public Connection getLobConnection() { String url = Constants.CONN_URL_INTERNAL; JdbcConnection conn = new JdbcConnection(systemSession, systemUser.getName(), url); conn.setTraceLevel(TraceSystem.OFF); return conn; } public void setLogMode(int log) { if (pageStore != null) { if (log != PageStore.LOG_MODE_SYNC || pageStore.getLogMode() != PageStore.LOG_MODE_SYNC) { // write the log mode in the trace file when enabling or // disabling a dangerous mode getTrace().error("log=" + log, null); } pageStore.setLogMode(log); } } public int getLogMode() { if (pageStore != null) { return pageStore.getLogMode(); } return PageStore.LOG_MODE_OFF; } public int getDefaultTableType() { return defaultTableType; } public void setDefaultTableType(int defaultTableType) { this.defaultTableType = defaultTableType; } public void setMultiVersion(boolean multiVersion) { this.multiVersion = multiVersion; } }