/*
 * Copyright 2004-2011 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.test.unit;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.Random;
import java.util.Set;
import java.util.TreeSet;
import org.h2.api.DatabaseEventListener;
import org.h2.constant.ErrorCode;
import org.h2.result.Row;
import org.h2.store.Page;
import org.h2.test.TestBase;
import org.h2.util.IOUtils;
import org.h2.util.New;

/**
 * Test the page store.
 */
public class TestPageStore extends TestBase implements DatabaseEventListener {

    static StringBuilder eventBuffer = new StringBuilder();

    /**
     * Run just this test.
     *
     * @param a ignored
     */
    public static void main(String... a) throws Exception {
        System.setProperty("h2.check2", "true");
        System.setProperty("h2.lobInDatabase", "true");
        TestBase.createCaller().init().test();
    }

    public void test() throws Exception {
        testRecoverLobInDatabase();
        testWriteTransactionLogBeforeData();
        testDefrag();
        testInsertReverse();
        testInsertDelete();
        testCheckpoint();
        testDropRecreate();
        testDropAll();
        testCloseTempTable();
        testDuplicateKey();
        testUpdateOverflow();
        testTruncateReconnect();
        testReverseIndex();
        testLargeUpdates();
        testLargeInserts();
        testLargeDatabaseFastOpen();
        testUniqueIndexReopen();
        testExistingOld();
        testLargeRows();
        testRecoverDropIndex();
        testDropPk();
        testCreatePkLater();
        testTruncate();
        testLargeIndex();
        testUniqueIndex();
        testCreateIndexLater();
        testFuzzOperations();
        deleteDb("pageStore");
    }

    private void testRecoverLobInDatabase() throws SQLException {
        deleteDb("pageStore");
        String url = getURL("pageStore;MVCC=TRUE;CACHE_SIZE=1", true);
        Connection conn;
        Statement stat;
        conn = getConnection(url, getUser(), getPassword());
        stat = conn.createStatement();
        stat.execute("create table test(id int primary key, name clob)");
        stat.execute("create index idx_id on test(id)");
        stat.execute("insert into test select x, space(1100+x) from system_range(1, 100)");
        Connection conn2;
        Statement stat2;
        Random r = new Random(1);
        ArrayList<Connection> list = New.arrayList();
        for (int i = 0; i < 10; i++) {
            conn2 = getConnection(url, getUser(), getPassword());
            list.add(conn2);
            stat2 = conn.createStatement();
            conn2.setAutoCommit(false);
            if (r.nextBoolean()) {
                stat2.execute("update test set id = id where id = " + r.nextInt(100));
            } else {
                stat2.execute("delete from test where id = " + r.nextInt(100));
            }
        }
        stat.execute("shutdown immediately");
        try {
            conn.close();
        } catch (SQLException e) {
            // ignore
        }
        conn = getConnection(url, getUser(), getPassword());
        conn.close();
    }

    private void testWriteTransactionLogBeforeData() throws SQLException {
        deleteDb("pageStore");
        String url = getURL("pageStore;CACHE_SIZE=16;WRITE_DELAY=1000000", true);
        Connection conn;
        Statement stat;
        conn = getConnection(url, getUser(), getPassword());
        stat = conn.createStatement();
        stat.execute("create table test(name varchar) as select space(100000)");
        for (int i = 0; i < 100; i++) {
            stat.execute("create table test" + i + "(id int) as select x from system_range(1, 1000)");
        }
        conn.close();
        conn = getConnection(url, getUser(), getPassword());
        stat = conn.createStatement();
        stat.execute("drop table test0");
        stat.execute("select * from test");
        stat.execute("shutdown immediately");
        try {
            conn.close();
        } catch (Exception e) {
            // ignore
        }
        conn = getConnection(url, getUser(), getPassword());
        stat = conn.createStatement();
        for (int i = 1; i < 100; i++) {
            stat.execute("select * from test" + i);
        }
        conn.close();
    }

    private void testDefrag() throws SQLException {
        if (config.reopen) {
            return;
        }
        deleteDb("pageStore");
        Connection conn = getConnection("pageStore;LOG=0;UNDO_LOG=0;LOCK_MODE=0");
        Statement stat = conn.createStatement();
        int tableCount = 10;
        int rowCount = getSize(1000, 100000);
        for (int i = 0; i < tableCount; i++) {
            stat.execute("create table test" + i
                    + "(id int primary key, string1 varchar, string2 varchar, string3 varchar)");
        }
        for (int j = 0; j < tableCount; j++) {
            PreparedStatement prep = conn.prepareStatement("insert into test" + j + " values(?, ?, ?, ?)");
            for (int i = 0; i < rowCount; i++) {
                prep.setInt(1, i);
                prep.setInt(2, i);
                prep.setInt(3, i);
                prep.setInt(4, i);
                prep.execute();
            }
        }
        stat.executeUpdate("shutdown defrag");
        conn.close();
    }

    private void testInsertReverse() throws SQLException {
        deleteDb("pageStore");
        Connection conn;
        conn = getConnection("pageStore");
        Statement stat = conn.createStatement();
        stat.execute("create table test(id int primary key, data varchar)");
        stat.execute("insert into test select -x, space(100) from system_range(1, 1000)");
        stat.execute("drop table test");
        stat.execute("create table test(id int primary key, data varchar)");
        stat.execute("insert into test select -x, space(2048) from system_range(1, 1000)");
        conn.close();
    }

    private void testInsertDelete() {
        Row[] x = new Row[0];
        Row r = new Row(null, 0);
        x = Page.insert(x, 0, 0, r);
        assertTrue(x[0] == r);
        Row r2 = new Row(null, 0);
        x = Page.insert(x, 1, 0, r2);
        assertTrue(x[0] == r2);
        assertTrue(x[1] == r);
        Row r3 = new Row(null, 0);
        x = Page.insert(x, 2, 1, r3);
        assertTrue(x[0] == r2);
        assertTrue(x[1] == r3);
        assertTrue(x[2] == r);

        x = Page.remove(x, 3, 1);
        assertTrue(x[0] == r2);
        assertTrue(x[1] == r);
        x = Page.remove(x, 2, 0);
        assertTrue(x[0] == r);
        x = Page.remove(x, 1, 0);
    }

    private void testCheckpoint() throws SQLException {
        deleteDb("pageStore");
        Connection conn;
        conn = getConnection("pageStore");
        Statement stat = conn.createStatement();
        stat.execute("create table test(data varchar)");
        stat.execute("create sequence seq");
        stat.execute("set max_log_size 1");
        conn.setAutoCommit(false);
        stat.execute("insert into test select space(1000) from system_range(1, 1000)");
        long before = System.currentTimeMillis();
        stat.execute("select nextval('SEQ') from system_range(1, 100000)");
        long after = System.currentTimeMillis();
        // it's hard to test - basically it shouldn't checkpoint too often
        if (after - before > 10000) {
            if (!config.reopen) {
                fail("Checkpoint took " + (after - before) + " ms");
            }
        }
        stat.execute("drop table test");
        stat.execute("drop sequence seq");
        conn.close();
    }

    private void testDropRecreate() throws SQLException {
        if (config.memory) {
            return;
        }
        deleteDb("pageStore");
        Connection conn;
        conn = getConnection("pageStore");
        Statement stat = conn.createStatement();
        stat.execute("create table test(id int)");
        stat.execute("create index idx_test on test(id)");
        stat.execute("create table test2(id int)");
        stat.execute("drop table test");
        // this will re-used the object id of the test table,
        // which is lower than the object id of test2
        stat.execute("create index idx_test on test2(id)");
        conn.close();
        conn = getConnection("pageStore");
        conn.close();
    }

    private void testDropAll() throws SQLException {
        deleteDb("pageStore");
        Connection conn;
        String url = "pageStore";
        conn = getConnection(url);
        Statement stat = conn.createStatement();
        stat.execute("CREATE TEMP TABLE A(A INT)");
        stat.execute("CREATE TABLE B(A VARCHAR IDENTITY)");
        stat.execute("CREATE TEMP TABLE C(A INT)");
        conn.close();
        conn = getConnection(url);
        stat = conn.createStatement();
        stat.execute("DROP ALL OBJECTS");
        conn.close();
    }

    private void testCloseTempTable() throws SQLException {
        deleteDb("pageStore");
        Connection conn;
        String url = "pageStore;CACHE_SIZE=0";
        conn = getConnection(url);
        Statement stat = conn.createStatement();
        stat.execute("create local temporary table test(id int)");
        conn.rollback();
        Connection conn2 = getConnection(url);
        Statement stat2 = conn2.createStatement();
        stat2.execute("create table test2 as select x from system_range(1, 5000)");
        stat2.execute("shutdown immediately");
        assertThrows(ErrorCode.DATABASE_IS_CLOSED, conn).close();
        assertThrows(ErrorCode.DATABASE_IS_CLOSED, conn2).close();
    }

    private void testDuplicateKey() throws SQLException {
        deleteDb("pageStore");
        Connection conn;
        conn = getConnection("pageStore");
        Statement stat = conn.createStatement();
        stat.execute("create table test(id int primary key, name varchar)");
        stat.execute("insert into test values(0, space(3000))");
        try {
            stat.execute("insert into test values(0, space(3000))");
        } catch (SQLException e) {
            // ignore
        }
        stat.execute("select * from test");
        conn.close();
    }

    private void testTruncateReconnect() throws SQLException {
        if (config.memory) {
            return;
        }
        deleteDb("pageStore");
        Connection conn;
        conn = getConnection("pageStore");
        conn.createStatement().execute("create table test(id int primary key, name varchar)");
        conn.createStatement().execute("insert into test(id) select x from system_range(1, 390)");
        conn.createStatement().execute("checkpoint");
        conn.createStatement().execute("shutdown immediately");
        conn = getConnection("pageStore");
        conn.createStatement().execute("truncate table test");
        conn.createStatement().execute("insert into test(id) select x from system_range(1, 390)");
        conn.createStatement().execute("shutdown immediately");
        conn = getConnection("pageStore");
        conn.close();
    }

    private void testUpdateOverflow() throws SQLException {
        if (config.memory) {
            return;
        }
        deleteDb("pageStore");
        Connection conn;
        conn = getConnection("pageStore");
        conn.createStatement().execute("create table test(id int primary key, name varchar)");
        conn.createStatement().execute("insert into test values(0, space(3000))");
        conn.createStatement().execute("checkpoint");
        conn.createStatement().execute("shutdown immediately");

        conn = getConnection("pageStore");
        conn.createStatement().execute("update test set id = 1");
        conn.createStatement().execute("shutdown immediately");

        conn = getConnection("pageStore");
        conn.close();
    }

    private void testReverseIndex() throws SQLException {
        if (config.memory) {
            return;
        }
        deleteDb("pageStore");
        Connection conn = getConnection("pageStore");
        Statement stat = conn.createStatement();
        stat.execute("create table test(x int, y varchar default space(200))");
        for (int i = 30; i < 100; i++) {
            stat.execute("insert into test(x) select null from system_range(1, " + i + ")");
            stat.execute("insert into test(x) select x from system_range(1, " + i + ")");
            stat.execute("create index idx on test(x desc, y)");
            ResultSet rs = stat.executeQuery("select min(x) from test");
            rs.next();
            assertEquals(1, rs.getInt(1));
            stat.execute("drop index idx");
            stat.execute("truncate table test");
        }
        conn.close();
    }

    private void testLargeUpdates() throws SQLException {
        if (config.memory) {
            return;
        }
        deleteDb("pageStore");
        Connection conn;
        conn = getConnection("pageStore");
        Statement stat = conn.createStatement();
        int size = 1500;
        stat.execute("call rand(1)");
        stat.execute("create table test(id int primary key, data varchar, test int) as " +
                "select x, '', 123 from system_range(1, " + size + ")");
        Random random = new Random(1);
        PreparedStatement prep = conn.prepareStatement(
                "update test set data=space(?) where id=?");
        for (int i = 0; i < 2500; i++) {
            int id = random.nextInt(size);
            int newSize = random.nextInt(6000);
            prep.setInt(1, newSize);
            prep.setInt(2, id);
            prep.execute();
        }
        conn.close();
        conn = getConnection("pageStore");
        stat = conn.createStatement();
        ResultSet rs = stat.executeQuery("select * from test where test<>123");
        assertFalse(rs.next());
        conn.close();
    }

    private void testLargeInserts() throws SQLException {
        if (config.memory) {
            return;
        }
        deleteDb("pageStore");
        Connection conn;
        conn = getConnection("pageStore");
        Statement stat = conn.createStatement();
        stat.execute("create table test(data varchar)");
        stat.execute("insert into test values(space(1024 * 1024))");
        stat.execute("insert into test values(space(1024 * 1024))");
        conn.close();
    }

    private void testLargeDatabaseFastOpen() throws SQLException {
        if (config.memory) {
            return;
        }
        deleteDb("pageStore");
        Connection conn;
        String url = "pageStore";
        conn = getConnection(url);
        conn.createStatement().execute("CREATE TABLE TEST(ID INT PRIMARY KEY, NAME VARCHAR)");
        conn.createStatement().execute("create unique index idx_test_name on test(name)");
        conn.createStatement().execute("INSERT INTO TEST SELECT X, X || space(10) FROM SYSTEM_RANGE(1, 1000)");
        conn.close();
        conn = getConnection(url);
        conn.createStatement().execute("DELETE FROM TEST WHERE ID=1");
        conn.createStatement().execute("CHECKPOINT");
        conn.createStatement().execute("SHUTDOWN IMMEDIATELY");
        try {
            conn.close();
        } catch (SQLException e) {
            // ignore
        }
        eventBuffer.setLength(0);
        conn = getConnection(url + ";DATABASE_EVENT_LISTENER='" + getClass().getName() + "'");
        assertEquals("init;opened;", eventBuffer.toString());
        conn.close();
    }

    private void testUniqueIndexReopen() throws SQLException {
        if (config.memory) {
            return;
        }
        deleteDb("pageStore");
        Connection conn;
        String url = "pageStore";
        conn = getConnection(url);
        conn.createStatement().execute("CREATE TABLE test(ID INT PRIMARY KEY, NAME VARCHAR(255))");
        conn.createStatement().execute("create unique index idx_test_name on test(name)");
        conn.createStatement().execute("INSERT INTO TEST VALUES(1, 'Hello')");
        conn.close();
        conn = getConnection(url);
        assertThrows(ErrorCode.DUPLICATE_KEY_1, conn.createStatement()).
                execute("INSERT INTO TEST VALUES(2, 'Hello')");
        conn.close();
    }

    private void testExistingOld() throws SQLException {
        if (config.memory) {
            return;
        }
        Connection conn;
        deleteDb("pageStore");
        String url;
        url = "jdbc:h2:" + getBaseDir() + "/pageStore";
        conn = DriverManager.getConnection(url);
        conn.createStatement().execute("create table test(id int) as select 1");
        conn.close();
        conn = DriverManager.getConnection(url);
        conn.createStatement().execute("select * from test");
        conn.close();
        // the database is automatically converted
        conn = DriverManager.getConnection(url);
        assertResult("1", conn.createStatement(), "select * from test");
        conn.close();
    }

    private void testLargeRows() throws Exception {
        if (config.memory) {
            return;
        }
        for (int i = 0; i < 10; i++) {
            testLargeRows(i);
        }
    }

    private void testLargeRows(int seed) throws Exception {
        deleteDb("pageStore");
        String url = getURL("pageStore;CACHE_SIZE=16", true);
        Connection conn = null;
        Statement stat = null;
        int count = 0;
        try {
            Class.forName("org.h2.Driver");
            conn = DriverManager.getConnection(url);
            stat = conn.createStatement();
            int tableCount = 1;
            PreparedStatement[] insert = new PreparedStatement[tableCount];
            PreparedStatement[] deleteMany = new PreparedStatement[tableCount];
            PreparedStatement[] updateMany = new PreparedStatement[tableCount];
            for (int i = 0; i < tableCount; i++) {
                stat.execute("create table test" + i + "(id int primary key, name varchar)");
                stat.execute("create index idx_test" + i + " on test" + i + "(name)");
                insert[i] = conn.prepareStatement("insert into test" + i + " values(?, ? || space(?))");
                deleteMany[i] = conn.prepareStatement("delete from test" + i + " where id between ? and ?");
                updateMany[i] = conn.prepareStatement("update test" + i
                        + " set name=? || space(?) where id between ? and ?");
            }
            Random random = new Random(seed);
            for (int i = 0; i < 1000; i++) {
                count = i;
                PreparedStatement p;
                if (random.nextInt(100) < 95) {
                    p = insert[random.nextInt(tableCount)];
                    p.setInt(1, i);
                    p.setInt(2, i);
                    if (random.nextInt(30) == 5) {
                        p.setInt(3, 3000);
                    } else {
                        p.setInt(3, random.nextInt(100));
                    }
                    p.execute();
                } else if (random.nextInt(100) < 90) {
                    p = updateMany[random.nextInt(tableCount)];
                    p.setInt(1, i);
                    p.setInt(2, random.nextInt(50));
                    int first = random.nextInt(1 + i);
                    p.setInt(3, first);
                    p.setInt(4, first + random.nextInt(50));
                    p.executeUpdate();
                } else {
                    p = deleteMany[random.nextInt(tableCount)];
                    int first = random.nextInt(1 + i);
                    p.setInt(1, first);
                    p.setInt(2, first + random.nextInt(100));
                    p.executeUpdate();
                }
            }
            conn.close();
            conn = DriverManager.getConnection(url);
            conn.close();
            conn = DriverManager.getConnection(url);
            stat = conn.createStatement();
            stat.execute("script to '" + getBaseDir() + "/pageStore.sql'");
            conn.close();
            IOUtils.delete(getBaseDir() + "/pageStore.sql");
        } catch (Exception e) {
            try {
                stat.execute("shutdown immediately");
            } catch (SQLException e2) {
                // ignore
            }
            try {
                conn.close();
            } catch (SQLException e2) {
                // ignore
            }
            throw new RuntimeException("count: " + count, e);
        }
    }

    private void testRecoverDropIndex() throws SQLException {
        if (config.memory) {
            return;
        }
        deleteDb("pageStore");
        Connection conn = getConnection("pageStore");
        Statement stat = conn.createStatement();
        stat.execute("set write_delay 0");
        stat.execute("create table test(id int, name varchar) as select x, x from system_range(1, 1400)");
        stat.execute("create index idx_name on test(name)");
        conn.close();
        conn = getConnection("pageStore");
        stat = conn.createStatement();
        stat.execute("drop index idx_name");
        stat.execute("shutdown immediately");
        try {
            conn.close();
        } catch (SQLException e) {
            // ignore
        }
        conn = getConnection("pageStore;cache_size=1");
        conn.close();
    }

    private void testDropPk() throws SQLException {
        if (config.memory) {
            return;
        }
        deleteDb("pageStore");
        Connection conn;
        Statement stat;
        conn = getConnection("pageStore");
        stat = conn.createStatement();
        stat.execute("create table test(id int primary key)");
        stat.execute("insert into test values(" + Integer.MIN_VALUE + "), (" + Integer.MAX_VALUE + ")");
        stat.execute("alter table test drop primary key");
        conn.close();
        conn = getConnection("pageStore");
        stat = conn.createStatement();
        stat.execute("insert into test values(" + Integer.MIN_VALUE + "), (" + Integer.MAX_VALUE + ")");
        conn.close();
    }

    private void testCreatePkLater() throws SQLException {
        if (config.memory) {
            return;
        }
        deleteDb("pageStore");
        Connection conn;
        Statement stat;
        conn = getConnection("pageStore");
        stat = conn.createStatement();
        stat.execute("create table test(id int not null) as select 100");
        stat.execute("create primary key on test(id)");
        conn.close();
        conn = getConnection("pageStore");
        stat = conn.createStatement();
        ResultSet rs = stat.executeQuery("select * from test where id = 100");
        assertTrue(rs.next());
        conn.close();
    }

    private void testTruncate() throws SQLException {
        if (config.memory) {
            return;
        }
        deleteDb("pageStore");
        Connection conn = getConnection("pageStore");
        Statement stat = conn.createStatement();
        stat.execute("set write_delay 0");
        stat.execute("create table test(id int) as select 1");
        stat.execute("truncate table test");
        stat.execute("insert into test values(1)");
        stat.execute("shutdown immediately");
        try {
            conn.close();
        } catch (SQLException e) {
            // ignore
        }
        conn = getConnection("pageStore");
        conn.close();
    }

    private void testLargeIndex() throws SQLException {
        if (config.memory) {
            return;
        }
        deleteDb("pageStore");
        Connection conn = getConnection("pageStore");
        conn.createStatement().execute("create table test(id varchar primary key, d varchar)");
        PreparedStatement prep = conn.prepareStatement("insert into test values(?, space(500))");
        for (int i = 0; i < 20000; i++) {
            prep.setString(1, "" + i);
            prep.executeUpdate();
        }
        conn.close();
    }

    private void testUniqueIndex() throws SQLException {
        if (config.memory) {
            return;
        }
        deleteDb("pageStore");
        Connection conn = getConnection("pageStore");
        Statement stat = conn.createStatement();
        stat.execute("CREATE TABLE TEST(ID INT UNIQUE)");
        stat.execute("INSERT INTO TEST VALUES(1)");
        conn.close();
        conn = getConnection("pageStore");
        assertThrows(ErrorCode.DUPLICATE_KEY_1, conn.createStatement()).
                execute("INSERT INTO TEST VALUES(1)");
        conn.close();
    }

    private void testCreateIndexLater() throws SQLException {
        deleteDb("pageStore");
        Connection conn = getConnection("pageStore");
        Statement stat = conn.createStatement();
        stat.execute("CREATE TABLE TEST(NAME VARCHAR) AS SELECT 1");
        stat.execute("CREATE INDEX IDX_N ON TEST(NAME)");
        stat.execute("INSERT INTO TEST SELECT X FROM SYSTEM_RANGE(20, 100)");
        stat.execute("INSERT INTO TEST SELECT X FROM SYSTEM_RANGE(1000, 1100)");
        stat.execute("SHUTDOWN IMMEDIATELY");
        assertThrows(ErrorCode.DATABASE_IS_CLOSED, conn).close();
        conn = getConnection("pageStore");
        conn.close();
    }

    private void testFuzzOperations() throws SQLException {
        int best = Integer.MAX_VALUE;
        for (int i = 0; i < 10; i++) {
            int x = testFuzzOperationsSeed(i, 10);
            if (x >= 0 && x < best) {
                best = x;
                fail("op:" + x + " seed:" + i);
            }
        }
    }

    private int testFuzzOperationsSeed(int seed, int len) throws SQLException {
        deleteDb("pageStore");
        Connection conn = getConnection("pageStore");
        Statement stat = conn.createStatement();
        log("DROP TABLE IF EXISTS TEST;");
        stat.execute("DROP TABLE IF EXISTS TEST");
        log("CREATE TABLE TEST(ID INT PRIMARY KEY, NAME VARCHAR DEFAULT 'Hello World');");
        stat.execute("CREATE TABLE TEST(ID INT PRIMARY KEY, NAME VARCHAR DEFAULT 'Hello World')");
        Set<Integer> rows = new TreeSet<Integer>();
        Random random = new Random(seed);
        for (int i = 0; i < len; i++) {
            int op = random.nextInt(3);
            Integer x = random.nextInt(100);
            switch (op) {
            case 0:
                if (!rows.contains(x)) {
                    log("insert into test(id) values(" + x + ");");
                    stat.execute("INSERT INTO TEST(ID) VALUES(" + x + ");");
                    rows.add(x);
                }
                break;
            case 1:
                if (rows.contains(x)) {
                    log("delete from test where id=" + x + ";");
                    stat.execute("DELETE FROM TEST WHERE ID=" + x);
                    rows.remove(x);
                }
                break;
            case 2:
                conn.close();
                conn = getConnection("pageStore");
                stat = conn.createStatement();
                ResultSet rs = stat.executeQuery("SELECT * FROM TEST ORDER BY ID");
                log("--reconnect");
                for (int test : rows) {
                    if (!rs.next()) {
                        log("error: expected next");
                        conn.close();
                        return i;
                    }
                    int y = rs.getInt(1);
                    // System.out.println(" " + x);
                    if (y != test) {
                        log("error: " + y + " <> " + test);
                        conn.close();
                        return i;
                    }
                }
                if (rs.next()) {
                    log("error: unexpected next");
                    conn.close();
                    return i;
                }
            }
        }
        conn.close();
        return -1;
    }

    private void log(String m) {
        trace("   " + m);
    }

    public void closingDatabase() {
        event("closing");
    }

    public void diskSpaceIsLow() {
        event("diskSpaceIsLow");
    }

    public void exceptionThrown(SQLException e, String sql) {
        event("exceptionThrown " + e + " " + sql);
    }

    public void init(String url) {
        event("init");
    }

    public void opened() {
        event("opened");
    }

    public void setProgress(int state, String name, int x, int max) {
        if (name.startsWith("SYS:SYS_ID")) {
            // ignore
            return;
        }
        event("setProgress " + state + " " + name + " " + x + " " + max);
    }

    private static void event(String s) {
        eventBuffer.append(s).append(';');
    }

}
